Abstract:
An implantable digestive organ is provided for the transport of materials through the digestive tract and in one particular application to an artificial large bowel for replacing all or part of a colon or large bowel. The prosthetic organ of one embodiment includes an outer support structure, an expandable member or members located within the outer support structure, and a flexible inner member forming a conduit for the passage of material. The flexible inner member is located within the outer member and the expandable member or members are located between the inner member and the outer support structure. The expandable members are expanded and contracted, or inflated and deflated to provide a pumping action that pumps the material through the organ. The prosthesis may also include valves or sphincters at the entrance and/or exit points of the organ where material moves into and out of the prosthesis. An implantable pump unit may be included for inflating and deflating the expandable members according to a desired sequence.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 10/328,446, filed 23 Dec. 2002, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an artificial organ for the transport of materials through the digestive tract and in one particular application to an artificial large bowel for replacing all or part of a colon or large bowel. 
     2. Description of the Related Art 
     A number of diseases or conditions are known to compromise the ability of peristaltic digestive organs of the body to function. These diseases or conditions may require resection of all or part of the organ. Such organs may include, for example, the stomach, intestines and bowel. 
     A number of diseases and conditions of the colon or bowel cause the colon or bowel to malfunction. In some situations such diseases or condition cause dangerous obstructions in the colon or bowel. In other situations, gastroparesis may result. Many of the diseases result in chronic or acute inflammation. As a result many diseases or conditions require removal of sections of the colon or bowel or a portion of the ilieum of the small intestine. 
     Crohn&#39;s disease is one example of an inflammatory bowel disease in which the inner lining of the bowel may become inflamed and cause obstructions in the bowel. Ulcerative colitus is another example of a disease of the colon characterized by ulcerations in the colon. Diverticulitis is a disease in which diverticulum of the colon become inflamed, trapping fecal material and potentially leading to obstruction, perforation or bleeding, with fecal material possibly leaking out into the abdomen. Diverticulitis in its most severe form may require resection of the affected portion of the bowel. Colon cancer, other obstructive growths may require significant portions of the bowel to be removed and in doing so may seriously compromise the functioning of the bowel. Another example of a colon/bowel diseases is toxic megacolon, where the colon becomes very large and may contain excessive amounts of feces at a given time. 
     As noted above, many diseases are treated with colonostomies or ileostomies, where all or a portion of the colon or ileum of the small intestine are removed. Many of these procedures require provision of an artificial stoma in the abdomen for emptying waste from the shortened functioning bowel. Often a pouch secured around the waist by a belt, is coupled to the stoma and is used to collect the waste. Mortality rates for the procedures remain high and for those successfully treated, the pouches are cumbersome to use and manage. Furthermore, the annual health maintenance costs for patients who have received this treatment is high. 
     Artificial sphincters have been proposed to replace failing sphincters. Typically theses devices are cuffs to be placed around the outside of an organ to control the opening and closing of a stoma. Artificial sphincters may be used for example where fecal incontinence is present. This may occur in women as a result of childbirth. 
     Accordingly it would be desirable to provide a device and method for replacing all or part of the bowel including in some instances, the rectal sphincter. 
     SUMMARY OF THE INVENTION 
     The present invention provides an implantable prosthetic organ in which material is moved through the organ. In one embodiment the prosthetic organ moves material with peristaltic-like movement. The prosthetic organ includes an outer support structure, an expandable member or members located within the outer support structure, and a flexible inner member forming a conduit for the passage of material. The flexible inner member is located within the outer member and the expandable member or members are located between the inner member and the outer support structure. The expandable members are expanded and contracted, or inflated and deflated to provide a pumping action that pumps the material through the organ. The expandable members are isolated from the material moving through the prosthesis by the inner member in which the material is contained. Thus, the material avoids getting caught in the interstices around the expandable members. 
     The prosthesis may also include valves or sphincters at the entrance and/or exit points of the organ where material moves into and out of the prosthesis. These sphincters are also isolated from the material by the inner tube. 
     The organ is preferably an organ of the digestive system having an orad end through which the material enters and an aborad end out of which the material exits. The digestive organ of one particular embodiment comprises a prosthetic large intestine or bowel that replaces all or part of the large intestine or bowel. According to this embodiment, the outer member of the organ is a flexible tube. The prosthesis may include a valve or sphincter at the entrance (the orad end) and/or a rectal sphincter valve at the exit (the aborad end). A plurality of expandable members are arranged to be expanded in a sequence where the expandable members are expanded and contracted along the length of the prosthesis to provide a pumping action moving material through the organ. The prosthesis may work in sections that provide peristaltic movements according to a pattern or sequence of sections. For example an aborad section may be first actuated, followed by the adjacent section in the orad direction. The aborad section may then be actuated again. Thus, a build up of material and pressure from the entrance (orad end) to the end (aborad end) is avoided and the material is gradually moved through the organ. 
     The expandable members of one embodiment are balloons or inflatable members expandable with an inflation medium. The implantable organ further comprises an implantable pump system that includes a pump and a programmable controller. The implantable pump system in one embodiment also includes a reservoir of sterile inflation medium used to inflate the various expandable members. The reservoir may be implantable separate from the pump, e.g. in soft tissue. In general, the pump system is a closed system where the inflation medium is stored or passes through as it is pumped from one inflation member to another. Each expandable member may be configured in a number of manners in which the inflation of the expandable member causes the material in the inner tube to advance. For example, the expandable member may be configured as a plurality of opposing members that are inflated together through a common valve. Alternatively, the inflatable member may be in a doughnut type shape; or the inflatable member may also be staggered from other inflatable members such that together the inflatable members are in a spiral type configuration. Other patterns may also be used for the purpose of moving material through the inner tube. Preferably, each of the expandable members or groupings of expandable members has an input port and valve coupled to the pump such that a single valve is opened at a time. However, the system may alternatively have more than one valve open at a time. 
