Patent Publication Number: US-2023157846-A1

Title: Systems and methods for orthosis design

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 16/829,208, filed on Mar. 25, 2020, which claims priority of Chinese Patent Application No. 201911375163.7, filed on Dec. 27, 2019, Chinese Patent Application No. 201910590669.3, filed on Jul. 2, 2019, Chinese Patent Application No. 202010140173.9, filed on Mar. 3, 2020, and Chinese Patent Application No. 201911342643.3, filed on Dec. 23, 2019, the contents of each of which are hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure generally relates to medical devices, and in particular, to systems and methods for orthosis design. 
     BACKGROUND 
     Orthoses are externally applied devices for modifying or correcting the structural and functional characteristics of the neuromuscular and skeletal systems. These devices are widely used for subjects (e.g., a person or an animal) having a fracture, a dislocation, or a physical deformity of the spine (e.g., scoliosis). A three-dimensional (3D) orthosis model for a subject can be designed based on image data of the subject, and an orthosis may be manufactured (e.g., by 3D printing) based on the 3D orthosis model to meet correction needs of the subject. Thus, it is desirable to design precisely accurate 3D orthosis models for subjects. 
     During an orthosis design process, sometimes a 3D orthosis model needs to be edited (e.g., split) to generate a desired shape. For example, a 3D orthosis model can be split according to split curve having a smooth boundary to generate a 3D orthosis sub-model having a smooth shape. However, existing model splitting algorithms often produces a rough boundary (e.g., a sawtooth boundary), reducing the quality of the 3D orthosis model. Thus, it is desirable to provide systems and methods for splitting an orthosis model smoothly. 
     During the orthosis design process, a large amount of data (e.g., orthosis design data) is generated. It would be crucial, therefore, to store and transfer such data so that users can access and analyze the data timely and efficiently. In addition, in some cases, a number of users (e.g., a doctor, an orthosis designer, a 3D print manufacturer) need to design and/or print an orthosis for a subject collaboratively. However, the existing orthosis design systems are often based on a client/server (C/S) architecture, which only supports local storage, resulting in reduced efficiency for multi-user collaborative design and docking with a third-party 3D print manufacturer. Furthermore, the existing orthosis design systems often do not have a cross-platform and rapid deployment function, leading to low response speed and instability in a high concurrency environment. Therefore, it is desirable to provide effective systems and methods for orthosis design. 
     SUMMARY 
     According to an aspect of the present disclosure, a method for orthosis design may be implemented on a computing device having one or more processors and one or more storage devices. The method may include obtaining a three-dimensional (3D) model associated with a subject. The method may include obtaining one or more reference images associated with the subject. The method may include determining, based on the 3D model and the one or more reference images, orthosis design data for the subject. The orthosis design data may be used to determine an orthosis for the subject. 
     In some embodiments, the method may include obtaining the 3D model associated with the subject from a 3D camera device. 
     In some embodiments, the method may include obtaining image data associated with the subject. The method may include determining the 3D model associated with the subject based on the image data associated with the subject. 
     In some embodiments, the method may include determining a target area by performing an image segmentation operation on the image data associated with the subject. The method may include extracting body surface data associated with the target area from the image data associated with the subject. The method may include generating a plurality of meshes of the 3D model based on the body surface data associated with the target area. 
     In some embodiments, the one or more reference images may be digital radiography (DR) images. 
     In some embodiments, the method may include comparing the 3D model with the one or more reference images. The method may include determining the orthosis design data by modifying the 3D model based on a comparison result. 
     In some embodiments, the orthosis design data for the subject may include a processing result determined by performing at least one of a mesh deformation operation, a mesh smoothing operation, a mesh division operation, or a mesh splitting operation on the 3D model. 
     In some embodiments, the method may include determining, based on the 3D model and the orthosis design data, force data of at least one region of the subject after wearing an orthosis. The method may include altering, based on the force data of the at least one region of the subject, the orthosis design data. 
     In some embodiments, the method may include determining housing design data associated with a housing of the orthosis by performing a thickness-adjustment operation on the orthosis design data. 
     According to another aspect of the present disclosure, a method for splitting a 3D model may be implemented on a computing device having one or more processors and one or more storage devices. The method may include determining a spline curve associated with a 3D model. The spline curve may be generated based on a plurality of first coordinates input by a user in a screen coordinate system. The spline curve may include a plurality of second coordinates in a model coordinate system. For each second coordinate of the plurality of second coordinates, the method may include determining a center point corresponding to the second coordinate. The method may include determining a link line connecting the center point and the corresponding second coordinate. The method may include determining a plurality of boundary points along a direction of the link line. The method may include generating a split surface based on all the boundary points corresponding to the plurality of second coordinates. 
     In some embodiments, the method may include splitting the 3D model based on the split surface. 
     In some embodiments, the method may include obtaining the plurality of first coordinates input by the user. The method may include determining a plurality of third coordinates by performing a spline interpolation operation on the plurality of first coordinates. The method may include determining the plurality of second coordinates by projecting the plurality of third coordinates on the 3D model. The method may include determining the spline curve by connecting the plurality of second coordinates. 
     In some embodiments, the spline interpolation operation may include at least one of a cubic B-spline interpolation, a Bezier curve interpolation, or a catmull-rom curve interpolation. 
     In some embodiments, the plurality of boundary points may include an inner boundary point and an outer boundary point. The inner boundary point may be located inside the 3D model. The outer boundary point may be located outside the 3D model. For the each second coordinate of the plurality of second coordinates, the method may include determining the inner boundary point by extending the second coordinate to the inside of the 3D model along the direction of the link line. The method may include determining the outer boundary point by extending the second coordinate to the outside of the 3D model along the direction of the link line. 
     In some embodiments, the method may include generating a plurality of split sub-surfaces by connecting the inner boundary points and the outer boundary points corresponding to the plurality of second coordinates. The method may include generating the split surface by combining the plurality of split sub-surfaces. 
     In some embodiments, the method may include transforming the plurality of third coordinates in the screen coordinate system to a plurality of fourth coordinates in a view coordinate system. The method may include transforming the plurality of fourth coordinates in the view coordinate system to a plurality of fifth coordinates in a camera coordinate system. The method may include transforming the plurality of fifth coordinates in the camera coordinate system to a plurality of sixth coordinates in a world coordinate system. The method may include transforming the plurality of sixth coordinates in the world coordinate system to the plurality of second coordinates in the model coordinate system. 
     In some embodiments, prior to obtaining the plurality of first coordinates, the method may include obtaining data associated with the 3D model. The method may include determining an initial transformation matrix between the model coordinate system and the world coordinate system. The initial transformation matrix may be used to display a front view of the 3D model in the world coordinate system. The method may include rendering the 3D model based on the data associated with the 3D model and the initial transformation matrix. 
     In some embodiments, the method may include generating at least two sub-models by splitting the 3D model based on the split surface. The method may include displaying the at least two sub-models on a terminal device associated with the user. 
     According to another aspect of the present disclosure, a system for orthosis design may include at least one storage device storing a set of instructions, and at least one processor in communication with the at least one storage device. When executing the stored set of instructions, the at least one processor may cause the system to obtain a three-dimensional (3D) model associated with a subject. The at least one processor may cause the system to obtain one or more reference images associated with the subject. The at least one processor may cause the system to determine, based on the 3D model and the one or more reference images, orthosis design data for the subject. The orthosis design data may be used to determine an orthosis for the subject. 
     In some embodiments, the at least one processor may cause the system to obtain the 3D model associated with the subject from a 3D camera device. 
     In some embodiments, the at least one processor may cause the system to determine the 3D model associated with the subject based on the image data associated with the subject. 
     In some embodiments, the at least one processor may cause the system to determine a target area by performing an image segmentation operation on the image data associated with the subject. The at least one processor may cause the system to extract body surface data associated with the target area from the image data associated with the subject. The at least one processor may cause the system to generate a plurality of meshes of the 3D model based on the body surface data associated with the target area. 
     In some embodiments, the at least one processor may cause the system to compare the 3D model with the one or more reference images. The at least one processor may cause the system to determine the orthosis design data by modifying the 3D model based on a comparison result. 
     In some embodiments, the at least one processor may cause the system to determine, based on the 3D model and the orthosis design data, force data of at least one region of the subject after wearing an orthosis. The at least one processor may cause the system to alter, based on the force data of the at least one region of the subject, the orthosis design data. 
     In some embodiments, the at least one processor may cause the system to determine housing design data associated with a housing of the orthosis by performing a thickness-adjustment operation on the orthosis design data. 
     In some embodiments, the system may include at least one data obtaining device configured to obtain data associated with the subject. The data associated with the subject may include at least one of the image data associated with the subject, the 3D model associated with the subject, or one or more reference images associated with the subject. 
     In some embodiments, the system may include at least one first terminal device configured to import the data associated with the subject. 
     In some embodiments, the system may include the at least one second terminal device configured to send a request for orthosis design. 
     In some embodiments, the at least one processor may include a plurality of processing devices. The system may include a data interaction equipment, configured to transmit the request for orthosis design obtained from the at least one second terminal device to at least one processing device of the plurality of processing devices, according to a load balancing mechanism. 
     In some embodiments, the data interaction equipment may include a first load balancing device, a data interaction device cluster including a plurality of data interaction devices, and a second load balancing device. The first load balancing device may communicate with the at least one first terminal device and the at least one second terminal device, and may be configured to transmit data from the at least one first terminal device and the at least one second terminal device to at least one data interaction device of the data interaction device cluster according to the load balancing mechanism. The at least one data interaction device may be configured to determine the request for orthosis design based on the data obtained from the at least one first terminal device and the at least one second terminal device. The second load balancing device may communicate with the data interaction device cluster, and may be configured to transmit the request for orthosis design to the at least one data processing device of the data processing device cluster, according to the load balancing mechanism 
     In some embodiments, the at least one first terminal device and the at least one second terminal device may communicate with the data interaction device via a browser. 
     In some embodiments, the system may be based on ASP.NET Core technology. 
     In some embodiments, the data interaction equipment may be a reverse proxy. 
     In some embodiments, the at least one second terminal device may include a plurality of second terminal devices associated with a plurality of users. The plurality of second terminal devices may be configured to send a plurality of requests for determining the orthosis cooperatively. 
     In some embodiments, the system may include a 3D print device configured to print the orthosis based on the orthosis design data. 
     Additional features will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following and the accompanying drawings or may be learned by production or operation of the examples. The features of the present disclosure may be realized and attained by practice or use of various aspects of the methodologies, instrumentalities, and combinations set forth in the detailed examples discussed below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure is further described in terms of exemplary embodiments. These exemplary embodiments are described in detail with reference to the drawings. These embodiments are non-limiting exemplary embodiments, in which like reference numerals represent similar structures throughout the several views of the drawings, and wherein: 
         FIG.  1    is a schematic diagram illustrating an exemplary orthosis design system according to some embodiments of the present disclosure; 
         FIG.  2    is a schematic diagram illustrating hardware and/or software components of an exemplary computing device according to some embodiments of the present disclosure; 
         FIG.  3    is a schematic diagram illustrating hardware and/or software components of a mobile device according to some embodiments of the present disclosure; 
         FIG.  4    is a block diagram illustrating an exemplary processing device according to some embodiments of the present disclosure; 
         FIG.  5    is a flowchart illustrating an exemplary process for designing an orthosis according to some embodiments of the present disclosure; 
         FIG.  6    is a flowchart illustrating an exemplary process for obtaining a 3D model associated with a subject according to some embodiments of the present disclosure; 
         FIG.  7    is a flowchart illustrating an exemplary process for altering orthosis design data according to some embodiments of the present disclosure; 
         FIG.  8    illustrates an exemplary image of a reference image superimposed on a 3D model according to some embodiments of the present disclosure; 
         FIG.  9    is a schematic diagram illustrating a housing of an orthosis according to some embodiments of the present disclosure; 
         FIG.  10    is a block diagram illustrating an exemplary orthosis design data determination module according to some embodiments of the present disclosure; 
         FIG.  11    is a flowchart illustrating an exemplary process for splitting a 3D model according to some embodiments of the present disclosure; 
         FIG.  12    is a flowchart illustrating an exemplary process for determining a spline curve according to some embodiments of the present disclosure; 
         FIG.  13    is a flowchart illustrating an exemplary process for determining a plurality of second coordinates on a spline curve according to some embodiments of the present disclosure; 
         FIG.  14    is a schematic diagram illustrating an exemplary process for determining a center point according to some embodiments of the present disclosure; 
         FIG.  15 A  is a schematic diagram illustrating an exemplary split surface according to some embodiments of the present disclosure; 
         FIG.  15 B  is an enlarged view of a region A shown in  FIG.  15 A  according to some embodiments of the present disclosure; 
         FIG.  16    is a schematic diagram illustrating exemplary 3D sub-models according to some embodiments of the present disclosure; 
         FIG.  17    is a block diagram illustrating an exemplary data management system according to some embodiments of the present disclosure; 
         FIG.  18    is a flowchart illustrating an exemplary process for importing data associated with a subject according to some embodiments of the present disclosure; 
         FIG.  19    is a flowchart illustrating an exemplary process for storing data associated with an orthosis according to some embodiments of the present disclosure; 
         FIG.  20    is a flowchart illustrating an exemplary process for transmitting data to a 3D print database according to some embodiments of the present disclosure; 
         FIG.  21    is a schematic diagram illustrating an exemplary cloud design system according to some embodiments of the present disclosure; 
         FIG.  22    is a schematic diagram illustrating an exemplary orthosis design system according to some embodiments of the present disclosure; 
         FIG.  23    is a schematic diagram illustrating an exemplary user interface for displaying a patient list according to some embodiments of the present disclosure; and 
         FIG.  24    is a schematic diagram illustrating an exemplary user interface for displaying data associated with a subject in a bookmark mode according to some embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The following description is presented to enable any person skilled in the art to make and use the present disclosure and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present disclosure. Thus, the present disclosure is not limited to the embodiments shown but is to be accorded the widest scope consistent with the claims. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including” when used in this disclosure, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     These and other features, and characteristics of the present disclosure, as well as the methods of operations and functions of the related elements of structure and the combination of parts and economies of manufacture, may become more apparent upon consideration of the following description with reference to the accompanying drawing(s), all of which form part of this specification. It is to be expressly understood, however, that the drawing(s) is for the purpose of illustration and description only and are not intended to limit the scope of the present disclosure. It is understood that the drawings are not to scale. 
     The flowcharts used in the present disclosure illustrate operations that systems implement according to some embodiments of the present disclosure. It is to be expressly understood, the operations of the flowcharts may be implemented not in order. Conversely, the operations may be implemented in an inverted order, or simultaneously. Moreover, one or more other operations may be added to the flowcharts. One or more operations may be removed from the flowcharts. 
     An aspect of the present disclosure relates to methods and systems for orthosis design. According to some embodiments of the present disclosure, a processing device may obtain a three-dimensional (3D) model associated with a subject. The processing device may obtain one or more reference images (e.g., a digital radiography image) associated with the subject. The processing device may determine, based on the 3D model and the one or more reference images, orthosis design data for the subject. The orthosis design data may be used to determine an orthosis for the subject. In some embodiments, the processing device may compare the 3D model with the one or more reference images. The processing device may determine the orthosis design data by modifying (e.g., splitting) the 3D model based on a comparison result. Accordingly, orthosis design data for a subject may be generated based on one or more reference images of the subject and a 3D model of the subject. An orthosis generated based on the orthosis design data may meet correction needs of the subject. 
     Another aspect of the present disclosure relates to methods and systems for splitting a 3D model. The processing device may determine a spline curve associated with a 3D model. The spline curve may be generated based on a plurality of first coordinates input by a user in a screen coordinate system. The spline curve may include a plurality of second coordinates in a model coordinate system. For each second coordinate of the plurality of second coordinates, the processing device may determine a center point corresponding to the second coordinate. The processing device may determine a link line connecting the center point and the corresponding second coordinate. The processing device may determine a plurality of boundary points along a direction of the link line. The processing device may generate a split surface based on all the boundary points corresponding to the plurality of second coordinates. Accordingly, a method for determining a split surface based on a plurality of dynamic center points may be provided. The problems of split surface self-intersections and a non-smoothing boundary of the split surface caused by an irregular body surface of the 3D model may be avoided. 
     Another aspect of the present disclosure related to methods and systems for data management in an orthosis design system. The data management system may include an importing module, a storage module, and a printing module. The importing module (e.g., a terminal device associated with a doctor) may import data associated with a subject. The storage module (e.g., a terminal device associated with an orthosis designer) may store data associated with an orthosis during an orthosis design process. The printing module (e.g., a terminal device associated with a 3D print manufacturer) may print the orthosis based on the data associated with the subject and/or the data associated with the orthosis. Accordingly, a plurality of users (e.g., a doctor, an orthosis designer, a 3D print manufacturer) of the orthosis design system  100  may design and/or print an orthosis for a subject via a plurality of browsers on a plurality of terminal devices collaboratively. The orthosis design and print process may be simplified, and the orthosis production efficiency may be improved. 
