Abstract:
The invention is targeted at the process of separating gas, such as air, from a liquid path. Specifically, the invention provides a means to remove gas from a dynamic liquid path, manage the removed gas and liquid path. The invention provides a means to remove gas from a dynamic liquid path using the buoyant property of gas in a less buoyant liquid, having ingress and egress ports for liquid and gas flow, and separate points of egress for liquid and trapped gas and integral liquid channels.

Description:
This application is a non-provisional application claiming priority to provisional U.S. Patent Application No. 60/459,981 filed Apr. 4, 2003. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to an apparatus and method for the process of separating gas from a liquid path. 
     Perfusion circuits used to perfuse organs, tissues or the like (hereinafter generally referred to as organs) should be free of agents that can create emboli. These emboli are often comprised of gases such as air. Typically emboli range in volume between 1 ml and 0.01 ml but are not limited to these sizes. Gases may be introduced into perfusion circuits through leaks in the circuits, but are more often the result of bubbles trapped in components and geometric facets of the circuits. Gases may also be drawn out of the perfusion liquid by negative pressure due to liquid dynamics, cavitations and eddies and velocity changes throughout the liquid path. 
     SUMMARY OF THE INVENTION 
     It is desirable to separate bubbles from a perfusion liquid utilizing the buoyancy of the bubbles with respect to the liquid. 
     Embodiments of this invention provide systems and methods that separate gases from a liquid path, particularly useful in helping preserve organs and tissues for storage and/or transport. 
     Embodiments of this invention provide systems and methods to remove gases from a dynamic liquid path and manage the removed gases and liquid path. 
     Embodiments of this invention provide a means to remove gases from a dynamic liquid path using the buoyant property of the gases in a less buoyant liquid using ingress and egress ports for liquid and gas flow located on substantially the same plane. 
     Embodiments of this invention provide separate points of egress for liquid and gases. 
     Embodiments of this invention provide liquid channels formed by housing halves to substantially reduce sharp corners for gas entrapment. 
     Embodiments of this invention provide an organ cassette which allows an organ to be easily and safely moved between apparatus for perfusion, storing, analyzing and/or transporting the organ. The organ cassette may be configured to provide uninterrupted sterile conditions and efficient heat transfer during transport, recovery, analysis and storage, including transition between the transporter, the perfusion apparatus and the organ diagnostic apparatus. 
     Embodiments of this invention provide systems and methods for transporting an organ in a transporter, especially for transport over long distances. The organ transporter may be used for various organs, such as the kidneys, and may be adapted to more complex organs such as the liver, having multiple vascular structures, for example the hepatic and portal vasculatures of the liver. The organ transporter may include features of an organ perfusion apparatus, such as sensors and temperature controllers, as well as cassette interface features. 
     These and other features and advantages of this invention are described in, or are apparent from, the following detailed description of various exemplary embodiments of systems and methods according to this invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other aspects and advantages of the invention will become apparent from the following detailed description of embodiments when taken in conjunction with the accompanying drawings, in which: 
         FIGS. 1A-1D  shows perspective views of various embodiments of an organ cassette according to the invention; 
         FIGS. 2A and 2B  show an embodiment of an organ cassette of the present invention; 
         FIG. 3  shows an exterior perspective view of an organ transporter according to the present invention; 
         FIG. 4  shows a cross-section view of an organ transporter of  FIG. 3 ; 
         FIG. 5  shows an alternative cross-section view of an organ transporter of  FIG. 3 ; 
         FIG. 6  shows an exploded view of the housing and cover of a bubble trap device of the invention from the rear; 
         FIG. 7  shows a close-up view of a mounting slot and snap receiver of a bubble trap device according to the invention; 
         FIG. 8  shows an enlarged view of the interior of the housing of a bubble trap device according to the invention; 
         FIG. 9  shows an exploded view of the housing and cover of a bubble trap device of the invention from the front; 
         FIG. 10  shows a cross-sectional view of the cover of  FIG. 9 ; 
         FIG. 11  shows a cross-sectional view of the housing to cover interface of a bubble trap device according to the invention; 
         FIG. 12  shows a diagram of the liquid and gas path within a bubble trap device according to the invention; 
         FIG. 13  shows a diagram of the bubble trap device of  FIG. 12  tilted clockwise; 
         FIG. 14  shows a diagram of the bubble trap device of  FIG. 12  tilted counter-clockwise; and 
         FIG. 15  shows a tube frame for holding a tube frame and the bubble trap according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     For a general understanding of various features of the invention, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to designate like elements. 
