Abstract:
Embodiments are directed to methods and apparatuses for ensuring that mechanisms that are used to position components of an apheresis machine are not broken as a result of rotation of a centrifuge. In embodiments, a safety mechanism is provided that contacts components of the centrifuge and pushes them into a position to ensure that they do not break when the centrifuge is operated at high rpm.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION(S) 
       [0001]    This patent application claims priority to U.S. Provisional Patent Application No. 61/919,679, entitled CENTRIFUGE SAFETY MECHANISM, filed on Dec. 20, 2013, which is hereby incorporated by reference in its entirety as if set forth herein in full. 
     
    
     BACKGROUND  
       [0002]    There are a number of processes that are used to separate a composite fluid into components. Some examples of composite fluids that are separated include biological fluids, which may include an aqueous component and one or more cellular components, e.g., whole blood. Separation of whole blood may occur as part of an apheresis procedure, which may be performed on apheresis machines. The machines remove whole blood from a donor, separate the blood, collect one or more blood components from the donor and return the other component(s) to the donor. 
         [0003]    Some apheresis machines utilize centrifugal force to separate blood into components. These machines therefore include a centrifuge, which spins at relatively high rotations per minute (rpm). Accordingly, it is important that all components of the machine are safely positioned to avoid failure of any part of the machine when the centrifuge operates at high rpm. When the centrifuge is operating at high rpm any component that breaks may cause catastrophic failure of the machine if it strikes any portion of the centrifuge rotating at a high rpm. 
         [0004]    Embodiments of the present invention have been made in light of these and other considerations. However, the relatively specific problems discussed above do not limit the applicability of the embodiments of the present invention to the specific problems. 
       SUMMARY 
       [0005]    Embodiments are directed to methods and apparatuses for ensuring that mechanisms that are used to position components of an apheresis machine are not broken as a result of rotation of a centrifuge. In embodiments, a safety mechanism is provided that contacts components of the centrifuge and pushes them into a safe position to ensure that they do not break when the centrifuge is operated at high rpm. In one specific embodiment, a safety mechanism is provided on a tubing arm designed to hold tubing of a disposable component used in an apheresis machine. The disposable component may be held in place, at least in part by a latch arm. As the centrifuge begins rotating, the safety mechanism is designed to contact the latch arm and push it into a position, so that when the centrifuge spins at high rpm, the latch arm does not break and strike the centrifuge while it spins at high rpm. 
         [0006]    This summary is provided to introduce aspects of some embodiments of the present invention in a simplified form, and is not intended to identify key or essential elements of the claimed invention, nor is it intended to limit the scope of the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    Non-limiting and non-exhaustive embodiments are described with reference to the following figures. 
           [0008]      FIG. 1  illustrates an apheresis machine that may utilize mechanism(s) according to some embodiments. 
           [0009]      FIG. 2A  illustrates a centrifuge that may be part of an apheresis machine and includes a latch arm in a first position. 
           [0010]      FIG. 2B  illustrates a centrifuge that may be part of an apheresis machine and includes the latch arm of  FIG. 2A  in a second position. 
           [0011]      FIG. 3  illustrates a bottom view of a safety mechanism according to an embodiment. 
           [0012]      FIG. 4  illustrates a top view of the safety mechanism illustrated in  FIG. 3 . 
           [0013]      FIG. 5  illustrates a front view of the safety mechanism illustrated in  FIG. 3 . 
           [0014]      FIG. 6  illustrates a back view of the safety mechanism illustrated in  FIG. 3 . 
           [0015]      FIG. 7  illustrates a side view of the safety mechanism illustrated in  FIG. 3 . 
           [0016]      FIG. 8  illustrates another side view of the safety mechanism illustrated in  FIG. 3 . 
           [0017]      FIG. 9  illustrates an exploded view of the safety mechanism illustrated in  FIG. 3 . 
           [0018]      FIG. 10  illustrates a process for preventing failure of a centrifuge assembly. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    The principles of the present invention may be further understood by reference to the following detailed description and the embodiments depicted in the accompanying drawings. It should be understood that although specific features are shown and described below with respect to detailed embodiments, the present invention is not limited to the embodiments described below. 
         [0020]    Embodiments below may be described with respect to separating whole blood and blood components. However, this is done simply for illustrative purposes. It is noted that the embodiments are not limited to the description below. The embodiments are intended for use in products, processes, devices, and systems for separating any composite liquid. Accordingly, the present invention is not limited to machines or devices used in separation of whole blood or blood components. 