       FIG.  1    is a schematic diagram illustrating an exemplary orthosis design system  100  according to some embodiments of the present disclosure. The orthosis design system  100  may include a data obtaining device  110 , a network  120 , at least one terminal device  130 , a server  144 , a data interaction equipment  140 , and a storage device  150 . The server  144  and the data interaction equipment  140  may also be referred to as a cloud design system. The components of the orthosis design system  100  may be connected in one or more of various ways. Merely by way of example, as illustrated in  FIG.  1   , the data obtaining device  110  may be connected to the storage device  150  directly as indicated by the bi-directional arrow in dotted lines linking the data obtaining device  110  and the storage device  150 , or through the network  120 . As another example, the terminal device  130  may be connected to the storage device  150  directly as indicated by the bi-directional arrow in dotted lines linking the terminal device  130  and the storage device  150 , or through the network  120 . As another example, the server  144  may be connected to the data obtaining device  110  directly as indicated by the bi-directional arrow in dotted lines linking the server  144  and data obtaining device  110 , or through the network  120 . As still another example, the at least one terminal device  130  may be connected to the server  144  via the network  120 . 
     The data obtaining device  110  may be configured to acquire image data relating to at least one part of a subject. The image data relating to at least one part of a subject may include an image (e.g., an image slice), projection data, or a combination thereof. For example, the data obtaining device  110  may scan a portion of the subject to be corrected to obtain scanned image data or a 3D model of the portion of the subject to be corrected. In some embodiments, the image data may be a two-dimensional (2D) imaging data, a three-dimensional (3D) imaging data, a four-dimensional (4D) imaging data, or the like, or any combination thereof. In some embodiments, the image data may include a magnetic resonance imaging (MRI) image, a computerized tomography (CT) image, a direct digital X-ray photography image, a computer X-ray image, or the like, or any combination thereof. 
     The subject may be biological or non-biological. In some embodiments, the subject may include a patient, a man-made object, etc. In some embodiments, the subject may include a specific portion, an organ, and/or tissue of the patient. For example, the subject may include the head, the neck, the thorax, the heart, the stomach, a blood vessel, soft tissue, a tumor, nodules, or the like, or any combination thereof. 
     In some embodiments, the data obtaining device  110  may include a single modality imaging device. For example, the data obtaining device  110  may include a positron emission tomography (PET) device, a single-photon emission computed tomography (SPECT) device, a magnetic resonance imaging (MRI) device, a computed tomography (CT) device, an ultrasound (US) device, a X-ray imaging device (e.g., a suspended X-ray imaging device, a digital radiography (DR) scanner), or the like, or any combination thereof. In some embodiments, the data obtaining device  110  may include a multi-modality imaging device. Exemplary multi-modality imaging devices may include a PET-CT device, a PET-MRI device, or the like, or a combination thereof. 
     In some embodiments, the data obtaining device  110  may be a 3D camera (e.g., a 3D scanner). The 3D camera may obtain a 3D model of the subject. In some embodiments, the data obtaining device  110  may be configured to acquire one or more reference images of the subject. In some embodiments, the reference image may include a 2D digital radiography image (e.g., a DR plain film). 
     The network  120  may include any suitable network that can facilitate the exchange of information and/or data for the orthosis design system  100 . In some embodiments, one or more components of the orthosis design system  100  (e.g., the data obtaining device  110 , the at least one terminal device  130 , the server  144 , the data interaction equipment  140 , the storage device  150 , etc.) may communicate information and/or data with one or more other components of the orthosis design system  100  via the network  120 . For example, the processing device  114  may obtain image data (e.g., one or more reference images) and/or a 3D model of a subject from the data obtaining device via the network  120 . As another example, the processing device  114  may obtain user instruction(s) from the terminal device  130  via the network  120 . The network  120  may be and/or include a public network (e.g., the Internet), a private network (e.g., a local area network (LAN), a wide area network (WAN)), etc.), a wired network (e.g., an Ethernet network), a wireless network (e.g., an 802.11 network, a Wi-Fi network, etc.), a cellular network (e.g., a Long Term Evolution (LTE) network), a frame relay network, a virtual private network (VPN), a satellite network, a telephone network, routers, hubs, switches, server computers, and/or any combination thereof. For example, the network  120  may include a cable network, a wireline network, a fiber-optic network, a telecommunications network, an intranet, a wireless local area network (WLAN), a metropolitan area network (MAN), a public telephone switched network (PSTN), a Bluetooth™ network, a ZigBee™ network, a near field communication (NFC) network, or the like, or any combination thereof. In some embodiments, the network  120  may include one or more network access points. For example, the network  120  may include wired and/or wireless network access points such as base stations and/or internet exchange points through which one or more components of the orthosis design system  100  may be connected to the network  120  to exchange data and/or information. 
     The terminal device  130  may communicate and/or connect with the data obtaining device  110 , the server  144 , the data interaction equipment  140 , and/or the storage device  150 . For example, at least one terminal device  130  may obtain orthosis design data from the server  144  for design an orthosis. As another example, the at least one terminal device  130  may obtain image data acquired by the data obtaining device  110 , and send the image data to the data interaction equipment  140  and the server  144  for processing. In some embodiments, the at least one terminal device  130  may include a mobile device  131 , a tablet computer  132 , a laptop computer  133 , or the like, or any combination thereof. For example, the mobile device  131  may include a mobile phone, a personal digital assistant (PDA), a gaming device, a navigation device, or the like, or any combination thereof. In some embodiments, the at least one terminal device  130  may include an input device, an output device, or the like. The input devices may include alphanumeric and other keys. The input device may use keyboard input, touch screen (for example, with tactile or haptic feedback) input, voice input, eye tracking input, brain monitoring system input, or any other similar input mechanism. The input information received through the input device may be transmitted to the cloud design system via a bus for further processing. Other types of input devices may include cursor control devices, such as a mouse, a trajectory ball, or a cursor direction key. The output device may include a display, a speaker, a printer, etc. or any combination thereof. In some embodiments, the at least one terminal device  130  may be portion of the cloud design system. In some embodiments, the terminal device  130  may communicate with the data interaction equipment  140  and/or the server  144  via a browser. 
     In some embodiments, the terminal device  130  may include one or more first terminal devices and one or more second terminal devices. The first terminal device may be associated with a first type of user in the orthosis design system  100 . For example, the first terminal device may be associated with a doctor. The doctor may import data associated with the subject to one or more storage device (e.g., the storage device  150 ) of the orthosis design system via the first terminal device. The data associated with the subject may include identification information of the subject (e.g., an identification (ID) number of the subject, a name of the subject, the gender of the subject, the age of the subject, a portion of the subject to be corrected), image data associated with the subject, a 3D model associated with the subject, a reference image associated with the subject, or the like, or any combination thereof. The second terminal device may be associated with a second type of user in the orthosis design system  100 . For example, the second terminal device may be associated with an orthosis designer. The orthosis designer may send a request for orthosis design via the second terminal device. In some embodiments, a plurality of users associated with the plurality of terminal devices  130  may send a plurality of requests for determining an orthosis collaboratively. For example, a first terminal device associated with a first user is located in a first location. A second terminal device associated with a second user is located in a second location. The first location may be different from the second location. The first user and the second user may send requests for designing an orthosis to the data interaction equipment  140  synchronously. 
     In some embodiments, the server  144  may be a single server or a server group. The server group may be centralized or distributed (e.g., the server  144  may be a distributed system). For example, the server  144  may include a plurality of servers, e.g., a server  144 - 1 , a server  144 - 2 , a server  144 - 4 , as illustrated in  FIG.  21   . In some embodiments, the server  144  may be local or remote. For example, the server  144  may access information and/or data stored in the terminal device  130 , the storage device  150 , the data obtaining device  110  via the network  120 . As another example, the server  144  may be directly connected to the terminal device  130 , the storage device  150 , the data obtaining device  110  to access stored information and/or data. In some embodiments, the server  144  may be implemented on a cloud platform or an onboard computer. Merely by way of example, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an inter-cloud, a multi-cloud, or the like, or any combination thereof. In some embodiments, the server  144  may be implemented on a computing device  200  having one or more components illustrated in  FIG.  2    in the present disclosure. 
     In some embodiments, the server  144  may include a processing device  114 . 
     The processing device  114  may process information and/or data to perform one or more functions described in the present disclosure. For example, the processing device  114  may obtain a 3D model associated with a subject. As another example, the processing device  114  may obtain one or more reference images associated with a subject. As still another example, the processing device  114  may determine, based on a 3D model and one or more reference images, orthosis design data for a subject. As still another example, the processing device  114  may edit (e.g., split) a 3D model. As still another example, the processing device  114  may initialize a 3D model. As still another example, the processing device  114  may determine a spline curve associated with a 3D model. As still another example, for each second coordinate of a plurality of second coordinates on a spline curve, the processing device  114  may determine a center point corresponding to the second coordinate. As still another example, the processing device  114  may determine a link line connecting a center point and a corresponding second coordinate. As still another example, the processing device  114  may determine a plurality of boundary points along a direction of a link line. As still another example, the processing device  114  may generate a split surface based on all boundary points corresponding to a plurality of second coordinates. As still another example, the processing device  114  may split a 3D model based on a split surface. 
     In some embodiments, the processing device  114  may include one or more processing engines (e.g., single-core processing engine(s) or multi-core processor(s)). Merely by way of example, the processing device  114  may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), an application-specific instruction-set processor (ASIP), a graphics processing unit (GPU), a physics processing unit (PPU), a digital signal processor (DSP), a field programmable gate array (FPGA), a programmable logic device (PLD), a controller, a microcontroller unit, a reduced instruction-set computer (RISC), a microprocessor, or the like, or any combination thereof. 
     In some embodiments, the server  144  may be connected to the network  120  to communicate with one or more components (e.g., the terminal device  130 , the storage device  150 , the data obtaining device  110 ) of the orthosis design system  100 . In some embodiments, the server  144  may be directly connected to or communicate with one or more components (e.g., the terminal device  130 , the storage device  150 , and/or the data obtaining device  110 ) of the orthosis design system  100 . 
     The data interaction equipment  140  may be configured to transmit data obtained from the terminal device  130  to the server  144 . In some embodiments, the data interaction equipment  140  may transmit one or more requests for orthosis design obtained from one or more terminal devices  130  to one or more servers according to a load balancing mechanism. In some embodiments, the data interaction equipment  140  may include a first load balancing device, a data interaction device cluster including a plurality of data interaction devices, and a second load balancing device. More descriptions of the data interaction equipment  140  may be found elsewhere in the present disclosure (e.g.,  FIG.  21    and descriptions thereof). 
     In some embodiments, the data interaction equipment  140  may be a reverse proxy. As used herein, a reverse proxy may refer to a type of proxy server that retrieves resources on behalf of a client from one or more servers. These resources are then returned to the client, appearing as if they originated from the proxy server itself. In some embodiments, the reverse proxy may include a nginx, a haproxy, or the like. More descriptions of the proxy server may be found elsewhere in the present disclosure (e.g.,  FIG.  22    and descriptions thereof). 
     The storage device  150  may store data, instructions, and/or any other information. In some embodiments, the storage device  150  may store data obtained from the data obtaining device  110 , the terminal device  130 , the processing device  114 . In some embodiments, the storage device  150  may store data and/or instructions that the processing device  114  may execute or use to perform exemplary methods described in the present disclosure. In some embodiments, the storage device  150  may include a mass storage, removable storage, a volatile read-and-write memory, a read-only memory (ROM), or the like, or any combination thereof. Exemplary mass storage may include a magnetic disk, an optical disk, a solid-state drive, etc. Exemplary removable storage may include a flash drive, a floppy disk, an optical disk, a memory card, a zip disk, a magnetic tape, etc. Exemplary volatile read-and-write memory may include a random access memory (RAM). Exemplary RAM may include a dynamic RAM (DRAM), a double date rate synchronous dynamic RAM (DDR SDRAM), a static RAM (SRAM), a thyristor RAM (T-RAM), and a zero-capacitor RAM (Z-RAM), etc. Exemplary ROM may include a mask ROM (MROM), a programmable ROM (PROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a compact disk ROM (CD-ROM), and a digital versatile disk ROM, etc. In some embodiments, the storage device  150  may be implemented on a cloud platform as described elsewhere in the disclosure. 
     In some embodiments, the storage device  150  may be connected to the network  120  to communicate with one or more other components in the orthosis design system  100  (e.g., the terminal device  130 , the server  144 , the data obtaining device  110 ). At least one component in the orthosis design system  100  may access data or instructions stored in the storage device  150  through the network  120 . In some embodiments, the storage device  150  may be portion of the cloud design system. 
     This description is intended to be illustrative, and not to limit the scope of the present disclosure. Many alternatives, modifications, and variations will be apparent to those skilled in the art. The features, structures, methods, and other characteristics of the exemplary embodiments described herein may be combined in various ways to obtain additional and/or alternative exemplary embodiments. However, those variations and modifications do not depart the scope of the present disclosure. 
     In some embodiments, the orthosis design system  100  may be based on a browser/server (B/S) architecture. The B/S architecture may run an application directly from an internet browser on any device that has a browser (e.g., a laptop, a tablet, a smartphone). For example, a browser may be installed on the terminal device  130 . The user of the terminal device  130  may communicate with the server  144  via the browser. In some embodiments, a plurality of main functions of the orthosis design system  100  may be implemented on the server  144 . For example, the server  144  may determine orthosis design data for a subject. As still another example, the sever  144  may edit (e.g., split) a 3D model. In some embodiments, a plurality of relatively simple functions of the orthosis design system  100  may be implemented on the terminal device  130 . For example, the terminal device  130  may obtain data associated with a subject (e.g., a 3D model of the subject, a reference image of the subject). Accordingly, a computing load of the terminal device  130  may be reduced. The maintenance and upgrade cost of the orthosis design system  100  may be reduced. The total cost of a user of the orthosis design system  100  may further be reduced. 
     In some embodiments, the orthosis design system  100  may be based on ASP.NET Core technology. As used herein, ASP.NET Core may refer to a cross-platform, high-performance, open-source framework for building modern, cloud-based, internet-connected applications. In some embodiments, the orthosis design system  100  may be developed on Windows, macOS, and/or Linux. In some embodiments, the orthosis design system  100  may be deployed to cloud or on-premises. In some embodiments, the orthosis design system  100  may be hosted in internet information services (IIS), nginx, apache, docker, or the like. Accordingly, a cross-platform orthosis design system  100  may be developed. 
     In some embodiments, the orthosis design system  100  may include a database. In some embodiments, the database may include a medical imaging information system. For example, the database may be a picture archiving and communication system (PACS). The PACS may refer to a medical imaging technology which provides economical storage and convenient access to images from multiple modalities (source machine types). For example, the PACS may store a plurality of images (e.g., a plurality of medical images) generated by a plurality of medical devices (e.g., a nuclear magnetic resonance (NMR), a computer tomography (CT) device, a digital X-ray (DR) device, an ultrasound device, an X-ray imaging device) in a medical imaging department of a hospital. The format for PACS image storage and transfer may be digital imaging and communications in medicine (DICOM). 
     In some embodiments, the orthosis design system  100  may include a 3D printing server. The 3D printing server may be connected to a 3D printing device to print an orthosis based on housing design data, orthosis design data, and/or a plurality of 3D printing parameters associated with the orthosis as described elsewhere in the present disclosure. 
     In some embodiments, the orthosis design system  100  may include a data management system (e.g., a data management system  1700  as illustrated in  FIG.  17   ). The data management system may be configured to manage data associated with the orthosis design system  100 . The data associated with the orthosis design system  100  may include identification information of the subject (e.g., an identification (ID) number of the subject, a name of the subject, the gender of the subject, the age of the subject, a portion of the subject to be corrected), image data of the subject, a 3D model of the subject, orthosis design data, housing design data associated with a housing of the orthosis, a 3D printing parameter of the orthosis, or the like, or any combination thereof. In some embodiments, the data management system may include an importing module (e.g., an importing module  1701  as illustrated in  FIG.  17   ), a storage module (e.g., a storage module  1702  as illustrated in  FIG.  17   ), and a printing module (e.g., a printing module  1703  as illustrated in  FIG.  17   ). More descriptions of the data management system may be found elsewhere in the present disclosure (e.g.,  FIGS.  17 ,  18 ,  19 ,  20   , and descriptions thereof). 
       FIG.  2    is a schematic diagram illustrating hardware and/or software components of an exemplary computing device according to some embodiments of the present disclosure. As illustrated in  FIG.  2   , the computing device  200  may include a processor  210 , a storage  220 , an input/output (I/O)  230 , and a communication port  240 . In some embodiments, the processing device  114  and/or the terminal device  130  may be implemented on the computing device  200 . 
     The processor  210  may execute computer instructions (program code) and, when executing the instructions, cause the processing device  114  to perform functions of the processing device  114  in accordance with techniques described herein. The computer instructions may include, for example, routines, programs, objects, components, signals, data structures, procedures, modules, and functions, which perform particular functions described herein. In some embodiments, the processor  210  may process data and/or images obtained from the data obtaining device  110 , the terminal device  130 , the storage device  150 , and/or any other components of the orthosis design system  100 . For example, the processor  210  may obtain image data from the data obtaining device  110 . In some embodiments, the processor  210  may include one or more hardware processors, such as a microcontroller, a microprocessor, a reduced instruction set computer (RISC), an application-specific integrated circuits (ASICs), an application-specific instruction-set processor (ASIP), a central processing unit (CPU), a graphics processing unit (GPU), a physics processing unit (PPU), a microcontroller unit, a digital signal processor (DSP), a field-programmable gate array (FPGA), an advanced RISC machine (ARM), a programmable logic device (PLD), any circuit or processor capable of executing one or more functions, or the like, or any combinations thereof. 
