U.S. patent application number 13/545514 was filed with the patent office on 2014-01-16 for organ transporter with oxygen generation.
This patent application is currently assigned to LIFELINE SCIENTIFIC, INC.. The applicant listed for this patent is Aaron R. FERBER, David KRAVITZ, Ross LOCKWOOD, Rodney H. MONSON, Evan D. SHAPIRO, Christopher P. STEINMAN. Invention is credited to Aaron R. FERBER, David KRAVITZ, Ross LOCKWOOD, Rodney H. MONSON, Evan D. SHAPIRO, Christopher P. STEINMAN.
Application Number | 20140017665 13/545514 |
Document ID | / |
Family ID | 48875183 |
Filed Date | 2014-01-16 |
United States Patent
Application |
20140017665 |
Kind Code |
A1 |
STEINMAN; Christopher P. ;
et al. |
January 16, 2014 |
ORGAN TRANSPORTER WITH OXYGEN GENERATION
Abstract
An apparatus for perfusing an organ or tissue includes a
perfusion circuit for perfusing the organ or tissue; an oxygenator
for oxygenating perfusate that circulates through the perfusion
circuit; and an oxygen supply device such as an oxygen concentrator
or an oxygen generator configured to supply oxygen to the
oxygenator. A method of perfusing an organ or tissue includes
producing oxygen from a device such as an oxygen concentrator and
an oxygen generator; supplying the produced oxygen, preferably as
the oxygen is produced, to a perfusate to oxygenate the perfusate;
and perfusing the organ or tissue with the oxygenated perfusate.
The produced oxygen preferably has a concentration greater than the
oxygen concentration in air.
Inventors: |
STEINMAN; Christopher P.;
(Sandy, UT) ; KRAVITZ; David; (Barrington Hills,
IL) ; FERBER; Aaron R.; (Chicago, IL) ;
LOCKWOOD; Ross; (Chicago, IL) ; MONSON; Rodney
H.; (Waukegan, IL) ; SHAPIRO; Evan D.;
(Chicago, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
STEINMAN; Christopher P.
KRAVITZ; David
FERBER; Aaron R.
LOCKWOOD; Ross
MONSON; Rodney H.
SHAPIRO; Evan D. |
Sandy
Barrington Hills
Chicago
Chicago
Waukegan
Chicago |
UT
IL
IL
IL
IL
IL |
US
US
US
US
US
US |
|
|
Assignee: |
LIFELINE SCIENTIFIC, INC.
Itasca
IL
|
Family ID: |
48875183 |
Appl. No.: |
13/545514 |
Filed: |
July 10, 2012 |
Current U.S.
Class: |
435/1.2 ;
435/284.1 |
Current CPC
Class: |
A01N 1/0247
20130101 |
Class at
Publication: |
435/1.2 ;
435/284.1 |
International
Class: |
A01N 1/02 20060101
A01N001/02 |
Claims
1. An apparatus for perfusing an organ or tissue, the apparatus
comprising: a perfusion circuit for perfusing the organ or tissue
with liquid perfusate; an oxygenator for oxygenating perfusate that
recirculates through the perfusion circuit; and an oxygen supply
device configured to supply oxygen to the oxygenator, the oxygen
supply device comprising at least one member selected from the
group consisting of an oxygen concentrator and an oxygen
generator.
2. The apparatus according to claim 1, wherein the oxygen supply
device is an oxygen generator that supplies oxygen by decomposing
water.
3. The apparatus according to claim 1, wherein the oxygen supply
device is an oxygen concentrator that supplies oxygen by
concentrating oxygen by way of pressure swing adsorption.
4. The apparatus according to claim 1, wherein the oxygen supply
device is an oxygen concentrator comprising a solid state oxygen
pump.
5. The apparatus according to claim 1, wherein the oxygen supply
device is configured to supply oxygen by starting with an oxygen
supply with relatively low oxygen concentration and outputting
oxygen with a concentration that is higher relative to the oxygen
supply.
6. The apparatus according to claim 5, wherein the oxygen supply
device is configured to operate with the oxygen supply being
air.
7. The apparatus according to claim 6, wherein the air is
compressed air.
