System and method for patient positioning during a medical imaging procedure

The present disclosure relates to a positioning system suitable for use in an imaging system. The positioning system may include one or more cameras configured to capture images or videos of an imaging object and surrounding environment thereof for ROI targeting or patient position recognition. The positioning system may also include one or more position probes and sources configured to determine an instant location of an imaging object or an ROI thereof in a non-contact manner.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. national stage under 35 U.S.C. § 371 of International Application No. PCT/CN2016/075233, filed on Mar. 1, 2016, designating the United States of America, which claims priority of Chinese Patent Application No. 201510092839.7 filed on Mar. 2, 2015, the contents of which are hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present invention relates to medical imaging, more particularly, the invention relates to a system and method for patient positioning during a medical imaging procedure.

BACKGROUND

Imaging systems, such as CT scanners, MRI scanners, PET scanners, are widely used for creating images of interior of a patient's body for medical diagnosis and/or treatment purposes. Generally, a region of interest (ROI) covering a portion of the patient's body, such as a limb or an internal organ, is selected before an imaging session starts. Data is then acquired from within the ROI and analyzed, giving swift and accurate diagnosis thereafter. Thus, to ensure high quality imaging and accurate diagnosis, the ROI must be properly targeted during imaging.

Patient positioning is an increasingly important consideration for medical imaging, of which application ranges from dental treatment to radiotherapy. Traditional patient positioning methods include the use of a laser pointer to mark the ROI on a patient's body, thereby allowing the imaging system to properly align with the patient.

However, some traditional positioning methods require human intervention, such as requiring a system operator to manually manipulate the laser for locating the ROI, which affects accuracy. Further, traditional positioning methods lack the feature for monitoring the ROI in real time. Thus, when the location of an ROI changes during an imaging session, such as due to body movement of the patient, the system cannot be easily adjusted to target the ROI properly.

Additionally, an imaging system usually need to know the patient position (e.g., whether the patient is lying in a prone or supine position) before an imaging session may be performed. Traditionally, a system operator may instruct a patient to take and maintain a particular patient position during an imaging session, and manually input that information for the imaging system to perform, such as choosing and executing a scanning protocol particularly designed for that patient position. When the patient position changes during an imaging session, such as mandated by the diagnosis or the patient's health condition, the operator may need to manually update the information before the imaging session may continue. Thus, the updating process again depends on human intervention, leaving room for human error. Further, the manual updating process sometimes consumes considerable amount of time, causing substantial delay and patient discomfort.

Thus, there exists a need for developing a new positioning method and system that is capable of real-time monitoring of a patient and accordingly adjusting an imaging system for any positional change with less or no human intervention. The new positioning system and method thus improve efficiency and accuracy of medical imaging.

SUMMARY OF THE INVENTION

In a first aspect of the present disclosure, provided herein is a positioning system. In some embodiments, the positioning system may include a position acquiring unit, a position processing unit, and a control unit. In some embodiments, the position acquiring unit may include one or more cameras. The camera(s) may be configured to monitor or communicate with an imaging object in real time. The position processing unit may be configured to process or analyze one or more images to produce an outcome. The control unit may be configured to generate control information based on the outcome. In some embodiments, the positioning system may be configured to compose a set of images and/or videos taken by the cameras in to a panoramic rendering of the imaging object and its surrounding environment.

In some embodiments, one or more images may include at least one characteristic feature indicative of a patient position and the positioning processing unit may be further configured to recognize the characteristic feature to determine the patient position.

In some embodiments, the control unit may be further configured to generate control information for defining an imaging protocol suitable for the patient position and may be capable of updating the control information pursuant to change of the patient position.

In some embodiments, one or more images may include at least one characteristic feature indicative of a region of interest (ROI) and the positioning processing unit may be further configured to recognize the characteristic feature to determine the ROI. In some embodiments, the control unit may be further configured to generate control information for targeting the ROI.

In some embodiments, the positioning processing unit may be further configured to calibrate the one or more images to generate a calibrated display and the control unit may be further configured to receive selection of a region of interest (ROI) from the calibrated display and generate control information for targeting the ROI.

In some embodiments, one or more images comprise at least one characteristic feature indicative of a reference position and the positioning processing unit may be further configured to recognize the characteristic feature to determine the reference position. In some embodiments, the control unit may be further configured to generate the control information based on the reference position.

In some embodiments, one or more cameras may have overlapping fields of view and the position processing unit may also further configured to compose the one or more images to generate a panoramic image.

In some embodiments, the positioning system may be configured to automatically recognize a patient position. In some embodiments, the positioning system may be configured to target a region of interest (ROI) on a patient's body on during an imaging session. In some embodiments, the ROI may cover an imaging object or a portion thereof. In some embodiments, the positioning system may be configured to communicate with an imaging system. In some embodiments, the positioning system may be configured to process patient's positional information, including but not limited to information regarding the patient position and the ROI, to generate control information. In some embodiments, the positioning system may send patient's positional information to the imaging system. In some embodiments, the positioning system may be configured to communicate with a hospital information system. In some embodiments, the positioning system may enable an operator of a imaging system to monitor a patient's status in real time.

In a second aspect of the present disclosure, provided herein is a positioning system, and the positioning system may include a position acquiring unit, a position processing unit, and a control unit. In some embodiments, the positioning system may include one or more position sources and position probes. The position source(s) and position probe(s) are used to monitor the instant location of an ROI. In some embodiments, the positioning system may be configured to determine a distance between a pair of position probe and position source based on communication between them. In some embodiments, ultrasound distance sensing may be used to determine the distance between a pair of position probe and position source.

In some embodiments, each position probe may have a communication range and be configured to terminate the non-contact communication of position probe(s) and source(s) when a position source leaves the communication range and to establish the non-contact communication when the position source enters the communication range of another position probe. In some embodiments, the non-contact communication may be conducted via ultrasound signaling.

In some embodiments, one or more position probes may include at least three position probes and the control unit may be further configured to execute control information.

In a third aspect of the present disclosure, provided herein is a method for positioning a patient for medical imaging. The method may include: obtaining one or more images of the patient; recognizing at least one characteristic marker from the images, the characteristic marker is indicative of a region of interest (ROI); generating control information based on the characteristic marker; positioning the patient based on the control information.

In some embodiments, the images may further include surrounding environment of the patient, and the at least one characteristic marker is located in the surrounding environment.

In a fourth aspect of the present disclosure, provided herein is a method for positioning a patient for medical imaging. The method may include: setting a position source indicative of region of interest (ROI) of the patient; establishing one or more position probes at known locations; measuring distances between the position source and the one or more position probes; calculating a location of the position source based on the measured distances; generating control information based on the calculated position of the position source; positioning the patient based on the control information.

In some embodiments, measuring distances between the position source and the one or more position probes may be performed by ultrasound distance sensing.

DETAILED DESCRIPTION

It will be understood that when a module or unit is referred to as being “on”, “connected to” or “coupled to” another module or unit, it may be directly on, connected or coupled to the other module or unit or intervening module or unit may be present. In contrast, when a module or unit is referred to as being “directly on,” “directly connected to” or “directly coupled to” another module or unit, there may be no intervening module or unit present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

FIG. 1illustrates an imaging system comprising a positioning system according to some embodiments of the present disclosure. In some embodiments, the positioning system100may be configured to automatically recognize a patient position. The term “patient position” as used herein refers to the physical positions of a patient's body, including the body's gesture, location within an imaging system, and orientation relative to components of the imaging system. For example, exemplary patient positions for a whole body scan include the supine, prone, right lateral recumbent, and left lateral recumbent positions. Further, in some embodiments, a patient position also includes information regarding the orientation of the body in the imaging system, such that the body is to be scanned in a certain direction, such as head to toe (e.g., head-first position), or toe to head (feet-first position).