     Merely for illustration, only one processor is described in the computing device  200 . However, it should be noted that the computing device  200  in the present disclosure may also include multiple processors. Thus operations and/or method steps that are performed by one processor as described in the present disclosure may also be jointly or separately performed by the multiple processors. For example, if in the present disclosure the processor of the computing device  200  executes both process A and process B, it should be understood that process A and process B may also be performed by two or more different processors jointly or separately in the computing device  200  (e.g., a first processor executes process A and a second processor executes process B, or the first and second processors jointly execute processes A and B). 
     The storage  220  may store data/information obtained from the data obtaining device  110 , the terminal device  130 , the storage device  150 , the server  144 , or any other components of the orthosis design system  100 . In some embodiments, the storage  220  may include a mass storage device, removable storage device, a volatile read-and-write memory, a read-only memory (ROM), or the like, or any combination thereof. For example, the mass storage may include a magnetic disk, an optical disk, a solid-state drive, etc. The removable storage may include a flash drive, a floppy disk, an optical disk, a memory card, a zip disk, a magnetic tape, etc. The volatile read-and-write memory may include a random-access memory (RAM). The RAM may include a dynamic RAM (DRAM), a double date rate synchronous dynamic RAM (DDR SDRAM), a static RAM (SRAM), a thyristor RAM (T-RAM), and a zero-capacitor RAM (Z-RAM), etc. The ROM may include a mask ROM (MROM), a programmable ROM (PROM), an erasable programmable ROM (PEROM), an electrically erasable programmable ROM (EEPROM), a compact disk ROM (CD-ROM), and a digital versatile disk ROM, etc. In some embodiments, the storage  220  may store one or more programs and/or instructions to perform exemplary methods described in the present disclosure. For example, the storage  220  may store a program (e.g., in the form of computer-executable instructions) for the processing device  114  to determine orthosis design data. As another example, the storage  220  may store a program (e.g., in the form of computer-executable instructions) for the processing device  114  to determine a split surface of a 3D model. 
     The I/O  230  may input or output signals, data, and/or information. In some embodiments, the I/O  230  may enable user interaction with the processing device  114 . In some embodiments, the I/O  230  may include an input device and an output device. Exemplary input devices may include a keyboard, a mouse, a touch screen, a microphone, or the like, or a combination thereof. Exemplary output devices may include a display device, a loudspeaker, a printer, a projector, or the like, or a combination thereof. Exemplary display devices may include a liquid crystal display (LCD), a light-emitting diode (LED)-based display, a flat panel display, a curved screen, a television device, a cathode ray tube (CRT), or the like, or a combination thereof. 
     The communication port  240  may be connected to a network (e.g., the network  160 ) to facilitate data communications. The communication port  240  may establish connections between the processing device  114  and the data obtaining device  110 , the terminal device  130 , or the storage device  150 . The connection may be a wired connection, a wireless connection, or a combination of both that enables data transmission and reception. The wired connection may include an electrical cable, an optical cable, a telephone wire, or the like, or any combination thereof. The wireless connection may include Bluetooth, Wi-Fi, WiMAX, WLAN, ZigBee, mobile network (e.g., 3G, 4G, 5G, etc.), or the like, or a combination thereof. In some embodiments, the communication port  240  may be a standardized communication port, such as RS232, RS485, etc. In some embodiments, the communication port  240  may be a specially designed communication port. For example, the communication port  240  may be designed in accordance with the digital imaging and communications in medicine (DICOM) protocol. 
       FIG.  3    is a schematic diagram illustrating hardware and/or software components of a mobile device according to some embodiments of the present disclosure. In some embodiments, the processing device  114  and/or the terminal device  130  may be implemented on the computing device  200 . As illustrated in  FIG.  3   , the mobile device  300  may include a communication platform  310 , a display  320 , a graphics processing unit (GPU)  330 , a central processing unit (CPU)  340 , an I/O  350 , a memory  360 , and storage  390 . In some embodiments, any other suitable component, including but not limited to a system bus or a controller (not shown), may also be included in the mobile device  300 . In some embodiments, a mobile operating system  370  (e.g., iOS, Android, Windows Phone, etc.) and one or more applications  380  may be loaded into the memory  360  from the storage  390  in order to be executed by the CPU  340 . The applications  380  may include a browser or any other suitable mobile apps for receiving and rendering information relating to orthosis design or other information from the processing device  114 . User interactions with the information stream may be achieved via the I/O  350  and provided to the processing device  114  and/or other components of the orthosis design system  100  via the network  120 . 
     To implement various modules, units, and functionalities described in the present disclosure, computer hardware platforms may be used as the hardware platform(s) for one or more of the elements described herein. The hardware elements, operating systems and programming languages of such computers are conventional in nature, and it is presumed that those skilled in the art are adequately familiar therewith to adapt those technologies to generate a high-quality image of a scanned object as described herein. A computer with user interface elements may be used to implement a personal computer (PC) or another type of work station or terminal device, although a computer may also act as a server if appropriately programmed. It is believed that those skilled in the art are familiar with the structure, programming and general operation of such computer equipment and as a result, the drawings should be self-explanatory. 
       FIG.  4    is a block diagram illustrating an exemplary processing device according to some embodiments of the present disclosure. The processing device  114  may include a first obtaining module  401 , a second obtaining module  402 , an orthosis design data determination module  403 , an altering module  404 , a thickness adjustment module  405 , a storage module  406 , and an uploading module  407 . The modules may be hardware circuits of at least part of the processing device  114 . The modules may also be implemented as an application or set of instructions read and executed by the processing device  114 . Further, the modules may be any combination of the hardware circuits and the application/instructions. For example, the modules may be part of the processing device  114  when the processing device  114  is executing the application or set of instructions. 
     The first obtaining module  401  may be configured to obtain a 3D model associated with a subject. In some embodiments, the first obtaining module  401  may obtain a 3D model associated with a subject from a 3D camera device (e.g., a 3D scanner). In some embodiments, the first obtaining module  401  may obtain image data (e.g., a plurality of medical images) associated with a subject. The first obtaining module  401  may determine a 3D model associated with the subject by processing the image data associated with the subject. For example, the first obtaining module  401  may determine a target area by performing an image segmentation operation on the image data associated with the subject. The first obtaining module  401  may extract body surface data associated with the target area from the image data associated with the subject. The first obtaining module  401  may generate a plurality of meshes of the 3D model based on the body surface data associated with the target area. In some embodiments, the first obtaining module  401  may process body surface data. For example, the first obtaining module  401  may perform a filtering operation, a smoothing operation, a boundary calculation operation, or the like, or any combination thereof, on the body surface data. More descriptions of the obtaining of the 3D model may be found elsewhere in the present disclosure (e.g.,  FIGS.  5 ,  6   , and descriptions thereof). 
     The second obtaining module  402  may be configured to obtain a reference image associated with a subject. In some embodiments, the second obtaining module  402  may obtain one or more reference images associated with a subject from the data obtaining device  110  (e.g., a DR device, an X-ray imaging device, a camera). In some embodiments, the second obtaining module  402  may obtain one or more reference images based on the identification information of a subject. In some embodiments, the second obtaining module  402  may obtain one or more reference images based on a machine learning model. More descriptions of the obtaining of the one or more reference images may be found elsewhere in the present disclosure (e.g.,  FIG.  5    and descriptions thereof). 
     The orthosis design data determination module  403  may be configured to determine orthosis design data for a subject. In some embodiments, the orthosis design data determination module  403  may determine orthosis design data for a subject based on a 3D model of the subject and one or more reference images of the subject. For example, the orthosis design data determination module  403  may compare a 3D model of a subject with one or more reference images of the subject. The orthosis design data determination module  403  may determine orthosis design data by modifying the 3D model based on a comparison result. More descriptions of determination of orthosis design data for a subject may be found elsewhere in the present disclosure (e.g.,  FIG.  5    and descriptions thereof). 
     The altering module  404  may be configured to alter orthosis design data. In some embodiments, the altering module  404  may determine force data of at least one region of a subject after wearing an orthosis based on a 3D model of the subject and orthosis design data for the subject. The altering module  404  may alter the orthosis design data based on the force data of the at least one region of the subject. More descriptions for altering orthosis design data for a subject may be found elsewhere in the present disclosure (e.g.,  FIG.  5    and descriptions thereof). 
     The thickness adjustment module  405  may be configured to determine housing design data associated with a housing of an orthosis. In some embodiments, the thickness adjustment module  405  may determine housing design data associated with a housing of an orthosis by performing a thickness-adjustment operation on orthosis design data. In some embodiments, the housing design data may represent a size of the orthosis. For example, the housing design data may include a length, a width, a height, a thickness of the orthosis, or the like, or any combination thereof. More descriptions of determination of the housing design data may be found elsewhere in the present disclosure (e.g.,  FIG.  5    and descriptions thereof). 
     The storage module  406  may be configured to store data and/or information associated with the orthosis design system  100 . The data associated with the orthosis design system  100  may include identification information of the subject (e.g., an identification (ID) number of the subject, a name of the subject, the gender of the subject, the age of the subject, a portion of the subject to be corrected), image data of the subject, a 3D model of the subject, orthosis design data, housing design data associated with a housing of the orthosis, a 3D printing parameter of the orthosis, or the like, or any combination thereof. 
     The uploading module  407  may be configured to transmit data and/or information associated with the orthosis design system  100  to one or more other components of the orthosis design system  100 . In some embodiments, the uploading module  407  may transmit housing design data to a server (e.g., a 3D print server) for 3D printing. 
     It should be noted that the above description of the processing device  114  is merely provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. For persons having ordinary skills in the art, multiple variations and modifications may be made under the teachings of the present disclosure. However, those variations and modifications do not depart from the scope of the present disclosure. In some embodiments, one or more modules may be combined into a single module. For example, the first obtaining module  401  and the second obtaining module may be combined into a single module, which may both obtain a 3D model of a subject and one or more reference images of the subject. In some embodiments, one or more modules may be added or omitted in the processing device  114 . For example, the storage module  406  may be omitted. Data associated with the orthosis design system  100  may be stored in one or more storage devices (e.g., the storage device  150 ) of the orthosis design system  100 , or an external storage device. As another example, the altering module  404  may be omitted. The orthosis design data determination module  403  may alter the orthosis design data. 
       FIG.  5    is a flowchart illustrating an exemplary process for designing an orthosis according to some embodiments of the present disclosure. Process  500  may be executed by the orthosis design system  100 . For example, process  500  may be implemented as a set of instructions (e.g., an application) stored in the storage device  150  in the orthosis design system  100 . The processing device  114  may execute the set of instructions and may accordingly be directed to perform process  500  in the orthosis design system  100 . The operations of the illustrated process  500  presented below are intended to be illustrative. In some embodiments, process  500  may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. Additionally, the order in which the operations of process  500  as illustrated in  FIG.  5    and described below is not intended to be limiting. 
     In  510 , the processing device  114  (e.g., the first obtaining module  401 ) may obtain a 3D model associated with a subject. 
     The subject may be biological or non-biological. In some embodiments, the subject may include a patient, an animal, a man-made object, etc. In some embodiments, the subject may include a specific portion, organ, and/or tissue of the patient or the animal to be corrected. For example, the subject may include the spine, an upper limb bone, an olecranon fracture, an ulna, phalanges of fingers, metatarsal bones, thigh bone, an ossa cruris, an ankle joint, or the like, or any combination thereof. 
     In some embodiments, the 3D model associated with the subject may include a 3D model of the whole or a portion of the patient or the animal. For example, the 3D model associated with the subject may be a 3D model of a human body or an animal body, a 3D model of a leg, a 3D model of a spine, or the like. A size of the 3D model associated with the subject may be relating to an actual size of the subject. For example, the size of the 3D model may be determined by scaling (e.g., scaling down or scaling up) the actual size of the subject proportionally. 
     In some embodiments, the processing device  114  may obtain the 3D model associated with the subject uploaded by a 3D camera device (e.g., a 3D scanner). The 3D model may be obtained by scanning the subject via the 3D camera device (e.g., the 3D scanner). In some embodiments, the processing device  114  may obtain the 3D model associated with the subject from a terminal device (e.g., the terminal device  130 ) via the network  120 . For example, a user may input a 3D model of the subject to the terminal device (e.g., the terminal device  130 ) via a network port directly. 
     In some embodiments, the processing device  114  may obtain image data (e.g., a plurality of medical images) associated with the subject. For example, the processing device  114  may obtain the image data from the data obtaining device  110  directly via the network  120 . As another example, the processing device  114  may obtain the image data from a database based on identification information of the subject input by a user. The identification information of the subject may include an identification (ID) number of the subject, a name of the subject, the gender of the subject, the age of the subject, a portion of the subject to be corrected, or the like, or any combination thereof. In some embodiments, the database may include a medical imaging information system. For example, the database may be a picture archiving and communication system (PACS). The PACS may refer to a medical imaging technology which provides economical storage and convenient access to images from multiple modalities (source machine types). In some embodiments, the PACS may store a plurality of images (e.g., a plurality of medical images) generated by a plurality of medical devices (e.g., a nuclear magnetic resonance (NMR), a computer tomography (CT) device, a digital X-ray (DR) device, an ultrasound device, an X-ray imaging device) in a medical imaging department of a hospital. The format for PACS image storage and transfer may be digital imaging and communications in medicine (DICOM). 
     The processing device  114  may determine the 3D model associated with the subject by processing the image data associated with the subject. For example, the processing device  114  may determine a target area by performing an image segmentation operation on the image data associated with the subject. The processing device  114  may extract body surface data associated with the target area from the image data associated with the subject. The processing device  114  may generate a plurality of meshes of the 3D model based on the body surface data associated with the target area. More descriptions of obtaining of the 3D model may be found elsewhere in the present disclosure (e.g.,  FIG.  6    and descriptions thereof). 
     In some embodiments, an instruction to obtain the 3D model of the subject may be stored in a storage device (e.g., the storage device  150 ) of the orthosis design system  100 , and may be executed by the processing device  114  (e.g., the first obtaining module  401 ). 
     In  520 , the processing device  114  (e.g., the second obtaining module  402 ) may obtain one or more reference images associated with the subject. 
     In some embodiments, the one or more reference images may include a DR image, a CT image, an MR image, or the like, or any combination thereof. For example, the one or more reference images may be two-dimensional DR images (e.g., a DR plain film). In some embodiments, the reference image may include annotation information. The annotation information may include a Cobb angle. As used herein, the Cobb angle may refer to a measurement of the degree of side-to-side spinal curvature. The Cobb angle may describe the maximum distance from straight a scoliotic curve may be. In some embodiments, the degree of spinal curvature of a human (or an animal) may be evaluated based on the Cobb angle. A treatment method (e.g., an orthosis treatment, a surgical treatment) may be determined based on the degree of spinal curvature of the human (or the animal). For example, if the Cobbe angle annotated on the reference image is in a range from 20° to 45°, it may indicate that the degree of spinal curvature is relatively low and an orthosis may be used to correct the spine. If the Cobbe angle exceeds 45°, it may indicate that the degree of spinal curvature is relatively high and a surgical treatment may be performed to correct the spine. 
     In some embodiments, the processing device  114  may obtain the one or more reference images associated with the subject from the data obtaining device  110  (e.g., a DR device, an X-ray imaging device, a camera). The data obtaining device  110  (e.g., a DR device, an X-ray imaging device, a camera) may perform a laser scanning or an optical scanning on the subject. For example, the data obtaining device  110  (e.g., a DR device, an X-ray imaging device, a camera) may capture a plurality of images associated with the subject, and store the plurality of images in a storage device (e.g., the storage device  150 ) of the orthosis design system  100 . The processing device  114  may access the storage device and retrieve the one or more reference images from the storage device. As another example, the data obtaining device  110  (e.g., a DR device, an X-ray imaging device, a camera) may send one or more captured reference images to the processing device  114  directly. 
     In some embodiments, the processing device  114  may obtain the one or more reference images based on the identification information of the subject. For example, the processing device  114  may obtain the identification information of the subject (e.g., a patient). The processing device  114  may select one or more images from a plurality of historical images based on the identification information of the subject. The user identification information associated with the selected one or more images may be similar with the identification information of the subject. The processing device  114  may determine the selected one or more images as the one or more reference images of the subject. 
     In some embodiments, the processing device  114  may obtain the one or more reference images based on a machine learning model. For example, the processing device  114  may determine an image generation model by training a preliminary model based on historical image data. The processing device  114  may obtain the one or more reference images by inputting the identification information of the subject into the image generation model. 
     In some embodiments, an instruction to obtain the one or more reference images of the subject may be stored in a storage device (e.g., the storage device  150 ) of the orthosis design system  100 , and may be executed by the processing device  114  (e.g., the second obtaining module  402 ). 
     In  530 , the processing device  114  (e.g., the orthosis design data determination module  403 ) may determine orthosis design data for the subject based on the 3D model and the one or more reference images. 
     In some embodiments, the orthosis design data may refer to data for designing an orthosis for the subject to be corrected. The orthosis design data may be used to determine the orthosis for the subject. In some embodiments, the orthosis may be an extracorporeal device configured on the subject or a portion thereof to be corrected. In some embodiments, the processing device  114  may compare the 3D model with the reference image(s). For example, the processing device  114  may superimpose the reference image on the 3D model, as illustrated in  FIG.  8   . Specifically, the processing device  114  may determine one or more first reference points (or one or more first feature points) in the reference image. The processing device  114  may determine one or more second reference points (or one or more second feature points) corresponding to the one or more first reference points in the 3D model. The processing device  114  may superimpose the reference image on the 3D model by aligning the one or more first reference points in the reference image and the one or more corresponding second reference points in the 3D model. 