8. The apparatus according to claim 6, wherein the air is ambient
air.
9. The apparatus according to claim 5, wherein the oxygen supply
device is configured to operate with the oxygen supply being
water.
10. The apparatus according to claim 5, further comprising a
container to store the oxygen supply.
11. The apparatus according to claim 5, further comprising: a
bubble trap disposed within the perfusion circuit downstream of the
oxygenator relative to a direction of perfusate flow.
12. The apparatus according to claim 1, wherein the apparatus does
not include an oxygen storage device.
13. The apparatus according to claim 1, wherein the apparatus is
transportable and weighs less than 90 pounds.
14. The apparatus according to claim 1, configured to sterilize or
prevent contamination of oxygen supplied by the oxygen supply
device.
15. A method of perfusing an organ or tissue, the method
comprising: producing oxygen from a device comprising at least one
member selected from the group consisting of an oxygen concentrator
and an oxygen generator; supplying the oxygen, as the oxygen is
produced, to a liquid perfusate to oxygenate the perfusate; and
perfusing the organ or tissue with the oxygenated perfusate,
wherein the oxygen has a concentration greater than the oxygen
concentration in air and the perfusate is recirculated.
16. The method according the claim 15, wherein the device is an
oxygen concentrator and the oxygen is produced from air by pressure
swing adsorption.
17. The method according to claim 15, wherein the device is an
oxygen generator and the oxygen is produced from water.
18. The method according the claim 15, wherein the device is an
oxygen concentrator and the oxygen is produced from air by way of a
solid state oxygen pump.
19. The method according the claim 15, wherein the oxygen is
produced on board a portable organ perfusion apparatus,
20. The method according to claim 15, wherein the oxygen is
produced by starting with an oxygen supply with relatively low
oxygen concentration and outputting the oxygen with a concentration
that is higher relative to the oxygen supply.
21. The method according to claim 20, wherein the oxygen supply is
air.
22. The method according to claim 21, wherein the air is compressed
air.
23. The method according to claim 21, wherein the air is drawn from
ambient atmosphere.
24. The method according to claim 15, wherein the oxygen is
produced from water.
25. The method according to claim 15, wherein the oxygen is
sterilized or decontaminated.
26. A method of perfusing an organ or tissue, the method
comprising: producing oxygen by a process comprising at least one
member selected from the group consisting of pressure swing
adsorption, water decomposition, and pumping oxygen by way of a
solid state oxygen pump; supplying the produced oxygen to a liquid
perfusate to oxygenate the perfusate; perfusing the organ or tissue
with the oxygenated perfusate; and recirculating the perfusate.
27. The method according to claim 26, wherein the process is
performed using a transportable perfusion apparatus.
28. The method according to claim 26, wherein the oxygen is
supplied as the oxygen is produced.
29. A method of perfusing an organ or tissue, the method
comprising: producing oxygen on board a portable perfusion
apparatus; oxygenating liquid perfusate in the portable perfusion
apparatus with the produced oxygen; perfusing an organ or tissue
with the oxygenated perfusate; and recirculating the perfusate.
30. The method according to claim 29, wherein the oxygen is
produced by a process comprising at least one member selected from
the group consisting of pressure swing adsorption, water
decomposition, and pumping oxygen by way of a solid state oxygen
pump.
Description
BACKGROUND
[0001] Related technical fields include organ or tissue perfusion
apparatuses that are capable of sustaining and/or restoring
viability of organs or tissue and preserving organs or tissues for
diagnosis, treatment, storage and/or transport. For convenience,
the term "organ" as used herein should be understood to mean organ
and/or tissue unless otherwise specified.
[0002] It is an objective of organ perfusion apparatus to mimic the
conditions of the human body such that the organ remains viable
before being used for research, diagnosis, treatment or
transplantation. Many times the organ needs to be stored and/or
transported between facilities. A goal of sustaining and restoring
organs during perfusion is to reduce ischemia and reperfusion
injury. The increase in storage periods in a normal or near normal
functioning state also provides certain advantages, for example,
organs can be transported greater distances and there is increased
time for testing, treatment and evaluation of the organs.