     The controller controls the inflation and deflation of the expandable members by controlling the opening and closing of the valves coupled to each of the expandable members, and by controlling the pump direction. In one embodiment, the inflatable members are inflated to a predetermined pressure. The pump may determine the inflation pressure by monitoring the pumping action or work of its motor. The inflation pressure may also be sensed by sensors that sense the pressure of the system, e.g. in the fluid header of the pump system. In one embodiment, the reservoir contains sufficient inflation medium to inflate two sections of expandable members (and if present, the rectal sphincter). According to one embodiment, a first section of expandable members corresponding to a first section of the tube is inflated, then a second adjacent section is inflated. The second section is inflated before the first section is deflated so that the material in the prosthesis cannot move back in an orad direction when the second section is inflated. The first section is then deflated. Then the fluid used to inflate the first section is then used to inflate the third section, etc. until each section is sequentially inflated. 
     The controller may also control selection of a section of the organ for the peristaltic movement. In this regard, sections may be selected according to a desired sequence of the section actuation. The controller may be preprogrammed to control the peristalsis pattern or may be reprogrammed externally or in response to sensed conditions at various locations in the bowel. For example the sensors may sense presence or absence of material in a section of the bowel and may direct a pattern of peristaltic movement in the various sections accordingly. 
     In one embodiment, a single electromechanical device actuates the opening and closing of the valves according to the sequence. The valve actuator selectively actuates a particular valve at a given time according to instructions from the controller. 
     The pump and the valve actuating mechanism may be powered through a coil inductively coupled transcutaneously to an external power source, or by a battery rechargeable through such coil and external power source. According to one embodiment, a user positions and actuates the external power source to evacuate the prosthesis. The electronics unit may be powered by a rechargeable or replaceable battery as the controller consumes relatively little power in its operation. 
     The implantable bowel may further include a rectal sphincter valve located at the aborad end of the organ. In one embodiment, the rectal sphincter valve includes expandable members configured to close the inner member into an S-shaped configuration. The S-shaped configuration tends to tighten and squeeze the inner member further closed when a pressure is applied at either end (orad or aborad) of the valve thus preventing leakage. 
     The implantable bowel may also include an orad valve located at the orad end. Preferably the orad valve is a one-way valve that opens to permit substance to enter into the inner member of the prosthesis while resisting backflow of material out of the organ in an orad direction through the orad valve. In the case of the colon replacement, the orad valve may replace the ileocecal valve. In one embodiment of the valve, a plurality of inflated members are inflated to a threshold pressure that when met permits movement of substance through the orad valve into the inner member of the prosthesis. The pressure is generally set to a typical threshold pressure that a small bowel exerts when it is contracting. In one embodiment of the orad valve, the inflated members are hinged at the orad end into the prosthesis so that when a pressure is applied from within the prosthesis tube, the hinged balloons tend to compress towards each other and further close the valve, preventing backflow of material. In another embodiment, the orad valve may include a combination of a low pressure valve and a high pressure valve where the low pressure valve permits the ingress of material into the prosthesis at a given external pressure, and the high pressure valve is selectively closed when the prosthesis is actively pumping material through it to prevent backward movement of the material into the small bowel. 
     The implantable prosthetic organ may also include a pressure sensor arranged to sense a pressure corresponding to a pressure within the inner member. The pressure sensor may sense a pressure that indicates to a user the bowel should be emptied, whether from material or gas filling the prosthesis. The pressure sensor is coupled to the controller, which has a telemetry coil arranged to communicate a telemetric signal with an external device. The controller is configured to communicate an alarm signal to the external device when a pressure sensed by the pressure sensor exceeds a threshold pressure. The external control device may communicate via telemetry with the controller, receive the alarm signal, and generate a user perceivable alarm in response to the alarm signal. Upon sensing the alarm, the user may activate the external control device which communicates to the controller to release material and/or gas from the device. The controller may also be programmed to gently, partially open the rectal sphincter to release gas, e.g. upon receipt of a telemetrically delivered user activated control signal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic drawing of an implanted artificial large bowel according to an embodiment of the invention. 
         FIG. 2  is a schematic of an artificial large bowel, pump, valve actuator and controller of an embodiment of the invention in a resting state. 
         FIG. 2A  is a cross section of  FIG. 2  along the lines  2 A- 2 A. 
         FIG. 2B  is a cross section of  FIG. 2  along the lines  2 B- 2 B. 
         FIG. 2C  is an enlarged view of a portion of the artificial large bowel of  FIG. 2  illustrating the wire sensors. 
         FIG. 3  is a schematic of the artificial bowel of the embodiment of  FIG. 2  during a first step of emptying the bowel in which the first inflation member of the rectal sphincter is deflated and the fluid is stored in the bladder. 
         FIG. 3A  is a cross section of  FIG. 3  along the lines  3 A- 3 A. 
         FIG. 4  is a schematic of the artificial bowel of  FIG. 2  during a subsequent step of emptying the bowel where a first inflation member is inflated with the fluid stored in the bladder. 
         FIG. 5  is a schematic of the artificial bowel of  FIG. 2  during a further step of emptying the bowel where fluid is emptied from a second inflation member of the rectal sphincter. 
         FIG. 6  is a schematic of the artificial bowel of  FIG. 2  during a further step of emptying the bowel where a second inflation member is inflated with the fluid stored in the bladder. 
         FIG. 7  is a schematic of the artificial bowel of  FIG. 2  during a further step wherein the first inflation member is deflated. 
         FIG. 8  is a schematic of the artificial bowel of  FIG. 2  during a further step wherein a third inflation member is inflated. 
         FIG. 9  is a schematic of the artificial bowel of  FIG. 2  during a further step wherein the second inflation member is deflated. 
         FIG. 10  is a schematic of the artificial bowel of  FIG. 2  during a further step wherein the last inflation member is in an inflated state and the first inflation member of the rectal sphincter is inflated. 
         FIG. 11  is a schematic of the artificial bowel of  FIG. 2  during a further step wherein the last inflation member is in a deflated state and the second inflation member of the rectal sphincter is inflated closing the rectal sphincter. 
         FIG. 12A  is a schematic of another embodiment of an orad valve of the invention in a first position. 
         FIG. 12B  is a schematic of the orad valve of  FIG. 12A  in a second position. 
         FIG. 12C  is a schematic of an alternative embodiment of a two stage valve in a first position. 
         FIG. 12D  is a schematic of the two stage valve of  FIG. 12C  in a second position. 
         FIG. 13  is a schematic of an embodiment of the artificial bowel of the invention in which the bowel is divided into segments, and of a sequence of segmental peristalsis according to the invention. 
         FIG. 14  is a schematic side view of another embodiment of an artificial bowel of the invention. 
         FIG. 15  is a schematic side view of another embodiment of an artificial bowel of the present invention. 
         FIG. 16  is a schematic of a miniature valve-actuating device for controlling the valves of the pump of an embodiment of the invention in a first position with a valve closed and a rotational position in which none of the openings of the device are aligned with a valve. 
         FIG. 16A  is an end view of the device as illustrated in  FIG. 16  in the first position. 
         FIG. 17  is a schematic of the valve-actuating device of  FIG. 16  in a second position. 
         FIG. 17A  is an end view of the device illustrated in  FIG. 17  with the valve open and an inflation being inflated. 
         FIG. 18  is a schematic of the micro valve-actuating device in the rotational position of  FIG. 17  with the valve closed and the inflation member in an inflated position. 
         FIG. 18A  is an end view of the device illustrated in  FIG. 18 . 
         FIG. 18B  is a schematic side cross-section of the cylinder and rod of  FIG. 18 . 
         FIG. 18C  is a cross section of  FIG. 18B  along the lines  18 B- 18 B. 
         FIG. 18D  is a cross section of  FIG. 18B  along the lines  18 D- 18 D. 
         FIG. 18E  is a top view of the cylinder of  FIG. 18 . 
         FIG. 18F  is a cross section of a portion of the cylinder as illustrate in  FIG. 18E  along the lines  18 F- 18 F. 
         FIG. 19  is a schematic of another embodiment of an artificial bowel of the present invention. 
         FIG. 19A  is a cross section of  FIG. 19  along the lines  19 A- 19 A. 
         FIG. 20  is a schematic of a valve/sphincter of another embodiment according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , according to one embodiment of the invention, a prosthetic large bowel  30 ′ with a housing  60 ′ including a hermetically sealed pump unit is implanted in a patient&#39;s abdomen  200 ′. The housing  60 ′ may also include a controller for controlling the pump and the prosthesis. The controller may also be implanted separately (in the abdomen or subcutaneously) or located externally of the patient&#39;s body, and coupled to the pump by an electrical connector. A bladder  49 ′ for supplying inflation medium is implanted in the soft tissue and is coupled to the pump unit in the housing  60 ′. Alternatively, the bladder may be located with the pump unit. An electromagnetic coil for inductively receiving power from an external source may also be implanted subcutaneously and coupled to the pump. 
     A schematic of a prosthetic digestive tract organ of one embodiment is illustrated in  FIGS. 2-11 . The prosthesis includes a large bowel  30 , a hermetically sealed pump unit  40  and a hermetically sealed electronics unit  50  including a controller  51  for controlling the pump unit  40 . The pump unit  40  and electronics unit  50  may be contained in the same housing such as the housing  60 ′ illustrated in  FIG. 1  or may be separate. 
     The large bowel  30  includes an outer tube  31  which comprises an inner  31   i  and outer layer  31   o  of material, a series of inflatable member pairs  36   a - e , an orad valve  37  an aborad valve or rectal sphincter  38 , and an inner tube  32  comprising an inner layer  32   i  and outer layer  32   o  of material. If the rectal sphincter is functional or if a partial bowel replacement is desired, the rectal sphincter may not be necessary to provide in the prosthesis. 
     The outer tube  31  comprises a flexible, relatively inelastic material such as, for example, polyethylene or polyurethane, and provides structural support for the prosthetic bowel  30 . However, an elastic material may also be used. The inflatable member pairs  36   a - e  form a bowel emptying mechanism  35 . Hinged inflated members  37   a ,  37   b  located at the orad end portion  33  of the prosthetic bowel  30  form the orad valve  37 . Inflatable members  36   f  and  36   g  form the rectal sphincter  38  at the aborad end portion  34  of the prosthetic bowel  30 . The inner tube  32  comprises a thin-walled, non-elastic flexible material such as polyethylene or polyurethane. The inside of the inner tube  32  may be coated with an antibiotic surface, such as a silver coating, to reduce bacterial growth. The inner tube  32  is attached to the outer tube  31  at the orad end portion  33  and the aborad end portion  34  of the prosthetic bowel  30  (for example, by welding) to provide an isolated conduit through which material may pass. The orad end portion  33  of the outer tube  31  includes a relatively thicker portion for suturing the outer tube  31  to a small bowel or an orad section of the colon that is to remain intact. The inner tube  32  defines a lumen through which material may enter from the small bowel or small intestine and exit through the anus. The hinged members  37   a ,  37   b  forming the valve  37 , the inflatable member pairs  36   a - e  forming the bowel emptying mechanism  35  and the inflatable members  36   f ,  36   g  forming the rectal sphincter  38  are located between the outer tube  31  and the inner tube  32 . The inner tube  32  floats relatively loosely within the outer tube  31  so as to permit movement including the inflation and deflation of the inflatable member pairs  36   a - e  and inflatable members  36   f ,  36   g.    
     The orad end portion  33  of the prosthetic bowel  30  is sewn onto the end of the small intestine, or in the case of a partial replacement of the bowel, the section of the bowel that is in communication with the small intestine. If the ileocecal valve is functional or in the case of a partial bowel replacement, the orad valve  37  may not be necessary for the prosthesis. 