     In some embodiments, the processing device  114  may determine the orthosis design data by modifying the 3D model based on a comparison result (e.g., a superimposing result). The orthosis design data for the subject may include a processing result determined by performing a mesh deformation operation, a mesh smoothing operation, a mesh division operation, a mesh splitting operation, or the like, or any combination thereof, on the 3D model. 
     In some embodiments, the processing device  114  may perform a mesh splitting operation (also referred to as a model splitting operation) on the 3D model to generate a desired shape. For example, the processing device  114  may determine a spline curve associated with the 3D model. For each point of a plurality of points on the spline curve, the processing device  114  may determine a center point corresponding to the point. The processing device  114  may determine a link line connecting the center point and the corresponding point. The processing device  114  may determine a plurality of boundary points along a direction of the link line. The processing device  114  may generate a split surface based on all the boundary points corresponding to the plurality of points on the spline curve. The processing device  114  may split the 3D model based on the split surface. More descriptions for splitting a 3D model may be found elsewhere in the present disclosure (e.g.,  FIGS.  10 - 16   , and descriptions thereof). 
     In some embodiments, the orthosis design data may be determined manually by a user (e.g., an orthosis designer). For example, an orthosis designer may modify the 3D model based on the comparison result between the 3D model and the reference image(s) to determine the orthosis design data (e.g., a plurality of parameters associated with the orthosis). 
     In some embodiments, an instruction to determine the orthosis design data may be stored in a storage device (e.g., the storage device  150 ) of the orthosis design system  100 , and may be executed by the processing device  114  (e.g., the orthosis design data determination module  403 ). 
     According to some embodiments of the present disclosure, the reference image(s) and the 3D model of the subject may be obtained by the processing device  114  based on an orthosis design instruction obtained via a network access port. The orthosis (e.g., an orthosis model) may be designed by comparing the reference image(s) of the subject with the 3D model of the subject (e.g., superimposing the reference image(s) on the 3D model). Accordingly, problems of complicated and low efficiency of an orthosis design process in prior arts may be solved. A plurality of users may access the server for designing the orthosis via the network access port to complete the design of the orthosis. The orthosis design process may be simplified, and the efficiency of the orthosis design process may be improved. 
     It should be noted that the above description is merely provided for the purpose of illustration, and not intended to limit the scope of the present disclosure. For persons having ordinary skills in the art, multiple variations and modifications may be made under the teachings of the present disclosure. However, those variations and modifications do not depart from the scope of the present disclosure. In some embodiments, operations  510  and  520  may be combined into one operation. In operation  510 , the processing device  114  may obtain the 3D model and the reference image of the subject. 
     In some embodiments, one or more operations may be added in process  500 . For example, an operation for altering the orthosis design data may be added in process  500 . More descriptions for altering of the orthosis design data may be found elsewhere in the present disclosure (e.g.,  FIG.  7    and descriptions thereof). 
     As another example, an operation for determining housing design data associated with a housing of the orthosis may be added in process  500 . In some embodiments, the processing device  114  (e.g., the thickness adjustment module  405 ) may determine the housing design data associated with the housing of the orthosis by performing a thickness-adjustment operation on the orthosis design data. In some embodiments, the housing design data may represent a size of the orthosis. For example, the housing design data may include a length, a width, a height, a thickness of the orthosis, or the like, or any combination thereof. In some embodiments, the thickness of the orthosis may be in a range from 3 mm to 4 mm. In some embodiments, the processing device  114  (e.g., the storage module  406 ) may store the housing design data in one or more components (e.g., the terminal device  130 , the storage device  150 ) of the orthosis design system  100 . In some embodiments, the processing device  114  (e.g., the uploading module  407 ) may transmit the housing design data to a server (e.g., a 3D print server). 
     As still another example, an operation for printing the orthosis may be added in process  500 . In some embodiments, the server  144  may be connected to a 3D printing server with a communication protocol directly. The processing device  114  may transmit the orthosis design data, the housing design data, and/or a plurality of 3D printing parameters associated with the orthosis to the 3D printing server. The plurality of 3D printing parameters associated with the orthosis may include a printing material, a printing orientation, a layer thickness, a printing orientation angle, a filling ratio, a filament feed rate, or the like, or any combination thereof. The 3D printing server may be connected to a 3D printing device to print the orthosis based on the housing design data, the orthosis design data, and/or a plurality of 3D printing parameters associated with the orthosis. Accordingly, an orthosis design and print process may be achieved. 
     According to some embodiments of the present disclosure, the reference image(s) and the 3D model of the subject may be obtained by the processing device  114  based on an orthosis design instruction obtained via a network access port. The orthosis may be designed by comparing the reference image(s) of the subject with the 3D model of the subject (e.g., superimposing the reference image(s) on the 3D model). Data associated with the orthosis (e.g., the orthosis design data, the housing design data) may be transmitted to the 3D printing server, and an orthosis may be printed. Accordingly, the problems of complicated and low efficiency of an orthosis design process in prior arts may be solved. The user may access the server for designing the orthosis and the server for printing the orthosis via the network access port to complete the design and the print of the orthosis. The orthosis design and print process may be simplified, and the efficiency of the orthosis design and print process may be improved. 
       FIG.  6    is a flowchart illustrating an exemplary process for obtaining a 3D model associated with a subject according to some embodiments of the present disclosure. Process  600  may be executed by the orthosis design system  100 . For example, process  600  may be implemented as a set of instructions (e.g., an application) stored in the storage device  150  in the orthosis design system  100 . The processing device  114  may execute the set of instructions and accordingly be directed to perform process  600  in the orthosis design system  100 . The operations of the illustrated process  600  presented below are intended to be illustrative. In some embodiments, process  600  may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. Additionally, the order in which the operations of process  600  as illustrated in  FIG.  6    and described below is not intended to be limiting. 
     In  610 , the processing device  114  (e.g., the first obtaining module  401 ) may obtain image data associated with a subject. 
     In some embodiments, the image data may include a medical image. For example, the image data may include an MR image, a CT image, a digital X-ray image, a computer X-ray image, or the like, or any combination thereof. In some embodiments, the image data may include a data set of a plurality of tomographic images. The processing device  114  may determine the 3D model based on the data set of the plurality of tomographic images. For example, the processing device  114  may superimpose the plurality of tomographic images to generate the 3D model. In some embodiments, the processing device  114  may obtain the image data from a database (e.g., a PACS), as described elsewhere in the present disclosure (e.g.,  FIG.  5    and descriptions thereof). 
     In some embodiments, the image data may be in a form of digital imaging and communications in medicine (DICOM). DICOM may refer to a standard for image data storage and transfer. DICOM may use a specific file format and a communication protocol to define a medical image format that can be used for data exchange with a quality that meets clinical needs. For example, an image (e.g., a medical image) may be saved as a DICOM file format. In some embodiments, a medical imaging device (e.g., a CT device, a DR device, an MRI device, a 3D scanner) may change a format of a medical image to a DICOM file format. A user (e.g., a doctor, an orthosis designer) of the orthosis design system  100  may use a viewer with a function to read a DICOM file, to read the medical image in the DICOM file format, and to determine information associated with the medical image. 
     In some embodiments, the image data in the DICOM file format may include data related to an image in the DICOM file format, personal information of the subject (e.g., a patient), medical information of the subject, or the like, or any combination thereof. The data related to the image in the DICOM file format may include data associated with a device that captures the image, medical background data (e.g., historical diseases), or the like, or any combination thereof. The personal information of the subject may include a name, the gender, the age, a weight, a height, an identification (ID) number (e.g., an ID card number) of the subject, or the like, or any combination thereof. The medical information may include a medical history of the subject, surgery information, or the like, or any combination thereof. The surgery information may include a start time of a surgery, an estimated end time of the surgery, a surgical operation procedure, or the like, or any combination thereof. 
     In some embodiments, an instruction to obtain the image data may be stored in a storage device (e.g., the storage device  150 ) of the orthosis design system  100 , and may be execute by the processing device  114  (e.g., the first obtaining module  401 ). 
     In some embodiments, the processing device  114  may preprocess the image data. For example, the processing device  114  may perform an image segmentation operation, an image filtering operation, a smoothing operation, a mesh generation operation, or the like, or any combination thereof, on the image data. 
     In  620 , the processing device  114  (e.g., the first obtaining module  401 ) may determine a target area by performing an image segmentation operation on the image data associated with the subject. 
     In some embodiments, the image segmentation operation may include a threshold segmentation operation, an edge segmentation operation, a region segmentation operation, a motion segmentation operation, a segmentation operation based on an active contour model, a segmentation operation based on fuzzy clustering algorithm, a segmentation operation based on wavelet transform, or the like, or any combination thereof. In some embodiments, the threshold segmentation operation may include a histogram threshold segmentation operation, an inter-class variance threshold segmentation operation, a two-dimensional maximum entropy image segmentation operation, a fuzzy threshold segmentation operation, or the like, or any combination thereof. In some embodiments, the region segmentation operation may include a region growth operation, a region merging operation, or the like, or any combination thereof. In some embodiments, the target area may include an area to be corrected in the image data. The processing device  114  may perform an image segmentation operation on the image data to obtain the target area. 
     In some embodiments, an instruction for performing an image segmentation operation on the image data may be stored in a storage device (e.g., the storage device  150 ) of the orthosis design system  100 , and may be executed by the processing device  114  (e.g., the first obtaining module  401 ). 
     In  630 , the processing device  114  (e.g., the first obtaining module  401 ) may extract body surface data associated with the target area from the image data associated with the subject. 
     In some embodiments, the body surface data may include a plurality of pixels of a body surface contour (e.g., a skin contour) obtained from the segmented image data. In some embodiments, the body surface data may include a mask. The mask may include, but is not limited to, a two-dimensional matrix array, a multi-value image, or the like, or any combination thereof. In some embodiments, the processing device  114  may extract the body surface data associated with the target area from the segmented image data. 
     In some embodiments, the processing device  114  may process the body surface data. For example, the processing device  114  may delete a plurality of noise points (e.g., a plurality of pixels of clothes or accessories) in the body surface data. Accordingly, the processed body surface data may be more suitable for constructing the 3D model. As another example, the processing device  114  may perform a filtering operation, a smoothing operation, a boundary calculation operation, or the like, or any combination thereof, on the body surface data. 
     In some embodiments, an instruction for extracting body surface data of the target area may be stored in a storage device (e.g., the storage device  150 ) of the orthosis design system  100 , and may be executed by the processing device  114  (e.g., the first obtaining module  401 ). 
     In  640 , the processing device  114  (e.g., the first obtaining module  401 ) may generate a plurality of meshes of the 3D model based on the body surface data associated with the target area. 
     In some embodiments, the mesh may be formed by combining a plurality of feature points of the body surface data associated with the target area. In some embodiments, the feature points may include a plurality of pixels of a body surface contour of the target area. For example, a plurality of feature points of the body surface data may be connected to form a plurality of faces. The plurality of faces may be combined to form the plurality of meshes of the 3D model. In some embodiments, the face may have a shape of a triangle, a quadrilateral, or other concave or convex polygons. Accordingly, the plurality of meshes of the 3D model may be formed by combining the plurality of faces, a rendering process (or a display process) may be simplified. 
     In some embodiments, an instruction for generating the plurality of meshes may be stored in a storage device (e.g., the storage device  150 ) of the orthosis design system  100 , and may be executed by the processing device  114  (e.g., the first obtaining module  401 ). 
     Taking an orthosis design process for a scoliosis patient as an example. The processing device  114  may segment image data associated with a torso of a subject. The processing device  114  may extract body surface data and spine data of the subject. The processing device  114  may process the body surface data. For example, the processing device  114  may perform a smoothing operation, a filtering operation, or a boundary correction operation, on the body surface data, to achieve a good segmentation effect on the body surface data and the spine data. The processing device  114  may generate a plurality of polygon meshes based on the processed body surface data to form a 3D model. In some embodiments, the plurality of polygon meshes may include point cloud data of the subject. The 3D model may be generated based on the point cloud data. As used herein, the point cloud data may refer to the body surface data of the subject. 
     It should be noted that the above description is merely provided for the purpose of illustration, and not intended to limit the scope of the present disclosure. For persons having ordinary skills in the art, multiple variations and modifications may be made under the teachings of the present disclosure. However, those variations and modifications do not depart from the scope of the present disclosure. For example, operations  410  and  420  may be performed simultaneously. 
       FIG.  7    is a flowchart illustrating an exemplary process for altering orthosis design data according to some embodiments of the present disclosure. The process  700  may be executed by the orthosis design system  100 . For example, process  700  may be implemented as a set of instructions (e.g., an application) stored in the storage device  150  in the orthosis design system  100 . The processing device  114  may execute the set of instructions and accordingly be directed to perform the process  700  in the orthosis design system  100 . The operations of the illustrated process  700  presented below are intended to be illustrative. In some embodiments, the process  700  may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. Additionally, the order in which the operations of the process  700  as illustrated in  FIG.  7    and described below is not intended to be limiting. 
     In  710 , the processing device  114  (e.g., the altering module  404 ) may determine, based on the 3D model and the orthosis design data, force data of at least one region of the subject after wearing an orthosis. 
     In some embodiments, the force data may include a force magnitude and/or a force direction generated by the orthosis on the at least one region of the subject after wearing the orthosis. In some embodiments, the processing device  114  may determine the force data by performing one or more simulation experiments. For example, the processing device  114  may generate a 3D orthosis model based on the orthosis design data. The processing device  114  may simulate force data generated by the 3D orthosis model on the 3D model of the subject after wearing the 3D orthosis model. For example, the processing device  114  may simulate a curvature degree of at least one mesh of the 3D model of the subject after wearing the orthosis. The processing device  114  may determine the force data based on the bending degree of the at least one mesh of the 3D model of the subject. 
     In some embodiments, the force data (e.g., the force magnitude, the force direction) generated by the 3D orthosis model on different regions of the 3D model of the subject may be different. For example, the processing device  114  may determine the force data of a plurality of meshes of the 3D model of the subject by simulating the force data of the at least one region of the subject after wearing the orthosis. In some embodiments, the processing device  114  may display different force data (e.g., different magnitudes of force) in different colors. For example, the processing device  114  may determine preset force data for the plurality of meshes of the 3D model of the subject. The processing device  114  may display different preset force data in different colors. The preset force data for a mesh of the 3D model of the subject may refer to a force generated by the 3D orthosis model on the mesh. For illustration purposes, if the force applied on a mesh is relatively large, the processing device  114  may display the mesh in a red color. If the force applied on a mesh is relatively low, the processing device  114  may display the mesh in a blue color. 
     In some embodiments, an instruction for simulating the force data may be stored in a storage device (e.g., the storage device  150 ) of the orthosis design system  100 , and may be executed by the processing device  114  (e.g., the altering module  404 ). 
     In  720 , the processing device  114  (e.g., the altering module  404 ) may alter, based on the force data of the at least one region of the subject, the orthosis design data. 
     In some embodiments, the processing device  114  may alter the orthosis design data based on the force data of the at least one region of the subject. For example, the processing device  114  may alter the orthosis design data based on the force magnitudes and force directions of the plurality of meshes of the 3D model of the subject, and an applied force of the 3D orthosis model. In some embodiments, the applied force of the 3D orthosis model may refer to a force of a pressure region of the orthosis applied on different regions of the subject during the correcting of the subject. In some embodiments, the applied force may be determined according to statistical clinical data. In some embodiments, the applied force may be determined based on a trained machine learning model. 
     For illustration purposes, a process for altering the orthosis design data may be taken as an example. When a 3D model of the subject does not wear the 3D orthosis model, a triangular face on the 3D model of the subject is at a position of d and the force is 0. After the 3D model of the subject wears the 3D orthosis model, the triangular face is at a position of e, and the force is A. The preset applied force of the 3D orthosis model on the triangular face is B. The value of B is different from the value of A. If B is greater than A, it may indicate that the force applied on the triangular face is relatively low after the 3D orthosis model is worn on the 3D model of the subject. The processing device  114  may mark the position of e in a blue color. The orthosis design data may need to be altered to increase the force applied on the triangular face. That is, a curvature degree of one or more meshes in the triangle face may need to be increased. During the altering of the orthosis design data, the color of the position of e may change from blue to light blue or transparent gradually, as the force applied on the triangular face increases. If B is less than A, it may indicate that the force applied on the triangle face is relatively large after the 3D orthosis model is worn on the 3D model of the subject. The processing device  114  may mark the position of e in a red color. The orthosis design data may need to be altered to reduce the force applied on the triangle face. That is, a curvature degree of one or more meshes in the triangle face may need to be reduced. During the altering of the orthosis design data, the color of the position of e may change from red to light red or transparent gradually, as the force applied on the triangular face decreases. By adjusting the orthosis design data, the force A generated by the 3D orthosis model on the triangular face may be equal to (or substantially equal to) the preset applied force B, so that the force of the triangular face at the position of e may be equal to (or substantially equal to) the applied force. Similarly, the processing device  114  may alter the orthosis design data by correcting the plurality of meshes (or a plurality of pressure regions) of the 3D model of the subject. Accordingly, the orthosis determined based on the altered orthosis design data may match the subject closely, and a correction effect of the orthosis may be ensured. 