[0003] In maintaining organs in near ideal conditions and
physiological states it is known to provide oxygenated perfusate to
an organ. U.S. Pat. No. 6,673,594 discloses, for example, a
configuration in which an organ is provided with perfusate that is
oxygenated by way of gaseous oxygen provided to an oxygenating
membrane, which is hereby incorporated by reference in its entirety
and in which the present invention could be used.
SUMMARY
[0004] When an organ or tissue has been harvested, it may be
beneficial to perfuse the organ with oxygenated perfusate, which
may preferably be a liquid perfusate. Although perfusate can be
pre-oxygenated, the perfusate may require further oxygen during the
perfusion process as the organ uses oxygen from the perfusate.
Accordingly, it is desirable to provide a perfusion apparatus that
can supply oxygen to the perfusate so that the perfusate can be
oxygenated during perfusion. However, pre-stored oxygen has
drawbacks. For example, both pressurized and liquefied oxygen have
serious flammability risks that can require considerable design
efforts to provide adequate safety. Further, considerable
logistical efforts are required to provide and maintain an adequate
supply of compressed or liquefied oxygen to the point of use of a
perfusion apparatus. Compressed or liquefied oxygen requires heavy
containers that must be switched out when the container is empty.
Extended oxygenation of perfusate may require a large container or
plural small containers. Additionally, switching containers
provides an opportunity to contaminate the apparatus and/or
jeopardize sterility of the apparatus. Thus, disclosed herein is a
perfusion apparatus that provides oxygen produced in real time to
oxygenate perfusate. An organ perfusion apparatus that is able to
produce oxygen to oxygenate the perfusate avoids hazards of high
pressure or liquefied oxygen and also avoids logistical
difficulties associated with pre-stored oxygen.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a schematic diagram of an organ perfusion
apparatus.
DETAILED DESCRIPTION OF EMBODIMENTS
[0006] According to exemplary implementations, an apparatus is
provided for producing oxygen, preferably in real time, using
oxygen to oxygenate a perfusate, and perfusing the organ with the
oxygenated perfusate. The apparatus may include a perfusion circuit
for perfusing the organ or tissue, an oxygenator for oxygenating
perfusate that recirculates through the perfusion circuit; and an
oxygen supply device configured to supply oxygen to the oxygenator.
Preferably, the oxygen supply device is at least one member
selected from the group consisting of an oxygen concentrator and an
oxygen generator. As discussed herein, the term oxygen concentrator
refers to a device that uses a source that includes molecular
oxygen, and increases the concentration of the oxygen relative to
the source; and the term oxygen generator refers to a device that
uses a source other than molecular oxygen to produce oxygen from
that source.
[0007] One example of an oxygen generator is a device that
generates oxygen by decomposing water. Water may be decomposed by
applying an electrical charge to water to break the water molecules
into hydrogen and oxygen molecules. Another example of an oxygen
generator (which also can be considered to decompose water) is an
electrochemical device that utilizes a proton exchange membrane to
generate oxygen from water such as is disclosed in U.S. Patent
Application Publication No. 2010/0330547 to Tempelman et al., which
is hereby incorporated by reference in its entirety. One example of
an oxygen concentrator is a device that concentrates oxygen by way
of pressure swing adsorption. One example of pressure swing
adsorption involves passing pressurized air through an adsorbent
material such as zeolite or a similar molecular sieve, which
selectively adsorbs nitrogen, while allowing oxygen and argon to
pass through the adsorbent material, resulting in a product with
increased oxygen concentration. As another alternative, an oxygen
concentrator may supply oxygen by way of a solid state oxygen pump.
As used herein, a solid state oxygen pump refers to a device that
passes only oxygen through a ceramic or similar material by
applying an electric potential which disassociates oxygen molecules
into two oxygen ions, drives the ions across the ceramic, and
allows the ions to re-associate as an oxygen molecule. Thus, oxygen
can be extracted from air, increasing oxygen concentration. This
process is essentially driving a ceramic oxygen sensor in
reverse.