     The invention is described herein largely in the context of apparatus and methods involved in transport, storage, perfusion and diagnosis of tissues and organs. However, the inventive apparatus and methods have many other applications, and thus the various inventive structures, devices, apparatus and methods described herein should not be construed to be limited to, particular contexts of use. Various features of the disclosed invention are particularly suitable for use in the context of, and in conjunction and/or connection with the features of the apparatus and methods disclosed in U.S. patent application Ser. No. 09/645,525, the entire disclosure of which is hereby incorporated by reference herein. 
       FIG. 1  shows a cassette  65  which holds an organ  60  to be perfused. Various embodiments of the cassette  65  are shown in  FIGS. 1A-1D . The cassette  65  is preferably formed of a material that is light but durable so that the cassette  65  is highly portable. The material may also be transparent to allow visual inspection of the organ. 
     Preferably the cassette  65  includes side walls  67   a , a bottom wall  67   b  and an organ supporting surface  66 , which is preferably formed of a porous, perforated or mesh material to allow liquids to pass therethrough. The cassette  65  may also include a top  67   d  and may be provided with an opening(s)  63  for tubing (see, for example,  FIG. 1D ). The opening(s)  63  may include seals  63   a  (e.g., septum seals or o-ring seals) and optionally be provided with plugs (not shown) to prevent contamination of the organ and maintain a sterile environment. Also, the cassette  65  may be provided with a closeable and/or filtered air vent  61  (see, for example,  FIG. 1D ). Additionally, the cassette  65  may be provided with tubing for connection to an organ and/or to remove medical liquid from the organ bath, and a connection to an organ and/or to remove medical liquid from the organ bath, and a connection device(s)  64  for connecting the tubing to, for example, tubing  50   c ,  81 ,  82 ,  91  and/or  132 , (see, for example,  FIG. 1D ) of an organ storage, transport, perfusion and/or diagnostic apparatus. 
     The cassette  65 , and/or the organ support, opening(s), tubing(s) and/or connections(s), may be specifically tailored to the type of organ and/or size of organ to be perfused. Flanges  67   c  of the side support walls  67   a  can be used to support the cassette  65  disposed in an organ storage, transport, perfusion and/or diagnostic apparatus. The cassette  65  may further include a handle  68  which allows the cassette  65  to be easily handled, as shown, for example, in  FIGS. 1C and 1D . Each cassette  65  may also be provided with its own mechanism (e.g., stepping motor/cam valve  75  (for example, in the handle portion  68 , as shown in  FIG. 1C )) for fine tuning the pressure of medical liquid perfused into the organ  60  disposed therein, as discussed in more detail below. Alternatively, pressure may, in embodiments, be controlled by way of a pneumatic chamber, such as an individual pneumatic chamber for each organ (not shown), or by any suitable variable valve such as a rotary screw valve or a helical screw valve. 
       FIGS. 2A and 2B  show an alternative embodiment of cassette  65 . In  FIG. 2A , cassette  65  is shown with tubeset  400 . Tube set  400  can be connected to an inlet tube port connector  11 , bubble outlet tube port connector  10  and liquid outlet tube port connector  9  of a bubble trap device according to this invention. When the tube set  400  is connected to the bubble trap device, the cassette  65  can be readily moved between various apparatus, and preferably allows cassette  65  to be moved between various apparatus without jeopardizing the sterility of the interior of cassette  65 . For example, when the cassette  65 , and the accompanying tube set  400  and bubble trap device, is placed in a transporter, the tube set  400  and bubble trap device are preferably connectable to the transporter to secure the tube set  400  and bubble device to the transporter during operation. The tube set  400  and bubble trap device can also be connected to an organ perfusion, storage and/or diagnostic apparatus. Additionally, the tube set  400  can be connected to any number of devices that are connected to the perfusion, storage, diagnostic, transport and/or other apparatus. 