     In some embodiments, after the orthosis design data is altered by the processing device  114 , the altered orthosis design data may further be confirmed by the user of the orthosis design system  100 . For example, if the altered orthosis design data cannot meet a correction requirement, the user may further modify the alter orthosis design data. In some embodiments, a user (e.g., a doctor, an orthosis designer) of the orthosis design system  100  may alter the orthosis design data based on the force data of the at least one region of the subject after wearing the orthosis. 
     In some embodiments, an instruction to obtain the altered orthosis design data may be stored in a storage device (e.g., the storage device  150 ) of the orthosis design system  100 , and may be executed by the processing device  114  (e.g., the altering module  404 ). 
     It should be noted that the above description is merely provided for the purpose of illustration, and not intended to limit the scope of the present disclosure. For persons having ordinary skills in the art, multiple variations and modifications may be made under the teachings of the present disclosure. However, those variations and modifications do not depart from the scope of the present disclosure. In some embodiments, in  710 , the processing device  114  may determine the force data of the at least one region of the subject after wearing the orthosis based on a trained machine learning model. For example, the processing device  114  may input the orthosis design data and the 3D model of the subject into the trained machine learning model. The trained machine learning model may output the force data of the at least one region of the subject after wearing the orthosis. 
       FIG.  8    illustrates an exemplary image of a reference image superimposed on a 3D model according to some embodiments of the present disclosure. 
     As shown in  FIG.  8 ,  810    refers to a reference image (e.g., a DR image) of a subject, and  820  refers to a 3D model of the subject. The reference image  810  may reflect a degree of scoliosis of the subject, as shown in a position  830  in the reference image  810 . The processing device  114  may superimpose the reference image  810  on the 3D model  820 . The processing device  114  may determine orthosis design data by modifying the 3D model  820  based on a superimposing result, as described elsewhere in the present disclosure (e.g.,  FIG.  5    and descriptions thereof). 
       FIG.  9    is a schematic diagram illustrating a housing of an orthosis according to some embodiments of the present disclosure. 
     In some embodiments, the processing device  114  may perform one or more processing operations on orthosis design data based on correction needs of different regions of a subject. For example, as shown in  FIG.  9   , the processing device  114  may perform a mesh deformation operation on a pressure region  910  of the orthosis. As another example, the processing device  114  may perform a mesh splitting operation on an edge and/or an opening of the orthosis, as shown in a region  920  in  FIG.  9   . As still another example, the processing device  114  may perform a mesh smoothing and/or a mesh division operation on one or more other regions  930  of the orthosis. In some embodiments, the processing device  114  may determine housing design data associated with a housing of the orthosis by performing a thickness-adjustment operation on the orthosis design data, as described elsewhere in the present disclosure. The housing design data may be used to determine the housing of the orthosis with a certain thickness, as shown in a position  940  in  FIG.  9   . 
       FIG.  10    is a block diagram illustrating an exemplary orthosis design data determination module according to some embodiments of the present disclosure. The orthosis design data determination module  403  may include an initialization unit  1001 , a spline curve determination unit  1002 , a center point determination unit  1003 , a link line determination unit  1004 , a boundary point determination unit  1005 , a split surface determination unit  1006 , and a splitting unit  1007 . The units may be hardware circuits of at least part of the orthosis design data determination module  403 . The units may also be implemented as an application or set of instructions read and executed by the orthosis design data determination module  403 . Further, the units may be any combination of the hardware circuits and the application/instructions. For example, the units may be part of the orthosis design data determination module  403  when the orthosis design data determination module  403  is executing the application or set of instructions. 
     The initialization unit  1001  may be configured to initialize a 3D model. In some embodiments, the initialization unit  1001  may obtain data associated with a 3D model. In some embodiments, the initialization unit  1001  may initialize camera parameters. In some embodiments, the initialization unit  1001  may determine an initial transformation matrix between a model coordinate system and a world coordinate system. In some embodiments, the initialization unit  1001  may render a 3D model based on data associated with the 3D model. More descriptions of the initialization of the 3D model may be found elsewhere in the present disclosure (e.g.,  FIG.  11   , and descriptions thereof). 
     The spline curve determination unit  1002  may be configured to determine a spline curve associated with a 3D model. In some embodiments, the spline curve determination unit  1002  may obtain a plurality of first coordinates input by a user. In some embodiments, the spline curve determination unit  1002  may determine a plurality of third coordinates by performing a spline interpolation operation on a plurality of first coordinates. In some embodiments, the spline curve determination unit  1002  may determine a plurality of second coordinates by projecting a plurality of third coordinates on the 3D model. For example, the spline curve determination unit  1002  may transform a plurality of third coordinates in a screen coordinate system to a plurality of fourth coordinates in a view coordinate system. The spline curve determination unit  1002  may transform the plurality of fourth coordinates in the view coordinate system to a plurality of fifth coordinates in a camera coordinate system. The spline curve determination unit  1002  may transform the plurality of fifth coordinates in the camera coordinate system to a plurality of sixth coordinates in the world coordinate system. The spline curve determination unit  1002  may transform the plurality of sixth coordinates in the world coordinate system to the plurality of second coordinates in the model coordinate system. In some embodiments, the spline curve determination unit  1002  may determine a spline curve by connecting a plurality of second coordinates. More descriptions of the determination of the spline curve may be found elsewhere in the present disclosure (e.g.,  FIGS.  11 ,  12 ,  13   , and descriptions thereof). 
     The center point determination unit  1003  may be configured to determine a center point corresponding to a point (e.g., a second coordinate) on a spline curve associated with a 3D model. In some embodiments, the center point determination unit  1003  may determine a center point corresponding to a point on a spline curve based on model coordinates of the point. In some embodiments, the center point determination unit  1003  may determine a center point corresponding to a point on a spline curve by projecting the point on a Z-axis of a model coordinate system. More descriptions of the determination of the center point may be found elsewhere in the present disclosure (e.g.,  FIGS.  11 ,  14   , and descriptions thereof). 
     The link line determination unit  1004  may be configured to determine a link line connecting a center point and a corresponding point (e.g., a second coordinate) on a spline curve associated with a 3D model. In some embodiments, the link line determination unit  1004  may draw a straight line passing through a center point and a corresponding point on a spline curve. More descriptions of the determination of the link line may be found elsewhere in the present disclosure (e.g.,  FIGS.  11 ,  14   , and descriptions thereof). 
     The boundary point determination unit  1005  may be configured to determine a plurality of boundary points along a direction of a link line for a point (e.g., a second coordinate) on a spline curve associated with a 3D model. In some embodiments, the plurality of boundary points may include an inner boundary point and an outer boundary point. The inner boundary point may be located inside a 3D model. The outer boundary point may be located outside the 3D model. In some embodiments, the boundary point determination unit  1005  may determine an inner boundary point by extending a second coordinate to the inside of a 3D model along a direction of a link line. In some embodiments, the boundary point determination unit  1005  may determine an outer boundary point by extending a second coordinate to the outside of the 3D model along a direction of a link line. More descriptions of the determination of the plurality of boundary points may be found elsewhere in the present disclosure (e.g.,  FIG.  11   , and descriptions thereof). 
     The split surface determination unit  1006  may be configured to generate a split surface. In some embodiments, the split surface determination unit  1006  may generate a split surface based on all boundary points corresponding to a plurality of points (e.g., a plurality of second coordinates) on a spline curve. For example, the split surface determination unit  1006  may generate a plurality of split sub-surfaces by alternately connecting a plurality of inner boundary points and a plurality of outer boundary points corresponding to a plurality of second coordinates. As another example, the split surface determination unit  1006  may generate a split surface by combining a plurality of split sub-surfaces. More descriptions of the generation of the split surface may be found elsewhere in the present disclosure (e.g.,  FIGS.  11 ,  15 A,  15 B , and descriptions thereof). 
     The splitting unit  1007  may be configured to split a 3D model based on a split surface. In some embodiments, the splitting unit  1007  may generate at least two sub-models by splitting a 3D model based on a split surface. In some embodiments, the splitting unit  1007  may render at least one sub-model (e.g., a desired model). In some embodiments, the splitting unit  1007  may display at least one rendered sub-model (e.g., a desired model) on a terminal device (e.g., the terminal device  130 ) associated with a user. More descriptions for splitting the 3D model may be found elsewhere in the present disclosure (e.g.,  FIGS.  11 ,  16   , and descriptions thereof). 
     It should be noted that the above description of the orthosis design data determination module  403  is merely provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. For persons having ordinary skills in the art, multiple variations and modifications may be made under the teachings of the present disclosure. However, those variations and modifications do not depart from the scope of the present disclosure. In some embodiments, one or more units may be combined into a single unit. For example, the center point determination unit  1003 , the link line determination unit  1004 , the boundary point determination unit  1005 , and the split surface determination unit  1006  may be combined into a single unit. In some embodiments, one or more units may be added or omitted in the orthosis design data determination module  403 . For example, the orthosis design data determination module  403  may further include a storage unit (not shown in  FIG.  10   ) configured to store data and/or information (e.g., a spline curve, a center point, a link line) associated with the orthosis design system  100 . As another example, the initialization unit  1001  may be omitted. 
       FIG.  11    is a flowchart illustrating an exemplary process for splitting a 3D model according to some embodiments of the present disclosure. Process  1100  may be executed by the orthosis design system  100 . For example, process  1100  may be implemented as a set of instructions (e.g., an application) stored in the storage device  150  in the orthosis design system  100 . The processing device  114  may execute the set of instructions and may accordingly be directed to perform process  1100  in the orthosis design system  100 . The operations of the illustrated process  1100  presented below are intended to be illustrative. In some embodiments, process  1100  may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. Additionally, the order in which the operations of process  1100  as illustrated in  FIG.  11    and described below is not intended to be limiting. 
     In  1110 , the processing device  114  (e.g., the initialization unit  1001 ) may initialize a 3D model. 
     In some embodiments, the 3D model may include a 3D model of a subject, a 3D model of an orthosis, or the like, as described elsewhere in the present disclosure. In some embodiments, the processing device  114  may obtain data associated with the 3D model. The data associated with the 3D model may be used to construct the 3D model. In some embodiments, the 3D model may be a 3D mesh structure where a plurality of 3D points (or vertices) are connected via edges (or lines) and faces (or polygons). In some embodiments, the data associated with the 3D model may include point data, line data, face data, or the like, or any combination thereof. The point data may include position information of a point, e.g., a position, an orientation, a distance between a point and another point. The line data may represent data of a plurality of lines, each of which connects various points. The line data may include point data that a line includes, position information of a line (e.g., a position represented by positions of two vertices, an orientation of a line, a distance between a line and another line), length information of a line, etc. The face data may represent data of one or more faces, each of which formed by lines and/or points. The face data may include point data, line data that a face includes, position information of a face (e.g., a position of a face, an orientation of a face, a distance between a face and another face), a size of a face, a shape of a face (e.g., a triangle shape, a quadrilateral shape, a hexagon shape), etc. 
     In some embodiments, a position of a point in the 3D model may be represented by model coordinates in a model coordinate system. The model coordinate system may refer to a coordinate system that describes shapes of a subject (e.g., a 3D model). In some embodiments, different model coordinate systems may be constructed for different 3D models. For example, for the model coordinate system of the 3D model in some embodiments of the present disclosure, an origin may be a center point of the 3D model. The X-axis may be from a left side to a right side of the 3D model viewed from a direction facing the front of the 3D model. The Y-axis may be from a front side to a rear side of the 3D model. The Z axis direction may be from a lower side to an upper side of the 3D model. 
     In some embodiments, the processing device  114  may obtain the data associated with the 3D model from a storage device (e.g., the storage device  150 ) of the orthosis design system  100 , or an external storage device. For example, the processing device  114  may obtain the data associated with the 3D model from a surface mesh stored in the storage device  150 . As used herein, the surface mesh may refer to a representation of a surface that includes vertices, edges and faces. In some embodiments, the surface mesh may store the data associated with the 3D model in a 3D file format. Exemplary 3D file formats may include STL, OBJ, FBX, COLLADA, 3DS, IGES, STEP, VRML/X3D, etc. 
     In some embodiments, the processing device  114  may initialize one or more camera parameters. Exemplary camera parameters may include intrinsic parameters, extrinsic parameters, distortion parameters, etc. The intrinsic parameters of a camera may represent the optical, geometric, and digital characteristics of the camera. For example, the intrinsic parameters of a camera may include a camera focal length, an optical center, etc. The extrinsic parameters of a camera may represent the relative location and orientation of the camera with respect to a world coordinate system. As used herein, the world coordinate system may refer to a fixed coordinate system for representing a subject in the world. For example, the extrinsic parameters of a camera may include a tilt angle of the camera, a yaw angle of the camera, a height of the camera above a plane of the scene captured by the camera, etc. The distortions of a camera may be caused by characteristics of optical lens of the camera and assembly errors; and the distortion parameters quantitatively reflect the distortion. For example, the distortion parameters of a camera may include a radial distortion coefficient, a tangential distortion coefficient, etc. 
     In some embodiments, the initialized camera parameters may be used to perform a transformation between camera coordinates denoted by a camera coordinate system and world coordinates denoted by the world coordinate system. As used herein, the camera coordinate system may refer to a coordinate system that uses the camera center as its origin and the optic axis as the Z-axis. The X-axis and Y-axis of the camera coordinate system may define an image plane. In some embodiments, the initialized camera parameters may be default parameter stored in a storage device (e.g., the storage device  150 ). In some embodiments, the initialized camera parameters may be set manually by a user (e.g., an orthosis designer, a doctor) of the orthosis design system  100 , or determined by one or more components (e.g., the processing device  114 ) of the orthosis design system  100  according to different situations. For example, the initialized distortion parameters of the camera may be set as 0. 
     In some embodiments, the processing device  114  may determine an initial transformation matrix between the model coordinate system and the world coordinate system. The initial transformation matrix may be used to perform a transformation between world coordinates denoted by the world coordinate system and model coordinates denoted by the model coordinate system. 
     In some embodiments, the processing device  114  may display the 3D model on a screen of the terminal device  130 . For example, the processing device  114  may display a front view of the 3D model on the screen of the terminal device  130 . In some embodiments, a plurality of points of the 3D model represented by a plurality of model coordinates may be transformed to a plurality of screen coordinates denoted by a screen coordinate system for display. As used herein, the screen coordinate system may refer to physical coordinates of pixels on a computer screen, based on a screen resolution. For the screen coordinate system, an origin may be an upper-left corner point of the screen. The X-axis may be from a left side to a right side of the screen, the Y-axis may be from an upper side to a lower side of the screen. In some embodiments, the processing device  114  may transform the plurality of model coordinates to the plurality of screen coordinates based on the initialized camera parameters and the initial transformation matrix. For example, the plurality of model coordinates may be transformed to a plurality of world coordinates based on the initial transformation matrix. The plurality of world coordinates may be transformed to a plurality of camera coordinates based on the initialized camera parameters. The plurality of camera coordinates may be transformed to a plurality of view coordinates. The plurality of view coordinates may be transformed to the plurality of screen coordinates. More descriptions of the coordinate transformations may be found elsewhere in the present disclosure (e.g.,  FIG.  13    and descriptions thereof). 
     In some embodiments, the processing device  114  may render the 3D model based on the data associated with the 3D model. As used herein, rendering may refer to a process of generating a photorealistic or non-photorealistic image from a 2D or 3D model. In some embodiments, the processing device  114  may transform the data associated with the 3D model stored in the surface mesh to a format that can be rendered. For example, the processing device  114  may transform the data associated with the 3D model stored in the surface mesh from the STL format to a polydata format. As used herein, polydata may refer to a surface mesh structure that can hold data arrays in points, cells or in the dataset itself. The processing device  114  may render the 3D model based on the data associated with the 3D model with the polydata format according to one or more rendering algorithms. Exemplary rendering algorithms may include a scanline rendering algorithm, a ray tracing algorithm, a luminous energy radiosity algorithm, a physically based rendering technique, a light field rendering technique, or the like, or any combination thereof. 
     In  1120 , the processing device  114  (e.g., the spline curve determination unit  1002 ) may determine a spline curve associated with the 3D model. 
     In some embodiments, a spline curve may refer to a mathematical representation for which it is easy to build an interface that will allow a user to design and control the shape of complex curves and surfaces. In some embodiments, the processing device  114  may determine the spline curve based on a plurality of first coordinates input by a user in a screen coordinate system. In the present disclosure, each first coordinate may correspond to a point input by the user, and the plurality of first coordinates may correspond to a plurality of points input by the user. For example, in the screen coordinate system, a position of a point may be represented by an X-axis coordinate and a Y-axis coordinate. The X-axis coordinate and the Y-axis coordinate of the point may be referred to as a coordinate of the point. 
     For example, the processing device  114  may obtain a plurality of first points input by the user via a terminal device (e.g., the terminal device  130 ). Each first point may be represented by screen coordinates in the screen coordinate system. The processing device  114  may perform a spline interpolation operation on the plurality of first points to determine a plurality of interpolation points. Each interpolation point may be represented by screen coordinates in the screen coordinate system. The processing device  114  may project the plurality of interpolation points on the 3D model to determine a plurality of second points. Each second point may be represented by model coordinates in a model coordinate system. The processing device  114  may connect the plurality of second points to generate the spline curve on the 3D model. More descriptions of the determination of the spline curve may be found elsewhere in the present disclosure (e.g.,  FIG.  12   , and descriptions thereof). 