[0008] Oxygen concentrators such as pressure swing adsorption
devices and solid state oxygen pumps may use air as an input; the
air may be stored, compressed prior to use, and/or drawn from the
ambient atmosphere. The apparatus may or may not include a
container to store the source used to generate or concentrate the
oxygen, For example, the apparatus may include a container to store
air such as a pressurized air tank. Similarly, a water tank may be
provided for an oxygen generator that decomposes water.
[0009] Exemplary implementations may include a method of perfusing
an organ or tissue, Such a method may include producing oxygen
using at least one device selected from the group consisting of an
oxygen concentrator and an oxygen generator, supplying the produced
oxygen, preferably as the oxygen is produced, to a perfusate to
oxygenate the perfusate, and perfusing the organ or tissue with the
oxygenated perfusate. Preferably, the produced oxygen has a
concentration greater than the oxygen concentration in air. Any of
the devices discussed above, or other devices, may be used in
exemplary implementations.
[0010] FIG. 1 is a schematic diagram of an exemplary perfusion
apparatus 10 for an organ 20. The organ 20 may preferably be a
liver, kidney, heart, lung or intestine, but may be any human or
animal, natural or engineered, healthy, injured or diseased organ
or tissue. The apparatus includes a basin 30 in which the organ may
be placed. The basin 30 may hold a cradle on which the organ 20 is
disposed when the organ 20 is in the apparatus 10. The basin 30 may
include a first filter 33 that can function as a gross particulate
filter. The basin 30 and/or the cradle are preferably configured to
allow a perfusate bath to form around the organ 20. The basin 30 or
apparatus 10 may also include a temperature sensor 40 located or
focused in or near the cradle. The basin 30 or apparatus 10 may
include multiple temperature sensors 40, which may provide
redundancy in the event of a failure and/or may provide temperature
measurement at multiple locations. Preferably, the temperature
sensor(s) 40 is an infrared temperature sensor. The temperature
sensor(s) 40 is preferably disposed as close as practical to the
organ 20 when the organ 20 is disposed in the cradle in order to
improve usefulness and accuracy of the temperature sensors 40,
which preferably provide a temperature measurement of the perfusate
that may be correlated to a temperature of the organ 20.
Alternatively or additionally, the temperature sensor(s) 40 may be
used to directly measure the temperature of the organ 20.
[0011] The basin 30 is preferably disposed within a recess of an
insulating coolant container 50 that may contain cold materials
such as ice, ice water, brine or the like. Coolant container 50 may
be permanently or removably attached to, or an integral, monolithic
part of, apparatus 10. Thus, in use, the organ 20 is disposed
within the cradle, which is disposed within the basin 30, which is
disposed within the coolant container 50. The configuration of the
coolant container 50, basin 30 and cradle preferably provides a
configuration that provides cooling for the organ 20 without the
contents of coolant container 50 contacting the organ 20 or the
cradle. Although the coolant container 50 is described herein as
containing ice or ice water, any suitable cooling medium can be
used. Ice or ice water may be preferable due to the ease with which
ice can procured, but one of ordinary skill would understand that
any suitable cooling medium, which could be an active cooling
medium (such as a thermo electric cooler or a refrigerant loop) or
a passive cooling medium similar to ice or ice water, or a
combination thereof, may be utilized. The amount of ice, or other
cooling medium, that can be placed within the coolant container 50
should be determined based upon the maximum time that cooling is to
be provided while the organ 20 will be in the apparatus 10.
[0012] The cradle may include components configured to securely
restrain the organ 20 in place. Such components may, for example,
include user selectable netting that is fastened to the cradle. The
user selectable netting keeps the organ 20 in place while the organ
20 is manipulated or moved. For example, the organ may be held in
place with the netting on the cradle while being manipulated (e.g.,
vasculature trimmed, cannulas attached, or the like) before being
placed in the basin or perfusion apparatus. Similarly, the organ
may be held in place when the organ 20 is moved with the cradle
into the basin 30, when the basin 30 is moved into the coolant
container 50 and when the apparatus 10 itself is moved during
transport.