In some embodiments, the positioning system100may be configured to target a region of interest (ROI) on a patient's body on during an imaging session. The term “region of interest” or “ROI” as used herein refers to a subset of an image, a video, or a dataset identified for a particular purpose. Particularly, images and videos include but are not limited to 2-dimensional image (2D), three-dimensional (3D), and four-dimensional (4D) ones, as well as those covering a narrow or a panoramic field of view. Datasets as used herein refers to sets of values of qualitative or quantities variables in any form, including but not limited to a digital, analog, or wave form. Exemplary embodiments of an ROI pertaining to the present disclosure include a time interval for data acquisition, a frequency interval for waveform data, a spatial region defined by boundaries on or within an object or a representation thereof, including but not limited to images or drawings illustrating the object's contours, surfaces or internal structures.

The term “target” as used herein refers to determining the ROI and/or acquiring data from within the ROI. Particularly, exemplary embodiments of targeting an ROI pertaining to the present disclosure include determining the ROI's form (e.g., a time interval or a spatial boundary), status (e.g., static or dynamic), location (e.g., in 3D space or on a 2D image), as well as positioning the ROI so as to acquire information from within the ROI (e.g., image or sound data).

In some embodiments, the ROI may cover an imaging object or a portion thereof. The term “imaging object” as used herein broadly relates to any organic or inorganic mass, natural or man-made, that has a chemical, biochemical, biological, physiological, biophysical and/or physical activity or function. Exemplary embodiments of an imaging object pertaining to the present disclosure include cells, tissues, organs or whole bodies of human or animal. Other exemplary embodiments include but not limited to man-made composition of organic and/or inorganic matters that are with or without life. In some embodiments, the imaging object may be a human patient. In some embodiments, the positioning system100may control the movement and positioning of an imaging object by controlling the movement of a support configured to carry the imaging object. In some embodiment the support is a patient support160that is a part of an imaging system170.

In some embodiments, the positioning system100may be configured to communicate with an imaging system170. Imaging systems that can be used in connection with the present disclosure include components and combinations of single-modality or multi-modality imaging systems and devices, some of which are used for non-invasive diagnosis, intervention and/or research in the biomedical field.

The term “imaging modality” or “modality” as used herein broadly refers to an imaging method or technology that gathers, generates, processes and/or analyzes imaging information of a target body through a particular mechanism. Accordingly, a multi-modality imaging system of the present disclosure can include more than one imaging modality, such as two, three, or more different modalities. In a multi-modality system, the mechanisms through which different imaging modalities operate or function can be the same or different. Accordingly, the imaging information can also be the same or different. For example, in some embodiments, the imaging information can be internal and/or external information, and can be functional and/or structural information of the target body. Particularly, in some embodiments, the imaging information of different modalities complement one another, thereby providing a set of imaging data describing a target body from different analytical angles. For example, in some embodiments, the multi-modality imaging achieves merging of morphological and functional images.

In various embodiments, the imaging system may comprise imaging modalities for conducting various different medical scans or studies, including but not limited to digital subtraction angiography (DSA), computed tomography (CT), computed tomography angiography (CTA), positron emission tomography (PET), X-ray, magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), single-photon emission computerized tomography (SPECT), ultrasound scanning (US), ultrasound scan, bone densitometry, fluoroscopy. In various embodiments, exemplary multi-modality combination of the imaging system may include CT-MR, CT-PET, CE-SPECT, DSA-MR, PET-MR, PET-US, SPECT-US, TMS (transcranial magnetic stimulation)-MR, US-CT, US-MR, X-ray-CT, X-ray-MR, X-ray-portal, X-ray-US, Video-CT, Vide-US.

Particularly, in some embodiments, the positioning system100may be configured to process patient's positional information, including but not limited to information regarding the patient position and the ROI, to generate control information. The imaging system170then receives the control information and performs the positioning procedure accordingly.

In some embodiments, the positioning system100may send patient's positional information to the imaging system170. The imaging system170then processes the patient's positional information to generate control information and performs the positioning procedure accordingly.

In some embodiments, the positioning system100may be configured to communicate with a hospital information system (HIS; not shown in the figure). As used herein, the term “hospital information system” or “HIS” refers to the whole or part of a comprehensive, integrated information system designed to manage all aspects of a hospital's operation, such as the hospital's medical, administrative, financial, and legal issues, and the corresponding processing of services. In some embodiments, the positioning system100may send patient's positional information or control information to the HIS. In some embodiments, the HIS may store and/or process information received from the positioning system100. In some embodiments, the HIS may execute the control information to perform the positioning procedure. In some embodiments, the positioning system and/or the imaging system may be part of the HIS.

The term “control information” as used herein broadly relates to any information that directs operation of a system, including the positioning system and imaging system described herein. Exemplary embodiments of control information include information that specifies locations and/or directs movement of an ROI, an imaging object and/or one or more system components. In some embodiments, control information specifies a time, speed, path, angle and/or instruction for moving an ROI, an imaging object and/or one or more system components. In some embodiments, control information may be in the form of a machine-generated and/or user-input command that upon execution directs operation of the system, such as initiating a camera, running an algorithm, receiving, storing, or sending data, selecting an imaging protocol, and performing a positioning procedure etc. The term “positioning procedure” as used herein refers to the process of placing an imaging object in a particular physical position relative to an imaging system during the operation of the system.

In some embodiments, the positioning system100may enable an operator of the system to monitor a patient's status in real time. Particular, in some embodiments, the operator may input control information for the imaging system170to target a selected ROI. In some embodiment, an operator inputs control information via a console150. In some embodiments, the positioning system100is configured to execute the control information. Particularly in some embodiments, the positioning system100, upon receiving the control information, may move and position the imaging object and one or more components of the imaging system170relative to one another, such that the ROI is targeted in the corresponding imaging session.

In various embodiments, system components moved and positioned during the positioning procedure include but are not limited to a support (e.g., a patient bed, a handle etc.), a data acquisition device (e.g., an X-ray generator, a PET detector, etc.), a monitoring device (e.g., a camera, a lamp etc.), a communication device (e.g., a microphone, a keypad, etc.), and a mechanical part (e.g., for carrying the system components, for adjusting a patient position, etc.). In some embodiments, during the positioning procedure, the system sends voice instruction for a patient to perform. It should be noted that the above examples are provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. After consulting the present disclosure, one skilled in the art may envisage numerous other changes, substitutions, variations, alterations, and modifications without inventive activity, and it is intended that the present disclosure encompasses all such changes, substitutions, variations, alterations, and modifications as falling within its scope.

Structure-wise, in some embodiments as shown inFIG. 1, the positioning system100may comprise a position acquiring unit110. In some embodiments, the position acquiring unit110may include one or more cameras. In some embodiments, the camera(s) are used to monitor or communicate with an imaging object (such as a human patient) in real time. Particularly, in some embodiments, the camera(s) may be configured to capture images and/or videos of a patient near or in the imaging system170. In some embodiments, the captured images and/or videos are used to monitor instant status of the patient, such as the patient's expression, gesture, and/or movement. In some embodiments, the captured images and/or videos are used for automatic patient position recognition. In some embodiments, the captured images and/or videos are used to assist ROI selection and targeting.

In some embodiments, multiple cameras may have a same or different field of view (FOV). For example, in some embodiments, one or more cameras may have a FOV covering a 90-180 degrees field. In some embodiments, one or more cameras may have a FOV covering 0-90 degrees field. In some embodiments, respective fields of view of multiple cameras may overlap.