         [0021]      FIG. 1  illustrates one embodiment of an apheresis system  100 , which can be used in, or with, embodiments. In embodiments, apheresis system  100  provides for a continuous whole blood separation process, e.g., apheresis procedure including therapeutic procedures. In one embodiment, whole blood is withdrawn from a donor and is substantially continuously provided to a blood component separation device, e.g., apheresis machine  104  where the blood is separated into various components and at least one of these blood components is collected using the apheresis machine  104 . One or more of the separated blood components may be either collected for subsequent use or returned to the donor. In embodiments, blood is withdrawn from the donor and directed through a bag and a disposable component, e.g., tubing set  108 , which includes an extracorporeal tubing circuit  112 , and a blood processing vessel  116 , which together define a closed, sterile and disposable system. The set  108  is adapted to be mounted in the apheresis machine  104 . The apheresis machine  104  includes a pump/valve/sensor assembly  120 , which interfaces with the extracorporeal tubing circuit  112 , and a centrifuge assembly  124 , which interfaces with the blood processing vessel  116  and is located in an internal volume  106  of the apheresis machine  104 . 
         [0022]    Examples of systems that include apheresis machines (e.g., machine  104 ) and other separation devices that may be used with embodiments of the present invention, include the SPECTRA OPTIA® apheresis system, COBE® spectra apheresis system, and the TRIMA ACCEL® automated blood collection system, all manufactured by Terumo BCT, of Lakewood, Colo. 
         [0023]    The centrifuge assembly  124  may include a channel  128  in a rotatable rotor assembly  132 , which provides the centrifugal forces required to separate blood into its various blood component(s) by centrifugation. The blood processing vessel  116  may then be fitted within the channel  128 . Blood can flow substantially continuously from the donor, through the extracorporeal tubing circuit  112 , and into the rotating blood processing vessel  116 . Within the blood processing vessel  116 , blood may be separated into various blood component types and at least one of these blood component types (e.g., white blood cells, platelets, plasma, or red blood cells) may be removed from the blood processing vessel  116 . Blood components that are not being retained for collection or for therapeutic treatment (e.g., platelets and/or plasma) are also removed from the blood processing vessel  116  and returned to the donor via the extracorporeal tubing circuit  112 . Various alternative apheresis systems (not shown) may also make use of embodiments of the present invention, including batch processing systems (non-continuous inflow of whole blood and/or non-continuous outflow of separated blood components) or smaller scale batch or continuous RBC/plasma separation systems, whether or not blood components may be returned to the donor. 
         [0024]    Operation of the apheresis machine  104  may be controlled by one or more processors included therein, and may advantageously comprise a plurality of embedded computer processors that are part of a computer system. The computer system may also include components that allow a user to interface with the computer system, including for example, memory and storage devices (RAM, ROM (e.g., CD-ROM, DVD), magnetic drives, optical drives, flash memory,); communication/networking devices (e.g., wired such as modems/network cards, or wireless such as Wi-Fi); input devices such keyboard(s), touch screen(s), camera(s), and/or microphone(s); and output device(s) such as display(s), and audio system(s) a. In order to assist the operator of the apheresis system  100  with various aspects of its operation, the embodiment of the blood component separation device  104  (shown in  FIG. 1 ) includes a graphical user interface  136  with a display that includes an interactive touch screen. 
         [0025]      FIGS. 2A and 2B  illustrate an example of a centrifuge assembly  200  that may be part of an apheresis machine e.g.,  104  ( FIG. 1 ), and in embodiments may be housed within the internal volume of an apheresis machine, e.g.,  106  ( FIG. 1 ). Centrifuge assembly  200  may utilize some safety mechanism(s)  208  according to embodiments of the present invention. As described in greater detail below, the safety mechanism  208  may be used to move a latch arm  212  into a position that prevents it from breaking when the centrifuge  200  is spinning at high rpm. Axis  220  indicates the axis of rotation of the centrifuge assembly  200 . 
         [0026]    As illustrated by  FIG. 2A , latch arm  212  is positioned in what may be referred to as an upward position. While in  FIG. 2B , the latch arm  212  is positioned in what may be referred to as a downward position. When a disposable tubing set (e.g., tubing set  108  of  FIG. 1 ) is placed in the centrifuge assembly  200 , latch arm  212  is initially positioned in the upward position ( FIG. 2A ). After a tubing set has been loaded into the centrifuge assembly  200 , the latch arm  212  is positioned in the downward position to maintain a portion of the disposable tubing set in a predetermined position or alignment. In embodiments, the portion may be part of the separation vessel, tubing, a separation chamber, or other portions of the disposable tubing set. When centrifuge assembly  200  does not have the second portion of disposable tubing set  108 , the latch arm  212  may be free to move from the upward position (as shown in  FIG. 2A ) to the downward position (as shown in  FIG. 2B ). As discussed below, a problem may arise when latch arm  212  is in an upward position and the centrifuge  200  starts to spin. 