[0013] In the exemplary perfusion apparatus 10 of FIG. 1, after
passing through the filter 33, the perfusate flows along a first
flow path 70 that includes a suitable fluid conduit 72, such as
flexible or rigid tubing, a pump 80, a pressure sensor 90, a second
filter 34, an oxygenator 100 and a bubble trap 110, each of which
is discussed below. In combination with one or both of the portal
flow path 120 and the hepatic flow path 130 (discussed below), the
first flow path 70 may form a recirculating perfusate flow path
that provides perfusate to the organ 20 and then recirculates the
perfusate.
[0014] The first filter 33 is preferably a relatively coarse filter
(relative to the second filter 34). Such a coarse filter may be
provided to prevent large particles, which may for example be
byproducts of the organ or of the organ being removed from the
donor, from entering and clogging fluid paths of the apparatus 10.
The first filter 33 may be an integral part of the basin 30 or the
first filter 33 may be disposed elsewhere in the first flow path 70
downstream of the basin 30. For example, the first filter 33 may
also be a separate component from the basin 30 or disposed within
the fluid conduit 72.
[0015] The first flow path 70 may also include a pump 80. The pump
80 may be any pump that is suitable in connection with perfusing of
organs. Examples of suitable pumps may include hand operated pumps,
centrifugal pumps and roller pumps. If a roller pump is included,
the roller pump may include a single channel or flow path (where
only one tube is compressed by the rollers) or the roller pump may
include multiple, parallel channels or flow paths (where multiple
tubes are compressed by the rollers). If multiple, parallel
channels or flow paths are included, the rollers may preferably be
disposed out of phase or offset so that pulses created by the
rollers are out of phase, which may result in a fluid flow out of
the roller pump that is relatively less pulsatile than would be the
case with a single roller. Such a multiple channel roller pump may
achieve a constant flow rate or a minimally pulsatile flow rate,
which may be advantageous depending on the other components in the
flow path and/or the type of organ being perfused.
[0016] The flow path 70 may include a pressure sensor 90. The
pressure sensor 90 may preferably be disposed after the outlet of
the pump 80 in order to monitor and/or be used to control the
pressure produced at the outlet of the pump by way of a suitable
controller 400. The pressure sensor 90 may provide continuous or
periodic monitoring of pressure.
[0017] The flow path 70 may include an oxygenator 100 such as an
oxygenator membrane or body to provide oxygenation to the
perfusate. The oxygen may be provided by way of an oxygen generator
or oxygen concentrator 102 as shown in FIG. 1, which may be
separate from the apparatus 10 or integral to the apparatus 10. For
example, the oxygen generator or concentrator 102 may be contained
within the apparatus 10 or the oxygen generator or concentrator 102
may be an external device that can be connected to the apparatus to
supply oxygen to the apparatus. Oxygen may be generated through any
suitable means, some examples of which include through pressure
swing adsorption using a molecular sieve (such as a zeolite),
through a ceramic oxygen generator (a solid state oxygen pump) or
through decomposition of water. Each type of oxygen generator or
concentrator 102 discussed above may be adapted to be separate from
or integral to the apparatus 10; however, some devices may be more
advantageously adapted to be integral or separate. For example, an
electrochemical oxygen generator may be relatively compact (on the
order of a few cubic inches including a water reservoir) and
therefore well suited to being integral, whereas a pressure swing
adsorption device may be relatively large (due to the size of
adsorbent material containers and need for a pressurized air
source, such as a compressor) and therefore well suited to be
separate.
[0018] The oxygen generator or concentrator 102 preferably produces
oxygen in real time to provide oxygenation to the perfusate, but
oxygen may also be produced and stored for short or long periods as
dictated by the oxygen consumption requirements and the technology
selected for producing oxygen. The oxygen generator or concentrator
102 may continuously or non-continuously produce oxygen depending
on the need to oxygenate perfusate and/or the type of device used
to produce the oxygen. The apparatus 10 may be configured such that
there is no oxygen storage for oxygen produced from the oxygen
generator or concentrator 102, except for any residual oxygen
contained within plumbing or a conduit(s) from an outlet of the
oxygen generator or concentrator 102 to the oxygenator 100. In
other words, it may be preferable that the apparatus 10 does not
include any structures specifically configured for oxygen storage.
The apparatus 10 may include a device, such as a microbial filter,
to ensure sterility, or otherwise prevent contamination, of the
oxygen supplied to the oxygenator. Preferably such a device is
located between the oxygen generator or concentrator 102 and the
oxygenator 100, but may also be upstream of the oxygen generator or
concentrator 102 or in both locations. Preferably, any device
utilized to ensure sterility, or otherwise prevent contamination,
of the oxygen supply is a disposable component. As would be
appreciated by one of ordinary skill, any suitable device to ensure
sterility of, or prevent contamination of, the oxygen may be
provided instead of a microbial filter.
[0019] The flow path 70 may include a bubble trap 110. The bubble
trap 110 preferably separates gas bubbles that may be entrained in
the perfusate flow and prevents such bubbles from continuing
downstream and entering the organ 20. The bubble trap 110 may also
function as an accumulator that reduces or eliminates pulsatility
of the perfusate flow. The bubble trap 110 may include a volume of
gas, initially or through the accumulation of bubbles, such that
pressure fluctuations in the perfusate are dampened or
eliminated.
[0020] The bubble trap 110 may include a vent that allows purging
of gas during start up or a purging process. The vent may be
connected to or part of purge flow path 140 (which is discussed in
detail below). The vent is preferably open during a start up
process so that any air or other gas may be purged from the
perfusate path 70. Once the gas is purged from the perfusate path
70, the vent may preferably be closed. The vent may be closed
manually or may be closed automatically by way of controller
400.
[0021] The bubble trap 110 may include a level sensor 112. A level
sensor 112 may optionally be used during the purging process to
determine when the purging is complete and/or may be used to
determine when the purging process needs to be repeated, which may
happen after bubbles have been trapped in the bubble trap 110.
Also, through the use of the level sensor 112 and the vent, the
accumulator function of the bubble trap can be tuned to account for
differing amplitudes and frequencies of pulsatility in the
perfusate flow.
[0022] The bubble trap 110 may have any number of outlets, as
needed for a given application of the perfusion apparatus. In FIG.
1, three outlets are shown connected to three different flow paths,
which may be particularly suited for the perfusion of a liver. When
perfusing a liver, the three paths preferably include portal flow
path 120 connected to the portal vein of a liver, hepatic flow path
130 connected to the hepatic artery of a liver, and bypass flow
path 140 that provides a return path to the basin 30. There may
also be a port in any fluid path that allows fluid access to the
perfusate solution. The port may preferably be located in the
bubble trap 110. This port may preferably include a luer type
fitting such that a user may extract a small a sample of the
perfusate for analysis. The port may also be utilized by a user to
administer substances to the perfusate without opening the basin.
Although FIG. 1 illustrates a single oxygenator 100 and single
bubble trap 110, one of ordinary skill would appreciate that more
than one oxygenator 100 and/or bubble trap 110 may be provided. For
example, an oxygenator 100 and a bubble trap 110 could be provided
for each of the portal flow path 120 and the hepatic flow path 130.
Such a configuration may allow for different levels of oxygenation
in each of the portal flow path 120 and hepatic flow path 130. A
single oxygen concentrator or generator 102 may provide oxygen to
both the portal flow path 120 and the hepatic flow path 130, or
separate oxygen concentrators or generators 102 may be provided for
each flow path. If a single oxygen concentrator or generator 102
provides oxygen to both flow paths, suitable valves such as on/off
valves and/or pressure regulators may control the oxygen supplied
to each flow path to be different.
[0023] As shown in FIG. 1, the portal flow path 120 and hepatic
flow path 130 may optionally include similar or different
components such as valves 122, 132; bubble sensors 124, 134; flow
sensors 126, 136; flow control clamps 127, 137; and pressure
sensors 128, 138. Each similar component may function in a similar
manner, and such pairs of components may optionally be structurally
and/or functionally identical to reduce manufacturing costs. Flow
sensors 126, 136 may preferably be ultrasonic sensors disposed
around tubing, although any suitable sensor may be used. Ultrasonic
sensors may be advantageous because in normal usage such sensors do
not come into contact with the perfusate and therefore are not in
the sterile path. Such an implementation of ultrasonic sensors does
not require replacement and/or cleaning after use.