In some embodiments, the positioning system100is configured to compose the set of images and/or videos taken by these cameras into a panoramic rendering of the imaging object and its surrounding environment. In some embodiments, the panorama is displayed to an operator of the system. As used herein, the term “panoramic” or “panorama” refers to an image or video that covers the maximum area of data acquisition of an imaging system, or an imaging object in its entirety, or an ROI in its entirety. In some embodiments, in addition to the imaging object or an ROI, a panorama also covers nearby environment where the imaging object or ROI is positioned. In some embodiments, a panorama has a field of view (FOV) of 0 to 45 degrees; in other embodiments, a panorama has a FOV of 45 to 90 degrees; in other embodiments, a panorama has a FOV of 90 to 180 degrees; in yet other embodiments, a panorama has a FOV of 180 to 360 degrees.

In some embodiments, the position acquiring unit110may comprise one or more position sources and probes. In some embodiments, the position source(s) and probe(s) are used to monitor the instant location of an ROI. Particularly, in some embodiments, the position sources and probes are configured to conduct non-contact communication. Particularly, in some embodiments, position sources may be configured to emit or receive a position signal, while position probes may be configured to receive or emit such position signal. In some embodiments, the position signal may be a non-contact signal of any form, including but not limited to optical signal, sound signal or magnetic signal. In some embodiments, a position source or a position probe may be placed on or near an ROI, thus the position signal may be used to determine the physical location of a ROI.

In some embodiments, the positioning system100is configured to determine a distance between of a pair of position probe and source based on communication between them. Particularly, in some embodiments, a position source's physical location in a three-dimensional space may be calculated based on its distance to one or more position probe(s) of known physical location in the three-dimensional space. The number of position probe(s) needed for the calculation depends on the relative spatial relationship between the source and the probe(s).

In some embodiments, ultrasound distance sensing may be used to determine the distance between a pair of position probe and source. For example, in some embodiments, a position source configured to emit an ultrasound signal is placed near an ROI, while one or more position probe(s) configured to receive the ultrasound signal are placed at known positions of the imaging system. The distance between the source and the probe(s) can be calculated based on the time delay between when the source emits the signal and when the probe receives it.

It should be noted that the implementation of ultrasound distance sensing is provided merely for the purposes of illustration, and not intended to limit the scope of the present disclosure. As would be appreciated by skilled person in the art, other mechanisms for non-contact distance sensing could also be used in connection with the present disclosure. For example, in some embodiments, infrared distance sensing and/or laser distance sensing may be used. In some embodiments, multiple distance sensing mechanisms may be used in combination.

In some embodiments, positional information obtained by the positing acquiring unit110is transmitted to be processed by a module external to the positioning system100, such as by a processor of the imaging system or the HIS. In other embodiments, positional information is processed locally by the positioning system100. As shown inFIG. 1, in some embodiments, the positioning system100comprises a stand-alone position processing unit120configured for receiving and processing the positional information. In other embodiments, a position processing unit120may be integrated with other modules of the positioning system100. For example, in some embodiments, the position acquiring unit110and the position processing unit120may be an integrated unit.

In some embodiments, the position processing unit120is configured to analyze an image and/or video of an imaging object, such as a human patient. Particularly, in some embodiments, the position processing unit120is configured to recognize patient position based on the image and/or video. In some embodiments, the position processing unit120is configured to generate panoramic images and/or videos of an imaging object. In some embodiment, the position processing unit120is configured to target an ROI of an imaging object and generate control information. In some embodiments, the position processing unit120is configured to transmit processed positional information or control information to external modules, including but not limited a module of the positioning system100, of the imaging system170, or of an HIS.

According to the present disclosure, the position processing unit120may include any processor-based and/or microprocessor-based units. Merely by way of example, the processor may include a microcontroller, a reduced instruction set computer (RISC), 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 acorn reduced instruction set computing (RISC) machine (ARM), or any other circuit or processor capable of executing the functions described herein, or the like, or any combination thereof. The exemplary types of processors that may be used in connection with the present system are not exhaustive and are not limiting. After consulting the present disclosure, one skilled in the art may envisage numerous other changes, substitutions, variations, alterations, and modifications without inventive activity, and it is intended that the present disclosure encompasses all such changes, substitutions, variations, alterations, and modifications as falling within its scope.

As shown inFIG. 1, in some embodiments, the positioning system100may further comprise a stand-alone control unit130configured for receiving and executing control information to perform a positioning procedure. In other embodiments, a control unit130may be integrated with other modules of the positioning system100, such as integrated with the position acquiring unit110, the position processing unit120or both. In various embodiments, control information received and executed by the control unit130may include machine-generated information, such as control information generated by the positioning system100, an imaging system or a HIS. Control information may also be input by a human operator of the system.

According to the present disclosure, the control unit130may include any processor-based and/or microprocessor-based units. Merely by way of example, the processor may include a microcontroller, a reduced instruction set computer (RISC), 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 acorn reduced instruction set computing (RISC) machine (ARM), or any other circuit or processor capable of executing the functions described herein, or the like, or any combination thereof. The exemplary types of processors that may be used in connection with the present system are not exhaustive and are not limiting. After consulting the present disclosure, one skilled in the art may envisage numerous other changes, substitutions, variations, alterations, and modifications without inventive activity, and it is intended that the present disclosure encompasses all such changes, substitutions, variations, alterations, and modifications as falling within its scope.

As shown inFIG. 1, in some embodiments, the positioning system100may further comprise one or more displaying devices140. In some embodiments, the displaying device(s)140may be configured to display, among other things, patient's positional information acquired and/or processed by the positioning system100. Further, in some embodiments, based on displayed information, a system operator may input control information for the imaging system to target a selected ROI.

According to the present disclosure, the displaying device140may be any suitable device that is capable of receiving, converting, processing, and/or displaying media content and/or performing any other suitable functions. For example, the display140can be and/or include a Liquid Crystal Display (LCD) panel, Organic Light Emitting Diodes (OLED), a cathode ray tube (CRT) display, a plasma display, a touch-screen display, a simulated touch screen, the like, or any combination thereof. In some embodiments, the display140may be capable of three-dimensional (3D) displaying. In some embodiments, the displaying device140can be implemented as a touchscreen configured to detect a touch input pressure, a touch input position, or the like, or any combination thereof.

As shown inFIG. 1, in some embodiments, the positioning system100may further comprise a console150. In some embodiments, the console150may be any suitable input device that is capable of inputting information to the positioning system100. Exemplary input devices may include but are not limited to a keyboard, a mouse, a touch screen, a voice controller, or the like, or any combination thereof.

It should be noted that the description of the positioning system is provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. After consulting the present disclosure, one skilled in the art may envisage numerous other changes, substitutions, variations, alterations, and modifications without inventive activity, and it is intended that the present disclosure encompasses all such changes, substitutions, variations, alterations, and modifications as falling within its scope. For example, in some embodiments, the position processing unit120and the control unit130may be combined as a single unit.

FIG. 2is a flowchart illustrating a process performed by the present positioning system according to some embodiments of the present disclosure.

In step201, positional information may be acquired. Exemplary mediums carrying the positional information may include images, videos, ultrasound, infrared beams, or any suitable medium for monitoring the status of a patient. Particularly, in some embodiments, the positioning system100comprises one or more cameras configured to monitor an imaging object and its surrounding environment. For example, in some embodiments, the cameras capture real-time images or videos of a patient lying on a patient support160of the imaging system170.

In other embodiments, the positioning system100comprises pairing position sources and probes that are configured to communicate a position signal. For example, in some embodiments, one or more position sources are placed on a particular portion of a patient (e.g., near a ROI), and one or more position probes are placed at known locations. A position signal is transmitted between the position source(s) and position probe(s), thereby informing the positioning system100positional information of the imaging object. In various embodiments, the position signal may be ultrasound, infrared beams, or a combination thereof.