         [0027]    If the apheresis machine  104  is activated and centrifuge assembly  200  spins with latch arm  212  in the upward position, it will break and the pieces may damage other components of the apheresis machine  104 . Consistent with some embodiments, centrifuge assembly  200  may utilize safety mechanism  208  that may be designed to contact latch arm  212  when centrifuge  200  starts to spin and latch arm  212  is in the upward position. As a result of contacting safety mechanism  208 , latch arm  212  will move into the downward position ( FIG. 2B ). Accordingly, when centrifuge  200  reaches a higher rpm the latch arm  212  will be in the downward position and will not break off. In the embodiment shown in  FIGS. 2A and 2B , safety mechanism  208  is attached to a tubing arm  216 . The tubing arm  216  may used to hold tubing of disposable set (e.g.,  108 ). 
         [0028]      FIGS. 3-9  illustrate a safety mechanism  300  according to one embodiment.  FIG. 3  illustrates a bottom view of safety mechanism  300 .  FIG. 4  illustrates a top view of safety mechanism  300 .  FIG. 5  illustrates a front view of safety mechanism  300 .  FIG. 6  illustrates a back view of safety mechanism  300 .  FIG. 7  illustrates a side view of safety mechanism  300 .  FIG. 8  illustrates another side view of safety mechanism  300 .  FIG. 9  illustrates an exploded view of the safety mechanism  300 . As illustrated in  FIGS. 3-9 , safety mechanism  300  may be attached to a portion of a tubing arm  324 , e.g., an end of tubing arm  324 . It is noted that for purposes of simplicity, only a portion of tubing arm  324  is shown in  FIGS. 3-9 , namely an end of the tubing arm  324 . 
         [0029]    As illustrated in  FIGS. 3-9 , safety mechanism  300  includes a first portion  304  and a second portion  308 . The first portion  304  and second portion  308  may be connected using a fastener  320 . In embodiments, fastener  320  is a screw with threads that engage with threads on one or more of first portion  304  and second portion  308 . In some embodiments, safety mechanism  300  is attached to tubing arm  324  by positioning a portion of tubing arm  324  between first portion  304  and second portion  308  and tightening fastener  320  to secure mechanism  300  onto the tubing arm  324 , e.g., an end of tubing arm  324 . 
         [0030]    In some embodiments, portion  304  and portion  308  include a feature(s) that are designed to engage with features of arm  324 . For example, first portion  304  includes a first channel  332 , a second channel  348 , and a third channel  336  where a first portion, second portion, and third portion of tubing arm  324  may be positioned to secure the first portion  304  to tubing arm  324 . Similarly, second portion  308  includes a first channel  340  and a second channel  344  where a third portion and fourth portion of tubing arm  324  may be positioned to secure second portion  308  to the tubing arm  324 . 
         [0031]    First portion  304  in embodiments includes a first angled surface  312  and a second angled surface  316 . The angled surfaces  312  and  316  in embodiments are the portion of mechanism  300  that may contact a latch arm, for example latch arm  212  ( FIG. 2 ). As can be appreciated, the angled surfaces  312  and  316  are designed to guide a latch arm from a first position, e.g., an upward position, toward a second position, e.g., a downward position. In embodiments, the surfaces  312  and  316  may cause the latch arm to move enough so that it gains enough momentum to move to the second position where it may stay. In embodiments, the first angled surface  312  and the second angled surface  316  are positioned so that they face an axis of rotation of a centrifuge. For example, in  FIGS. 2A and 2B  safety mechanism  208  is shown with a first angled surface (e.g.  312 ) and a second angled surface (e.g.  316 ) facing axis  220 . 
         [0032]    As illustrated in  FIGS. 3-9 , in embodiments, the first surface  312  and second surface  316  may have different angles and different lengths. For example, the first surface  312  may have a shallower angle, e.g., a larger angle with respect to line  328 . The second surface  316  may have a sharper angle, e.g., a smaller angle with respect to line  328 . In the embodiments, shown, surface  312  is longer than surface  316 . 
         [0033]    It is noted that the present invention is not limited to the embodiment described in  FIGS. 3-9 . In other embodiments, the angled surfaces  312  and  316  may have the same angle and lengths, different angles and the same length, or the same angles and different lengths. 
         [0034]    It is noted that is some embodiments, angled surfaces  312  and  316  may include, or be made of, materials that provide low friction so that if they contact a latch arm, the latch arm may travel smoothly across the surface. For example, the angled surfaces  312  and  308  may be made of materials that include, or have a coating of, one or more of: polytetrafluoroethylene, polyoxymethylene, polyetheretherketon, polyethylene, Ultra-high molecular weight polyethylene, polyamide, or polycarbonate. In some embodiments, first portion  304  and/or second portion  308  may be molded or machined from the same material, which may be a low friction material, such as one or more of the materials mentioned above. In other embodiments, a low friction material may be added (as a coating or layer) to one or more of the angled surfaces  312  and  316 . 