[0024] Valves 122, 132 may be pinch valves that function to squeeze
tubing and reduce or shut off flow, but any suitable valve may be
used. Pinch valves may be advantageous because in normal usage they
do not come into contact with the perfusate and therefore do not
require replacement and/or cleaning after use.
[0025] Preferably, the bubble sensors 124, 134 are ultrasonic
sensors disposed around tubing, although any suitable sensor may be
used, Similar to pinch valves, ultrasonic sensors may be
advantageous because in normal usage they do not come into contact
with the perfusate and therefore do not require replacement and/or
cleaning after use. Instead, ultrasonic sensors can be disposed in
contact with, adjacent to or around an external surface of tubing
in order to sense bubbles.
[0026] Flow control clamps 127, 137 may be used to fine-tune the
flow rate in one or both of portal flow path 120 and hepatic flow
path 130. Preferably, the organ provides self-regulation to control
an amount of flow that exits the bubble trap 110 and is divided
between the portal flow path 120 and the hepatic flow path 130. In
such self regulated flow, pressure sensors 128, 138 provide
overpressure monitoring. In the event that pressure delivered to
the organ in either or both of the portal flow path 120 or the
hepatic flow path 130 exceeds a predetermined threshold, the
apparatus 10 can automatically stop and/or reduce the flow rate
provided by the pump 80 to prevent damage to the organ. In addition
or alternatively, the pressure sensors 128, 138 may be used to
generate warning signals to the user and/or to an appropriate
controller as pressures approach the predetermined threshold.
[0027] After exiting one or both of the portal flow path 120 and
hepatic flow path 130, perfusate flows through the organ and
returns to the basin 30 to form an organ bath.
[0028] Bypass flow path 140 may include a valve 142, and/or sensors
such as oxygen sensor 144 and pH sensor 146. Preferably, the valve
142 is a pinch valve and may be of similar configuration to valves
122 and 132, but any suitable valve may be used. The oxygen sensor
144 and the pH sensor 146 may be used to determine the state of the
perfusate. Preferably, the bypass flow path 146 is only used during
a purging or priming process, although it may also be used during
perfusion, preferably continuously, to monitor perfusate properties
in real time.
[0029] The organ perfusion apparatus 10 may also include an
accelerometer 150. Preferably the accelerometer 150 is a three-axis
accelerometer, although multiple single axis accelerometers may be
used to the same effect. The accelerometer 150 may be used to
continuously or periodically monitor and/or record the state of the
apparatus 10. Monitoring may include monitoring for excessive
shocks as well as attitude of the apparatus 10. By implementing
such monitoring, misuse or potentially inappropriate conditions of
the apparatus 10 can be detected and recorded.
[0030] The apparatus 10 may include storage compartments for items
other than the organ 20. For example, the apparatus 10 may include
a document compartment to store documents and/or charts related to
the organ 20. Also, the apparatus 10 may include one or more sample
compartment. The sample compartment may be configured, for example,
to store fluid and/or tissue samples. The sample compartment may be
advantageously disposed near the coolant container 50 to provide
cooling, which may be similar or equivalent to the cooling provided
for the organ 20.
[0031] The apparatus 10 may include one or more tamper evident
closures. A tamper evident closure may be used to alert a user that
the apparatus 10 has been opened at an unauthorized time and/or
location and/or by an unauthorized person. Evidence of tampering
may alert the user to perform additional testing, screening, or the
like before using the organ 20 and/or the apparatus 10.
[0032] The organ transporter is preferably portable for carrying
organs or tissues from place to place, and is sized to be carried
by one or two persons and loaded into an automobile or small
airplane. The perfusion apparatus 10 preferably may be an organ
transporter that is designed to be portable, for example, having
dimensions smaller than length 42 inches.times.width 18
inches.times.height 14 inches and a weight less than 90 lbs, which
includes the weight of the complete loaded system (for example,
transporter, disposable components, organ, ice and 3 liters of
perfusate solution),
[0033] What has been described and illustrated herein are preferred
embodiments of the invention along with some variations. The terms,
descriptions and figures used herein are set forth by way of
illustration only and are not meant as limitations, Those skilled
in the art will recognize that many variations are possible within
the spirit and scope of the invention.
* * * * *