     In some embodiments, the processing device  114  may obtain the plurality of first points inputted by the user. The processing device  114  may project the plurality of first points on the 3D model to determine a plurality of projection points. Each projection point may be represented by model coordinates in the model coordinate system. The processing device  114  may perform a spline interpolation operation on the plurality of projection points to determine the plurality of second points. The processing device  114  may connect the plurality of second points to generate the spline curve on the 3D model. 
     In  1130 , for each second coordinate of the plurality of second coordinates, the processing device  114  (e.g., the center point determination unit  1003 ) may determine a center point corresponding to the second coordinate. 
     In the present disclosure, each second coordinate may correspond to a point on the spline curve, and the plurality of second coordinates may correspond to a plurality of points on the spline curve of the 3D model. For example, in the model coordinate system, a position of a point may be represented by an X-axis coordinate, a Y-axis coordinate, and a Z-axis coordinate. The X-axis coordinate, the Y-axis coordinate, and the Z-axis coordinate of the point may be referred to as a coordinate of the point. 
     In some embodiments, the processing device  114  may determine a center point corresponding to a point on the spline curve based on model coordinates of the point. For example, the processing device  114  may determine the center point corresponding to the point by determining a value of X-axis coordinate and a value of Y-axis coordinate of the point as 0. For illustration purposes, if model coordinates of a specific point is (X1, Y1, Z1), the processing device  114  may set X1 and Y1 as 0, to determine model coordinates of a center point corresponding to the specific point. That is, the model coordinates of the center point may be (0, 0, Z1). 
     In some embodiments, the processing device  114  may determine the center point corresponding to the point by projecting the point on a Z-axis of the model coordinate system. For example, the processing device  114  may project the point (e.g., a point  1 , a point  2 , a point  3 , as illustrated in  FIG.  14   ) on the Z axis of the model coordinate system, to generate a projection point (e.g., a center  1 , a center  2 , a center  3 , as illustrated in  FIG.  14   ). The processing device  114  may determine the projection point as the center point corresponding to the point. 
     In  1140 , for each second coordinate of the plurality of second coordinates, the processing device  114  (e.g., the link line determination unit  1004 ) may determine a link line connecting the center point and the corresponding second coordinate. 
     In some embodiments, the link line (e.g., a link line L 1 , a link line L 2 , a link line L 3  as illustrated in  FIG.  14   ) may refer to a straight line passing through the second coordinate and the corresponding center point. In some embodiments, the processing device  114  may automatically connect the second coordinate and the corresponding center point to generate the link line. In some embodiments, a user (e.g., an orthosis designer) of the orthosis design system  100  may manually connect the second coordinate and the corresponding center point to generate the link line. 
     In  1150 , for each second coordinate of the plurality of second coordinates, the processing device  114  (e.g., the boundary point determination unit  1005 ) may determine a plurality of boundary points along a direction of the link line. 
     In some embodiments, the plurality of boundary points may include an inner boundary point (e.g., a point a 1 , a point b 1 , a point c 1 , as illustrated in  FIG.  15 B ) and an outer boundary point (e.g., a point a 2 , a point b 2 , a point c 2 , as illustrated in  FIG.  15 B ). The inner boundary point may be located inside the 3D model. The outer boundary point may be located outside the 3D model. 
     The processing device  114  may determine the inner boundary point by extending the second coordinate to the inside of the 3D model along the direction of the link line. For example, the processing device  114  may extend the second coordinate to the inside of the 3D model in a first extension distance along the direction of the link line. The processing device  114  may determine the outer boundary point by extending the second coordinate to the outside of the 3D model along the direction of the link line. For example, the processing device  114  may extend the second coordinate to the outside of the 3D model in a second extension distance along the direction of the link line. 
     The first extension distance may be the same as or different from the second extension distance. The first extension distance (and/or the second extension distance) may be default parameter stored in a storage device (e.g., the storage device  150 ). In some embodiments, the first extension distance (and/or the second extension distance) may be set manually by a user (e.g., an orthosis designer, a doctor) of the orthosis design system  100 , or determined by one or more components (e.g., the processing device  114 ) of the orthosis design system  100  according to different situations. For example, the first extension distance (and/or the second extension distance) may be determined based on a size (e.g., a length, a width) of the 3D model. In some embodiments, a relatively large size of the 3D model may correspond to a relatively large first extension distance and/or a relatively large second extension distance. 
     In  1160 , the processing device  114  (e.g., the split surface determination unit  1006 ) may generate a split surface based on all the boundary points corresponding to the plurality of second coordinates. 
     In some embodiments, the processing device  114  may generate a plurality of split sub-surfaces by connecting the inner boundary points and the outer boundary points corresponding to the plurality of second coordinates. The split sub-surface may have any shape. For example, the split sub-surface may have a polygonal shape, such as a regular triangle, a rectangle, a square, or a regular hexagon. The processing device  114  may generate the split surface by combining the plurality of split sub-surfaces. 
     For illustration purposes, assuming that a spline curve includes a plurality of points, e.g., a point a, a point b, . . . , and a point n, the processing device  114  may determine an inner boundary point a 1  and an outer boundary point a 2  for the point a, an inner boundary point b 1  and an outer boundary point b 2  for the point b, . . . , an inner boundary point n 1  and an outer boundary point n 2  for the point n. The processing device  114  may generate a first triangle split sub-surface by connecting the inner boundary point a 1 , the outer boundary point a 2 , and the inner boundary point b 1 , sequentially. The processing device  114  may generate a second triangle split sub-surface by connecting the inner boundary point b 1  and the outer boundary point b 2 . Similarly, the processing device  114  may generate a 2nth triangle split sub-surface by connecting the outer boundary point n 2  and the inner boundary point a 1 . Accordingly, the processing device  114  may generate a plurality of triangle split sub-surface by alternately connecting the inner boundary points and the outer boundary points corresponding to the plurality of points. The processing device  114  may combine the plurality of triangle split sub-surface (e.g., the first triangle split sub-surface, the second split sub-surface, . . . , and the 2nth triangle split sub-surface) to generate the split surface. More descriptions of the generation of the split surface may be found elsewhere in the present disclosure (e.g.,  FIGS.  15 A,  15 B , and descriptions thereof). 
     In  1170 , the processing device  114  (e.g., the splitting unit  1007 ) may split the 3D model based on the split surface 
     In some embodiments, the processing device  114  may generate at least two sub-models by splitting the 3D model based on the split surface. In some embodiments, the at least two sub-models may include a desired model, e.g., a 3D orthosis model, as described elsewhere in the present disclosure. In some embodiments, the processing device  114  may split the 3D model based on the split surface according to one or more splitting algorithms. Exemplary splitting algorithms may include a union set algorithm, a difference set algorithm, an intersection algorithm, or the like. In some embodiments, the processing device  114  may call a clip interface in a computational geometry algorithm library (CGAL) to split the 3D model based on the split surface. 
     In some embodiments, the processing device  114  may render at least one sub-model (e.g., the desired model). In some embodiments, the processing device  114  may transform data associated with the at least one sub-model stored in the surface mesh to a format that can be rendered. For example, the processing device  114  may transform the data associated with the at least one sub-model from a STL format to a polydata format. The processing device  114  may render the at least one sub-model based on the data associated with the at least one sub-model with the polydata format according to one or more rendering algorithms. 
     The processing device  114  may display the at least one rendered sub-model (e.g., the desired model) on a terminal device (e.g., the terminal device  130 ) associated with a user. For example, a 3D orthosis model may be displayed on the terminal device  130 . The 3D orthosis model may further be modified (e.g., split) by comparing the 3D orthosis model with one or more reference images of a subject. As another example, the 3D orthosis model may be transmitted to a 3D printer for printing. 
     It should be noted that the above description is merely provided for the purpose of illustration, and not intended to limit the scope of the present disclosure. For persons having ordinary skills in the art, multiple variations and modifications may be made under the teachings of the present disclosure. However, those variations and modifications do not depart from the scope of the present disclosure. In some embodiments, one or more operations may be omitted. For example, operation  1110  may be omitted. In some embodiments, one or more operations may be performed simultaneously. For example, operations  1130  and  1140  may be performed simultaneously. 
       FIG.  12    is a flowchart illustrating an exemplary process for determining a spline curve according to some embodiments of the present disclosure. Process  1200  may be executed by the orthosis design system  100 . For example, process  1200  may be implemented as a set of instructions (e.g., an application) stored in the storage device  150  in the orthosis design system  100 . The processing device  114  may execute the set of instructions and may accordingly be directed to perform process  1200  in the orthosis design system  100 . The operations of the illustrated process  1200  presented below are intended to be illustrative. In some embodiments, process  1200  may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. Additionally, the order in which the operations of process  1200  as illustrated in  FIG.  12    and described below is not intended to be limiting. 
     In  1210 , the processing device  114  (e.g., the spline curve determination unit  1002 ) may obtain a plurality of first coordinates input by a user. 
     In some embodiments, the processing device  114  may obtain the plurality of first coordinates in real time or periodically (e.g., per 0.1 seconds, pre 0.5 seconds). In some embodiments, the user may input the plurality of first coordinates via a terminal device (e.g., the terminal device  130 ). For example, the user may select (e.g., click) a plurality of points on a 3D model displayed on a screen of a terminal device (e.g., the terminal device  130 ) via a mouse or a finger. In some embodiments, the user may select the plurality of points on the 3D model while rotating the 3D model. The processing device  114  may obtain a plurality of screen coordinates (e.g., the plurality of first coordinates) corresponding to the plurality of selected points in a screen coordinate system. In some embodiments, the processing device  114  may transform the plurality of screen coordinates of the plurality of selected points to a plurality of view coordinates in a view coordinate system. The processing device  114  may store the plurality of view coordinates in a storage device (e.g., the storage device  150 ) of the orthosis design system  100 , or an external storage device for further processing. More descriptions of the coordinate transformations may be found elsewhere in the present disclosure (e.g.,  FIG.  13    and descriptions thereof). 
     In  1220 , the processing device  114  (e.g., the spline curve determination unit  1002 ) may determine a plurality of third coordinates by performing a spline interpolation operation on the plurality of first coordinates. 
     As used herein, spline interpolation may refer to a form of interpolation where the interpolant is a special type of piecewise polynomial called a spline. Exemplary spline interpolation operations may include a cubic B-spline interpolation, a Bezier curve interpolation, a catmull-rom curve interpolation, or the like. 
     In the present disclosure, each third coordinate may correspond to an interpolation point, and the plurality of third coordinates may correspond to a plurality of interpolation points. For example, in the screen coordinate system, a position of an interpolation point may be represented by an X-axis coordinate and a Y-axis coordinate. The X-axis coordinate and the Y-axis coordinate of the interpolation point may be referred to as a third coordinate of the interpolation point. 
     In some embodiments, the processing device  114  may perform the spline interpolation operation on the plurality of first coordinates after the plurality of first coordinates are all input by the user. In some embodiments, the processing device  114  may perform the spline interpolation operation on the plurality of first coordinates in real time. For example, a user may input a plurality of input points, e.g., a first input point, a second input point, a third input point, . . . , and a nth input point, via a terminal device (e.g., the terminal device  130 ) sequentially. After the second input point is input by the user, the processing device  114  may perform the spline interpolation operation on the first input point and the second input point, to determine a first group of interpolation points. After the third input point is input by the user, the processing device  114  may perform the spline interpolation operation on the second input point and the third input point, to determine a second group of interpolation points. Similarly, after the nth input point is input by the user, the processing device  114  may perform the spline operation on the (n−1)th input point and the nth input point, to determine a (n−1)th group of interpolation points. The processing device  114  may perform the spline operation on the nth input point and the first input point, to determine a nth group of interpolation points. In some embodiments, the processing device  114  may determine a plurality of screen coordinates of the plurality of groups of the interpolation points (e.g., the first group of interpolation points, the second group of interpolation points, . . . , the nth group of interpolation points) as the plurality of third coordinates. In some embodiments, the processing device  114  may determine a plurality of screen coordinates of the plurality of groups of the interpolation points (e.g., the first group of interpolation points, the second group of interpolation points, . . . , the nth group of interpolation points) and the plurality of input points, as the plurality of third coordinates. 
     In  1230 , the processing device  114  (e.g., the spline curve determination unit  1002 ) may determine the plurality of second coordinates by projecting the plurality of third coordinates on a 3D model. 
     In some embodiments, the processing device  114  may determine the plurality of second coordinates based on the plurality of third coordinates according to one or more coordinate transformation operations. For example, the processing device  114  may transform the plurality of third coordinates in the screen coordinate system to a plurality of fourth coordinates in a view coordinate system. The processing device  114  may transform the plurality of fourth coordinates in the view coordinate system to a plurality of fifth coordinates in a camera coordinate system. The processing device  114  may transform the plurality of fifth coordinates in the camera coordinate system to a plurality of sixth coordinates in the world coordinate system. The processing device  114  may transform the plurality of sixth coordinates in the world coordinate system to the plurality of second coordinates in the model coordinate system. More descriptions of the coordinate transformation operations may be found elsewhere in the present disclosure (e.g.,  FIG.  13   , and descriptions thereof). 
     In  1240 , the processing device  114  (e.g., the spline curve determination unit  1002 ) may determine a spline curve by connecting the plurality of second coordinates. 
     In some embodiments, the plurality of second coordinates may be connected manually by a user (e.g., an orthosis designer). For example, a user may draw a line passing through the plurality of second coordinates on the 3D model displayed on the screen of the terminal device  130  to generate the spline curve. In some embodiments, the plurality of second coordinates may be connected automatically by one or more components (e.g., the processing device  114 ) of the orthosis design system  100 . For example, the processing device  114  may connect the plurality of second coordinates by using a CATScript program. Specifically, the plurality of second coordinates may be transformed into a plurality of coordinate scripts via the CATScript program. The spline curve may be generated based on the plurality of coordinate scripts. 
     According to some embodiments of the present disclosure, by performing the spline interpolation operation on the plurality of first coordinates input by the user, the plurality of third coordinates may be determined. The plurality of second coordinates may be determined by projecting the plurality of third coordinates on the 3D model, and accordingly a relatively smooth spline curve may be generated based on the plurality of second coordinates. 
     It should be noted that the above description is merely provided for the purpose of illustration, and not intended to limit the scope of the present disclosure. For persons having ordinary skills in the art, multiple variations and modifications may be made under the teachings of the present disclosure. However, those variations and modifications do not depart from the scope of the present disclosure. 
       FIG.  13    is a flowchart illustrating an exemplary process for determining a plurality of second coordinates on a spline curve according to some embodiments of the present disclosure. Process  1300  may be executed by the orthosis design system  100 . For example, process  1300  may be implemented as a set of instructions (e.g., an application) stored in the storage device  150  in the orthosis design system  100 . The processing device  114  may execute the set of instructions and may accordingly be directed to perform process  1300  in the orthosis design system  100 . The operations of the illustrated process  1300  presented below are intended to be illustrative. In some embodiments, process  1300  may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. Additionally, the order in which the operations of process  1300  as illustrated in  FIG.  13    and described below is not intended to be limiting. 
     In  1310 , the processing device  114  (e.g., the spline curve determination unit  1002 ) may transform a plurality of third coordinates in a screen coordinate system to a plurality of fourth coordinates in a view coordinate system. 
     The view coordinate system may refer to a coordinate system for observing a 3D object at different distances and angles. The view coordinate system may be a three-dimensional coordinate system. The view coordinate system may describe a 3D object (e.g., a 3D model) with respect to a viewer (e.g., a camera), and may be defined by a viewpoint of the viewer. 
     In some embodiments, the processing device  114  may transform the plurality third coordinates (e.g., a plurality of screen coordinates) to the plurality of fourth coordinates (e.g., a plurality of view coordinates) based on depth information associated with the plurality of third coordinates. As used herein, the depth information associated with a point may reflect a Z-axis value of the point in the screen coordinate system. The Z-axis of the screen coordinate system may point out of the screen or into the screen. In some embodiments, the depth information may be determined using an open graphics library (OpenGL). For example, the depth information associated with screen coordinates may be determined using a gIReadPixels function in the OpenGL. As used herein, OpenGL may refer to a cross-language, cross-platform application programming interface (API) for rendering 2D and 3D vector graphics. 
     In  1320 , the processing device  114  (e.g., the spline curve determination unit  1002 ) may transform the plurality of fourth coordinates in the view coordinate system to a plurality of fifth coordinates in a camera coordinate system 
     In some embodiments, the processing device  114  may transform the plurality of fourth coordinates (e.g., the plurality of view coordinates) to the plurality of fifth coordinates (e.g., a plurality of camera coordinates) based on a projection matrix. For example, the processing device  114  may determine the plurality of fifth coordinates by multiplying the plurality of fourth coordinates with the projection matrix. 
     In some embodiments, the projection matrix may be related to a plurality of parameters (e.g., a plurality of intrinsic parameters) of a camera. For example, the plurality of intrinsic parameters of the camera may form the projection matrix. The projection matrix may be used to perform a transformation between view coordinates denoted by the view coordinate system and camera coordinates denoted by the camera coordinate system. 
     In some embodiments, the projection matrix may be manually set by a user of the orthosis design system  100 , or determined by one or more components (e.g., the processing device  114 ) of the orthosis design system  100 . In some embodiments, the projection matrix may be stored in one or more storage devices (e.g., the storage device  150 ) of the orthosis design system  100 . The processing device  114  may access the one or more storage devices and retrieve the projection matrix. 