     Preferably, cassette  65  is made of a sufficiently durable material that it can withstand penetration and harsh impact. Cassette  65  is provided with a lid, preferably two lids, an inner lid  410  and an outer lid  420 . The lids  410  and  420  may be removable or may be hinged or otherwise connected to the body of cassette  65 . Clasp  405 , for example, may provide a mechanism to secure lids  410  and  420  to the top of cassette  65 . Clasp  405  may additionally be configured with a lock to provide further security and stability. A biopsy and/or venting port  430  may additionally be included in inner lid  410  or both inner lid  410  and outer lid  420 . Port  430  may provide access to the organ to allow for additional diagnosis of the organ with minimal disturbance of the organ. Cassette  65  may also have an overflow trough  440  (shown in  FIG. 2B ). Overflow trough  440  is a channel present in the top of cassette  65 . When lids  410  and  420  are secured on cassette  65 , overflow trough  440  provides a region that is easy to check to determine if the inner seal is leaking. Perfusate may be poured into and out of cassette  65  and may be drained from cassette  65  through a stopcock or removable plug. 
     Cassette  65  and/or both lids  410  and  420  may be constructed of an optically transparent material to allow for viewing of the interior of cassette  65  and monitoring of the organ and to allow for video images or photographs to be taken of the organ. A perfusion apparatus or cassette  65  may be wired and fitted with a video camera or a photographic camera, digital or otherwise, to record the progress and status of the organ. Captured images may be made available over a computer network such as a local area network or the internet to provide for additional data analysis and remote monitoring. Cassette  65  may also be provided with a tag that would signal, e.g., through a bar code, magnetism, radio frequency, or other means, the location of the cassette, that the cassette is in the apparatus, and/or the identity of the organ to perfusion, storage, diagnostic and/or transport apparatus. Cassette  65  may be sterile packaged and/or may be packaged or sold as a single-use disposable cassette, such as in a peel-open pouch. A single-use package containing cassette  65  may also include tubeset  400 . 
     Cassette  65  is preferably configured such that it may be removed from an organ perfusion apparatus and transported to another organ perfusion apparatus in a portable transporter apparatus, such as, for example, a conventional cooler or a portable container such as that disclosed in U.S. patent application Ser. No. 09/161,919, or U.S. Pat. No. 5,586,438 to Fahy, both of which are hereby incorporated by reference in their entirety. 
     In various exemplary embodiments according to this invention, when transported, the organ may be disposed on the organ supporting surface  66  and the cassette  65  may be enclosed in a preferably sterile bag  69 , as shown, for example, in  FIG. 1A . When the organ is perfused with medical liquid, effluent medical liquid collects in the bag  69  to form an organ bath. Alternatively, cassette  65  can be formed with a liquid tight lower portion in which effluent medical liquid may collect, or effluent medical liquid may collect in another compartment of an organ storage, transport, perfusion and/or diagnostic apparatus, to form an organ bath. In either case, the bag  69  would preferably be removed prior to inserting the cassette into an organ storage, transporter, perfusion and/or diagnostic apparatus. Further, where a plurality of organs are to be perfused, multiple organ compartments may be provided. Alternatively, an organ in the dual-lid cassette can be transported of  FIG. 2A  and additionally carried within a portable organ transporter. 
       FIG. 3  shows an external view of an embodiment of transporter  1900  of the invention. The transporter  1900  of  FIG. 3  has a stable base to facilitate an upright position and handles  1910  for carrying transporter  1900 . Transporter  1900  may also be fitted with a shoulder strap and/or wheels to assist in carrying transporter  1900 . A control panel  1920  is preferably also provided. Control panel  1920  may display characteristics, such as, but not limited to, infusion pressure, power on/off, error or fault conditions, flow rate, flow resistance, infusion temperature, bath temperature, pumping time, battery charge, temperature profile (maximums and minimums), cover open or closed, history log or graph, and additional status details and messages, some or all of which are preferably further transmittable to a remote location for data storage and/or analysis. Flow and pressure sensors or transducers in transporter  1900  may be provided to calculate various organ characteristics including pump pressure and vascular resistance of an organ, which can be stored in computer memory to allow for analysis of, for example, vascular resistance history, as well as to detect faults in the apparatus, such as elevated pressure. 