     The orad valve  37  at the orad end portion  33  of the prosthetic bowel  30  is a unidirectional valve through which material may enter into the inner tube  32  for collection and ultimate excretion from the prosthetic bowel  30 . The unidirectional feature of the valve  37  serves to prevent gas or substances from backing into the small intestine from the prosthetic bowel  30 . In one application, the valve  37  may replace or augment the ileo-cecal valve between the small intestine and colon of a patient. The valve  37  comprises hinged members  37   a ,  37   b  coupled to the outer tube  31  at pivot locations  31   a ,  31   b  respectively and extending in an aborad direction from the pivot locations  31   a ,  31   b  to form a constricted passage through which material may pass into the prosthetic bowel  30 . The hinged members  37   a ,  37   b  are anchored at the pivot locations  31   a ,  31   b  so that they can pivotally rotate within the outer tube  31 , from the locations  31   a ,  31   b . The inner tube  32  extends from the orad end portion  33  (where it is coupled to the outer tube  31 ) over the valve  37 , so that materials passing through the prosthetic bowel  30  do not contact the valve  37 , thus preventing materials from becoming lodged in interstices created by the hinged members  37   a ,  37   b  of the valve  37 . In addition the hinged members  37   a ,  37   b  and inner tube  32  in combination form a valve-sealing surface. The hinged members  37   a ,  37   b  are inflated to a threshold pressure that is generally lower than that exerted by the small intestine when it is contracting to move materials into the bowel. Thus, when the small intestine is active and moving materials, a pressure is created that pushes the materials into the inner tube  32  through the valve  37 . When pressure is created within the inner tube  32  from gases or the pumping action of the prosthetic bowel  30  ( FIGS. 3-11 ), the hinged members  37   a ,  37   b  are pushed by the pressure, back in an orad direction, causing them to converge and close the valve  37 . In this situation, the pressure within the prosthesis presses the inner tube  32  against the hinged members  37   a ,  37   b , and resulting pressure on the hinged members  37   a ,  37   b  causes the valve  37  to close or tighten. In the illustrated embodiment, the hinged members  37   a ,  37   b  are inflated to a predetermined pressure. 
     The bowel emptying mechanism  35  comprises a series inflatable member pairs  36   a - e  attached to the inside of the outer tube  31  between the outer tube  31  and the inner tube  32  along the length of the prosthetic bowel  30 . Although pairs  36   a - e  are illustrated, the number of pairs of inflation members depend on a selected prosthesis length and size of the inflation member pairs. According to one embodiment, the inflatable member pairs are approximately 1.5 inches long in an uninflated state, with about 16 pairs for a 24-inch long bowel emptying mechanism. The length of the prosthesis may vary from patient to patient depending on the size of the patient and the amount of bowel to be replaced. The inflatable members may also be longer or shorter. 
     Each inflatable member of a pair converges together when inflated, to move material through the prosthetic bowel  30 . Each inflatable member pair  36   a - e  is coupled to and is in fluid communication with a corresponding one of conduits  39   a - e , respectively. Conduits  39   a - e  are used to selectively deliver inflation medium to and from inflatable members  36   a - e  by an implanted pump unit  40 . 
     The rectal sphincter  38  is located at the aborad end portion  34  of the prosthesis where the prosthesis is attached to the anus  202 . The rectal sphincter  38  comprises inflation members  36   f ,  36   g  attached to the inside of the outer tube  31  between the outer tube  31  and the inner tube  32 . The inflation members  36   f ,  36   g  are attached on opposing sides of the outer tube  31  from each other so that when inflated, the inflation members  36   f ,  36   g  direct the inner tube  32  around in an S-configuration and pinch the inner tube  32  closed. The S-shaped configuration closes the inner tube  32  in a manner such that if pressure is exerted from within the prosthetic bowel  30  against the inflation member  36   f , it will cause the inflation member  36   f  to further seal together or approximate any gap between the inflation member  36   f  and the inflation member  36   g , and pinch the inner tube  32  closed further between the inflation members  36   f ,  36   g . As such, when the sphincter  38  is subject to increases in pressure, the possibility of stress incontinence will be reduced. The inflation members  36   f ,  36   g  are coupled by way of conduits  39   f ,  39   g  respectively to ports  35   f ,  35   g  in the header  45 . The inflation members  36   f ,  36   g  may be selectively inflated or deflated by the pump unit  40  as described in more detail below. In this embodiment, two opposing inflation members are illustrated. However, additional opposing inflation members may be provided. Furthermore, although the inflation medium is described as being pumped to and from a reservoir into and out of the inflation members  36   f ,  36   g  and inflation member pairs  36   a - e , in an alternative configuration, the inflation members  36   f ,  36   g  of the rectal sphincter  38  act as the fluid reservoir so as to preserve space. 
     Additionally, one or more of the inflation member pairs  36   a - e  may be partially inflated during the resting stage and may be periodically monitored by opening the corresponding valve and sensing the pressure with the pressure transducer  48 . Accordingly, if pressure builds up from materials or gas, the controller  51  may provide an alarm or feedback signal telemetrically to an external device, which causes a user perceivable alarm. The user then may proceed to actuate the device for evacuation. In one embodiment in order to release gas, the external device may be actuated to deliver a control signal via telemetry to the controller  51 , which in turn opens the rectal sphincter valve  38  by partially emptying the inflation members  36   f ,  36   g  by controlling the valves  46   f ,  46   g  and the pump  41 . The pump  41  gradually and partially pumps fluid from the inflation members  36   f ,  36   g  to release gas. The pump  41  then pumps fluid back into the inflation members  36   f ,  36   g.    
     As illustrated in  FIG. 2 , a controller  51  of an electronics unit  50  controls the implantable pump unit  40  to selectively inflate and deflate inflatable member pairs  36   a - e  and inflatable members  36   f ,  36   g . The pump unit  40  includes a bi-directional hydraulic pump  41  having an intake  47  coupled to a fluid reservoir  49  and an output  44  in fluid communication with a header  45  having fluid ports  45   a - g . The bi-directional pump  41  may be configured in a number of ways to provide pumping in two directions, for example, by controlling a series of valves that direct fluid into or out of the reservoir  49  or by providing a DC powered reversible pump. The fluid reservoir  49  contains a sterile, radiopaque inflation medium sufficient to inflate two pairs of inflation members  36   a - e , two inflation members  36   f ,  36   g  or a combination thereof at a given time. The fluid reservoir  49  may be implanted at a location adjacent to or away from the pump unit  40  (e.g. in soft tissue). 
     Each fluid port  45   a - g  is coupled to a respective valve  46   a - g , which is coupled to a respective conduit  39   a - g . Each conduit  39   a - g  is coupled to a corresponding inflation member pair  36   a - e  or inflation member  36   f ,  36   g . The valves  46   a - g  are controlled by a valve actuating device  300  which operation is controlled by an electronics unit  50  of the controller  51 . The valves  46   a - g  in this particular embodiment are controlled by a electromechanical device described in more detail with reference to  FIGS. 16-18F . Alternative valve actuating mechanisms are also contemplated, for example, individually operated bistable solenoid valves may be used. 
     A pressure transducer  48  is located between the output  44  of the pump  41  and the header  45 . The pressure transducer  48  senses the pressure of the fluid of a particular section of inflation members when the corresponding solenoid valve of the corresponding port is in an open position. The pressure transducer  48  is coupled to the controller  51 , which controls the pump  41  in response to a sensed pressure. 
     The electronics unit  50  includes a controller  51  and a battery  52  powering the controller  51 . The controller  51  is programmed to control the action of the various elements of the prosthesis and to respond to various sensed conditions. The controller  51  is coupled to the pump unit  40  and controls when and in which direction the pump  41  is actuated. The controller  51  is also coupled to a valve-actuating device  300  that opens and closes the valves  46   a - g  according to a program stored in the controller  51 , thereby sequentially inflating and deflating inflation member pairs  36   a - e  and inflation members  36   f ,  36   g . According to one embodiment, only one valve is opened at a time. The controller  51  also includes a telemetry coil  54  for communicating information to and receiving information from an external device. The external device may be used to program operation parameters into the controller  51 . The external device may also receive signals from the controller  51  or electronics unit  50  representative of various sensed conditions, e.g., pressure or system leaks. The external device may program or reprogram the controller  51  based on sensed parameters or other patient conditions. An external device may also power the pump  41  and the valve-actuating device  300  through an electronics unit  70  comprising an electromagnetic coil  71  for inductively receiving power from an external source. The electromagnetic coil  71  is coupled to the electronics unit  50  which included a voltage regulating circuit. The electronics unit  50  and controller  51  control the pump  41  by powering the pump  41  and by controlling the valve actuating device  300 . The voltage regulating circuit in the electronics unit  50  operates to convert a high frequency AC signal to a regulated voltage signal that powers the pump  41  and valve actuating mechanism  300 . Alternatively, coil  59  may be used for both powering the pump and electronics unit  50  and for bi-directional telemetry communication. 
     The prosthetic large bowel  30  is illustrated in  FIG. 2  in an inactive position in which it is collecting waste material from the small bowel  201  to which it is attached at the orad end portion  33 . In this position the rectal sphincter  38  at the aborad end portion  34  is in a closed position with inflation members  36   f ,  36   g  inflated. The inflation member pairs  36   a - e  of the bowel emptying mechanism  35  are relaxed and deflated. The orad valve  37  is free to open to permit the ingress of waste material when there is sufficient pressure in the small bowel  201 . 
     The prosthetic bowel  30  also further includes wires  55   a - f  ( FIG. 2C ) embedded in the prosthetic bowel  30  along its length and communicating with the electronic circuit  50 . The wires  55   a  and  55   d  are located in the outer tube  31  each between layers  31   i  and  31   o  and on opposing sides along the prosthetic bowel  30 . Wires  55   b  and  55   e  are exposed between the inflation member pairs  36   a - e  and the outer tube  31  on opposing sides along the prosthetic bowel  30 . Wires  55   c  and  55   f  are located in the inner tube  32  along the bowel  30  between layer  32   i  and  32   o . Wire pairs  55   a  and  55   d  form an open circuit as do wire pairs  55   b  and  55   e , and wire pairs  55   c  and  55   f . The electronic circuit  50  is configured to sense a large drop in impedance in one or more of the pairs wires  55   a - f , where a fluid closes the circuit of one or more of the wire pairs indicating potential leakage of fluid into, out of or within the bowel  30 , e.g. from material external the prosthetic bowel  30 , material passing through the inner member  32  of the bowel  30  or from an inflation member, or otherwise. In particular, a low impedance may be detected by the controller  51 , which is configured to sense impedance changes in the wires  55   a - f . The impedance of the pairs of wires  55   a - f  is periodically monitored by the controller  51 . If a leak is detected a patient alarm may be triggered, e.g., by telemetrically delivering an alarm signal from the electronics unit  50  to an external device. Furthermore, the location or cause of the leak may be determined by which sires  55   a - f  have changed impedances. The wire pairs may be placed in different configurations within layers  31   i ,  31   o ,  32   i ,  32   o  or between the inner  32  and outer members  31 , for example, they may be is parallel spiraled configurations to maximize the sensing of potential leaks. 
     The prosthetic bowel  30  also includes a conduit  56  through the prosthetic bowel  30 , into a port  57  inside the inner tube  31  for receiving an antibiotic material from a reservoir  58 . The reservoir  58  is coupled to the controller  51  and may include a pump controlled by the controller  51  that provides a periodic or otherwise actuated (e.g. by a patient) injection of antibiotic material or gas dissolving material into the inner tube  32 . 
       FIGS. 3-11  illustrate a sequence of emptying the bowel  30  of one embodiment of the invention. In  FIG. 3 , the inflation member  36   f  of the rectal sphincter  38  is emptied through the conduit  39   f  by opening valve  46   f . The pump  41  pumps the inflation medium out of the inflation member  36   f  and into the reservoir  49 , which is then partially full. The valve  46   f  is then closed. 