         [0035]    It is also noted that fastener  320  may be positioned, and its threads designed, to be self tightening when arm  324  is spinning with the centrifuge. For example, in embodiments, the fastener  320  is positioned so that any coriolis effect experienced by the fastener serves to tighten the fastener. In this embodiment, the head of fastener  320  may face an axis of rotation, e.g., axis  220  ( FIG. 2 ) and be threaded so that rotation of the centrifuge will tend to cause the fastener to tighten. 
         [0036]    Additionally, in some embodiments, additional features may be provided to secure fastener  320  to one or more of first portion  304 , second portion  308 , or tubing arm  324 . For example, in some embodiments, an adhesive material may be places over the head of fastener  320  after it has been used to connect first portion  304  and second portion  308 . The adhesive will further attach or adhere fastener  320  to first portion  304 . 
         [0037]      FIG. 10  illustrates flow chart  1000  which may be performed in embodiments of the present invention. Although specific components may be described below for performing steps in flow chart  1000 , the present invention is not limited thereto. This is done merely for illustrative purposes, because flow chart  1000  is not limited to being performed by or with any specific components, structures, or combinations thereof. 
         [0038]    Flow  1000  starts at  1004  and passes to step  1008  where a first portion of a safety mechanism is positioned. In one embodiment, the first portion, such as first portion  304 , may be positioned on an end of a tubing arm, e.g., tubing arm  324 . In embodiments, step  1008  may involve a number of sub-steps. For example, at sub-step  1012 , a portion of a tubing arm may be positioned in a first channel in the first portion of the safety mechanism. For example, a portion of tubing arm  324  may be positioned in first channel  332 . A second optional step  1016  may be performed to position another portion of tubing arm  324  in a second channel, such as channel  348 . In other embodiments, step  1008  may include additional steps not shown in flow  1000 . For example, a third portion of the tubing arm may be placed in another, third channel (e.g., channel  336 ), of the first portion of the safety mechanism. This is merely an example and other sub-steps may be performed in other embodiments. 
         [0039]    Following step  1008 , a second portion of the safety mechanism may be positioned at step  1020 . In embodiments, the second portion is also positioned on an end of a tubing arm. Similar to step  1008 , step  1020  may involve a number of sub-steps. At sub-step  1024 , a portion of a tubing arm may be positioned in a fourth channel in the second portion of the safety mechanism. For example, a portion of tubing arm  324  may be positioned in channel  340 . At optional step  1028  another portion of tubing arm  324  may be positioned in a fifth channel, such as channel  340 . 
         [0040]    Flow passes from step  1020  to step  1032  where the first portion and the second portion of the safety mechanism are connected. In embodiments, the portions may be connected by a fastener (e.g., fastener  320 ). The fastener may be any appropriate fastener for connecting the portions together, some non-limiting examples including bolts, nuts, screws, washers, brackets, hooks, pins, nails, rivets, spacers, rings, stables, etc. In one embodiment, the fastener may be a threaded screw or bolt that engages threads on one or more of first portion and second portion of the safety mechanism. 
         [0041]    After step  1032 , an optional step  1036  may be performed to add an adhesive to the fastener to adhere it to one or more of first portion and second portion of the safety mechanism. The adhesive may be any appropriate type of adhesive for connecting a fastener to another part. A thread-locking adhesive is one example of an adhesive that may be used, which may be used before or during step  1032 . Flow  1000  ends at  1040 . 
         [0042]    With respect to the flow chart illustrated in  FIG. 10 , the operational steps depicted are offered for purposes of illustration and may be rearranged, combined into other steps, used in parallel with other steps, etc., according to embodiments of the present disclosure. Fewer or additional steps may be used in embodiments without departing from the spirit and scope of the present disclosure. Also, the steps (and any sub-steps) may be performed automatically in some embodiments and manually in others. 
         [0043]    It will be apparent to those skilled in the art that various modifications and variations can be made to the methods and structure of the present invention without departing from its scope. Thus it should be understood that the invention is not limited to the specific examples given. Rather, the invention is intended to cover modifications and variations within the scope of the following claims and their equivalents. The steps, features, structures, and/or media are disclosed as illustrative embodiments for implementation of the claims and are not intended to limit the claims. 
         [0044]    While example embodiments and applications of the present invention have been illustrated and described, it is to be understood that the invention is not limited to the precise configuration and resources described above. Various modifications, changes, and variations apparent to those skilled in the art may be made in the arrangement, operation, and details of the method(s) and apparatus of the present invention disclosed herein without departing from the scope of the claimed invention.