     Transporter  1900  preferably has latches  1930  that require positive user action to open, thus avoiding the possibility that transporter  1900  inadvertently opens during transport. Latches  1930  hold top  1940  in place on transporter  1900  in  FIG. 3 . Top  1940  or a portion thereof may be constructed with an optically transparent material to provide for viewing of the cassette and organ perfusion status. Transporter  1900  may be configured with a cover open detector that monitors and displays whether the cover is open or closed. Transporter  1900  may be configured with an insulating exterior of various thicknesses to allow the user to configure or select transporter  1900  for varying extents and distances of transport. In embodiments, compartment  1950  may be provided to hold patient and organ data such as charts, testing supplies, additional batteries, hand-held computing devices and/or configured with means for displaying a UNOS label and/or identification and return shipping information. 
       FIG. 4  shows a cross-section view of a transporter  1900 . Transporter  1900  contains cassette  65  and pump  2010 . Cassette  65  may preferably be placed into or taken out of transporter  1900  without disconnecting tubeset  400  from cassette  65 , thus maintaining sterility of the organ. In embodiments, sensors in transporter  1900  can detect the presence of cassette  65  in transporter  1900 , and depending on the sensor, can read the organ identity from a barcode or radio frequency or other “smart” tag that may be attached or integral to cassette  65 . This can allow for automated identification and tracking of the organ and helps monitor and control the chain of custody. A global positioning system may be added to transporter  1900  and/or cassette  65  to facilitate tracking of the organ. Transporter  1900  may be interfaceable to a computer network by hardwire connection to a local area network or by wireless communication while in transit. This interface may allow data such as perfusion parameters, vascular resistance, and organ identification and transporter and cassette location to be tracked and displayed in real-time or captured for future analysis. 
     Transporter  1900  also preferably contains a filter  2020  to remove sediment and other particulate matter, preferably ranging in size from 0.05 to 15 microns in diameter or larger, from the perfusate to prevent clogging of the apparatus or the organ. Transporter  1900  preferably also contains batteries  2030 , which may be located at the bottom of transporter  1900  or beneath pump  2010  or at any other location but preferably one that provides easy access to change batteries  2030 . Batteries  2030  may be rechargeable outside of transporter  1900  or while within transporter  1900  and/or are preferably hot-swappable one at a time. Batteries  2030  are preferably rechargeable rapidly and without full discharge. Transporter  1900  may also provide an additional storage space  2040 , for example, at the bottom of transporter  1900 , for power cords, batteries and other accessories. Transporter  1900  may also include a power port for a DC hookup, e.g., to a vehicle such as an automobile or airplane, and/or for an AC hookup. 
       FIG. 5  shows an alternative cross-section of transporter  1900 . In  FIG. 5 , the transporter  1900  may have an outer enclosure  2310  which may, for example, be constructed of metal, or preferably a plastic or synthetic resin that is sufficiently strong to withstand penetration and impact. Transporter  1900  contains insulation  2320 , preferably a thermal insulation made of, for example, glass wool or expanded polystyrene. Insulation  2320  may be various thicknesses ranging from 0.5 inches to 5 inches thick or more, preferably 1 to 3 inches, such as approximately 2 inches thick. Transporter  1900  may be cooled by coolant  2110 , which may be, e.g., an ice and water bath or a cryogenic material. In embodiments using cryogenic materials, the design should be such that organ freezing is prevented. An ice and water mixture is preferably an initial mixture of approximately 1 to 1, however, in embodiments the ice and water bath may be frozen solid. Transporter  1900  can be configured to hold various amounts of coolant, preferably up to 10 to 12 liters. An ice and water bath is preferable because it is inexpensive and generally can not get cold enough to freeze the organ. Coolant  2110  preferably lasts for a minimum of 6 to 12 hours and more preferably lasts for a minimum of 30 to 50 hours without changing coolant  2110 . The level of coolant  2110  may, for example, be viewed through a transparent region of transporter  1900  or be automatically detected and monitored by a sensor. Coolant  2110  can preferably be replaced without stopping perfusion or removing cassette  65  from transporter  1900 . Coolant  2110  is preferably maintained in a watertight compartment  2115  of transporter  1900 . Compartment  2115  preferably prevents the loss of coolant  2110  in the event transporter  1900  is tipped or inverted. Heat is conducted from the walls of the perfusion reservoir and cassette  65  into coolant  2110  enabling control within the desired temperature range. Coolant  2110  is a failsafe cooling mechanism because transporter  1900  automatically reverts to cold storage in the case of power loss or electrical or computer malfunction. Transporter  1900  may also be configured with a heater to raise the temperature of the perfusate. 