     Next as shown in  FIG. 4 , the valve  46   a  is opened and the pump  41  pumps inflation medium from the reservoir  49  into the inflation member pair  36   a  through the conduit  39   a . The inflation member pair  36   a  is inflated to a predetermined pressure as sensed by pressure transducer  48  or alternatively as sensed by the motor. Once the inflation member pair  36   a  is inflated, the valve  46   a  is closed by the valve actuating mechanism  60  ( FIG. 2 ). Inflation of the inflation member pair  36   a  closes the valve  37  on the orad end portion  33  due to the pressure from the inflation of pair  36   a . Waste material is moved in an aborad direction within the inner tube  32 , due to the mechanical movement of the inflation member pair  36   a  and any pressure gradient resulting therefrom. 
     Next, as shown in  FIG. 5 , the rectal sphincter  38  is completely opened by opening the valve  46   g  and pumping the fluid from the inflation member  36   g  through conduit  39   g  and into the reservoir  49 . Thus material is permitted to exit through the rectal sphincter  38 . 
     As illustrated in  FIG. 6 , inflation member pair  36   b  is next inflated to advance material through the prosthetic bowel  30 . Before the adjacent inflation member pair  36   a  is deflated, the inflation member pair  36   b  is inflated by opening the valve  46   b  and inflating by pumping fluid from the reservoir  49  that was pumped out of the inflation member  36   g , into inflation member pair  36   b  through conduit  39   b . Thus, any materials are moved further in the aborad direction without allowing the material to move back in the direction of the inflation member pair  36   a . The valve  46   b  is then closed. 
     Referring to  FIG. 7 , the valve  46   a  is selected again. The pump direction is reversed and the inflation medium is pumped out of the inflation member pair  36   a  and is returned to the reservoir  49 . The orad end portion  33  of the prosthetic bowel  30  is isolated from the material moving through the inner tube  32  by the inflation member pair  36   b . The valve  46   a  is then closed. 
     Referring to  FIG. 8 , inflation member pair  36   c  is next inflated to advance material further through the prosthetic bowel  30 . Before the adjacent inflation member pair  36   b  is deflated, the inflation member pair  36   c  is inflated by opening the valve  46   c  and inflating by pumping fluid from the reservoir  49  into inflation member pair  36   c  through conduit  39   c . Thus, any materials are moved further in the aborad direction without permitting the material to move back in the direction of the inflation member pair  36   b . The valve  46   c  is then closed. 
     Referring to  FIG. 9 , the valve  46   b  is selected again, the pump direction is reversed and the inflation medium is pumped out of the inflation member pair  36   b  and is returned to the reservoir  49 . The orad end portion  33  of the prosthetic bowel  30  is isolated from the material moving through the inner tube  32  by the inflation member pair  36   c . The valve  46   b  is then closed. A number of inflation member pairs may be provided in the prosthetic bowel  30  and the sequence of inflating and deflating the inflation members continues until the last inflation member pair  36   e  is inflated. 
     As illustrated in  FIGS. 10 and 11 , after inflation member pair  36   e  is inflated and subsequently inflation member pair  36   d  is deflated, the remaining material is advanced through the rectal sphincter  38  and the sphincter  38  is closed by first inflating the inflation member  36   f  by opening valve  46   f  and pumping inflation medium from reservoir  49  through conduit  39   f . The inflation member pair  36   e  is deflated by opening valve  46   e  and pumping the inflation medium into the reservoir  49 . ( FIG. 10 ) The valve  46   e  is closed and valve  46   g  is opened and the inflation medium from the reservoir  49  is pumped into the inflation member  36   g  to close the valve  38 . 
     This cycle of inflating and deflating inflation members may be repeated in subsequent bowel emptying steps or sequences. The cycle may also be modified and the order of emptying along the length of the prosthetic bowel may be done is subsections according to a program, such as for example, as illustrated in  FIG. 13 . Referring to  FIG. 13 , a sequence of emptying of one embodiment is illustrated. According to the embodiment, a prosthetic bowel  330  is illustrated as being divided into five sections, Sections A-E with section A being the aborad most section coupled to the anus and section E being coupled to the small intestine. Each section includes a series of inflatable members such as, for example, the inflatable members of the prosthesis described with respect to  FIGS. 2-11 . As illustrated in  FIG. 13 , the sections of inflatable members are actuated in a sequence of sections. In the first sequence I, section A is actuated so that the inflatable members are inflated in a sequence in an aborad direction, excreting the material in section A. 
     After A is actuated, a second sequence II of inflatable member sections is actuated in which section B is actuated so that the inflatable members of section B are inflated in a sequence in an aborad direction and then section A is actuated inflating inflatable members of section A in an aborad direction. Thus, material is moved through sections B, then A and then is excreted. 
     A third sequence III of inflatable member sections is actuated in which section C is actuated, then section B is actuated and then section A is actuated. Thus material is moved through sections C, B, and A, and then is excreted. And similarly the fourth sequence IV of inflatable member sections is actuated with section D followed by Section C followed by section B and then followed by Section A. Finally a fifth sequence V of inflatable member sections is actuated with section E, followed by Section D, followed by section C, followed by Section B and followed by Section A. Thus, the prosthetic bowel  330  is emptied by first emptying the aborad most section and slowly working towards the orad end so that the pump does not have to pump the entire prosthetic bowel out at one time. 
       FIGS. 12A and 12B  illustrate an alternative embodiment of a prosthetic bowel of the invention with a two stage orad valve. The prosthetic bowel  130  includes an outer tube  131 , a plurality of inflatable member pairs  136 , an inner tube  132  and an orad valve  137 . The outer tube  131  comprises a first portion  131   a  constructed of a flexible, elastic material coupled to a second portion  131   b  constructed of a flexible, inelastic material. The inner tube  132  comprises a thin-walled, in-elastic flexible material such as polyethylene or polyurethane. Alternatively an elastic material may be used. The inside of the inner tube  132  may be coated with an antibiotic surface, such as a silver coating, to reduce bacterial growth. The inner tube  132  is attached to the outer tube  131  at the orad end portion  133  and the aborad end portion (not shown) of the prosthetic bowel  130  (for example, by welding) to provide an isolated conduit through which material may pass. The orad end portion  133  of the outer tube  131  includes a relatively thicker portion  138  for suturing the outer tube  131  to a small bowel or an orad section of the colon that is to remain intact. The inner tube  132  defines a lumen through which material may enter from the small bowel or small intestine and exit through the anus. The inflatable member pairs  136 , located between the inner member  131  and the second portion  131   b  of the outer member form a bowel emptying mechanism  135 . The number of inflatable member pairs  136  may be selected based on the desired length of the prosthetic bowel  130 . 