     In  1330 , the processing device  114  (e.g., the spline curve determination unit  1002 ) may transform the plurality of fifth coordinates in the camera coordinate system to a plurality of sixth coordinates in a world coordinate system. 
     In some embodiments, the processing device  114  may transform the plurality of fifth coordinates (e.g., the plurality of camera coordinates) to the plurality of sixth coordinates (e.g., a plurality of world coordinates) based on a view matrix. For example, the processing device  114  may determine the plurality of sixth coordinates by multiplying the plurality of fifth coordinates with the view matrix. 
     In some embodiments, the view matrix may be related to a plurality of parameters (e.g., a plurality of extrinsic parameters) of the camera. For example, the plurality of extrinsic parameters of the camera may form the view matrix. The view matrix may be used to perform a transformation between world coordinates denoted by the world coordinate system and camera coordinates denoted by the camera coordinate system. 
     In some embodiments, the view matrix may be manually set by a user of the orthosis design system  100 , or determined by one or more components (e.g., the processing device  114 ) of the orthosis design system  100 . In some embodiments, the view matrix may be stored in one or more storage devices (e.g., the storage device  150 ) of the orthosis design system  100 . The processing device  114  may access the one or more storage devices and retrieve the view matrix. 
     In  1340 , the processing device  114  (e.g., the spline curve determination unit  1002 ) may transform the plurality of sixth coordinates in the world coordinate system to the plurality of second coordinates in the model coordinate system. 
     In some embodiments, the processing device  114  may transform the plurality of sixth coordinates (e.g., the plurality of world coordinates) to the plurality of second coordinates (e.g., a plurality of model coordinates) based on a model matrix. The model matrix may be a transformation matrix that translates, scales and/or rotates a 3D model to place it in a world space at a location/orientation it belongs to. For example, the processing device  114  may determine the plurality of second coordinates by multiplying the plurality of sixth coordinates with an inverse of the model matrix. 
     In some embodiments, the model matrix may be manually set by a user of the orthosis design system  100 , or determined by one or more components (e.g., the processing device  114 ) of the orthosis design system  100 . In some embodiments, the model matrix may be stored in one or more storage devices (e.g., the storage device  150 ) of the orthosis design system  100 . The processing device  114  may access the one or more storage devices and retrieve the model matrix. 
     In some embodiments, the processing device  114  may perform a ray casting operation on the plurality of second coordinates according to a ray casting algorithm. As used herein, ray casting may be the use of ray-surface intersection tests to solve a variety of problems in 3D computer graphics and computational geometry. The ray casting may be a computer graphics rendering algorithm that use the geometric algorithm of ray tracing. Ray tracing-based rendering algorithms may operate in image order to render 3D scenes to 2D images. 
     It should be noted that the above description is merely provided for the purpose of illustration, and not intended to limit the scope of the present disclosure. For persons having ordinary skills in the art, multiple variations and modifications may be made under the teachings of the present disclosure. However, those variations and modifications do not depart from the scope of the present disclosure. In some embodiments, model coordinates may be transformed to screen coordinates. In some embodiments, the model coordinates in the model coordinate system may be transformed to world coordinates based on the model matrix. For example, the world coordinates may be determined by multiplying the model coordinates with the model matrix. The world coordinates may be transformed to camera coordinates based on the view matrix. For example, the camera coordinates may be determined by multiplying the world coordinates with an inverse of the view matrix. The camera coordinates may be transformed to view coordinates based on the projection matrix. For example, the view coordinates may be determined by multiplying the camera coordinates with an inverse of the projection matrix. The view coordinates may be transformed to the screen coordinate by performing a viewport transformation operation on the view coordinates. As used herein, a viewport transformation may refer to a process of mapping view coordinates to screen coordinates where each coordinate corresponds to a point on a screen. For example, the view coordinates may be transformed to screen coordinates by performing the viewport transformation operation on the view coordinates using the OpenGL. 
       FIG.  14    is a schematic diagram illustrating an exemplary process for determining a center point according to some embodiments of the present disclosure. 
     As illustrated in  FIG.  14 ,  1401    refers to a 3D model of a human body. The 3D model  1401  may be positioned in a model coordinate system. An origin (not shown in  FIG.  14   ) of the model coordinate system may be a center point of the 3D model  1401 . A positive X axis direction (not shown in  FIG.  14   ) may be from a right side to a left side of the 3D model  1401  viewed from the direction facing the front of the 3D model  1401 . A positive Y axis direction (not shown in  FIG.  14   ) may be from a front side to a rear side of the 3D model  1401 . A positive Z axis direction may be from an upper side to a lower side of the 3D model  1401 . 
     As illustrated in  FIG.  14 ,  1402    refers to a spline curve associated with the 3D model  1401 . The spline curve  1401  includes a plurality of points, e.g., a first point P 1 , a second point P 2 , and a third point P 3 . The processing device  114  may project the first point P 1  on the Z-axis of the model coordinate system, to generate a first center point C 1  corresponding to the first point P 1 . The processing device  114  may determine a first link line L 1  connecting the first point P 1  and the first center point C 1 . The processing device  114  may project the second point P 2  on the Z-axis of the model coordinate system, to generate a second center point C 2  corresponding to the second point P 2 . The processing device  114  may determine a second link line L 2  connecting the second point P 2  and the second center point C 2 . The processing device  114  may project the third point P 3  on the Z-axis of the model coordinate system, to generate a third center point C 3  corresponding to the third point P 3 . The processing device  114  may determine a third link line L 3  connecting the third point P 3  and the third center point C 3 . 
       FIG.  15 A  is a schematic diagram illustrating an exemplary split surface according to some embodiments of the present disclosure.  FIG.  15 B  is an enlarged view of the region A shown in  FIG.  15 A  according to some embodiments of the present disclosure. 
     As illustrated in  FIG.  15 A,  1501    refers to a split surface. The split surface includes a plurality of triangle split sub-surface. The plurality of triangle split sub-surface may be determined based on a plurality of inner boundary points and a plurality of outer boundary points corresponding to a plurality of points on a spline curve (not shown in  FIGS.  15 A and  15 B ). 
     As shown in  FIG.  15 B , a 1  and a 2  refer to an inner boundary point and an outer boundary point for a first point (not shown in  FIGS.  15 A and  15 B ) on the split curve, respectively, b 1  and b 2  refer to an inner boundary point and an outer boundary point for a second point (not shown in  FIGS.  15 A and  15 B ) on the split curve, respectively, c 1  and c 2  refer to an inner boundary point and an outer boundary point for a third point (not shown in  FIGS.  15 A and  15 B ) on the split curve. The processing device  114  may generate a first triangle split sub-surface s 1  by connecting the inner boundary point a 1 , the outer boundary point a 2 , and the inner boundary point b 1 , sequentially. The processing device  114  may generate a second triangle split sub-surface s 2  by connecting the inner boundary point b 1  and the outer boundary point b 2 . The processing device  114  may generate a third triangle split sub-surface by connecting the outer boundary point b 2  and the inner boundary point c 1 . The processing device  114  may generate a fourth triangle split sub-surface by connecting the inner boundary point c 1  and the outer boundary point c 2 . Similarly, the processing device  114  may generate the plurality of triangle split sub-surface by alternately connecting the plurality inner boundary points and the plurality of outer boundary points corresponding to the plurality of points on the spline curve. The processing device  114  may combine the plurality of triangle split sub-surface (e.g., the first triangle split sub-surface s 1 , the second split sub-surface s 2 , the third split sub-surface s 3 , the fourth split sub-surface s 4 ) to generate the split surface  1501 . 
       FIG.  16    is a schematic diagram illustrating exemplary 3D sub-models according to some embodiments of the present disclosure. 
     As illustrated in  FIG.  16 ,  1602    refers to a split surface of a 3D model  1601 . The 3D model  1601  may be split into two 3D sub-models (e.g., a 3D sub-model  1603  and a 3D sub-model  1604 ) based on the split surface  1602 . In some embodiments, the 3D sub-model  1604  may be deleted, and the 3D sub-model may be displayed on an interface of a terminal device of a user. 
       FIG.  17    is a block diagram illustrating an exemplary data management system according to some embodiments of the present disclosure. In some embodiments, a data management system  1700  may include an importing module  1701 , a storage module  1702 , and a printing module  1703 . The modules may be hardware circuits of at least part of the data management system  1700 . The modules may also be implemented as an application or set of instructions read and executed by the data management system  1700 . Further, the modules may be any combination of the hardware circuits and the application/instructions. For example, the modules may be part of the data management system  1700  when the data management system  1700  is executing the application or set of instructions. In some embodiments, the data management system  1700  may be part of the orthosis design system  100 . 
     The data management system  1700  may be configured to manage data associated with the orthosis design system  100 . The data associated with the orthosis design system  100  may include identification information of the subject (e.g., an identification (ID) number of the subject, a name of the subject, the gender of the subject, the age of the subject, a portion of the subject to be corrected), image data of the subject, a 3D model of the subject, orthosis design data, housing design data associated with a housing of the orthosis, a 3D printing parameter of the orthosis, or the like, or any combination thereof. 
     The importing module  1701  may be configured to import data associated with the orthosis design system  100 . In some embodiments, the importing module  1701  may import data associated with a subject from a local database. In some embodiments, the importing module  1701  may import data associated with a subject from a web database. In some embodiments, the importing module  1701  may generate a patient list for a subject. In some embodiments, the importing module  1701  may be a first terminal device associated with a first type of user (e.g., a doctor) in the orthosis design system  100 . 
     The storage module  1702  may be configured to store data associated with the orthosis design system  100 . In some embodiments, the storage module  1702  may serialize data associated with an orthosis in an orthosis design process. In some embodiments, the storage module  1702  may store the serialized data associated with the orthosis in a local database. In some embodiments, the storage module  1702  may store the serialized data associated with the orthosis in a web database. In some embodiments, the storage module  1702  may be a second terminal device associated with a second type of user (e.g., an orthosis designer) in the orthosis design system  100 . 
     The printing module  1703  may be configured to print an orthosis. In some embodiments, the printing module  1703  may obtain data associated with an orthosis. In some embodiments, the printing module  1703  may obtain a plurality of 3D printing parameters associated with an orthosis. In some embodiments, the printing module  1703  may transmit design data associated with an orthosis and/or a plurality of 3D print parameters associated with the orthosis to a 3D print database. In some embodiments, the printing module  1703  may be a third terminal device associated with a third type of user (e.g., a 3D print manufacturer) in the orthosis design system  100 . 
     It should be noted that the above description of the data management system  1700  is merely provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. For persons having ordinary skills in the art, multiple variations and modifications may be made under the teachings of the present disclosure. However, those variations and modifications do not depart from the scope of the present disclosure. In some embodiments, one or more modules may be added or omitted in the data management system  1700 . For example, the printing module  1703  may be omitted. The orthosis design system  100  may include a 3D printing device. The 3D printing device may print the orthosis based on data associated with the orthosis and/or a plurality of 3D printing parameters associated with the orthosis. 
       FIG.  18    is a flowchart illustrating an exemplary process for importing data associated with a subject according to some embodiments of the present disclosure. The process  1800  may be executed by the importing module  1701  of the data management system  1700 . For example, process  1800  may be implemented as a set of instructions stored in a storage device in the data management system  1700 . The importing module  1701  may execute the set of instructions and accordingly be directed to perform the process  1800  in the data management system  1700 . The operations of the illustrated process  1800  presented below are intended to be illustrative. In some embodiments, the process  1800  may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. Additionally, the order in which the operations of the process  1800  as illustrated in  FIG.  18    and described below is not intended to be limiting. 
     In  1810 , the importing module  1701  may import data associated with a subject from a local database. 
     In some embodiments, the data associated with the subject an identification (ID) number of the subject, a name of the subject, the gender of the subject, the age of the subject, an address of the subject, a phone number of the subject, a height of the subject, a weight of the subject, a portion of the subject to be corrected, image data associated with the subject, a 3D model associated with the subject, a reference image associated with the subject, a description of medical service or medication that is supplied to the subject (e.g., an examination date, a scan date), or the like, or any combination thereof. 
     In some embodiments, the importing module  1701  may import the data associated with the subject from one or more components (e.g., the terminal device  130 ) of the orthosis design system  100 . For example, the terminal device  130  may obtain image data associated with the subject from the data obtaining device  110  via the network  120 . The importing module  1701  may import the image data associated with the subject from the terminal device  130 . 
     In  1820 , the importing module  1701  may import the data associated with the subject from a web database. 
     In some embodiments, the importing module  1701  may import the data associated with the subject from the web database via the network  120 . For example, the data associated with the subject may be serialized. The serialized data associated with the subject may be transmitted from the web databased to the importing module  1701 . The serialized data associated with the subject may be deserialized in the importing module  1701 . In some embodiments, the data associated with the subject may be imported in the importing module  1701  in a bookmark mode. 
     In  1830 , the importing module  1701  may generate a patient list for the subject. 
     As used herein, a patient list may refer to all records, documents, lists, electronic media, or any other method of recordation that shows a person to whom a doctor supplies a medical service. In some embodiments, the patient list may include the data associated with the subject, as illustrated in  FIG.  23   . 
     For illustration purposes, a user (e.g., a doctor) may log in the data management system  1700  via a browser on the terminal device  130 . The user may generate, edit, modify and/or delete a patient list for a subject in the data management system  1700 . For example, the user may import data associated with the subject (e.g., a 3D model, a reference image) from a local database and/or a web database. The user may select and view the data associated with the subject on an interface of the terminal device  130 . 
     It should be noted that the above description is merely provided for the purpose of illustration, and not intended to limit the scope of the present disclosure. For persons having ordinary skills in the art, multiple variations and modifications may be made under the teachings of the present disclosure. However, those variations and modifications do not depart from the scope of the present disclosure. For example, operations  1810  and  1820  may be performed simultaneously. As another example, operation  1820  may be performed before operation  1810 . 
       FIG.  19    is a flowchart illustrating an exemplary process for storing data associated with an orthosis according to some embodiments of the present disclosure. The process  1900  may be executed by the storage module  1702  of the data management system  1700 . For example, process  1900  may be implemented as a set of instructions stored in a storage device in the data management system  1700 . The storage module  1702  may execute the set of instructions and accordingly be directed to perform the process  1900  in the data management system  1700 . The operations of the illustrated process  1900  presented below are intended to be illustrative. In some embodiments, the process  1900  may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. Additionally, the order in which the operations of the process  1900  as illustrated in  FIG.  19    and described below is not intended to be limiting. 
     In  1910 , the storage module  1702  may serialize data associated with an orthosis in an orthosis design process. 
     As used herein, data serialization may refer to a process of translating data structures or object state into a format that can be stored (e.g., in a file or memory buffer) or transmitted (e.g., across a network connection link) and reconstructed later (e.g., in a different computer environment). 
     In some embodiments, during the orthosis design process, the data associated with the orthosis may be generated. The data associated with the orthosis may include orthosis design data, housing design data, a spline curve associated with an orthosis model, a split surface of the orthosis model, or the like, or any combination thereof. The storage module  1702  may convert the data associated with the orthosis into a sequence of bytes which can be stored in a database or can be transmitted through the network  120 . 
     In  1920 , the storage module  1702  may store the serialized data associated with the orthosis in a local database. In some embodiments, the storage module  1702  may store the serialized data associated with the orthosis in the terminal device  130 . 
     In  1930 , the storage module  1702  may store the serialized data associated with the orthosis in a web database. In some embodiments, the storage module  1702  may store the serialized data associated with the orthosis in the web database via the network  120 . 
     In some embodiments, the storage module  1702  may store the serialized data associated with the orthosis in the local database and/or the web database automatically. For example, the storage module  1702  may store the serialized data associated with the orthosis in the local database and/or the web database in real time. As another example, the storage module  1702  may store the serialized data associated with the orthosis in the local database and/or the web database periodically (e.g., per 5 seconds, pre 10 seconds). In some embodiments, the storage module  1702  may store the serialized data associated with the orthosis in the local database and/or the web database in response to a request for storage from a user. For example, when the user presses or clicks a “save” button on an interface of the terminal device  130 , the storage module  1702  may store the serialized data associated with the orthosis in the local database and/or the web database. 
     For illustration purposes, a user (e.g., an orthosis designer) may log in the orthosis design system  100  via a browser on a terminal device (e.g., the terminal device  130 ). The user may view data associated with a subject (e.g., a patient list) imported by another user (e.g., a doctor) via the browser. The user may design an orthosis model based on the data associated with the subject. In some embodiments, during the orthosis design process, the user may generate, edit, modify and/or delete the data associated with the orthosis in the orthosis design system  100 . For example, the user may determine orthosis design data based on a 3D model of a subject and one or more reference images of the subject. The orthosis design data may be stored in the local database and/or the web databased automatically. 
     In some embodiments, a plurality of users (e.g., a plurality of orthosis designers) may design the orthosis model collaboratively. For example, a first user may determine first orthosis design data associated with a first part of orthosis model via a browser on a first terminal device in the orthosis design system  100 . The first orthosis design data associated with the first part of orthosis model may be stored in the local database and/or the web database. A second user may determine second orthosis design data associated with a second part of orthosis model via a browser on a second terminal device in the orthosis design system  100 . The second orthosis design data associated with the second part of orthosis model may be stored in the local database and/or the web database. A third user may view the first orthosis design data and the second orthosis design data via a browser on a third terminal device in the orthosis design system  100 . The third user may determine a 3D orthosis model based on the first orthosis design data and the second orthosis design data. In some embodiments, the first terminal device may be located in a first location. The second terminal device may be located in a second location. The third terminal device may be located in a third location. The first location, the second location, and the third location may be different form each other. 