     Transporter  1900  may be powered by batteries or by electric power provided through plug  2330 . An electronics module  2335  may be provided in transporter  1900 . Electronics module  2335  may be cooled by vented air convection  2370 , and may further be cooled by a fan. Preferably, electronic module  2335  is positioned separate from the perfusion tubes to prevent the perfusate from wetting electronics module  2335  and to avoid adding extraneous heat from electronics module  2335  to the perfusate. Transporter  1900  preferably has a pump  2010  that provides pressure to perfusate tubing  2360  to deliver perfusate  2340  to organ  2350 . Transporter  1900  may be used to perfuse various organs such as a kidney, heart, liver, small intestine and lung. Transporter  1900  and cassette  65  may accommodate various amounts of perfusate  2340 , for example up to 3 to 5 liters. Preferably, approximately 1 liter of a hypothermic perfusate  2340  is used to perfuse organ  2350 . 
     Cassette  65  and transporter  1900  are preferably constructed to fit or mate such that efficient heat transfer is enabled. The geometric elements of cassette  65  and transporter  1900  are preferably constructed such that when cassette  65  is placed within transporter  1900 , the elements are secure for transport. 
       FIGS. 6-8  show the housing  2  and the housing cover  1  which, together make up a bubble trap device of the invention. The bubble trap device is designed and configured for connection to and use with the tube set  400  discussed above with respect to  FIG. 2A . The housing  2  and/or the cover  1  of the bubble trap device may be constructed of an optically clear material to allow for viewing of the interior of the bubble trap device, monitoring liquid located therein, and/or helping an infra-red temperature sensor measure the temperature of the perfusate. 
     The housing  2  of the bubble trap device is connected in line with a liquid path by way of inlet tube port connector  11 , bubble outlet tube port connector  10  and liquid outlet tube port connector  9 . Inlet tube port connector  11  is the primary path of ingress of liquid into the vertical entrance channel  8 . The vertical entrance channel  8  is preferably located in the housing  2  and connected to the entrance turn around channel  7  which is connected to the entrance separation chamber  6 . The entrance separation chamber  6  is connected to an opening in the separation chamber  12 . Accordingly, when housing  2  and housing cover  1  are secured together, liquid flowing into the housing will flow through the vertical entrance channel  8 , entrance turn around channel  7 , and entrance separation chamber  6  before reaching the separation chamber  12 . 
     When liquid and gas flow out of chamber  12 , there are two paths of exit. Gas can flow out of the bubble outlet tube port connector  10 . Liquid will leave the separation chamber  12  through a liquid exit separation chamber  5 . The liquid and/or gas will then flow through the horizontal liquid channel exit  4  and then through the vertical channel exit  3  before exiting from the housing  2  by way of the liquid outlet tube port connector  9 . When gas flows out of the bubble outlet tube port connector  10 , it will first flow from the separation chamber  12  through the outlet port  13  before exiting out through the bubble outlet tube port connector  10 . It should be appreciated that the orientation of the channels located within the housing  2  can be configured in any manner as long as they provide a channel for the passage of the liquid and gas. For example, the vertical entrance channel  8  can be situated in a less than vertical manner. 
     The inlet tube port connector  11 , the bubble outlet tube port connector  10  and the liquid outlet tube port connector  9  can provide a connection between the tube set  400  and the bubble trap device. 
     According to exemplary embodiments of this invention, the selected exit path may be controlled by opening and closing flow valves. During operation, a sensor (i.e., an ultrasonic sensor) associated with the inlet tube port connector  11  may detect the presence of bubbles. Preferably a liquid outlet tube port valve (not shown) associated with liquid outlet tube port connector  9  is open as the separation chamber  12  collects gas from bubbles. The captured gas may be expelled from separation chamber  12  by opening a valve (not shown) associated with the bubble outlet tube port  10  while closing the valve associated with the liquid outlet tube port connector  9 . It should be appreciated that this operation may be performed at preset time intervals or in response to a signal, such as a signal from a sensor, such as an optical or ultrasonic inlet tube port sensor, that manipulates the valves. The sensor may be any known or later developed sensor which is capable of performing the above discussed operation. A sensor may be associated with the liquid outlet tube port connector  9  to detect the presence of bubbles, whereby a signal can be sent to the control panel  1920  of transporter  1900  that will stop pump  2010  until a user corrects the problem. 