     The orad valve  137 , located at the orad end portion  133  of the prosthetic bowel  130  between the outer tube  131  and inner tube  132 , comprises a first low pressure valve  141  and a second high pressure valve  142 . The low pressure valve  141  includes two opposing inflated members  141   a ,  141   b  inflated to a predetermined pressure. The inflated members  141   a ,  141   b  are attached to the outer tube  131  and located between the inner tube  132  and the first portion  131   a  of the outer tube. The inflated members  141   a ,  141   b  tend to close together. ( FIG. 12A ) When a sufficient pressure or force is created in the small intestine from material moving from the small intestine into the prosthesis, the inflated members  141   a ,  141   b  open to permit the passage of material, pressing against the flexible elastic first portion of the outer tube  131  which expand under a threshold pressure. ( FIG. 12B ). 
     The high-pressure valve  142  is adjacent the low-pressure valve  141  in an aborad direction. The high-pressure valve  142  includes opposing inflatable members  142   a  and  142   b  located within the second portion of the valve  137 . When inflated to a predetermined pressure, the inflatable members squeezes the inner tube  132  together preventing movement of material between the small intestine and the prosthetic bowel  130 . To close the high-pressure valve  142 , it is inflated by way of pumping fluid through conduit  144  with a fluid pump such as the pump  41  described with reference to  FIGS. 2-11 . Typically the high-pressure valve  142  is left open when the prosthetic bowel  130  is collecting materials from the small intestine ( FIG. 12B ). The high-pressure valve  142  is typically closed during or just prior to the bowel emptying mechanism  135  being actuated ( FIG. 12A ). The inflatable members  142   a ,  142   b  are inflated to a high pressure that can with stand the pressure of the bowel emptying mechanism  135  when it is actuated to move material through the prosthetic bowel  130 . Alternatively or in addition, inflation members such as inflation member pairs  136  may be used as a high-pressure valve in the two-stage valve. 
     Alternatively, as illustrated in  FIGS. 12C and 12D  the inflated members  141   a ′,  141   b ′ are coupled through a conduit  143 ′ extending from the inflated members  141   a ′,  141   b ′ out of the outer tuber  131 ′, to an elastic bladder  146 ′. The outer tube  131 ′ of the prosthetic bowel  130 ′ is relatively inelastic. When a force exceeding a predetermined pressure is applied to the inflated members  141   a ′,  141   b ′, for example, by a pressure or by material entering the prosthetic bowel from the small bowel, a portion of the inflation medium within the inflated members  141   a ′,  141   b ′ is squeezed into the elastic bladder  146 ′ ( FIG. 12D ). When the force is removed, the elasticity of the bladder  146 ′ causes the bladder  146 ′ to contract and squeeze the fluid out of the bladder back into the inflated members  141   a ′,  141   b ′ to its original resting state ( FIG. 12C ). Generally, the pressure of the low-pressure valve  141 ′ is lower than or matches the pressure exerted by the small bowel when it contracts. Thus the low pressure valve remains closed unless a pressure is exerted on the orad side of the valve  141 ′. The valve  141 ′ tends to close when a pressure is exerted from the aborad side in a similar manner as described with reference to  FIGS. 2-11  above with respect to the valve  37 . A high-pressure valve  142 ′ operates in the same way as high pressure valve  142  described with reference to  FIGS. 12A and 12B . 
       FIG. 14  illustrates an alternative configuration of inflatable members  156   a - e  and  157   a - e  of a bowel emptying mechanism  155  of an alternative embodiment of a prosthetic bowel  150 . Upper inflatable members  156   a - e  are offset from the lower inflatable members  157   a - e  so that material is not stuck between opposing inflation member pairs. The inflatable members  156   a - e ,  157   a - e  may be inflated in a sequence similar to the sequence described above with respect to  FIGS. 2-11  or alternatively each inflation member may be inflated in an aborad moving sequence. 
       FIG. 15  illustrates another configuration of inflatable members  166   a - d  of a bowel emptying mechanism  165  of an alternative embodiment of a prosthetic bowel  160 . Each inflatable member  166   a - d  comprises an inflatable member wrapped in a spiral-like configuration around the inner circumference of the outer tube  162 . The inflatable members  166   a - d  may be inflated in a sequence similar to the sequence described above with respect to  FIGS. 2-11  and each inflation member may be inflated in an aborad moving sequence. 
       FIG. 19  illustrates an alternative embodiment of a prosthesis  170  of the invention. The prosthetic bowel  170  comprises an outer tube  171 , and inner tube  172  and an inflation member pair  176  located between the inner tube  172  and the outer tube  171 . Waste material enters the orad end portion  173 , which is coupled to the small intestine (not shown), and exits the aborad end portion  174  which is coupled to the anus (not shown). A pump  178  is controlled by a controller  180  to pump fluid from a bladder  179  through a fluid conduit  177  and into the inflation member pair  176 , and, visa versa to pump material out of the prosthetic bowel  170 . The prosthetic bowel  170  may be used to replace the bowel or a small portion of the small or large bowel. 
       FIG. 20  illustrates an alternative configuration of an inflation member  196  to be used in a prosthetic bowel  190  wherein the inflation member  196  has a U-shape or a donut-like shape. The inflation member  196  is located between an outer tube  191  and an inner tube  192  and is inflated and deflated with an inflation medium through a conduit  199 . 