     It should be noted that the above description is merely provided for the purpose of illustration, and not intended to limit the scope of the present disclosure. For persons having ordinary skills in the art, multiple variations and modifications may be made under the teachings of the present disclosure. However, those variations and modifications do not depart from the scope of the present disclosure. For example, operations  1910  and  1920  may be performed simultaneously. As another example, operation  1920  may be performed before operation  1910 . 
       FIG.  20    is a flowchart illustrating an exemplary process for transmitting data to a 3D print database according to some embodiments of the present disclosure. The process  2000  may be executed by the printing module  1703  of the data management system  1700 . For example, process  2000  may be implemented as a set of instructions stored in a storage device in the data management system  1700 . The printing module  1703  may execute the set of instructions and accordingly be directed to perform the process  2000  in the data management system  1700 . The operations of the illustrated process  2000  presented below are intended to be illustrative. In some embodiments, the process  2000  may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. Additionally, the order in which the operations of the process  2000  as illustrated in  FIG.  20    and described below is not intended to be limiting. 
     In  2010 , the printing module  1703  may obtain data associated with an orthosis. 
     In some embodiments, the data associated with the orthosis may include orthosis design data, housing design data, a spline curve associated with an orthosis model, a split surface of the orthosis model, or the like, or any combination thereof. In some embodiments, the printing module  1703  may obtain the data associated with the orthosis from one or more components (e.g., the terminal device  130 , the data obtaining device  110 , the storage device  150 ) of the orthosis design system  100  or an external storage device (e.g., a web database) via the network  120 . For example, the processing device  114  may transmit the data associated with the orthosis to the storage device  150 , or any other storage device for storage. The printing module  1703  may obtain the data associated with the orthosis from the storage device  150 , or any other storage device. As another example, the processing device  114  may transmit the data associated with the orthosis to the printing module  1703  directly. 
     In  2020 , the printing module  1703  may obtain a plurality of 3D printing parameters associated with the orthosis. 
     In some embodiments, the plurality of 3D printing parameters associated with the orthosis may include a printing material, a printing orientation, a layer thickness, a printing orientation angle, a filling ratio, a filament feed rate, or the like, or any combination thereof. In some embodiments, the plurality of 3D printing parameters may be default parameter stored in a storage device (e.g., the storage device  150 ). In some embodiments, the plurality of 3D printing parameters may be set manually by a user (e.g., an orthosis designer, a doctor) of the orthosis design system  100 , or determined by one or more components (e.g., the processing device  114 ) of the orthosis design system  100  according to different situations. For example, the plurality of 3D printing parameters may be determined based on a portion of the subject to be corrected. 
     In  2030 , the printing module  1703  may transmit the design data associated with the orthosis and the plurality of 3D print parameters associated with the orthosis to a 3D print database. 
     In some embodiments, the printing module  1703  may transmit the design data associated with the orthosis and the plurality of 3D print parameters associated with the orthosis to a cloud print database of a print manufacturer via the network  120 . The print manufacturer may view the design data associated with the orthosis and the plurality of 3D print parameters associated with the orthosis via a browser on a terminal device (e.g., the terminal device  130 ) in the orthosis design system  100 . The print manufacturer may print the orthosis based on the design data associated with the orthosis and the plurality of 3D print parameters associated with the orthosis via a 3D printing device. 
     Accordingly, a plurality of users (e.g., a doctor, an orthosis designer, a 3D print manufacturer) of the orthosis design system  100  may design and/or print an orthosis for a subject via a plurality of browsers on a plurality of terminal devices (e.g., the plurality of terminal devices  130 ) collaboratively. The orthosis design and print process may be simplified, and the orthosis production efficiency may be improved. 
     It should be noted that the above description is merely provided for the purpose of illustration, and not intended to limit the scope of the present disclosure. For persons having ordinary skills in the art, multiple variations and modifications may be made under the teachings of the present disclosure. However, those variations and modifications do not depart from the scope of the present disclosure. For example, operations  2010  and  2020  may be performed simultaneously. As another example, operation  2020  may be performed before operation  2010 . As still another example, operation  2030  may be omitted. The printing module  1703  may be a 3D printing device. The 3D printing device may print the orthosis based on the data associated with the orthosis and the plurality of 3D printing parameters associated with the orthosis. 
       FIG.  21    is a schematic diagram illustrating an exemplary cloud design system according to some embodiments of the present disclosure. 
     As shown in  FIG.  21   , a cloud design system  2100  may include a data interaction equipment  140 , the server  144 , and a file server  145 . The data interaction equipment  140  may include a first load balancing device  141 , a data interaction device cluster  142 , and a second load balancing device  143 . The data interaction device cluster  142  may include one or more data interaction devices, e.g., a data interaction device  142 - 1 , a data interaction device  142 - 2 , and a data interaction device  142 - 3 . In some embodiments, the server  144  may be a server group. For example, the server  144  may include a plurality of servers, e.g., a server  144 - 1 , a server  144 - 2 , and a server  144 - 3 . In some embodiments, the terminal device  130  may communicate with the data interaction equipment  140  (e.g., the first load balancing device  141 , the data interaction device cluster  142 , the second load balancing device  143 ) via a browser. 
     The first load balancing device  141  may communicate with the terminal device  130 . The first load balancing device  141  may receive data from the terminal device  130 , and transmit the received data to at least one data interaction device (e.g., the data interaction device  142 - 1 , the data interaction device  142 - 2 , the data interaction device  142 - 3 ) of the data interaction device cluster  142  according to a load balancing mechanism. The data received from the terminal device  130  may include one or more requests for orthosis design. As used herein, load balancing may improve a distribution of workloads across multiple computing resources, such as computers, a computer cluster, network links, central processing units, or disk drives. Load balancing may aim to optimize resource use, maximize throughput, minimize response time, and avoid overload of any single resource. 
     The data interaction device (e.g., the data interaction device  142 - 1 , the data interaction device  142 - 2 , the data interaction device  142 - 3 ) may be configured to determine one or more requests for orthosis design based on the data obtained from the terminal device  130 . In some embodiments, the one or more requests for orthosis design may include a medical image of a subject to be corrected, a 3D model of the subject to be corrected, a reference image of the subject to be corrected, a patient ID of the subject to be corrected (e.g., an ID number), a description of the subject to be corrected (e.g., a left tibia, the 3rd to 6th lumbar vertebrae), or the like, or any combination thereof. 
     The second load balancing device  143  may communicate with the data interaction device cluster  142 . The second load balancing device  143  may be configured to transmit the request for orthosis design to the at least one server (e.g., the server  144 - 1 , the server  144 - 2 , and the server  144 - 3 ), according to the load balancing mechanism. 
     The server  144  (e.g., the server  144 - 1 , the server  144 - 2 , and the server  144 - 3 ) may communicate with the data obtaining device  110 . The server  144  may be configured to perform one or more operations in process  500  to process  700 , process  1100  to process  1300 , in response to the request for orthosis design. In some embodiments, the server  144  may obtain image data from the data obtaining device  110  based on the request for orthosis design. In some embodiments, the server  144  may obtain image data from the file server  145 . 
     The file server  145  may be configured to store image data obtained by the data obtaining device  110 . In some embodiments, the data obtaining device  110  may include a DR device, a 3D camera, a CT device, an MRI device, or the like, as described elsewhere in the present disclosure. In some embodiments, the file server  145  may include a PACS. 
     For illustration purposes, when a user needs to perform an orthotics design operation, the user may send a request for orthosis design and establish an orthosis design task by accessing the data interaction equipment  140  via a network port (e.g., a browser on a terminal device). The data interaction equipment  140  may receive the request and the orthosis design task, and send the orthosis design task to an orthosis design server (e.g., the server  144 ). The orthosis design server (e.g., the server  144 ) may receive an instruction to design the orthosis for a subject. When a plurality of users need to perform the orthotics design operation, the plurality of users may send a plurality of requests for orthosis design and establish a plurality of orthosis design tasks via a plurality of terminal devices (e.g., browsers on the plurality of terminal devices). The data interaction equipment  140  may allocate a network resource load of the orthotics design server (e.g., the server  144 - 1 , the server  144 - 2 , and the server  144 - 3 ) according to a pre-set load balancing strategy. Accordingly, a plurality of orthosis design servers (e.g., the server  144 - 1 , the server  144 - 2 , and the server  144 - 3 ) may process the plurality of design orthosis tasks for the plurality of terminal devices synchronously. For example, the data interaction equipment  140  may allocate the orthosis design task to an orthosis design server that is idle or has a relatively small amount of tasks, according to an orthosis design server polling mechanism. 
     According to some embodiments of the present disclosure, orthosis design data may be generated based on reference image(s) and 3D model of the subject. The orthosis design data may be altered based on force data of at least one region of the subject after wearing the orthosis. Therefore, the orthosis generated based on the orthosis design data may meet correction needs of a user. In addition, one or more users may send one or more requests for orthosis design to a data interaction equipment (e.g. the data interaction equipment  140 ) via browsers on one or more terminal devices (e.g., the terminal device  130 ). The data interaction equipment may receive the one or more requests send the one or more requests to one or more orthosis design servers (e.g., the server  144 ). The one or more orthosis design servers may perform one or more operations in an orthosis design process, in response to the one or more requests for orthosis design. Accordingly, the orthosis design process may be simplified, and a collaborative design of the orthosis by a plurality of users associated with a plurality of terminal devices may be achieved. 
       FIG.  22    is a schematic diagram illustrating an exemplary orthosis design system according to some embodiments of the present disclosure. 
     As shown in  FIG.  22   , an orthosis design system  2200  may include a terminal device  130 , a server  144 , a reverse proxy  2220  (e.g., a nginx), and a DNS server  2210 . In some embodiments, the server  144  may be a server group. The server  144  may include a plurality of servers, e.g., a server  144 - 1 , a server  144 - 2 , . . . , and a server  144 - n.    
     The terminal device  130  may be configured to send data (e.g., one or more requests for orthosis design) to the reverse proxy  2220 . In some embodiments, the terminal device  130  may communicate with the reverse proxy  2220  via a browser. For example, a user associated with the terminal device  130  may input a domain name in the browser on the terminal device  130 . The browser may send the domain name to the DNS server  2210 . The DNS server  2210  may translate the domain name into an IP address. For illustration purposes, the DNS server  2210  may translate a domain name “Uihweb3d.com” into an IP address “192.168.0.1”, as shown in  FIG.  22   . The browser may receive the IP address from the DNS server, and transmit the IP address to the reverse proxy  2220 . 
     The reverse proxy  2220  may receive the data (e.g., an IP address) from the terminal device  130 , and transmit the data to one or more servers (e.g., the server  144 - 1 , the server  144 - 2 , . . . , the server  144 - n ) according to a load balancing mechanism. In some embodiments, the reverse proxy  2220  may receive the data from the terminal device  130  via the network  120  (e.g., a public network). The reverse proxy  2220  may transmit the data to the one or more servers via the network  120  (e.g., a local area network). 
     The server  144  (e.g., the server  144 - 1 , the server  144 - 2 , . . . , the server  144 - n ) may be configured to perform one or more functions described in the present disclosure. For example, the server group  144  may perform one or more operations in process  500  to process  700 , process  1100  to process  1300 , in response to a request for orthosis design, and generate processed data. The server  144  may transmit the processed data (e.g., orthosis design data) to the reverse proxy  2220 . The reverse proxy  2220  may receive the processed data from the server  144 , and transmit the processed data to the terminal device  130 . In some embodiments, the reverse proxy  2220  may receive the processed data from the server  144  via the network  120  (e.g., a local area network). The reverse proxy  2220  may transmit the processed data to the terminal device  130  via the network  120  (e.g., a public network). 
     In some embodiments, by the using of the reverse proxy, an original IP address of the server  144  may not be revealed. An IP address of the reverse proxy  2220  may only be visible. The security of the orthosis design system  100  may be improved. In some embodiments, the reverse proxy  2220  may expand the server capacity in real time. Accordingly, the orthosis design system  100  may be deployed on a plurality of servers, which may improve the response speed and stability of the orthosis design system in a high concurrency environment. The difficulty of development and maintenance of the orthosis design system  100  may be reduced. 
       FIG.  23    is a schematic diagram illustrating an exemplary user interface for displaying a patient list according to some embodiments of the present disclosure. 
     As illustrated, the patient list  2300  may include a personal information section  2301  for displaying personal information associated with a subject. The patient list  2300  may also include a data section  2302  for presenting medical data associated with the subject. The patient list  2300  may further include a function button section  2303  for presenting operations (e.g., “back”, “load in”) associated with the personal information of the subject and the data of the subject. 
       FIG.  24    is a schematic diagram illustrating an exemplary user interface for displaying data associated with a subject in a bookmark mode according to some embodiments of the present disclosure. 
     As illustrated, a user interface  2400  may include a 3D data section for displaying a plurality of 3D data files associated with a subject. The user interface  2400  may include a 2D data section for displaying a plurality of 2D data files associated with the subject. In some embodiments, the plurality of 2D data files and the plurality of 3D data files may be displayed in a bookmark mode. For example, a file name, a file size, a data format, or the like, of a 2D data file or a 3D data file may be displayed. The user interface  2400  may further include a function button section  2403  for presenting operations (e.g., “back”, “load in”) associated with the data of the subject. 
     Having thus described the basic concepts, it may be rather apparent to those skilled in the art after reading this detailed disclosure that the foregoing detailed disclosure is intended to be presented by way of example only and is not limiting. Various alterations, improvements, and modifications may occur and are intended to those skilled in the art, though not expressly stated herein. These alterations, improvements, and modifications are intended to be suggested by this disclosure and are within the spirit and scope of the exemplary embodiments of this disclosure. 
     Moreover, certain terminology has been used to describe embodiments of the present disclosure. For example, the terms “one embodiment,” “an embodiment,” and/or “some embodiments” mean that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Therefore, it is emphasized and should be appreciated that two or more references to “an embodiment” or “one embodiment” or “an alternative embodiment” in various portions of this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined as suitable in one or more embodiments of the present disclosure. 
     Further, it will be appreciated by one skilled in the art, aspects of the present disclosure may be illustrated and described herein in any of a number of patentable classes or context including any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof. Accordingly, aspects of the present disclosure may be implemented entirely hardware, entirely software (including firmware, resident software, micro-code, etc.) or combining software and hardware implementation that may all generally be referred to herein as a “unit,” “module,” or “system.” Furthermore, aspects of the present disclosure may take the form of a computer program product embodied in one or more computer-readable media having computer-readable program code embodied thereon. 
     A non-transitory computer-readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including electro-magnetic, optical, or the like, or any suitable combination thereof. A computer-readable signal medium may be any computer-readable medium that is not a computer-readable storage medium and that may communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a computer-readable signal medium may be transmitted using any appropriate medium, including wireless, wireline, optical fiber cable, RF, or the like, or any suitable combination of the foregoing. 
     Computer program code for carrying out operations for aspects of the present disclosure may be written in any combination of one or more programming languages, including an object-oriented programming language such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB. NET, Python or the like, conventional procedural programming languages, such as the “C” programming language, Visual Basic, Fortran 2003, Perl, COBOL 2002, PHP, ABAP, dynamic programming languages such as Python, Ruby, and Groovy, or other programming languages. The program code may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider) or in a cloud computing environment or offered as a service such as a Software as a Service (SaaS). 
     Furthermore, the recited order of processing elements or sequences, or the use of numbers, letters, or other designations therefore, is not intended to limit the claimed processes and methods to any order except as may be specified in the claims. Although the above disclosure discusses through various examples what is currently considered to be a variety of useful embodiments of the disclosure, it is to be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover modifications and equivalent arrangements that are within the spirit and scope of the disclosed embodiments. For example, although the implementation of various components described above may be embodied in a hardware device, it may also be implemented as a software-only solution, e.g., an installation on an existing server or mobile device. 
     Similarly, it should be appreciated that in the foregoing description of embodiments of the present disclosure, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the various inventive embodiments. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed subject matter requires more features than are expressly recited in each claim. Rather, inventive embodiments lie in less than all features of a single foregoing disclosed embodiment. 
     In some embodiments, the numbers expressing quantities, properties, and so forth, used to describe and claim certain embodiments of the application are to be understood as being modified in some instances by the term “about,” “approximate,” or “substantially.” For example, “about,” “approximate,” or “substantially” may indicate ±20% variation of the value it describes, unless otherwise stated. Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the application are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. 
     Each of the patents, patent applications, publications of patent applications, and other material, such as articles, books, specifications, publications, documents, things, and/or the like, referenced herein is hereby incorporated herein by this reference in its entirety for all purposes, excepting any prosecution file history associated with same, any of same that is inconsistent with or in conflict with the present document, or any of same that may have a limiting effect as to the broadest scope of the claims now or later associated with the present document. By way of example, should there be any inconsistency or conflict between the description, definition, and/or the use of a term associated with any of the incorporated material and that associated with the present document, the description, definition, and/or the use of the term in the present document shall prevail. 
     In closing, it is to be understood that the embodiments of the application disclosed herein are illustrative of the principles of the embodiments of the application. Other modifications that may be employed may be within the scope of the application. Thus, by way of example, but not of limitation, alternative configurations of the embodiments of the application may be utilized in accordance with the teachings herein. Accordingly, embodiments of the present application are not limited to that precisely as shown and described.