       FIGS. 9-11  show a preferred mating geometry between a housing  2  and cover  1 . The mating of the housing  2  and cover  1  provides a preferred way to form the entrance vertical channel  8 , the entrance turn around channel  7 , the liquid exit vertical channel  3  and the horizontal liquid channel exit  4 . In addition, the mating can form the separation chamber  12 . After mating the housing  2  and cover  1 , the inlet entrance vertical channel  8  and entrance turn around channel  7  receive the outlet vertical channel protrusion  23  and outlet turn around channel protrusion  22 , respectively. Similarly, the liquid exit vertical channel  3  and the horizontal liquid channel exit  4  and outlet channels receive vertical liquid outlet channel protrusion  18  and horizontal liquid outlet channel protrusion  19 . The mating of channels  3 ,  4 ,  7 , and  8  with protrusions  18 ,  19 ,  22 , and  23  form a passageway, preferably of cylindrical cross-section, normal to the direction of liquid flow, as best seen in  FIG. 11 . The mating configurations are preferably configured to minimize the potential for emboli entrapment by substantially eliminating sharp corners. 
     A similar mating feature can exist between the separation chamber  12  and the separation chamber protrusion  21 . The mating between the housing  2  and the cover  1 , and the accompanying channels  3 ,  4 ,  7 , and  8  and protrusions  18 ,  19 ,  22 , and  23 , can provide a sealed liquid path due to an interference fit between mating side walls of the housing  2  and the cover  1 . This is especially preferred if the primary hermetic seal for the device is formed by ultrasonically welding the housing and cover together. The cover  1  can contain an ultrasonic energy director  25 . The ultrasonic energy director  25  melts when placed against the housing and exposed to the energy and pressure of the ultrasonic welder. It should be appreciated that any method of hermetically sealing the device is within the scope of the invention. 
     The assembled bubble trap device is preferably provided with a feature for aligning, locating and/or fixing the bubble trap device to one or more additional components, such as a tube frame set (not shown). A mounting alignment slot  15 , for example, may be formed in the housing  2  and/or the cover  1  upon mating of the housing  2  and cover  1  to form the assembled bubble trap device, as best seen in  FIG. 7 . The mounting alignment slot  15  may provide a location in two axes, allowing the bubble trap device to be translated through a third axis. A mounting receiver notch  14  may be located in the direction of a third axis and receive a snap protrusion or similar device located on a mating component. Other methods can also be used to provide a connection between the bubble trap device and at least one other additional component. 
       FIG. 12  shows an exemplary embodiment of a bubble trap device according to this invention. In  FIG. 12 , the bubble trap device is configured with the inlet tube port connector  11  located on substantially the same plane as the bubble outlet tube port connector  10  and the liquid outlet tube port connector  9 . Having substantially single plane ingress and egress ports for liquid and air flow allows for easier connection of the bubble trap device with the tubeset  400 . Additionally, substantially single plane ingress and egress ports provides for easier manufacturing assembly processes of the bubble trap device. The substantially single plane orientation of the inlet tube port connector  11 , the bubble outlet tube port connector  10  and the liquid outlet tube port connector  9 , inter alia, permits connecting tubing, such as tube set  400 , to reside in a substantially single plane without bending or twisting of the tubes in tube set  400 . It also facilitates the tiltability of the device as discussed below. 
     In various exemplary embodiments, the inlet tube port connector  11 , the bubble outlet tube port connector  10  and the liquid outlet tube port connector  9  can be positioned at various other locations on housing  2 . For example, at least one of the inlet tube port connector  11 , the bubble outlet tube port connector  10  and the liquid outlet tube port connector  9  can be can be located on one or more of the sides, top, or bottom of the housing  2 . Additionally, any one of the connectors  9 ,  10 ,  11  can be oriented at an angle other than ninety degrees or normal to the surface of the housing  2 . It should be appreciated that the inlet tube port connector  11 , the bubble outlet tube port connector  10  and the liquid outlet tube port connector  9  can be provided at any location or orientation on the housing  2  that allows appropriate ingress and egress of liquid and gas between channels  3 ,  4 ,  7 , and  8  and the separation chamber  12  within the bubble trap device. 