       FIGS. 16-18F  illustrate a valve-actuating device  300  according to an embodiment of the invention. The valve-actuating device  300  comprises a cylinder  310  having a length Lc aligned parallel with the length Lh of the header  45  of the pump  41  and adjacent the valves  46   a - g . The cylinder  310  includes a plurality of openings  320   a - g , spaced a defined distance along the length Lc of the cylinder  310  with respect to the other openings so that each opening is aligned lengthwise with a corresponding one of the valves  46   a - g . Each opening  320   a - g  is also spaced a defined discrete distance circumferentially from the other openings. The cylinder  310  is coupled to a stepper motor  330  that rotates the cylinder  310  according to instructions from the controller  51  ( FIG. 2 ) into discrete circumferential positions to interfacingly align a selected opening with a corresponding selected valve. Thus, the cylinder  310  may be rotated to discrete positions wherein in each position one of the openings  320   a - g  is interfacing a corresponding one of the valves  46   a - g  to be actuated. 
     A valve is actuated by a peg extending out of an interfacing opening in the cylinder  310  to engage and move the valve into an open position. Each opening  320   a - g  in the cylinder  310  includes concentrically moveable peg  321   a - g  respectively. Each of the pegs  321   a - g  is capable of being partially advanced in a circumferential direction out of the corresponding opening  320   a - g  in the cylinder  310 . When interfacing with a corresponding valve  46   a - g , a corresponding peg  321   a - g  may be advanced to engage and open the corresponding valve  46   a - g  to open it. 
     Once a valve is selected and the controller  51  instructs the stepper motor  330  to rotatably position the cylinder  310  accordingly, an actuating rod  323  is advanced through the cylinder  310  to engage and advance the corresponding aligned, interfacing peg out of the cylinder  310  to open the corresponding valve. 
     The actuating rod  323  slidably extends axially through an axial opening  313  in the cylinder  310 . The rod  323  is coupled to a solenoid  328  that moves the rod  323  between two positions: a first resting position ( FIG. 16-16A ,  FIGS. 18-18F ) and a second valve actuating position ( FIG. 17-17A ). The solenoid  328  advances and retracts the rod  323  to and from a valve actuating position. The actuating rod  323  moves in a direction generally perpendicular to the circumferential sliding direction of the pegs  321   a - g . The actuating rod  323  includes a central rod  324  and a plurality of staggered fins  325   a - g  having cammed surfaces  326   a - g . In the first position, the fins  325   a - g  are staggered in a lengthwise relationship between the valves  46   a - g  and a second position, the fins  325   a - g  are generally aligned in a lengthwise relationship with the valves  46   a - g . The cammed surfaces  326   a - g  are arranged so that when the rod  323  is advanced to the second position, a corresponding one of the cammed surfaces  326   a - g  will engage a corresponding one of the pegs  321   a - g  to move the corresponding one of the pegs  321   a - g  circumferentially out of a corresponding one of the openings  320   a - g.    
     The axial opening  313  through the cylinder  310  includes a central rod portion  314  for receiving the rod  323  and a fin portion  315  for receiving in the fins  325   a - g . The central rod portion  314  extends axially through the cylinder  310 . The fin portion  315  of the axial opening  313  includes open portions  316   a - g  staggered in a lengthwise relationship between the valves  46   a - g . Each open portion  316   a - g  is open within the rod opening  313  about the circumference of the cylinder  310  so that when the rod  323  is in the first position, the cylinder  310  is fee to rotate without interference of the fins  325   a - g . The fin portion  315  also includes a plurality of slits  317   a - g  wherein each slit extends longitudinally through the cylinder, between each of the open portions  316   a - g  and perpendicularly through a corresponding one of the openings  320   a - g.    
     The fins  325   a - g  are aligned in a position with the circumferentially extending top portions facing the header  45 . The cylinder  310  may be rotated when the rod  323  and fins  325   a - g  are in the first position. The cylinder  310  when rotated to one of its discrete positions aligns a corresponding slit with the fins so that in the second position the fins advance through that slit. When the fins  325   a - g  are moved into the second position, the fins  325   a - g  extend through the slit corresponding to the opening that is positioned in alignment with a corresponding valve. In each discrete position the fins  325   a - g  are aligned with a slit permitting the corresponding fin to slide into the opening and engage the pin moving the pin out of the opening engaging the correspond valve with which it is aligned, thus actuating the corresponding valve. Each peg  321   a - g  is biased by a corresponding spring ( 329   a  only is shown) into a position circumferentially into the opening so that when the fins are retracted (e.g.  FIG. 18 ), the pin moves back into the opening. 
     The controller  51  controls the timing and actuation of the cylinder  310  rotation and the solenoid  328  positioning. Referring to  FIG. 16 , the cylinder  310  is rotated to a position in which none of the pegs are aligned with valve  36   a . The rod  323  is in a first position in which the cylinder  310  may rotate freely. The cylinder  310  is then rotated as illustrated in  FIG. 17  so that the opening  321   a  is aligned with the valve  46   a . The rod  323  is advanced so that the fins  325   a - g  extend through the slit  317   a . Fin  325   a  extends into the opening  320   a  that is aligned with the slit  325   a  and the cammed surface  326   a  of the fin  325   a  engages the peg  321   a  and advances it out of the opening  320   a  to actuate valve  46   a . The valve  46   a  is opened and the pump  41  pumps fluid from the reservoir  49  into the inflatable member pair  36   a . As illustrated in  FIG. 18 , the rod  323  is then retracted releasing the peg  321   a , which is biased by spring  329   a  into the cylinder opening  320   a , and the valve  46   a  is closed, leaving the inflation member pair  36   a  inflated. 
     While the invention has been described with reference to particular embodiments, it will be understood to one skilled in the art that variations and modifications may be made in form and detail without departing from the spirit and scope of the invention. 
     For example the peristalsis organ of the invention may be used in a prosthetic stomach organ or prosthetic pylorus such as, for example those disclosed in the U.S. application entitled “Stomach Prosthesis”, filed on even date herewith, which is incorporated into this patent application by reference.