In step202, positional information acquired in step201may be processed. In some embodiments, raw images and/or videos of an imaging object are processed. For example, in some embodiments, multiple cameras of the positioning system100are configured to each capture a portion of a patient's body. In step202, the set of images and/or videos may be composed into a panoramic rendering for showing on the displaying device140. The panorama covers the patient's full body and surrounding environment. In other embodiments, images of a patient may be analyzed for automatic recognition of the patient position. In yet other embodiments, the position signals transmitted between the position source and probe are analyzed to keep track of the instant location of an ROI.

In step203, control information may be generated based on the positional information. The control information may include but is not limited to selection of an ROI for imaging and parameters for moving and positioning an imaging object and components of the imaging system such that the ROI can be properly targeted. For example, in some embodiments, an operator of the imaging system may manually set or update an ROI by selecting a portion on a displayed image. In other embodiments, the imaging system may automatically set or update the ROI, such as based on the recognized patient position. In other embodiments, an operator may manually input and/or the system may automatically generate various parameters for moving one or more system components (such as the patient support160) to a suitable location, which parameters may include but are not limited to the distance, direction and speed of the movement. In yet other embodiments, an operator may manually input and/or the system may automatically generate or select protocols for controlling a subsequent imaging session, which parameters may include but are not limited to the method of image acquisition, duration, voltage, dosage, system components to be used in connection of the acquisition, and method of data processing, etc.

In step204, the control information may be executed accordingly to perform a positioning procedure. For example, in a positioning procedure, an imaging object or one or more system components may be moved to a suitable location at a suitable speed. In various embodiments, system components moved and positioned during a positioning procedure include but are not limited to a support (e.g., a patient bed, a handle etc.), a data acquisition device (e.g., an X-ray generator, a PET detector, etc.), a monitoring device (e.g., a camera, a lamp etc.), a communication device (e.g., a microphone, a keypad, etc.), and a mechanical part (e.g., for carrying the system components, for adjusting a patient position, etc.). In some embodiments, during the positioning procedure, the system sends voice instruction for a patient to perform.

It should be noted that the flowchart above is provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. After consulting the present disclosure, one skilled in the art may envisage numerous other changes, substitutions, variations, alterations, and modifications without inventive activity, and it is intended that the present disclosure encompasses all such changes, substitutions, variations, alterations, and modifications as falling within its scope.

FIG. 3is a block diagram of the positioning system100according to some embodiments of the present disclosure. As shown in the figure, the positioning system100comprises a position acquiring unit110, a position processing unit120, and a control unit130as described in connection withFIG. 1above.

Particularly, the position acquiring unit110may comprise one or more cameras for monitoring an imaging object. The cameras are labeled as camera1310, camera2311, camera3312, and camera N313. The position processing unit120may comprise an image recognition module320, an image composition module321, and an image calibration module322. The control unit130may comprise a control information module330and a positioning module331.

According to the present disclosure, the camera(s) may be configured to monitor at least part of an imaging object and its surrounding environment. In some embodiments, the cameras may be mounted in the imaging gantry of an imaging system and configured to monitor a patient therein. Characteristics and setting of the camera(s) may vary according to a user's preference and practical needs. For example, if a medical practitioner needs to monitor a relatively small portion of a patient's body during an imaging session, such as the head or a limb, initiating a single camera of narrow FOV during the imaging session may suffice for the purpose. However, if a medical practitioner prefers to monitor the patient's entire body, a panoramic imaging solution may be used.

In some embodiment, the panoramic imaging solution may involve the use of a single camera, typically equipped with a wide to ultra-wide-angle lens. Exemplary wide-angle lenses include non-flat lenses and fisheye lenses. Selection of camera FOV involves a tradeoff between imaging coverage and quality. Particularly, as the camera FOV increases, the amount of imaging information and the size of a scene captured by the camera also increase. On the other hand, however, visual distortion also increases, as rendering the larger and larger amount of imaging information onto a flat image unavoidably requires more and more excessive stretching of pixels near borders of the image. The result is that produced panoramas may appear warped and do not correspond to a natural human view, which reduces authenticity and aesthetics of the image. In practice, flat panoramas start to look severely distorted once the camera FOV exceeds 90°. Thus, in some embodiments, the single-lens panoramic solution may be less preferred. Particularly, in those embodiments where the panoramic image is used for analyzing a patient position and/or positioning an imaging object or an ROI, visual distortion may negatively impact accuracy of the system.

An alternative solution is to use more cameras to cover a desirable total FOV, with each camera covering a smaller field without causing visual distortion. Thus, in some embodiments, the position acquiring unit110comprises a set of cameras. Particularly, each camera may be configured to capture at least part of a desired total FOV, such as an entire patient body and the patient support160. Adjacent cameras' respective fields of view may overlap, such that the set of cameras together cover the desirable total FOV.

According to the present disclosure, the set of cameras may assume various different geometries as long as the captured set of images can be composed into a panorama covering a desirable total FOV. Particularly, the set of cameras may comprise any number of cameras. In some embodiments, the number of cameras may be greater than 1. Particularly in some embodiments, the number of cameras may range from 2 to 12. In some embodiments, the number of cameras may be any even number, such as 2, 4, 6, 8, 10, or 12 cameras. In some embodiments, the number of cameras may be any odd number, such as 3, 5, 7, 9, 10, or 11 cameras. Exemplary geometries of the camera set are described in details below in relation toFIGS. 5 and 6.

In some embodiments, the image composition module321may be configured to compose the set of images into a panoramic image. Depending on the geometry of how cameras are set around the imaging object and relative to one another, different image processing methods or algorithms may be used to generate the panorama. For example, in some embodiments, the imaging processing method registers set of images into alignment estimates, blends them in a seamless manner, and at the same time solves the potential problems such as blurring or ghosting caused by parallax and scene movements as well as varying image exposures. Particularly, in some embodiments, panorama composition may include registration, calibration and blending steps. Particularly, image registration may use the direct alignment method or the feature-based method to search for optimum alignments that minimize the sum of absolute differences between overlapping pixels of different images. Image calibration may be performed to minimize differences between an ideal lens model and the actual cameras and imaging condition, such as correcting optical defects, exposure differences, focus differences, vignetting, camera response, chromatic aberrations, blurring and ghosting etc. Image blending may be performed based on the result of image calibration, and combined with remapping of the images to an output projection.

In some embodiments, panorama composition may involve the direct alignment method and/or the feature-based method. Particularly, using the direct alignment method, each pixel of a first image may be compared with that of a second image, so as to find the optimum cut-and-stitch line for composing the two images. Using the feature-based method, features of the two images may be extracted and compared, so as to find the optimum cut-and-stitch line. Exemplary feature detecting and abstraction methods may include Harris, Scale-Invariant Feature Transform (SIFT), Speeded Up Robust Features (SURF), Features from Accelerated Segment Test (FAST), PCA-SIFT, and ORB techniques. In some embodiments, algorithms including mean square distance, least square, Euclidian distance, the linear weighted algorithm, Gaussian-weighted algorithm, may be used for panorama composition. Exemplary embodiments of panorama composition are described in details below in relation toFIGS. 7B and 7C.

In some embodiments, the display calibration module322may be configured to receive original images acquired by the position acquiring unit110or panoramic images generated by the image composition module321, and further calibrate the images for displaying on a displaying device140. Particularly, the display calibration module322registers positional information in physical space as corresponding positional information on a displayed image. Thus, when a system operator selects an ROI on a screen-displayed image, the positioning system110is able to translate the selection into a corresponding ROI in physical space. In some embodiments, the calibration may be based on a mapping relationship between the dimension of the panorama's total FOV and the dimension of the displayed image. An exemplary embodiment of the mapping relationship is described in details below in relation toFIG. 9.

In some embodiments, the image recognition module320may be configured to perform image-based automatic inspection and analysis for such applications as automatic patient position recognition and ROI targeting. Particularly, in some embodiments, the image recognition module320is configured to recognize one or more human body features from a captured image or video, the body feature(s) being indicative of the patient position. In some embodiments, the image recognition module320is configured to recognize one or more position markers from a captured image or video, the position marker(s) being indicative of the position of an ROI. Exemplary embodiments of image recognition are described in details below in relation toFIGS. 19 and 20.

In some embodiments, the control information module330may generate control information based on results transmitted from the position processing unit120. In some embodiments, the control information module330may be configured to receive a system operator's input. In some embodiments, a calibrated panoramic image may be displayed on the displaying device140. An operator of the imaging system may select an ROI on the displaying device140by manipulating the displayed panoramic image. For example, the operator may select the ROI by drawing a pair of lines or an area on the displayed image. The control information module330may receive the selection, translate the selection into parameters corresponding to the ROI's location in physical space, and generate a set of control information.

The positioning module331may be configured to receive and execute the control information. For example, in some embodiments, the positioning module331may execute the control information to perform a positioning procedure. Particularly, in some embodiments, the positioning module331, upon receiving and executing the control information, may move a patient to the parameter-specified position in the imaging gantry, such that the ROI may be targeted during the next imaging session.

It should be noted that the above description of the positioning system is provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. After consulting the present disclosure, one skilled in the art may envisage numerous other changes, substitutions, variations, alterations, and modifications without inventive activity, and it is intended that the present disclosure encompasses all such changes, substitutions, variations, alterations, and modifications as falling within its scope. For example, in some embodiments, the image recognition module320, the image composition module321and the display calibration module322may be combined into a single functional unit.

FIG. 4is a flowchart illustrating an exemplary process of patient positioning according to some embodiments of the present disclosure. In step401, images captured by at least two cameras may be recognized. In some embodiments, each camera of the at least two cameras may be configured to monitor at least part of the imaging object. Two adjacent cameras of the at least two cameras may overlap in their respective FOV. In some embodiments, the cameras may be mounted inside an imaging gantry of an imaging system and configured to monitor a patient therein.

In step402, images recognized in step401may be composed to generate a panoramic image that covers the entire imaging object and surrounding environment. Depending on the geometry of how cameras are set around the imaging object, different image-stitching algorithms may be used to generate the panorama.

In step403, the panoramic image may be calibrated for displaying, such as on a displaying device140as described in connection withFIG. 1. The calibration algorithm registers positional information in physical space as corresponding positional information in the displayed image. Thus, when a system operator selects an ROI on a screen-displayed image, the system is able to translate the selection into a corresponding ROI in physical space. In some embodiments, the calibration may be based on a mapping relationship between the size of the panorama's total FOV and the size of the displayed image.

In step404, an ROI may be selected based on the displayed panoramic image. In some embodiments, an operator of the imaging system may select an ROI either via the console150or directly on the displaying device140by manipulating the displayed panoramic image. For example, the operator may select the ROI by drawing a pair of lines or an area on the displayed image.

In step405, control information may be generated based on the ROI selection in step404. In the calibration step, the system keeps track of positional correspondence between the displayed image and the physical space. Thus, in some embodiments, after an ROI is selected, the system is able to translate the selection into parameters corresponding to the ROI's location in physical space, and generate a set of control information.

In step406, positioning procedure may be performed. For example, in some embodiments, upon executing of the control information, the system may move a patient to the parameter-specified position in the imaging gantry, such that the ROI may be targeted during the next imaging session.

It should be noted that the above flowchart is provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. After consulting the present disclosure, one skilled in the art may envisage numerous other changes, substitutions, variations, alterations, and modifications without inventive activity, and it is intended that the present disclosure encompasses all such changes, substitutions, variations, alterations, and modifications as falling within its scope.

FIGS. 5 and 6illustrate exemplary embodiments of an imaging device equipped with a positioning system according to the present disclosure.

Particularly,FIG. 5is a schematic illustration of a cross-sectional view of the imaging system according to some embodiments of the present disclosure. As can be seen from this view, a patient500lies on a patient support550. The patient support550is configured to move the patient500in and out of an imaging gantry520of an imaging system510. One or more reference pattern530is placed on the patient support550. One or more camera540is placed in the imaging gantry520above the centerline of the patient's body.

FIG. 6is a schematic illustration of a side view of the imaging system according to some embodiments of the present disclosure. As can be seen from this view, three cameras540are mounted inside the imaging gantry520. A patient500is lying on the patient support550. The cameras are arranged in a straight line above the center of the patient's body. Two adjacent cameras have an overlapping area in their respective FOV. Three reference patterns530are placed on the patient support550.

In this particular embodiment, the three cameras540are mounted at the same vertical height from the patient support550and are arranged in a straight line with respect to one another. Particularly, the straight line may be parallel with the longitudinal axis of the patient support550moves. In some embodiments, the straight line may superimpose with the centerline of the patient's body500; that is, the cameras540are mounted above the center of the patient's body500. In some embodiments, the cameras540are distributed evenly in a straight line; that is, distances between adjacent cameras540are the same.

However, it can be now appreciated that a variety of embodiments of the position acquiring unit110may be employed. These embodiments may have different numbers and/or arrangements of cameras, but a common feature is that each camera's FOV overlaps with that of at least one other camera, thereby enabling the positioning system100to capture a desirable total FOV. Those of ordinary skills in the art upon reading the present disclosure should become aware of how a position acquiring unit according to the present disclosure can be designed to satisfy particular needs. Particularly, skilled persons in the art would follow the guidance provided by the present disclosure to select a suitable number of cameras with reasonable fields of view and arrange the set of cameras such that neighboring cameras' fields of view have reasonable overlap that enables the system to cover a desirable total FOV and reliably process image information in the overlapping field to produce panoramas. Some exemplary geometries of the set of camera that may be employed are described further below.

Particularly, in some embodiments, the number of cameras may be less or more than 3. For example, in some embodiments, the system includes two or more lines of cameras aligned above a scanning area. Each line of cameras may or may not superimpose with the centerline of the scanning area. In some embodiments, overlapping FOV exists for adjacent cameras in the same line and/or in different lines.

In some embodiments, the cameras may not align in a straight line with respect to one another. For example, in some embodiments, the cameras may be scattered around an imaging object. In some embodiments, the set of cameras may be arranged in a curve or in a convex or concave surface, such as on the surface of a sphere.

In some embodiments, the cameras may not sit at the same vertical height from a reference plane, such as the patient support. For example, one camera may be placed at a lower position than other cameras, due to spatial constraint in the imaging gantry. In some embodiments, distances between adjacent cameras may not be the same. Particularly, in some embodiments, overlapping area of different pairs of adjacent cameras may be of different size.

Depending on the geometry of how cameras are set around the imaging object, different image-stitching algorithms may be used to generate the panorama. In the embodiments as shown inFIGS. 5 and 6, reference patterns are used to help locating the overlapping areas in adjacent images. Particularly, one or more characteristic reference patterns may be placed in the overlapping FOV of adjacent cameras. These reference patterns thus are indicative of the physical range covered by a given camera, as well as an overlapping area that is captured in both adjacent images. Thus, based on the location of a reference pattern, adjacent images may be cut and stitched along the edge of the overlapping area to form a continuous image covering a larger total FOV.

The reference pattern may have any combination of colors, shapes, and/or textures, including but not limited to black, white, gray scale, colorful, fluorescent; standard geometrical shapes such as circle, oval, triangle, square, trapezium, diamond, rhombus, parallelogram, rectangle, pentagon, hexagon, heptagon, oblong, octagon, nonagon, decagon or the like; symbols such as star, heart, moon, arrow, stripe, ladder or the like; icons or images such as a teddy bear, a national flag or the like; letters, barcodes and characters; textures such as rough, smooth, heat-absorbing, heat-reflective, etc. Merely by way of example,FIG. 7Aillustrates an exemplary embodiment of a reference pattern that may be employed in the positioning system according to some embodiments of the present disclosure. As shown in the figure, the reference pattern700comprises two columns of alternating black and white boxes.

In some embodiments, the reference patterns may be placed on the patient support. In other embodiments, the reference patterns may be placed in the coils of an MRI scanner.

FIGS. 7B and 7Cillustrate an exemplary method for panorama composition. Particularly,FIG. 7Bshows a pair of adjacent images having an overlapping FOV. Both images capture the reference pattern in the overlapping FOV (710,720). To find an optimum cutting-and-stitching line for composing the pair of image, the method first aligns the two images to the extent that the reference patterns (710,720) as in the two images overlap completely. Then the overlapped area in one of the two images may be cut and the remaining portions of the images may be stitched together to produce the panorama as shown inFIG. 7C.

FIG. 8illustrates a displaying device showing a calibrated panoramic image according to some embodiments of the present disclosure. As shown in the figure, a calibrated panoramic image may be shown on a display800. In various embodiments, the display800may be embodied as a touch screen, or other suitable displaying devices. In this figure, L9denotes a dimension of the displayed panorama.

An operator of the imaging system may select an ROI directly from the calibrated panoramic image by manipulating the touch screen800. In this particular embodiment, the operator draws a pair of lines flanking part of the patient's body as the ROI. In some embodiments, the operator may select an ROI via an input device, such as a keyboard or a mouse. In some embodiments, a rotary knob may be employed for fine adjustment of the position of the ROI selected by the operator. In some embodiments, the input devices may be integrated on the console150as described in connection withFIG. 1. It should be noted that the calibrated panoramic image described above is provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. After consulting the present disclosure, one skilled in the art may envisage numerous other changes, substitutions, variations, alterations, and modifications without inventive activity, and it is intended that the present disclosure encompasses all such changes, substitutions, variations, alterations, and modifications as falling within its scope.

FIG. 9illustrates exemplary procedures for calibrating an image and generating control information according to some embodiments of the present disclosure. Particularly, the image may be a single camera image or multi-camera panorama.

In the embodiment shown inFIG. 9, the positioning system comprises multiple cameras having overlapping fields of view. Each camera may comprise an image sensor910and a lens920. The cameras are mounted above the patient support550at the same height, and the cameras are arranged in a straight line. The straight line is parallel with the longitudinal axis of the patient support550.

As shown in the figure, L1denotes a dimension of the image sensor910. L2denotes the distance between the image sensor910and the lens920. L3denotes the distance between the lens920and the captured scene (for example, the patient support550). L5denotes a dimension of the captured FOV, which may change with L3. L6denotes the distance between adjacent cameras. In this configuration, a ratio between the dimension of the image sensor910(L1) and the dimension of the captured FOV (L5) is L2/L3. Thus, L5can be calculated as:
L5=L1*L3/L2  (Equation 1)

In some embodiments, calibrating the image for displaying may be based on a mapping relationship between the dimension of the captured FOV (L5) and the dimension of the displayed image (L9as shown inFIG. 8). Particularly, the mapping relationship can be written as the ratio: L9/L5.

Optionally, the system ofFIG. 9may perform panoramic imaging using multiple cameras. Let N denote the number of cameras used in the panoramic imaging solution, and L4denote a dimension of the total panoramic FOV. In this configuration, L4can be calculated as:
L4=L5+(N−1)*L6+(N−1)*L1  (Equation 2)

Accordingly, the mapping relationship for calibrating the multi-camera panoramic image for displaying can be written as the ratio: L9/L4.

The dimension of the displayed image (L9) correlates with the size of an area used for displaying the image, such as on a screen. In some embodiments, a system operator may customize the displaying area, such as having the image displayed in full screen, or enlarged to display in extended double screens, or reduced to display in a half-screen window. Thus, the mapping relationship may remain constant or change during operation of the imaging system. In any case, the display calibration module322of the positioning system100keeps track of the instant mapping relationship during calibration.

As such, the calibration process registers positional information in physical space (e.g., L4) as corresponding positional information in the displayed image (e.g., L9). Thus, when an operator specifies a particular region of the displayed patient's body as the ROI, the positioning system is able to calculate the corresponding region in physical space, and generate control information for moving and/or positioning various components of the imaging system, including but not limited to the patient support550, such that the corresponding physical region will be properly targeted during imaging.

For example, in the embodiment as shown inFIG. 9, the operator draws line P on the displayed image, which denotes the position where the scan should begin or end. To calculate the physical position of line P, in some embodiment, zero position900of known physical position is used as a reference point. Particularly, in some embodiment, zero position900is provided as a marker on the patient support550. In some embodiments, a reference pattern may be used to denote zero position900.

In some embodiments, height of the patient support550is adjusted such that zero position900is within the total panoramic FOV, and thus is shown on the displayed image. Particularly, in the embodiment as shown inFIG. 9, line O denotes the edge of the total panoramic FOV that covers zero position900. As shown in the figure, L7denotes the physical distance between edge O and the zero position900, and L8denotes the physical distance between line P and zero position900. Let L8′ (not shown in the figure) denotes the displayed distance between line P and zero position900. According to the mapping relationship described above,
L8′/L8=L9/L4  (Equation 3)

As described above, the mapping relationship (L9/L4) and the displayed distance (L8′) are known to the positioning system. Thus, the physical distance between line P and zero position900(L8) can be calculated. Further, because zero position900is known, the physical position of line P can be obtained.

FIGS. 10 and 11illustrate exemplary system components and procedure for image recognition according to several embodiments of the present disclosure. Depending on practical needs or user preferences, in various embodiments, the image and/or video for image recognition may be taken from various angles with respect to the imaging object; may cover the entire imaging object or certain feature-containing portions; may be a panoramic rendering or a narrow FOV rendering of the imaging object; and may be in 2D or 3D. For example,FIGS. 10A through 10Cillustrate exemplary locations of one or more cameras capturing a patient lying on a patient support according to the several embodiments of the present disclosure. As shown in the figure, the camera may be placed at various locations and angles with respect to the patient. For example, as shown inFIG. 10A, a camera may be placed lateral to the patient support and captures a FOV (a) that covers the vertical dimension of the patient. As shown inFIG. 10B, a camera may be placed above the patient support captures a FOV (a) that covers the horizontal dimension of the patient. As shown inFIG. 10C, the camera may be installed lateral to the patient support and captures a FOV (a) that covers the horizontal dimension of the patient. In some embodiments, these cameras may be initiated simultaneously or sequentially during image recognition. In some embodiments, one or more cameras may be only installed within a space where imaging takes place, such as installed inside an imaging gantry. Thus, the cameras are capable of monitoring and updating a patient's instant status during an imaging session.

FIG. 11illustrates an exemplary process of image recognition according to some embodiments of the present disclosure. The method or process1100may be performed by processing logic that comprises hardware (e.g., cameras, patient support, circuitry, dedicated logic, programmable logic, microcode, etc.), software (e.g., instructions run on a processing device to perform hardware simulation), or a combination thereof. In some embodiments, one or more operations of the method1100can be performed by one or more computing and/or console devices (e.g., one or more computing and/or console devices as described above in connection withFIG. 1) to generate and execute control information automatically.

In step1101, one or more images and/or videos of a patient assuming a patient position may be acquired. Depending on practical need or user preference, the one or more images and/or videos may be taken from different angles with respect to the patient; may cover the patient's entire body or certain feature-containing portions of the body, such as face, limbs, back or chest.

In step1102, characteristic features in the images are extracted. Pertaining to the present disclosure, characteristic features may include features of an imaging object itself and features in the surrounding environment of an imaging object.

Particularly, in some embodiments, characteristic features include human body features, such as facial features (e.g., eye or nose), body features (e.g., limb or chest), gender features (e.g., breast or laryngeal prominence), morphology features (e.g., lesion or tumor), gesture features (e.g., prone or supine), orientation features (e.g., head-first or feet-first), and behavior features (e.g., move or turn). One or more of these body features are indicative of the patient position, such as but not limited to a head-first supine position, a feet-first prone position, a head-first left lateral recumbent position or a feet-first right lateral recumbent position, etc.

In some embodiments, characteristic features include position markers placed on or near an imaging object. Particularly, in some embodiments, position markers may be placed on the patient support or other system components. In some embodiments, system components of distinctive exterior features may serve as positional markers, such as a coil or other accessories of the system. According to the present disclosure, position markers may be of any distinctive combination of shape, color and/or texture. Exemplary embodiments include black, white, gray scale, colorful, fluorescent; standard geometrical shapes such as circle, oval, triangle, square, trapezium, diamond, rhombus, parallelogram, rectangle, pentagon, hexagon, heptagon, oblong, octagon, nonagon, decagon or the like; symbols such as star, heart, moon, arrow, stripe, ladder or the like; icons or images such as a teddy bear, a national flag or the like; letters, barcodes and characters; textures such as rough, smooth, heat-absorbing, heat-reflective, etc.

Characteristic features captured on camera may be recognized due to their characteristic color, shape, texture, spatial relationship or any combination thereof. Various methods or algorithms may be used. For shape extraction, methods or algorithms that can be used include multi-scale edge detection, wavelets and Chamfer matching, low level feature selection, feature extraction by shape matching, flexible shape extraction, LBP, GLDM, GLRLM, Haralick and Gabor texture features. For color extraction, methods or algorithms that can be used include color-histogram, color sets, color matrix. For texture extraction, methods or algorithms that can be used include structural approach, signal processing method, geometric method, model technique, statistical technique. Special relationship extraction can be performed by extracting features after segmenting images either according to colors or targets in the images or segmenting images into several regular slave modules. Methods or algorithms that can be used in connection with the present disclosure also include other machine vision algorithms currently available or to be developed in the future.

In step1103, characteristic features are recognized. Various methods or algorithms may be used. For example, in some embodiments, an extracted feature is compared to a pre-stored reference feature for a match. If a match is found, the extracted feature is recognized and related information is recorded; otherwise, the extracted feature is ignored. Exemplary embodiments of algorithms that can be used in connection with the present disclosure include Principal component analysis using eigenfaces, Linear discriminate analysis, Elastic bunch graph matching using the fisherface algorithm, the hidden Markov model, the multilinear subspace learning using tensor representation, the neuronal motivated dynamic link matching, 3D model-based algorithms, recognition, skin texture analysis, thermal cameras, skeletal-based algorithms, appearance-based models, or other methods currently available or to be developed in the future.

In step1104, control information is generated according to the recognized characteristic features. The control information may be automatically generated by a system or input by a system operator based on the result of imaging recognition. For example, in some embodiments, a system is configured to automatically select a particular imaging protocol based on a recognized patient position. In some embodiments, the system is configured to display the result of image recognition for a system operator to input control information. In some embodiments, generated control information is executed locally by the positioning system. In other embodiments, generated control information is transmitted to a system external to the positioning system (such as an imaging system or a HIS) for execution.

It should be noted that the above embodiments are provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. After consulting the present disclosure, one skilled in the art may envisage numerous other changes, substitutions, variations, alterations, and modifications without inventive activity, and it is intended that the present disclosure encompasses all such changes, substitutions, variations, alterations, and modifications as falling within its scope.

FIG. 12illustrates an exemplary positioning procedure that is performed upon execution of the control information generated by the positioning system, according to some embodiments of the present disclosure. Particularly, as shown in the figure, the imaging system comprises one or more cameras (1210,1220), an imaging gantry1230, a patient support1240and a display1260. A patient1250lies on top of the patient support1240. An image1261of the patient lying on the patient support is generated and shown on the display1260.

Based on the displayed image, a system operator draws a line or an area across the displayed patient's chest, defining an edge of the ROI. For example, the system operator may draw an area1721on the displayed image. The positioning system100thus calculates corresponding physical position of the line1270and/or the area1721, and generates control information for moving and positioning the patient support1240relative to other components of the imaging system.

In some embodiments, the positioning system may comprise one or more position markers. For example, as shown in the figure, a set of position markers may be placed on the surface of the patient support1240. Additionally or alternatively, as shown in the figure, a position marker1271may be placed on the patient's body.

In some embodiments, these position markers may assist the system operator in defining the ROI by providing reference points. Particularly, the displayed image may show the patient's position relative to one or more position markers. If one or more position markers are placed on the edge of the ROI, the system operator may simply draws the line across the markers.

In some embodiments, these position markers may further assist the positioning system in generating control information. Particularly, physical locations of one or more position makers may be known to the positioning system. For example, in some embodiments, a position marker may be zero position900as described in relation toFIG. 9, with respect to which the ROI's physical location may be calculated. In some embodiments, physical locations of position markers may directly correspond to distances by which the patient support1240should be moved. For example, a set of rough and fine markers may function like a distance ruler, with the space between adjacent markers representing a distance of 10 centimeters. Thus, if the positioning system, via for example machine vision, recognizes that the line1270crosses the fourth fine marker1290between the first and second rough markers1280and1281, the positioning system generates control information, which upon execution, would move the patient support1240inward of the imaging gantry1250by 40 centimeters.

According to the present disclosure, position markers that may be used in connection with the present disclosure may be of any combination of colors, shapes, and/or textures. Exemplary embodiments include black, white, gray scale, colorful, fluorescent; standard geometrical shapes such as circle, oval, triangle, square, trapezium, diamond, rhombus, parallelogram, rectangle, pentagon, hexagon, heptagon, oblong, octagon, nonagon, decagon or the like; symbols such as star, heart, moon, arrow, strip, ladder or the like; icons or images such as a teddy bear, a national flag or the like; letters, barcodes and characters; textures such as rough, smooth, heat-absorbing, heart-reflecting, etc.

Further, in some embodiments, one or more position markers may be integrated with components of the imaging system. In some embodiments, components of the imaging system having characteristic features may serve the function of a position marker. For example, a head coil for MRI scanning wore by a patient may serve as a position marker. The positioning system, upon recognizing the characteristic shape of the coil, would generate control information that positions the patient's head and the coil in a targeted area.

In some embodiments, the control information is executed by the positioning system or an external system that communicates with the positioning system (such as a HIS). In some embodiments, execution of the control information involves a system operator to initiate an execution command (such as pressing a button). In other embodiments, execution of the control information is performed automatically by the system without human intervention, when certain conditions are met (such as immediately after control information is generated).

In various embodiments, the system executes control information to perform a positioning procedure that moves and positions an imaging object and one or more components of the imaging system relative to one another, such that the ROI is targeted in the corresponding imaging session. Particularly, system components moved and positioned during the positioning procedure include but are not limited to a support (e.g., a patient bed, a handle etc.), a data acquisition device (e.g., an X-ray generator, a PET detector, etc.), a monitoring device (e.g., a camera, a lamp etc.), a communication device (e.g., a microphone, a keypad, etc.), and a mechanical part (e.g., for carrying the system components, for adjusting a patient position, etc.). In some embodiments, during the positioning procedure, the system sends voice instruction for a patient to perform.

It should be noted that the above examples are provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. After consulting the present disclosure, one skilled in the art may envisage numerous other changes, substitutions, variations, alterations, and modifications without inventive activity, and it is intended that the present disclosure encompasses all such changes, substitutions, variations, alterations, and modifications as falling within its scope.

FIG. 13is a block diagram of the positioning system100according to some embodiments of the present disclosure. As shown in the figure, the positioning system100may comprise a position acquiring unit110, a position processing unit120, and a control unit130as described in connection withFIG. 1. Further, the position acquiring unit110may comprise one or more position probes, for example, position probe1310, position probe1311, position probe1312, and position probe1313. The position probes may be configured to communicate with one or more position sources.

The position processing unit120may comprise one or more position processing modules, for example, position processing module1320, position processing module1321, position processing module1322, and position processing module1323. The position processing module(s) may be configured to process the position information acquired by the position probe(s). Merely by way of example, the position of the position source(s) may be calculated by the position processing module(s). The control unit130may be configured to receive the position information calculated by the position processing unit120, and control imaging system accordingly.

In some embodiments, ultrasound may be employed in the positioning system100to enable intercommunication between a position probe and a position source. For example, in some embodiments, the position source may be configured to emit ultrasound, and the position probe may be configured to receive the ultrasound signal. The distance between the position source and the position probe can be calculated based on the time delay between when the position source emits and when the position probe receives the signal. Thus, the position of a position source in a three-dimensional space may be calculated based on the distance between the position source and one or more position probes of known locations in the three-dimensional space, depending on relative spatial relationships between the position source and the position probe(s).

In some embodiments, the positioning system100may use alternative non-contact distance sensors to measure a distance between a position source and a position probe. For example, in some embodiments, infrared sensors or laser sensors may be used to measure the distance.

It should be noted that the description of the above embodiment of the positioning system is provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. After consulting the present disclosure, one skilled in the art may envisage numerous other changes, substitutions, variations, alterations, and modifications without inventive activity, and it is intended that the present disclosure encompasses all such changes, substitutions, variations, alterations, and modifications as falling within its scope.

FIG. 14is a flowchart illustrating an exemplary process of patient positioning according to some embodiments of the present disclosure.

In step1401, position information may be transmitted. The position information may be an ultrasound signal, a laser signal or an infrared signal, or the like, or any combination thereof.

In step1402, the position information may be received. For example, in some embodiment, the position information may be received by an ultrasound sensor, a laser sensor or an infrared sensor, or the like, or any combination thereof.

In some embodiments, the positioning system may continuously monitor a patient's status by analyzing the position information. For example, in some embodiments, a position source may be placed on or near an ROI of a patient's body. Thus, the position information becomes indicative of the ROI's position. Accordingly, in some embodiments, in step1403, the ROI's position may be calculated based on the position information received in step1402. Merely by way of example, in some embodiments, location of a position source and thus the ROI can be calculated based on the distance between the position source and one or more position probes with known locations.

In step1404, the imaging system may be controlled according to the ROI's position as calculated in step1403. In some embodiments, the imaging system may be configured to monitor the status of a patient, including but not limited to monitoring the instant position of an ROI of the patient's body. In some embodiments, the positioning system may automatically adjust the location of the patient's body in real time, after the ROI's position is changed.

It should be noted the description above is provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. After consulting the present disclosure, one skilled in the art may envisage numerous other changes, substitutions, variations, alterations, and modifications without inventive activity, and it is intended that the present disclosure encompasses all such changes, substitutions, variations, alterations, and modifications as falling within its scope.

FIG. 15is an illustration of the positioning system100according to some embodiments of the present disclosure. As shown in the figure, the positioning system100is equipped with multiple position probes (1510,1520,1530,1540) for monitoring the status of a patient lying in the imaging system1560. A position source1550is placed on the patient's body near a ROI that is to be targeted during imaging. The position source1550communicates with each of the position probes (1510,1520,1530,1540) and the distance between the position source1550and each of the position probes (1510,1520,1540,1540) can be measured.

FIG. 16illustrates a coordinate system that can be used to calculate the location of the position source1650in a three-dimensional space. As shown in the figure, set a xyz coordinate system where the position source1650can be treated as a point in the x-y plane. The multiple position probes (1610,1620,1630,1640) can be treated as scattered points in the coordinate system, which may or may not in the x-y plane. In various embodiments, the multiple position probes (1610,1620,1630,1640) may or may not share a same line or share a same plane in the xyz coordinate system.

FIG. 17illustrates one exemplary method for calculating the location of a position source in a three-dimensional space according to some embodiments of the present disclosure. As shown in the figure, the position source1750is in the x-y plane and may move along the x-axis. In various embodiments, one or more position probes (e.g.,1710,1720,1730,1740) may assume various positional relationships with respect to the position source1750and/or with respect to one another. One or more of the position probes (e.g.,1710,1720,1730,1740) may or may not locate in the x-y plane.

In the figure, D1, D2, and D3denote respectively the distance between the position source1750and each of the position probes (1710,1720,1730); h1, h2, h3denote respectively the distance between the x-y plane and each of the position probes (1710,1720,1730). X1, X2, and X3denote respectively the projection of D1, D2, and D3on the x-y plane; a, c, e denote respectively the y-axis component of X1, X2and X3; and b, d, f denote respectively the x-axis component X1, X2, and X3. In some embodiments, a patient support as described in connection withFIG. 1moves along the x-axis. Therefore,
D12=a2+b2+h12
D22=c2+d2+h22
D32=e2+f2+h32
c−a=Δ1
b+d=Δ2
b+f=Δ3
e−c=Δ4
h1−h2=Δ5
h2−h3=Δ6
h3−h1=Δ7(Equation Set 1)
where Δ1, Δ2, Δ3, Δ4, Δ5, Δ6, Δ7are known design constants. By solving Equation Set 1, three-dimensional location of the position source1750can be obtained.

In some embodiments, the one or more position probes (e.g.,1710,1720,1730,1740) may share a same plane which is in parallel with the x-y plane in the xyz coordinate system as described in connection withFIG. 16. Under this circumstance, h1may equal to h2and h2may equal to h3. Thus Δ5, Δ6and Δ7all equal to 0.

In some embodiments, the perpendicular height to the x-y plane of the position probes (1710,1720,1730) may differ. In this case at least one of Δ5, Δ6, Δ7is nonzero.

In some embodiments, during operation of the imaging system, location of the position source may be moved. In some embodiments, the positioning system is configured to measures D1, D2, and D3constantly, for example via ultrasound distance sensing. Thus, location of the position source1750may be monitored in real time.

In some embodiments, each position probe has a signal range, within which range it communicates with a position source. In some embodiments, the system automatically establishes communication between a moving position source and a position probe, once the source enters the signal range of the probe. In some embodiments, the system automatically terminates communication between a moving position source and a position probe, once the source leaves the signal range of the probe.

In some embodiments, multiple position probes are arranged such that their respective signal ranges overlap. Particularly, in some embodiments, when a moving position source leaves the signal range of a position probe, it simultaneously enters the signal range of another position probe. In some embodiments, the positioning system is configured to use different sets of location probes for monitoring the instant location of a moving position source. For example, as shown inFIG. 17, if position source1750moves towards position probe1740and away from position probe1710, it may establish communication with probe1740while terminating communication with probe1710. Accordingly, the positioning system would then calculate location of source1750based on known locations of probes1720,1730and1740.

It should be noted the description above is provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. After consulting the present disclosure, one skilled in the art may envisage numerous other changes, substitutions, variations, alterations, and modifications without inventive activity, and it is intended that the present disclosure encompasses all such changes, substitutions, variations, alterations, and modifications as falling within its scope.