       FIGS. 13 and 14  show the advantageous range of tilt of preferred embodiments of the bubble trap device. This bubble trap device is designed with the liquid exit separation point  5  in approximately the center of separation chamber  12  and approximately opposite outlet port  13 . This location of features allows the bubble trap device to be tilted at various angles θ and α, depending on selection of liquid level and port locations, and can permit tilting at various angles including, for example, up to about 90, for example 90, 89, 88, 87, . . . , 1 degree, approximately 45-90, e.g., up to 70, degrees from side-to-side and front to back. It should be appreciated that the angle of tilt could increase or decrease depending on the amount of liquid and gas located within separation chamber  12 . The large angle of tilt for the bubble trap device is especially desirable in embodiments associated with an organ transporter or the like, which may undergo substantial tilting during handling and transportation. When the bubble trap device is connected to the tube set  400 , the large acceptable angle of tilt ensures that the bubble trap device functions when the cassette and transporter are not completely horizontal. 
       FIG. 15  shows a tube frame  200  of embodiments of the invention. The tube frame, may be used for holding tube set  400  discussed with respect to  FIG. 2A . The tube frame  200  is preferably formed of a material that is light but durable, such as for example plastic, so that tube frame  200  is highly portable. The tube frame  200  is designed to hold the tubing of the tube set  400  in desired positions. In  FIG. 15 , tube frame  200  is shown holding the tubes of tube set  400  of  FIG. 2A . It should be appreciated that there may be other numbers of tubes that comprise tube set  400 . Having the tubing in set positions allows for easier installation and connection with devices such as cassette  65  as shown in  FIG. 12 . The cassette  65  and tube frame  200  are then preferably mated with transporter  1900 . 
     When tube frame  200  is mated with cassette  65 , the tube set  400  is preferably already connected with the cassette  65 . For example, tube  270  provides an inlet to a pump  2010  from the stored liquid at the bottom of cassette  65 . The liquid travels through tube  290  and back out outlet  280  through a filter which may, for example, be located inside or outside, for example, below, cassette  65 . After traveling through the filter, the liquid will travel to tube  240  and into the bubble trap  210 . A sample port  295  may be provided with tube frame  200  to allow for drawing liquid out of or injecting liquid into the tube  240 . Liquid travels into the bubble trap  210  in tube  240  and travels out of bubble trap  210  in tube  260 , which carries the liquid into the cassette, for example, to infuse and/or wash the organ. Tube  250  will carry liquid or gas leaving the bubble trap  210  into cassette  65  bypassing infusion of, but optionally washing, the organ. 
     It should be appreciated that tube frame  200  can hold other devices in addition to tubes. For example, tube frame  200  can hold a bubble trap device  210  and a pressure sensor  220  used to control pump  2010 . It should also be appreciated that tube frame  200  and tube set  400  can be connected to a variety of devices such as the organ perfusion device  1  or an organ diagnostic device, as well as a cassette and/or transporter. 
     In various exemplary embodiments, tube frame  200  is preferably attachable to a portion of the transporter  1900 . The tube frame  200  may be connected to transporter  1900 , and other devices, by way of snaps  230  or other structure that will securely hold the tube frame to the device. Sensors, for example mechanical or electrical sensors, in transporter  1900 , or other devices, can be provided to detect the presence of tube frame  200  in transporter  1900 . If the tube frame  200  is not properly attached to the transporter, the sensors may be configured to send an appropriate alert message to control panel  1920  for notifying the user of a problem. If no action is taken to properly attach tube frame  200  in a given amount of time automatically set or programmed by the user, transporter  1900  can be programmed to prevent the beginning of perfusion. It should be appreciated that if perfusion has begun and tube frame  200  is not appropriately set, the transporter can be programmed to stop perfusion. 
     Another valuable feature of the tube frame is that makes the stationary surface for the tube  250 , and tube  260 . These tubes are used to route perfusion solution either directly to the organ or, bypassing the organ, into the reservoir. It is desirable to have tube  250  and tube  260  located in a relatively fixed position so that the routing may be done by pinching the tubing so that no liquid can pass. The tubes may, for example, be pinched by a solenoid (not shown) located on transporter  1900  that drives a blade that pinches tube  250  and/or tube  260  against the tube frame  200 . 
     The above described apparatus and method of the bubble trap device, cassette and transporter may be used for child or small organs as well as for large or adult organs with modifications as needed of the cassette. The organ cassette can be configured to the shapes and sizes of specific organs or organ sizes. 
     While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations may be apparent to those skilled in the art. Accordingly, the embodiments of the invention as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention.