Patent Description:
Stomach cancer is a serious condition and to save life it has been shown that the whole stomach needs to be surgically removed although the cancer may be small. Patients with stomach cancer normally get their whole stomach surgically removed, the operation called total gastrectomy. This means the oesophagus and the intestine is sutured together. These patients quality of life is dramatically reduced. Their food supply is normally without both reservoir and valves- creating serious problems in terms of ability to eat and ability to keep the weight. <CIT> discloses an artificial stomach with a food reservoir and an attachment cuff having a T-anchor as a tissue connector.

The placement of the normal stomach <NUM> of a person <NUM> is seen in <FIG>. A more detailed view of the anatomy of a normal stomach is shown in <FIG>. In the gastrointestinal tract, the oesophagus <NUM> normally transcends into the stomach <NUM> at the cardia area <NUM>. The stomach <NUM> then transcends downstream into the duodenum <NUM> of the intestine <NUM> at the pyloris <NUM>. For persons having their stomach <NUM> surgically removed (hereinafter referred to as patients), one method is to surgically connect the oesophagus <NUM> directly to the intestine <NUM>. The result of such a surgical operation is shown in <FIG>. The most proximal part of the intestine <NUM>, i.e. the duodenum <NUM>, is not able to reach to the oesophagus <NUM> and therefore the proximal jejunum <NUM> is cut and the distal side sutured to the oesophagus <NUM> and the proximal part of the jejunum <NUM> comprising duodenum <NUM> and the gall connection proximal is sutured end to side to jejunum <NUM> further distal creating a so called Roux-en-Y- connection.

Because it is not easy to reach the oesophagus <NUM> with the intestine <NUM>, they are normally connected end to end like a tube without any reservoir or valves. Normally the cardia <NUM> (the ring muscle between the stomach and oesophagus) keeps the food passage way closed to avoid reflux problems but cardia <NUM> is normally removed when performing a Roux-en-Y operation.

The overall result is a very unpleasant situation for the patient. The patients have large difficulties to keep their weight and normally feel themselves in a really bad shape, with several food related bad feelings. The situation for the patients is so complicated that studies have shown a dramatic increase in suicide in this group of patients.

Furthermore, there exist also other possible solutions, such as xenotransplantations and intravenous drip. Xenotransplantation is a method where an organ from an animal is transplanted to a patient. However, the immune rejection effects are serious and the method is not a usable alternative. The method of living with a nutrition drip has various disadvantages, for instance the patient needs to bring droplet equipment and loses also the moment of eating. The situation of life for a patient with nutrition drip is far from natural.

The ability to replace the stomach with an artificial stomach would increase quality of life dramatically for these patients. Such an artificial stomach may be used independently of the reason for removing the stomach.

An object of the present invention is to provide a solution to the above described problem for patients which have had their stomach surgically removed.

The invention is based on the realisation that an implanted artificial stomach can replace a natural stomach, which has been removed.

Thus, according to one embodiment of the invention there is provided an artificial stomach for replacing the normal stomach of a patient, comprising: a food reservoir adapted to collect food, an inlet connected to a first opening of the food reservoir and further being adapted to upstream connect to the patient's gastrointestinal tract, and an outlet connected to a second opening of the food reservoir and further being adapted to downstream connect to the patient's gastrointestinal tract.

In the preferred embodiment the artificial stomach comprises an inlet valve connected between the patient's gastrointestinal tract and the first opening of the food reservoir.

An alternative embodiment include:
An artificial stomach for replacing the normal stomach of a patient, comprising:.

The artificial stomach may be implantable in the patient's abdomen and may have the inlet further adapted to upstream connect to the oesophagus. The inlet may also be further adapted to upstream connect to the intestine.

In one embodiment the inlet valve is connected between the inlet and the first opening of the food reservoir or the artificial stomach comprises an inlet valve unit comprising an inlet valve connected between the patient's gastrointestinal tract and the first opening of the food reservoir.

The inlet valve is preferable adapted to open correlated to when food in the gastrointestinal tract upstream is transported down. Alternatively the inlet valve is adapted to open correlated to when a contracting wave is propagating along the gastrointestinal tract upstream or adapted to open correlated to when food is reaching the inlet valve.

In another embodiment the inlet valve unit comprising at least one connector adapted to upstream connect the inlet to the patient's gastrointestinal tract. The connector comprises a sleeve adapted to cover a part of the wall of the gastrointestinal tract, wherein the sleeve preferable has a structure adapted to promote in-growth of human tissue into the sleeve.

The artificial stomach preferable the inlet valve unit may further comprising a burp output, wherein the burp output further comprises a burp valve connecting the food reservoir with the inlet valve proximal to said burp valve.

The artificial stomach preferable have an outer wall that encloses both the food reservoir and a servo reservoir for regulating the size of the food reservoir, the food reservoir and the servo reservoir being separated by a flexible inner wall, where further both the food reservoir wall and the wall of the servo reservoir comprise parts of the outer wall and the flexible inner wall, wherein said servo reservoir is adapted to be filled with fluid in small steps, wherein the food reservoir is adapted to be emptied by the servo reservoir in small steps, when said servo reservoir is filled with said fluid in small steps, thereby emptying food in small steps into the intestine, when said artificial stomach is implanted.

The food reservoir is normally adapted to empty step by step, small portions of food at a time.

In yet another embodiment the artificial stomach have an the outlet valve adapted to functioning passively and opens related to a volume decrease in the food reservoir.

The artificial stomach normally include a servo reservoir, adapted to have a variable size and to be filled with different amounts of fluid. The servo reservoir in this embodiment is adapted to have a shape allowing variation in size without limitation from surrounded fibrosis, covering the implant when implanted.

The artificial stomach further may include a hydraulic fluid reservoir, hydraulically connected to said servo reservoir and a pump for fluid connecting the fluid supply reservoir to the servo reservoir. Preferable said pump is adapted to reversible move fluid between the servo reservoir and the hydraulic fluid reservoir.

In the artificial stomach according to another embodiment, an outer wall encloses both the food reservoir and a servo reservoir for regulating the size of the food reservoir, the food reservoir and the servo reservoir being separated by a flexible inner wall, where further both the food reservoir wall and the wall of the servo reservoir comprise parts of the outer wall and the flexible inner wall.

The servo reservoir may comprise a bellow.

The artificial stomach may in another embodiment have said servo reservoir adapted to be regulated by manually pressing a pumping reservoir in fluid connection with the servo reservoir, and may further comprising a reversed servo, wherein a small volume in the pumping reservoir is adapted to be moved manually to the servo reservoir in a closed system, compressed with a higher force per area unit and wherein said servo reservoir is adapted to create a larger volume change in a second closed system, having less force per area unit.

Preferable the artificial stomach having the outer wall being rigid. In one embodiment the stomach food part comprises the food reservoir and the servo reservoir, and where the hydraulic fluid reservoir is separated from the stomach food part by the rigid outer wall and is further enclosed by a fluid reservoir wall,.

In yet another embodiment the food reservoir is adapted to increase in volume when filled with food when the patient is eating, thereby causing a reduction in the volume of the servo reservoir, in turn moving fluid from said servo reservoir to said hydraulic fluid reservoir.

The artificial stomach outlet is further normally adapted to downstream connect to the intestine.

The artificial stomach preferable comprising an outlet valve connected between the second opening of the food reservoir and the outlet, wherein the outlet valve is adapted to open when the food reservoir should be emptied. Alternatively the outlet valve is adapted to open at a regulated rate.

In the artificial stomach according to another embodiment, the food reservoir, the inlet, and the outlet are manufactured of a biocompatible material.

The artificial stomach comprising at least one connector adapted to upstream connect the inlet to the patient's gastrointestinal tract, or downstream connect the outlet to the patient's gastrointestinal tract, wherein the connector comprises a sleeve adapted to cover a part of the wall of the gastrointestinal tract, and wherein the sleeve preferable has a structure adapted to promote in-growth of human tissue into the sleeve.

Thus the artificial stomach comprises a connector connecting the intestine to the outlet connector and / or a connector connecting the oesophagus or intestine to the inlet connector.

In one embodiment the artificial stomach comprising a food handling system, which may be adapted to;.

The liquid may comprises at least one of; an acid, an enzyme, an anti-bacterial substance.

In yet another embodiment the artificial stomach comprising a cleaning system adapted to clean the surface of the food reservoir by releasing at least one liquid into the food reservoir.

The liquid may comprises a cleaning substance and / or an anti-bacterial substance. The artificial stomach may further comprising a special container, wherein the special container preferable is adapted to accumulate and distribute at least one liquid to the food handling system and / or, wherein the special container is adapted to accumulate and distribute at least one liquid to the cleaning system.

The artificial stomach or the system connected thereto may include a food sensor arranged outside of the food reservoir on the inlet side of the same in order to register when food is to arrive to the artificial stomach, wherein preferable the food sensor is arranged at the oesophagus wall.

The system in one embodiment include, the registration that food is to arrive to the artificial stomach is made by registering change in volume of the oesophagus or change of the curvature or elongation of the oesophagus wall.

In yet another embodiment the artificial stomach, comprising at least one connector adapted to be connected to the oesophagus or the intestine of a patient, the connector comprising a conduit fixedly attached at a first, proximal end on the outside the artificial stomach and in fluid connection to the food passageway, where the proximal part of the conduit is formed like a tube, and distal to the tube a bulge is formed.

A blocking ring is arranged to be pushed against the bulge, the ring having an inner diameter less than the outer diameter of said bulge but large enough to allow the intestinal/oesophageal wall to be placed between said ring and said tube, thereby adapted to stop said intestinal/oesophageal wall from slipping away from the tube.

Preferable is included a flexible sleeve arranged to be rolled upon itself and then unrolled to cover part of the tube and the oesophagus or intestine, which is arranged to be pulled over the second end of the conduit sufficiently far so as to extend also over the bulge.

In one embodiment of the artificial stomach a blocking ring is arranged to be pushed over the flexible sleeve against the bulge, the ring having an inner diameter less than the outer diameter of said bulge but large enough to allow the intestinal/oesophageal wall to be placed between said ring and said tube, thereby adapted to stop said intestinal/oesophageal wall from slipping away from the tube.

The artificial stomach in one embodiment includes a return conduit arranged between the fluid reservoir and the servo reservoir for moving fluid between said servo reservoir and said hydraulic fluid reservoir via said return conduit.

In one embodiment of the artificial stomach; moving of fluid from the servo reservoir to the hydraulic fluid reservoir is done by that the food entering the food reservoir from the inlet presses on the flexible wall of the servo reservoir thus emptying fluid from there to the hydraulic fluid reservoir via a return conduit.

In another embodiment of the artificial stomach; moving of fluid from the servo reservoir to the hydraulic fluid reservoir is done by that a food sensor sends signals to the pump when food is to enters the food reservoir, the pump thus pumping out to said food corresponding amount of fluid from the servo reservoir to the hydraulic fluid reservoir.

In yet another embodiment the emptying of the food reservoir is direct or indirect regulated by a gear construction. Preferable the gear construction is driven by a motor.

The artificial stomach according to another embodiment, comprises a servo system connected to said motor, to save force against longer stroke.

Preferable a servo system is connected to said motor and a drive shaft connected to said servo system, wherein the drive shaft preferable direct or indirect affects the emptying of said food reservoir.

In another embodiment the the drive shaft comprises two ends comprising a thread, spiral ridges turning in different directions at the two ends, further comprising a nut placed on the shaft at each end of the drive shaft, the food reservoir comprising two movable walls of said reservoir, wherein said nuts is adapted to be placed onto said moving walls, the motor adapted to change the volume of said food reservoir, when turning said drive shaft placed into said nuts, by moving said movable walls.

The artificial stomach may comprise an elastic material, a bio-compatible material and/or silicone.

Suitably, is provided at least one layer. For example, a metal layer, a Parylene layer, a polytetrafluoroethylene layer or a polyurethane layer. Suitably, one of the layers may be made of metal, silicon or PTFE. The layers may comprise multiple layers in any order. The volume filling device may comprise an outer surface layer of silicone, polyurethane, Teflon®, or polytetrafluoroethylene, metal, parylene, PTFE or a combination thereof. The volume filling device may comprise an inner surface layer of silicone, polyurethane, Teflon®, or polytetrafluoroethylene, metal, parylene, PTFE or a combination thereof. Other combinations of layers include but not limited to an inner surface layer of polytetrafluoroethylene and an outer layer of silicone, an inner surface layer of polytetrafluoroethylene, an intermediate layer of silicone, and an outer layer of Parylene, an inner surface layer of polyurethane and an outer layer of silicone, and an inner surface layer of polyurethane, an intermediate layer of silicone, and an outer layer of Parylene.

The fluid may comprises large molecules, such as iodine molecules, to prevent diffusion.

The system may include a fastening device for the artificial stomach comprising a first unit adapted to be implanted at a first side of the abdominal wall in the patient, and where a second unit is adapted to be implanted in the abdominal cavity of the patient at a second side of the abdominal wall, and where the artificial stomach is fastened to the fastening device, wherein preferable the first or second unit has a circular or elliptical cross-sectional shape when viewed from outside the patient's body.

In one embodiment the first and second units are covered by a cover made of material providing protection, wherein preferable the cover seals the fastening device which also may be a control assembly, thereby protecting possible electronics and other sensitive components of the control assembly.

The system may include an interconnecting device constitutes a mechanical interconnection between the first and second units so that the fastening device is kept in place by the body tissue.

In another embodiment the interconnecting device is hollow so as to house various wires, hoses etc. electrically or hydraulically interconnecting the first and second units.

According to one embodiment the device is a part of a system that may comprise a switch for manually and non-invasively controlling the device. The switch is according to one embodiment an electric switch and designed for subcutaneous implantation.

According to another embodiment the system further comprises a hydraulic device having a hydraulic reservoir, which is hydraulically connected to the device. The device could be manually regulated by pressing the hydraulic reservoir or automatically operated using a wireless remote control.

The wireless remote control system comprises, according to one embodiment, at least one external signal transmitter and an internal signal receiver implantable in the patient for receiving signals transmitted by the external signal transmitter. The system could operate using a frequency, amplitude, or phase modulated signal or a combination thereof.

According to one embodiment the wireless control signal comprises an analogue or a digital signal, or a combination of an analogue and digital signal. It is also conceivable that the signal comprises an electric or magnetic field, or a combined electric and magnetic field. According to another embodiment the wireless remote control further transmits a carrier signal for carrying the wireless control signal, said signal could comprise a digital, analogue or a combination of digital and analogue signals.

For supplying the system with energy it comprises, according to one embodiment, a wireless energy-transmission device for non-invasively energizing said device. According to said embodiment the energy-transmission device transmits energy by at least one wireless energy signal, which for example comprises a wave signal such as an ultrasound wave signal, an electromagnetic wave signal, an infrared light signal, a visible light signal, an ultra violet light signal, a laser light signal, a micro wave signal, a radio wave signal, an x-ray radiation signal and a gamma radiation signal.

It is further conceivable that the energy signal comprises an electric or magnetic field, or a combined electric and magnetic field, which can be transmitted using a carrier signal such as a digital, analogue or a combination of digital and analogue signals.

According to one embodiment the system further comprises an energy source for powering said device, which can be an implantable or external energy source or a combination thereof, in which case the internal and external energy sources can be in electric communication.

In an embodiment in which the system comprises an internal energy source, a sensor sensing a functional parameter correlated to the transfer of energy for charging the internal energy source may be provided, it is furthermore conceivable that a feedback device for sending feedback information from the inside to the outside of the patient's is provided.

According to another embodiment the system further comprises a sensor sensing a parameter such as a functional or physical parameter. Said functional parameter is, according to one embodiment, correlated to the transfer of energy for charging an internal energy source implantable in the patient. Said embodiment could furthermore comprise a feedback device for sending feedback information from inside to the outside of the patient's body and an implantable internal control unit for controlling the sensing. Above mentioned physical parameter could be one of body temperature, blood pressure, blood flow, heartbeats and breathing, and the sensor could be a pressure or motility sensor.

According to one embodiment the system could further comprise an external data communicator and an implantable internal data communicator communicating with the external data communicator, wherein the internal communicator feeds data related to said device or the patient to the external data communicator and/or the external data communicator feeds data to the internal data communicator. It is also conceivable that the system further comprises an operation device for operating said device, such as a motor or a pump, which can be electrically, hydraulically or pneumatically operated.

According to another embodiment the system has an energy-transmission device for transmitting wireless energy, wherein the wireless energy is used to directly power the operation device through for example creating kinetic energy for the operation of said device.

In embodiments where the system comprises an energy-transmission device for transmitting wireless energy, an energy-transforming device for transforming the wireless energy from a first form into a second form may be provided. Said energy-transforming device may directly power by the second form of energy. The energy could be in the form of a direct current or pulsating direct current, or a combination of a direct current and pulsating direct current, or an alternating current or a combination of a direct and alternating current, it is also conceivable that the energy is in the form of magnetic energy, kinetic energy, sound energy, chemical energy, radiant energy, electromagnetic energy, photo energy, nuclear energy or thermal energy. The system may further comprise an implantable accumulator for storing energy.

To prevent damage of the system it is conceivable that it comprises implantable electrical components including at least one voltage level guard and/or at least one constant current guard.

In a preferred embodiment, the system comprises at least one switch implantable in the patient for manually and non-invasively controlling the apparatus
In another preferred embodiment, the system comprises a wireless remote control for non-invasively controlling the apparatus.

In a preferred embodiment, the system comprises a hydraulic operation device for operating the apparatus.

In one embodiment, the system comprises comprising a motor or a pump for operating the apparatus.

The method (not part of the invention) of filling the servo reservoir with fluid step by step in small steps so that the food reservoir is emptied or at least essentially emptied in small steps which results in food is received by the intestine in small subsequent portions.

Briefly described, the present invention provides a solution for enabling a more natural digestive process for patients which have their natural stomach removed, by providing and implanting an artificial stomach into the patient's body.

The term "food" used in this description will hereinafter represent food or liquid, as well as any combination of food and liquid eaten or drunk by a patient. With "patient" means any human or animal, suitable to have its normal stomach replaced by an artificial stomach. The "oesophagus" is also found to be spelled esophagus. Correspondingly, oesophageal may also be spelled esophageal.

Prior art has been described above with reference to <FIG>, <FIG>, and <FIG>.

A patient having an implanted artificial stomach in accordance with one embodiment of the present invention will now be described, with reference to <FIG>. The artificial stomach <NUM> is implanted in the body of the patient <NUM>, preferably at the same place as the normal stomach was removed from. The artificial stomach <NUM> may in this example be controlled by any suitable means, such as a remote control (not shown), which is either placed outside the patient's body or is implanted in the body.

An artificial stomach in accordance with an exemplary embodiment of the present invention will now be described with reference to <FIG> illustrating a block diagram. The artificial stomach <NUM> comprises an inlet <NUM>, connected to a first opening of a food reservoir <NUM>, and an outlet <NUM> connected to a second opening of the reservoir <NUM>. The inlet <NUM> is connected upstream to the oesophagus of a patient, and receives food when the patient eats or drinks. The inlet <NUM> feeds the food to the food reservoir <NUM> that collects the food. The outlet <NUM> is connected downstream to the intestine of the patient, and outputs the collected food. Alternatively, the inlet <NUM> may instead be connected to the intestine, at a point upstream from the point the outlet <NUM> is connected to. This is useful for patients having their normal stomach removed and their oesophagus connected to their intestine. Preferably, the artificial stomach <NUM> may be adapted to be implanted in the abdomen of the patient, but may also be designed to be used on other areas inside or outside the patient's body.

Another embodiment, different from the embodiment described above, will now be described with reference to <FIG>. The artificial stomach according to this embodiment comprises the corresponding inlet <NUM>, food reservoir <NUM>, and outlet <NUM>, as described above, but comprises also various additional components. The artificial stomach <NUM> comprises an inlet valve <NUM> and an optional outlet valve <NUM>, the valves opening and closing the food reservoir <NUM>. The inlet valve <NUM> is adapted to open correlated to when food and/or a contracting wave in the oesophagus is transported longitudinally down the oesophagus. Optionally, the inlet valve <NUM> may instead be adapted to open correlated to when food and/or a contracting wave in the oesophagus is reaching the inlet valve <NUM>. The outlet valve <NUM> is adapted to empty the food reservoir <NUM> relatively slowly into the intestine, and the outlet valve may be adapted to either open stepwise or steplessly. To connect the artificial stomach <NUM> to the oesophagus or intestine, an inlet connector <NUM> and an outlet connector <NUM> is used. The food will be transported through a food passageway <NUM>, defined as comprising all components which come into contact with the food, i.e. including the food reservoir <NUM>, the inlet valve <NUM>, the outlet valve <NUM>, and the connectors <NUM> and <NUM>. This food passageway is preferably manufactured of a biocompatible material. Preferably, the food reservoir <NUM> may be adapted to empty relatively slowly into the intestine. A food sensor <NUM> may be arranged outside of the food reservoir <NUM> on its inlet side in order to register when food is to arrive to the food reservoir <NUM>. The food sensor <NUM> is e.g. arranged at the position shown in <FIG>, but may as has been earlier mentioned be situated e.g. at the oesophagus wall (see <FIG>). The registration that food is to arrive to the food reservoir <NUM> is e.g. made by registering change in volume of the oesophagus or change of the curvature or elongation of the oesophagus wall in which case the food sensor is preferably arranged on or at the oesophagus wall as shown in <FIG>.

A food handling system <NUM> is connected to the food reservoir <NUM> is be adapted to handle the food in the food reservoir <NUM> mechanically and/or chemically. A mechanical food handling system may include at least one of: a moving system moving the food around in the food reservoir <NUM>, a squeezing system squeezing the food in the food reservoir <NUM>, a cutting system cutting the food in the food reservoir <NUM> (e.g. by rotating knifes), or any other system suitable for mechanically handling the food in the food reservoir <NUM>. On the other hand, a chemical food handling system may be adapted to release various chemicals into the food reservoir <NUM> for treating the food, e.g. by releasing digestion-facilitating chemicals (e.g. an enzyme, an acid, etc.), or disinfecting chemicals (e.g. an anti-bacterial substance) into the food. A cleaning system <NUM> is provided and may be adapted to treat the food passageway <NUM> with cleaning chemicals, e.g. including any anti-bacterial substance.

To enable the releasing of digestion-facilitating chemicals, disinfecting chemicals, or cleaning chemicals in the food reservoir <NUM>, the artificial stomach <NUM> comprises a special container <NUM> adapted to accumulate these chemicals before distributing them to the food reservoir <NUM>. Furthermore, an injection port <NUM> connected to the special container <NUM> is also provided to enable filling or re-filling of chemicals to the special container <NUM>. The injection port <NUM> is adapted to be placed subcutaneously on the patient's body, and is further adapted to be injected with at least one of: an anti-bacterial liquid, an acid, a cleaning fluid, a contrast medium, or any other suitable liquid.

In order to operate the artificial stomach <NUM>, an operating device <NUM> is provided. The operating device <NUM> may electrically and/or hydraulically operate the artificial stomach <NUM>, e.g. by operating the food handling system <NUM>, or the cleaning system <NUM>. In the case when the artificial stomach <NUM> is electrically operated, the operation device <NUM> is electrically powered and may e.g. comprise an electrical motor. In the case when the artificial stomach <NUM> is hydraulically operated, the operation device <NUM> is instead a hydraulic operation device. However, a skilled person will understand that the operation device <NUM> may also be designed to be powered and operated in different ways. For instance, the food handling system <NUM> may be operated hydraulically, but be powered electrically.

The artificial stomach <NUM> is adapted for various functions, e.g. mechanically food handling, chemical food handling, or cleaning the food passage way <NUM>, and at least one of the functions may be regulated from outside the patient's <NUM> body. For regulating a function from outside the patient's <NUM> body, a subcutaneous switch may be adapted to be pressed by the patient. Alternatively, when the artificial stomach <NUM> is hydraulically operated, a hydraulic reservoir having a connection with the hydraulic operation device <NUM> may be adapted to be manually pressed by the patient <NUM> for regulating the operation device <NUM>. The hydraulic reservoir may be the special container <NUM>, and may be placed invasively or non-invasively. When the operation device <NUM> is powered electrically, the artificial stomach <NUM> in one alternative may comprise an internal energy source (e.g. a battery or an accumulator), a remote control and a receiver for the information signals from the remote control. These components are adapted to enable for the patient to regulate the artificial stomach from outside the body. Different ways of controlling or regulating the artificial stomach will be described below with reference to <FIG>.

However, a skilled person will understand that the components of the described embodiment may be varied and he is also capable to construct an artificial stomach comprising various combinations of these components.

An artificial stomach in accordance with an exemplary embodiment of the present invention will now be described with reference to <FIG>, and with further reference to <FIG> and <FIG>. The artificial stomach <NUM> is preferably manufactured in order to have an anatomical structure similar to the structure of the normal stomach, and is adapted to be placed in the abdomen of a patient. In this embodiment the artificial stomach <NUM> is hydraulically operated. The artificial stomach <NUM> is connected to the gastrointestinal tract, upstream the inlet <NUM> is connected to the oesophagus <NUM> and downstream the outlet <NUM> is connected to the distal end of the cut jejunum <NUM>. However, a skilled person will understand that the artificial stomach <NUM> may be implanted on various places of the gastrointestinal tract. For instance, a patient <NUM> having the stomach removed by the Roux-en-Y method, may have the remaining gastrointestinal tract (oesophagus <NUM> sutured with distal end of jejunum <NUM>) cut and connected to the inlet <NUM> and outlet <NUM> of an artificial stomach <NUM>. In that case, an upstream part of the jejunum <NUM> may be connected to the inlet <NUM> of the artificial stomach <NUM> and a downstream part of the jejunum <NUM> may be connected to the outlet <NUM> of the artificial stomach <NUM>. A regulating bellow <NUM> of the artificial stomach <NUM> is connected through a hose <NUM> with a hydraulic reservoir, a servo reservoir, <NUM>. The hydraulic reservoir <NUM> is placed subcutaneously in the patient <NUM>, outside the abdominal wall <NUM>, i.e. between the patient's skin <NUM> and the abdominal wall <NUM>. The patient is then capable to operate the artificial stomach <NUM> by pressing or squeezing the hydraulic reservoir <NUM>. Squeezing the hydraulic reservoir <NUM> will regulate the flow of hydraulic fluid to the regulating bellow <NUM>. Alternatively, the hydraulic reservoir <NUM> may be placed on another suitable placement in the patient's <NUM> body and the squeezing of the hydraulic reservoir <NUM> may then be performed indirectly by e.g. pressing a subcutaneous switch, or activating a subcutaneously placed pump, etc. The switch and the pump may then be pressed and activated, respectively, by the patient <NUM>. The food reservoir of the artificial stomach is optionally adapted to increase in volume when filled with food when the patient is eating, thereby causing a change in the volume of the servo reservoir, in turn moving fluid between said servo reservoir and said hydraulic fluid reservoir.

An artificial stomach in accordance with an exemplary embodiment of the present invention will now be described with reference to <FIG>, and with further reference to <FIG> and <FIG>. The artificial stomach <NUM> is manufactured in order to have an anatomical structure similar to the structure of the normal stomach, and is adapted to be placed in the abdomen of a patient. In this embodiment the artificial stomach <NUM> is mechanically operated. The artificial stomach <NUM> is connected to the gastrointestinal tract; upstream the inlet <NUM> is connected to the oesophagus <NUM> and downstream the outlet <NUM> is connected to the distal end of the cut jejunum <NUM>. However, a skilled person will understand that the artificial stomach <NUM> may be implanted on various places of the gastrointestinal tract. For instance, a patient <NUM> having the stomach removed by the Roux. -en-Y method, may have the remaining gastrointestinal tract (oesophagus <NUM> sutured with distal end of jejunum <NUM>) cut and connected to the inlet <NUM> and outlet <NUM> of an artificial stomach <NUM>. In that case, an upstream part of the jejunum <NUM> may be connected to the inlet <NUM> of the artificial stomach <NUM> and a downstream part of the jejunum <NUM> may be connected to the outlet <NUM> of the artificial stomach <NUM>. The artificial stomach <NUM> is regulated by a gear <NUM> driven by a motor <NUM>. An operating unit <NUM>, operating the motor <NUM> is placed subcutaneously in the patient <NUM>, outside the abdominal wall <NUM>, i.e. between the patient's skin <NUM> and the abdominal wall <NUM>. The motor <NUM> is connected with the operating unit <NUM> and is also powered by the operating unit via a connector <NUM>. The operating unit <NUM> may have a subcutaneous switch and the patient <NUM> is capable to operate the artificial stomach <NUM> by pressing the switch. Alternatively, the operating unit may be controlled by a remote control, or other suitable unit from outside the patient's <NUM> body. The food reservoir of the artificial stomach is optionally adapted to increase in volume when filled with food when the patient is eating, thereby causing a change in the gear <NUM> driven by the motor, e.g. by that the gear is allowed to move due to influence of the increase of food in the food reservoir. Said change also causes a change in the position of the bellow. According to this embodiment, the emptying of the food reservoir is direct or indirect regulated by a gear construction, preferably driven by a motor.

A connector (at <NUM>) (earlier referred to as <NUM> and <NUM>) in accordance with the present invention will now be described with reference to <FIG>, and with further reference to <FIG> and <FIG>. The artificial stomach <NUM> comprises at least one connector (at <NUM>) adapted to be connected to the oesophagus <NUM> or the intestine <NUM> of a patient. The connector (at <NUM>) comprises a preferably circular conduit <NUM>, which is fixedly attached at a first, proximal end on the outside the artificial stomach <NUM> and in fluid connection to the food passageway. The proximal part of the conduit <NUM> is formed like a tube <NUM>, and distal to the tube <NUM> a bulge <NUM> is formed. A flexible sleeve <NUM> is rolled upon itself and then unrolled to cover part of the tube <NUM> and tubular tissue <NUM> (oesophagus <NUM> or intestine <NUM>), which, in this case, is pulled over the second end <NUM> of the conduit <NUM> sufficiently far so as to extend also over the bulge <NUM>. The flexible sleeve <NUM> has a structure adapted to facilitate in-growth of tissue through the flexible sleeve <NUM> to achieve a long term connection between the flexible sleeve <NUM> and the intestinal/oesophageal wall <NUM>. After the flexible sleeve <NUM> has been unrolled over the tubular tissue <NUM>, a blocking ring <NUM> is pushed over the flexible sleeve against the bulge <NUM>. The ring <NUM> has an inner diameter less than the outer diameter of said bulge <NUM> but large enough to allow the intestinal/oesophageal wall <NUM> to be placed between said ring <NUM> and said tube <NUM>, thereby adapted to stop said intestinal/oesophageal wall <NUM> to slip away from the tube <NUM>. After a while, the threads <NUM> sutured to the intestinal/oesophageal wall <NUM> and the wall <NUM> of the conduit <NUM> (<FIG>) will have been absorbed by the patient's <NUM> body and, about during the same time, living tissue will have formed in and connected the intestinal/oesophageal wall <NUM> to the in-growth layer <NUM> of the flexible sleeve <NUM>. Therefore, as the intestinal/oesophageal wall <NUM> tends to be pulled off from the second end <NUM> of the conduit <NUM>, the blocking ring <NUM> will also be moved, press the intestinal/oesophageal wall <NUM> and the flexible sleeve <NUM> against the bulge <NUM> and thereby prohibit any further slippage of the intestinal/oesophageal wall <NUM> over the bulge <NUM>. The friction coefficient between the blocking ring <NUM> and the outer surface of the flexible sleeve <NUM> should be higher than the friction coefficient which the outer surface of the conduit's wall <NUM> has in relation to the intestinal/oesophageal wall <NUM>. As has been described above, the connector (at <NUM>) preferably comprises a sleeve <NUM>, but it is also possible as an option to leave out said sleeve 720from the connector, in which case the blocking ring <NUM> is arranged with a somewhat smaller diameter compared to the one shown in <FIG> in order to preserve the functionality described above.

An artificial stomach system, generally designated <NUM> and comprising an artificial stomach as described above will now be described with reference to <FIG>.

The system of <FIG> comprises an artificial stomach <NUM> placed in the abdomen of the patient <NUM>. An internal energy source in the form of an implanted energy transforming device <NUM> is adapted to supply energy consuming components of the artificial stomach system with energy via a power supply line <NUM>. An external energy transmission device <NUM> includes a wireless remote control transmitting a wireless signal, which is received by a signal receiver which may be incorporated in the implanted energy transforming device <NUM> or be separated therefrom. The implanted energy transforming device <NUM> transforms energy from the signal into electric energy which is supplied via the power supply line <NUM>.

The system of <FIG> is shown in a more generalized block diagram form in <FIG>, wherein the patient's skin <NUM>, generally shown by a vertical line, separates the interior of the patient to the right of the line from the exterior to the left of the line.

<FIG> shows an embodiment of the invention identical to that of <FIG>, except that a reversing device in the form of an electric switch <NUM> operable by polarized energy also is implanted in the patient for reversing the artificial stomach <NUM>. The wireless remote control of the external energy transmission device <NUM> transmits a wireless signal that carries polarized energy and the implanted energy transforming device <NUM> transforms the wireless polarized energy into a polarized current for operating the electric switch <NUM>. When the polarity of the current is shifted by the implanted energy transforming device <NUM> the electric switch <NUM> reverses the function performed by the artificial stomach <NUM>.

<FIG> shows an embodiment of the invention identical to that of <FIG>, except that an operation device <NUM> implanted in the patient for regulating the artificial stomach <NUM> is provided between the implanted energy transforming device <NUM> and the artificial stomach <NUM>. This operation device can be in the form of a motor <NUM>, such as an electric servomotor. The motor <NUM> is powered with energy from the implanted energy transforming device <NUM>, as the remote control of the external energy transmission device <NUM> transmits a wireless signal to the receiver of the implanted energy transforming device <NUM>.

<FIG> shows an embodiment of the invention identical to that of <FIG>, except that it also comprises an operation device is in the form of an assembly <NUM> including a motor/pump unit <NUM> and a regulation reservoir <NUM> is implanted in the patient. In this case the artificial stomach <NUM> is hydraulically operated, i.e. hydraulic fluid is pumped by the motor/pump unit <NUM> from the regulation reservoir <NUM> through a conduit <NUM> to the artificial stomach <NUM> to operate the artificial stomach, and hydraulic fluid is pumped by the motor/pump unit <NUM> back from the artificial stomach <NUM> to the regulation reservoir <NUM> to return the artificial stomach to a starting position. The implanted energy transforming device <NUM> transforms wireless energy into a current, for example a polarized current, for powering the motor/pump unit <NUM> via an electric power supply line <NUM>.

Instead of a hydraulically operated artificial stomach <NUM>, it is also envisaged that the operation device comprises a pneumatic operation device. In this case, pressurized air can be used for regulation and the regulation reservoir is replaced by an air chamber and the fluid is replaced by air.

In all of these embodiments the implanted energy transforming device <NUM> may include a rechargeable accumulator like a battery or a capacitor to be charged by the wireless energy and supplies energy for any energy consuming part of the device.

The external energy transmission device <NUM> is preferably wireless and may include a remotely controlled control device for controlling the device from outside the human body.

Such a control device may include a wireless remote control as well as a manual control of any implanted part to make contact with by the patient's hand most likely indirect for example a button to press placed under the skin.

<FIG> shows an embodiment of the invention comprising the external energy transmission device <NUM> with its wireless remote control, the artificial stomach <NUM>, in this case hydraulically operated, and the implanted energy transforming device <NUM>, and further comprising a hydraulic fluid reservoir <NUM>, a motor/pump unit <NUM> and an reversing device in the form of a hydraulic valve shifting device <NUM>, all implanted in the patient. Of course the hydraulic operation could easily be performed by just changing the pumping direction and the hydraulic valve may therefore be omitted. The remote control may be a device separated from the external energy transmission or included in the same. The motor of the motor/pump unit <NUM> is an electric motor. In response to a control signal from the wireless remote control of the external energy transmission device <NUM>, the implanted energy transforming device <NUM> powers the motor/pump unit <NUM> with energy from the energy carried by the control signal, whereby the motor/pump unit <NUM> distributes hydraulic fluid between the hydraulic fluid reservoir <NUM> and the artificial stomach <NUM>. The remote control of the external energy transmission device <NUM> controls the hydraulic valve shifting device <NUM> to shift the hydraulic fluid flow direction between one direction in which the fluid is pumped by the motor/pump unit <NUM> from the hydraulic fluid reservoir <NUM> to the artificial stomach <NUM> to operate the artificial stomach, and another opposite direction in which the fluid is pumped by the motor/pump unit <NUM> back from the artificial stomach <NUM> to the hydraulic fluid reservoir <NUM> to return the artificial stomach to a starting position.

<FIG> shows an embodiment of the invention identical to that of <FIG>, except that an internal control unit <NUM> controlled by the wireless remote control of the external energy transmission device <NUM>, an accumulator <NUM> and a capacitor <NUM> also are implanted in the patient. The internal control unit <NUM> arranges storage of electric energy received from the implanted energy transforming device <NUM> in the accumulator <NUM>, which supplies energy to the artificial stomach <NUM>. In response to a control signal from the wireless remote control of the external energy transmission device <NUM>, the internal control unit <NUM> either releases electric energy from the accumulator <NUM> and transforms the released energy via power lines <NUM> and <NUM>, or directly transforms electric energy from the implanted energy transforming device <NUM> via a power line <NUM>, the capacitor <NUM>, which stabilizes the electric current, a power line <NUM> and the power line <NUM>, for the operation of the artificial stomach <NUM>.

The internal control unit is preferably programmable from outside the patient's body. In a preferred embodiment, the internal control unit is programmed to regulate the artificial stomach <NUM> to stretch the stomach according to a pre-programmed time-schedule or to input from any sensor sensing any possible physical parameter of the patient or any functional parameter of the device.

In accordance with an alternative, the capacitor <NUM> in the embodiment of <FIG> may be omitted. In accordance with another alternative, the accumulator <NUM> in this embodiment may be omitted.

<FIG> shows an embodiment of the invention identical to that of <FIG>, except that a battery <NUM> for supplying energy for the operation of the artificial stomach <NUM> and an electric switch <NUM> for switching the operation of the artificial stomach <NUM> also are implanted in the patient. The electric switch <NUM> is operated by the energy supplied by the implanted energy transforming device <NUM> to switch from an off mode, in which the battery <NUM> is not in use, to an on mode, in which the battery <NUM> supplies energy for the operation of the artificial stomach <NUM>.

<FIG> shows an embodiment of the invention identical to that of <FIG>, except that an internal control unit <NUM> controllable by the wireless remote control of the external energy transmission device <NUM> also is implanted in the patient. In this case, the electric switch <NUM> is operated by the energy supplied by the implanted energy transforming device <NUM> to switch from an off mode, in which the wireless remote control is prevented from controlling the internal control unit <NUM> and the battery is not in use, to a standby mode, in which the remote control is permitted to control the internal control unit <NUM> to release electric energy from the battery <NUM> for the operation of the artificial stomach <NUM>.

<FIG> shows an embodiment of the invention identical to that of <FIG>, except that an accumulator <NUM> is substituted for the battery <NUM> and the implanted components are interconnected differently. In this case, the accumulator <NUM> stores energy from the implanted energy transforming device <NUM>. In response to a control signal from the wireless remote control of the external energy transmission device <NUM>, the internal control unit <NUM> controls the electric switch <NUM> to switch from an off mode, in which the accumulator <NUM> is not in use, to an on mode, in which the accumulator <NUM> supplies energy for the operation of the artificial stomach <NUM>.

<FIG> shows an embodiment of the invention identical to that of <FIG>, except that a battery <NUM> also is implanted in the patient and the implanted components are interconnected differently. In response to a control signal from the wireless remote control of the external energy transmission device <NUM>, the internal control unit <NUM> controls the accumulator <NUM> to deliver energy for operating the electric switch <NUM> to switch from an off mode, in which the battery <NUM> is not in use, to an on mode, in which the battery <NUM> supplies electric energy for the operation of the artificial stomach <NUM>.

Alternatively, the electric switch <NUM> may be operated by energy supplied by the accumulator <NUM> to switch from an off mode, in which the wireless remote control is prevented from controlling the battery <NUM> to supply electric energy and is not in use, to a standby mode, in which the wireless remote control is permitted to control the battery <NUM> to supply electric energy for the operation of the artificial stomach <NUM>.

It should be understood that the switch should be interpreted in its broadest embodiment. This means an Field-programmable gate array (FPGA) or a D/A converter or any other electronic component or circuit may switch power on and off preferably being controlled from outside the body or by an internal control unit.

<FIG> shows an embodiment of the invention identical to that of <FIG>, except that a motor <NUM>, a mechanical reversing device in the form of a gear <NUM>, and an internal control unit <NUM> for controlling the gear <NUM> also are implanted in the patient. The internal control unit <NUM> controls the gear <NUM> to reverse the function performed by the artificial stomach <NUM> (mechanically operated). Even simpler is to switch the direction of the motor electronically.

<FIG> shows an embodiment of the invention identical to that of <FIG> except that the implanted components are interconnected differently. Thus, in this case the internal control unit <NUM> is powered by the battery <NUM> when the accumulator <NUM>, suitably a capacitor, activates the electric switch <NUM> to switch to an on mode. When the electric switch <NUM> is in its on mode the internal control unit <NUM> is permitted to control the battery <NUM> to supply, or not supply, energy for the operation of the artificial stomach <NUM>.

<FIG> schematically shows conceivable combinations of implanted components of the apparatus for achieving various communication options. Basically, there are the artificial stomach <NUM>, the internal control unit <NUM>, motor or pump unit <NUM>, and the external energy transmission device <NUM> including the external wireless remote control. As already described above the wireless remote control transmits a control signal which is received by the internal control unit <NUM>, which in turn controls the various implanted components of the apparatus.

A feedback device, preferably in the form of a sensor <NUM>, may be implanted in the patient for sensing a physical parameter of the patient, such as a contraction wave in the oesophagus informing the patient is eating. The internal control unit <NUM>, or alternatively the external wireless remote control of the external energy transmission device <NUM>, may control the artificial stomach <NUM> in response to signals from the sensor <NUM>. A transceiver may be combined with the sensor <NUM> for sending information on the sensed physical parameter to the external wireless remote control. The wireless remote control may comprise a signal transmitter or transceiver and the internal control unit <NUM> may comprise a signal receiver or transceiver. Alternatively, the wireless remote control may comprise a signal receiver or transceiver and the internal control unit <NUM> may comprise a signal transmitter or transceiver. The above transceivers, transmitters and receivers may be used for sending information or data related to the artificial stomach <NUM> from inside the patient's body to the outside thereof.

Alternatively, the sensor <NUM> may be arranged to sense a functional parameter of the artificial stomach <NUM>.

Where the motor/pump unit <NUM> and battery <NUM> for powering the motor/pump unit <NUM> are implanted, the battery <NUM> may be equipped with a transceiver for sending information on the condition of the battery <NUM>. To be more precise, when charging a battery or accumulator with energy feed back information related to said charging process is sent and the energy supply is changed accordingly.

<FIG> shows an alternative embodiment wherein the artificial stomach <NUM> is regulated from outside the patient's body. The artificial stomach system <NUM> comprises an artificial stomach <NUM> connected to a battery <NUM> via a subcutaneous switch <NUM>. Thus, the regulation of the artificial stomach <NUM> is performed non-invasively by manually pressing the subcutaneous switch, whereby the operation of the artificial stomach <NUM> is switched on and off. It will be appreciated that the shown embodiment is a simplification and that additional components, such as an internal control unit or any other part disclosed in the present application can be added to the artificial stomach system.

<FIG> shows an alternative embodiment, wherein the artificial stomach system <NUM> comprises an artificial stomach <NUM> in fluid connection with a hydraulic fluid reservoir <NUM>. Non-invasive regulation is performed by manually pressing the hydraulic reservoir connected to the artificial stomach <NUM>.

A further embodiment of a system according to the invention comprises a feedback device for sending information from inside the patient's body to the outside thereof to give feedback information related to at least one functional parameter of the artificial stomach or system or a physical parameter of the patient, thereby optimizing the performance of the system.

One preferred functional parameter of the device is correlated to the transfer of energy for charging the internal energy source.

In <FIG>, an arrangement is schematically illustrated for supplying an accurate amount of energy to an artificial stomach system <NUM> implanted in a patient, whose skin <NUM> is indicated by a vertical line. An artificial stomach <NUM> is connected to an implanted energy transforming device <NUM>, likewise located inside the patient, preferably just beneath the patient's skin <NUM>. Generally speaking, the implanted energy transforming device <NUM> may be placed in the abdomen, thorax, muscle fascia (e.g. in the abdominal wall), subcutaneously, or at any other suitable location. The the implanted energy transforming device <NUM> is adapted to receive wireless energy E transmitted from an external energy source 34a provided in the external energy transmission device <NUM> located outside the patient's skin <NUM> in the vicinity of the implanted energy transforming device <NUM>.

As is well known in the art, the wireless energy E may generally be transferred by means of any suitable Transcutaneous Energy Transfer (TET) device, such as a device including a primary coil arranged in the external energy source 34a and an adjacent secondary coil arranged in the implanted energy transforming device <NUM>. When an electric current is fed through the primary coil, energy in the form of a voltage is induced in the secondary coil which can be used to operate an artificial stomach, e.g. after storing the incoming energy in an energy storing device or accumulator, such as a battery or a capacitor. However, the present invention is generally not limited to any particular energy transfer technique, TET devices or energy storing devices, and any kind of wireless energy may be used.

The amount of energy received inside the body to the device may be compared with the energy used by the device. The term used by the device is then understood to include also energy stored by the device. The amount of transferred energy can be regulated by means of an external control unit 34b controlling the external energy source 34a based on the determined energy balance, as described above. In order to transfer the correct amount of energy, the energy balance and the required amount of energy can be determined by means of an internal control unit <NUM> connected to the artificial stomach <NUM>. The internal control unit <NUM> may thus be arranged to receive various measurements obtained by suitable sensors or the like, not shown, measuring certain characteristics of the artificial stomach <NUM>, somehow reflecting the required amount of energy needed for proper operation of the artificial stomach <NUM>. Moreover, the current condition of the patient may also be detected by means of suitable measuring devices or sensors, in order to provide parameters reflecting the patient's condition. Hence, such characteristics and/or parameters may be related to the current state of the artificial stomach <NUM>, such as power consumption, operational mode and temperature, as well as the patient's condition reflected by, e.g., body temperature, blood pressure, heartbeats and breathing.

Furthermore, an energy storing device or accumulator <NUM> may optionally be connected to the implanted energy transforming device <NUM> for accumulating received energy for later use by the artificial stomach <NUM>. Alternatively or additionally, characteristics of such an accumulator, also reflecting the required amount of energy, may be measured as well. The accumulator may be replaced by a battery, and the measured characteristics may be related to the current state of the battery, such as voltage, temperature, etc. In order to provide sufficient voltage and current to the artificial stomach <NUM>, and also to avoid excessive heating, it is clearly understood that the battery should be charged optimally by receiving a correct amount of energy from the implanted energy transforming device <NUM>, i.e. not too little or too much. The accumulator may also be a capacitor with corresponding characteristics.

For example, battery characteristics may be measured on a regular basis to determine the current state of the battery, which then may be stored as state information in a suitable storage means in the internal control unit <NUM>. Thus, whenever new measurements are made, the stored battery state information can be updated accordingly. In this way, the state of the battery can be "calibrated" by transferring a correct amount of energy, so as to maintain the battery in an optimal condition.

Thus, the internal control unit <NUM> is adapted to determine the energy balance and/or the currently required amount of energy, (either energy per time unit or accumulated energy) based on measurements made by the above-mentioned sensors or measuring devices on the artificial stomach <NUM>, or the patient, or an energy storing device if used, or any combination thereof. The internal control unit <NUM> is further connected to an internal signal transmitter <NUM>, arranged to transmit a control signal reflecting the determined required amount of energy, to an external signal receiver 34c connected to the external control unit 34b. The amount of energy transmitted from the external energy source 34a may then be regulated in response to the received control signal.

Alternatively, sensor measurements can be transmitted directly to the external control unit 34b wherein the energy balance and/or the currently required amount of energy can be determined by the external control unit 34b, thus integrating the above-described function of the internal control unit <NUM> in the external control unit 34b. In that case, the internal control unit <NUM> can be omitted and the sensor measurements are supplied directly to the internal signal transmitter <NUM> which sends the measurements over to the external signal receiver 34c and the external control unit 34b. The energy balance and the currently required amount of energy can then be determined by the external control unit 34b based on those sensor measurements.

Hence, the present solution employs the feed back of information indicating the required energy, which is more efficient than previous solutions because it is based on the actual use of energy that is compared to the received energy, e.g. with respect to the amount of energy, the energy difference, or the energy receiving rate as compared to the energy rate used by the artificial stomach. The artificial stomach may use the received energy either for consuming or for storing the energy in an energy storage device or the like. The different parameters discussed above would thus be used if relevant and needed and then as a tool for determining the actual energy balance. However, such parameters may also be needed per se for any actions taken internally to specifically operate the artificial stomach.

The internal signal transmitter <NUM> and the external signal receiver 34c may be implemented as separate units using suitable signal transfer means, such as radio, IR (Infrared) or ultrasonic signals. Alternatively, the internal signal transmitter <NUM> and the external signal receiver 34c may be integrated in the implanted energy transforming device <NUM> and the external energy source 34a, respectively, so as to convey control signals in a reverse direction relative to the energy transfer, basically using the same transmission technique. The control signals may be modulated with respect to frequency, phase or amplitude.

To conclude, the energy supply arrangement illustrated in <FIG> may operate basically in the following manner. The energy balance is first determined by the internal control unit <NUM>. A control signal reflecting the required amount of energy is also created by the internal control unit <NUM>, and the control signal is transmitted from the internal signal transmitter <NUM> to the external signal receiver 34c. Alternatively, the energy balance can be determined by the external control unit 34b instead depending on the implementation, as mentioned above. In that case, the control signal may carry measurement results from various sensors. The amount of energy emitted from the external energy source 34a can then be regulated by the external control unit 34b, based on the determined energy balance, e.g. in response to the received control signal. This process may be repeated intermittently at certain intervals during ongoing energy transfer, or may be executed on a more or less continuous basis during the energy transfer.

The amount of transferred energy can generally be regulated by adjusting various transmission parameters in the external energy source 34a, such as voltage, current, amplitude, wave frequency and pulse characteristics.

A method is thus provided for controlling transmission of wireless energy supplied to an electrically operable artificial stomach implanted in a patient. The wireless energy E is transmitted from an external energy source located outside the patient and is received by an internal energy receiver located inside the patient, the internal energy receiver being connected to the artificial stomach for directly or indirectly supplying received energy thereto. An energy balance is determined between the energy received by the internal energy receiver and the energy used for the artificial stomach. The transmission of wireless energy E from the external energy source is then controlled based on the determined energy balance.

A system is also provided for controlling transmission of wireless energy supplied to an electrically operable artificial stomach implanted in a patient. The system is adapted to transmit the wireless energy E from an external energy source located outside the patient which is received by an implanted energy transforming device located inside the patient, the implanted energy transforming device being connected to the artificial stomach for directly or indirectly supplying received energy thereto. The system is further adapted to determine an energy balance between the energy received by the implanted energy transforming device and the energy used for the artificial stomach, and control the transmission of wireless energy E from the external energy source, based on the determined energy balance.

The functional parameter of the device is correlated to the transfer of energy for charging the internal energy source.

In yet an alternative embodiment, the external source of energy is controlled from outside the patient's body to release electromagnetic wireless energy, and released electromagnetic wireless energy is used for operating the artificial stomach.

In another embodiment, the external source of energy is controlling from outside the patient's body to release non-magnetic wireless energy, and released non-magnetic wireless energy is used for operating the artificial stomach.

Those skilled in the art will realize that the above various embodiments according to <FIG> could be combined in many different ways. For example, the electric switch <NUM> operated polarized energy could be incorporated in any of the embodiments of <FIG>, <FIG>, the hydraulic valve shifting device <NUM> could be incorporated in the embodiment of <FIG>, and the gear <NUM> could be incorporated in the embodiment of <FIG>. Please observe that the switch simply could mean any electronic circuit or component.

Wireless transfer of energy for operating the artificial stomach has been described to enable non-invasive operation. It will be appreciated that the artificial stomach can be operated with wire bound energy as well. On such example is shown in <FIG>, wherein an external switch <NUM> is interconnected between the external energy source 34a and an operation device, such as an electric motor regulating the artificial stomach <NUM>, by means of power lines <NUM> and <NUM>. An external control unit 34b controls the operation of the external switch to effect proper operation of the artificial stomach <NUM>.

<FIG> show in more detail block diagrams of four different ways of hydraulically or pneumatically powering an artificial stomach according to the invention.

<FIG> shows an artificial stomach system as described above. The system comprises an artificial stomach <NUM> and further a separate regulation reservoir <NUM>, a one way pump <NUM> and an alternate valve <NUM>.

<FIG> shows the artificial stomach <NUM> and a regulation reservoir <NUM>. By moving the wall of the regulation reservoir or changing the size of the same in any other different way, the adjustment of the artificial stomach may be performed without any valve, just free passage of fluid any time by moving the reservoir wall.

<FIG> shows the artificial stomach <NUM>, a two way pump <NUM> and the regulation reservoir <NUM>.

<FIG> shows a block diagram of a reversed servo system with a first closed system controlling a second closed system. The servo system comprises a regulation reservoir <NUM> and a servo reservoir <NUM>. The servo reservoir <NUM> mechanically controls an artificial stomach <NUM> via a mechanical interconnection <NUM>. The artificial stomach has an expandable/contactable cavity. This cavity is preferably expanded or contracted by supplying hydraulic fluid from the larger adjustable reservoir <NUM> in fluid connection with the artificial stomach <NUM>. Alternatively, the cavity contains compressible gas, which can be compressed and expanded under the control of the servo reservoir <NUM>.

The servo reservoir <NUM> can also be part of the artificial stomach itself.

In one embodiment, the regulation reservoir is placed subcutaneous under the patient's skin and is operated by pushing the outer surface thereof by means of a finger. This artificial stomach system is illustrated in <FIG>. In <FIG>, a flexible subcutaneous regulation reservoir <NUM> is shown connected to a bulge shaped servo reservoir <NUM> by means of a conduit <NUM>. This bellow shaped servo reservoir <NUM> is comprised in a a flexible artificial stomach <NUM>. In the state shown in <FIG>, the servo reservoir <NUM> contains a minimum of fluid and most fluid is found in the regulation reservoir <NUM>. Due to the mechanical interconnection between the servo reservoir <NUM> and the artificial stomach <NUM>, the outer shape of the artificial stomach <NUM> is contracted, i.e., it occupies less than its maximum volume. This maximum volume is shown with dashed lines in the figure.

<FIG> shows a state wherein a user, such as the patient in with the artificial stomach is implanted, presses the regulation reservoir <NUM> so that fluid contained therein is brought to flow through the conduit <NUM> and into the servo reservoir <NUM>, which, thanks to its bellow shape, expands longitudinally. This expansion in turn expands the artificial stomach <NUM> so that it occupies its maximum volume, thereby stretching the stomach wall (not shown), which it contacts.

The regulation reservoir <NUM> is preferably provided with means 46a for keeping its shape after compression. This means, which is schematically shown in the figure, will thus keep the artificial stomach <NUM> in a stretched position also when the user releases the regulation reservoir. In this way, the regulation reservoir essentially operates as an on/off switch for the artificial stomach system.

An alternative embodiment of hydraulic or pneumatic operation will now be described with reference to <FIG> and 33a-c. The block diagram shown in <FIG> comprises with a first closed system controlling a second closed system. The first system comprises a regulation reservoir <NUM> and a servo reservoir <NUM>. The servo reservoir <NUM> mechanically controls a larger adjustable reservoir <NUM> via a mechanical interconnection <NUM>. An artificial stomach <NUM> having an expandable/contactable cavity is in turn controlled by the larger adjustable reservoir <NUM> by supply of hydraulic fluid from the larger adjustable reservoir <NUM> in fluid connection with the artificial stomach <NUM>.

An example of this embodiment will now be described with reference to <FIG>. Like in the previous embodiment, the regulation reservoir is placed subcutaneous under the patient's skin and is operated by pushing the outer surface thereof by means of a finger. The regulation reservoir <NUM> is in fluid connection with a bellow shaped servo reservoir <NUM> by means of a conduit <NUM>. In the first closed system comprising parts <NUM>, <NUM>, <NUM> shown in <FIG>, the servo reservoir <NUM> contains a minimum of fluid and most fluid is found in the regulation reservoir <NUM>.

The servo reservoir <NUM> is mechanically connected to a larger adjustable reservoir <NUM>, in this example also having a bellow shape but with a larger diameter than the servo reservoir <NUM>. The larger adjustable reservoir <NUM> is in fluid connection with the artificial stomach <NUM>. This means that when a user pushes the regulation reservoir <NUM>, thereby displacing fluid from the regulation reservoir <NUM> to the servo reservoir <NUM>, the expansion of the servo reservoir <NUM> will displace a larger volume of fluid from the larger adjustable reservoir <NUM> to the artificial stomach <NUM>. In other words, in this reversed servo, a small volume in the regulation reservoir is compressed with a higher force and this creates a movement of a larger total area with less force per area unit.

Like in the previous embodiment described above with reference to Figs. 31a-c, the regulation reservoir <NUM> is preferably provided with means 46a for keeping its shape after compression. This means, which is schematically shown in the figure, will thus keep the artificial stomach <NUM> in a stretched position also when the user releases the regulation reservoir. In this way, the regulation reservoir essentially operates as an on/off switch for the artificial stomach system.

An artificial stomach in accordance with an exemplary embodiment of the present invention will now be described with reference to <FIG>, and with further reference to <FIG>, <FIG> and <FIG>. The artificial stomach <NUM> is preferably manufactured in order to have an anatomical structure similar to the structure of the normal stomach, and is adapted to be placed in the abdomen of a patient. In this embodiment the artificial stomach <NUM> is hydraulically operated. The artificial stomach <NUM> is connected to the gastrointestinal tract, upstream the inlet <NUM> is connected to the oesophagus <NUM> and downstream the outlet <NUM> is connected to the distal end of the cut jejunum <NUM>.

The artificial stomach <NUM> has a stomach food part, which is enclosed by an outer wall <NUM> manufactured from a rigid material. This rigid outer wall encloses two reservoirs: a food reservoir <NUM> and a servo reservoir <NUM>, which are separated by a flexible inner wall <NUM>. A hydraulic fluid reservoir <NUM> is separated from the stomach food part by the rigid outer wall <NUM> and is further enclosed by a fluid reservoir wall <NUM>, which fluid reservoir wall <NUM> preferably is flexible but may as an option be rigid. If the fluid reservoir wall <NUM> is flexible, it may be arranged to flex in a way similar to that of the regulation reservoir wall <NUM> shown in <FIG>.

The food reservoir <NUM> is adapted to receive and treat the food mechanically and/or chemically. The hydraulic fluid reservoir <NUM> is adapted to comprise a hydraulic fluid to be fed through conduits 44a, 44b to the servo reservoir <NUM>. A pump <NUM> connected to the conduits 44a and 44b is adapted to move the hydraulic fluid between the hydraulic fluid reservoir <NUM> and the servo reservoir <NUM>.

By manufacturing the walls <NUM>, <NUM>, <NUM>, and <NUM> of materials of the above defined qualities and employing the pump <NUM> to feed the hydraulic fluid between the hydraulic fluid reservoir <NUM> and the servo reservoir <NUM> in an alternating direction, a mechanical treatment is achieved by squeezing the food in the food reservoir <NUM>, as will now be described with reference to <FIG> and <FIG>.

Initially, food is allowed to enter into the food reservoir <NUM>, optionally by opening the inlet valve <NUM> while maintaining the optional outlet valve <NUM> in a closed position (see <FIG>). This food may increase the volume of the food reservoir <NUM> and thereby compress the servo reservoir <NUM> so that part of the fluid contained therein is moved to the hydraulic fluid reservoir <NUM>. The inlet valve is closed and fluid is moved repeatedly between the hydraulic fluid reservoir <NUM> and the servo reservoir <NUM>. When fluid is moved into the servo reservoir <NUM>, the inner wall <NUM> presses against the food contained in the food reservoir <NUM>, thereby treating it in a way similar to that of the walls of a natural stomach. Furthermore, by releasing various chemicals a chemical treatment is achieved, as described above.

Emptying the food reservoir <NUM> may be done in different ways depending on if the optional outlet valve <NUM> is arranged at the outlet end of the artificial stomach or not.

When the food contained in the food reservoir has been sufficiently treated, and if an outlet valve <NUM> is present, the outlet valve <NUM> is opened and the servo reservoir <NUM> is filled with fluid so that the food reservoir <NUM> is emptied or at least essentially emptied. The food reservoir is adapted to empty step by step, small portions at a time. The outlet valve <NUM> is then closed, fluid is moved from the servo reservoir <NUM> to the hydraulic fluid reservoir, and the process is repeated over again. The outlet valve may also be adapted to functioning passively and to open related to a volume decrease in the food reservoir.

The above mentioned moving of fluid from the servo reservoir <NUM> to the hydraulic fluid reservoir <NUM> is preferably done in one of two ways: either the food entering the food reservoir <NUM> from the inlet <NUM> presses on the flexible wall <NUM> of the servo reservoir <NUM> thus emptying fluid therefrom to the hydraulic fluid reservoir <NUM> via the return conduit <NUM>; or the food sensor <NUM> sends signals to the pump <NUM> when food is to enter the food reservoir <NUM> the pump <NUM> thus pumping out to said food corresponding amount of fluid from the servo reservoir <NUM> to the hydraulic fluid reservoir <NUM> via conduits 44a, 44b. If the emptying of the servo reservoir <NUM> is done in one of the above ways, entry of already treated food from the intestine <NUM> into the food reservoir <NUM> is avoided.

When the food contained in the food reservoir has been sufficiently treated, and if no optional outlet valve <NUM> is present, the servo reservoir <NUM> is filled with fluid stepwise, i.e. step by step in small steps so that the food reservoir <NUM> is emptied or at least essentially emptied in small steps which results in that the sufficiently treated food is received by the intestine in small subsequent steps thereby making it possible for the intestine to treat it without difficulty, i.e. the food reservoir is adapted to empty step by step, small portions at a time. Thereafter, fluid is moved from the servo reservoir <NUM> to the hydraulic fluid reservoir, and the process is repeated over again. The above mentioned moving of fluid from the servo reservoir <NUM> to the hydraulic fluid reservoir <NUM> is preferably done in one of two ways: either the food entering the food reservoir <NUM> from the inlet <NUM> presses on the flexible wall <NUM> of the servo reservoir <NUM> thus emptying fluid therefrom to the hydraulic fluid reservoir <NUM> via the return conduit <NUM>; or the food sensor <NUM> sends signals to the pump <NUM> when food is to enter the food reservoir <NUM> the pump <NUM> thus pumping out to said food corresponding amount of fluid from the servo reservoir <NUM> to the hydraulic fluid reservoir <NUM> via conduits 44a, 44b. If the emptying of the servo reservoir <NUM> is done in one of the above ways, entry of already treated food from the intestine <NUM> into the food reservoir <NUM> is avoided.

As mentioned above, a return conduit <NUM> may be arranged between the fluid reservoir <NUM> and theservo reservoir <NUM> if the food reservoir of the artificial stomach is adapted to increase in volume when filled with food when the patient is eating, thereby causing a change in the volume of the servo reservoir, in turn moving fluid between said servo reservoir and said hydraulic fluid reservoir via said return conduit <NUM>. Said return conduit <NUM> is preferably of smaller diameter than the conduits 44a, 44b.

Corresponding processed can be applied to the embodiments described above with reference to <FIG> and <FIG>.

Optionally, the pump <NUM> may be comprised in an operating unit (not shown), implanted subcutaneously under the patient's skin. The operating unit may also comprise various additional components as e.g. injection port, a special container, as described above, and/or a switch for controlling the artificial stomach <NUM> (not shown).

Optionally, a pumping reservoir may be provided, preferably subcutaneously, like in the embodiment described above with reference to <FIG>.

Optionally, the inlet <NUM> and the outlet <NUM> of the food reservoir <NUM> may be provided with non return valves <NUM> and <NUM>, respectively. Furthermore, in addition the food reservoir <NUM> may also be provided with a burp output <NUM>, which may comprise a burp valve <NUM>, which bypasses the inlet valve <NUM> to allow gases from the food reservoir <NUM> to leave through the oesophagus <NUM>.

In <FIG> a flow chart illustrating steps performed when implanting an artificial stomach in accordance with the present invention. First in a step <NUM>, an opening is cut in the abdominal wall. Next, in a step <NUM> an area around the stomach is dissected. Thereupon, in a step <NUM> at least one artificial stomach in accordance with the invention is placed in contact with the stomach wall, in particular the fundus wall. The stomach wall is then sutured in a step <NUM>. As can be seen from <FIG>, <FIG> and <FIG>, in some embodiments of the invention an outer wall encloses both the food reservoir and the servo reservoir, the servo reservoir regulating the size of the food reservoir, the food reservoir and the servo reservoir being separated by a flexible inner wall, where further both the food reservoir wall and the servo reservoir wall comprise parts of the outer wall and the flexible inner wall. As can be seen from said <FIG>, <FIG> and <FIG>, the servo reservoir may be a bellow, and the regulating means may be a gear or a fluid. The servo reservoir is adapted to have a variable size and to be filled with different amounts of fluid. The servo reservoir is adapted to have a shape allowing variation in size without limitation from surrounding fibrosis, covering the implant when implanted. The artificial stomach further comprises a hydraulic fluid reservoir, hydraulically connected to said servo reservoir and a pump for fluid connecting the fluid supply reservoir to the servo reservoir, wherein said pump for fluid connecting the hydraulic fluid reservoir to the servo reservoir is adapted to reversible move fluid between the servo reservoir and the hydraulic fluid reservoir.

In some embodiments, an outer wall encloses both the food reservoir and a servo reservoir for regulating the size of the food reservoir, the food reservoir and the servo reservoir being separated by a flexible inner wall, where further both the food reservoir wall and the wall of the servo reservoir comprise parts of the outer wall and the flexible inner wall, wherein said servo reservoir is adapted to be filled with fluid in small steps, wherein the food reservoir is adapted to be emptied by the servo reservoir in small steps, when said servo reservoir is filled with said fluid in small steps, thereby emptying food in small steps into the intestine, when said artificial stomach is implanted.

According to one embodiment, a method of using the artificial stomach by regulating the artificial stomach postoperatively to slowly empty food in the artificial stomach into the intestine or adapting the stomach to receive food by filling the servo reservoir with fluid step by step in small steps so that the food reservoir is emptied or at least essentially emptied in small steps which results in food is received by the intestine in small subsequent portions.

<FIG> shows a side view of an embodiment of a fastening device for an artificial stomach according to the invention mounted to a body tissue.

A fastening device for the artificial stomach may comprise a first unit adapted to be implanted at a first side of the abdominal wall in the patient, and where a second unit is adapted to be implanted in the abdominal cavity of the patient at a second side of the abdominal wall, and where the artificial stomach is fastened to the fastening device.

A fastening device <NUM> for the artificial stomach may be placed in the abdomen, thorax, muscle fascia (e.g. in the abdominal wall), preferably subcutaneously, or at any other suitable location.

The fastening device <NUM> comprises a first unit <NUM> preferably subcutaneously implanted at a first side of a body tissue <NUM> in the patient, such as the rectus abdominis muscle running vertically on each side of the anterior wall of the human abdomen. In other words, the first unit is positioned between the skin <NUM> of the patient and the body tissue <NUM>.

A second unit <NUM> is implanted in a body cavity <NUM> of the patient at a second side of the body tissue <NUM>, i.e., that the side opposite of the side at which the first unit <NUM> is provided.

The first and/or second units <NUM>, <NUM> preferably have circular or elliptical cross-sectional shape when viewed from outside the patient's body. Combined with a smoothly curved sectional shape, this avoids any sharp corners on the units <NUM>, <NUM>, which could cause injuries to the patient in which the fastening device <NUM> is implanted.

The first and second units <NUM>, <NUM> may be covered by a cover <NUM> made of for example silicone or another material providing protection. The cover <NUM>, which preferably is resilient so as to follow the contours of the first and second units, also seals the fastening device <NUM> which also may be a control assembly, thereby protecting possible electronics and other sensitive components of the possible control assembly.

If a cover encloses the first and second units <NUM>, <NUM>, these will be kept together mechanically, thereby assisting an interconnecting device <NUM> in its interconnecting function.

The interconnecting device <NUM> constitutes a mechanical interconnection between the first and second units <NUM>, <NUM> so that the fastening device <NUM> is kept in place by the body tissue <NUM>. The interconnecting device has a cross-sectional area which is smaller than the cross-sectional area of the first unit and the second unit in a plane parallel to the extension of the body tissue. In this way, a hole <NUM> in the body tissue <NUM> through which the interconnecting device <NUM> extends can be sufficiently small so that it is avoided that one or the other of the units <NUM>, <NUM> "slips through" the body tissue <NUM>. Also, the cross-sectional shape of the interconnecting device <NUM> is preferably circular so as to avoid damage to the body tissue <NUM>.

The interconnecting device <NUM> can be integral with one of the first and second units <NUM>, <NUM>. Alternatively, the interconnecting device <NUM> is a separate part, which is connected to the first and second units122, <NUM> during implantation of the fastening device <NUM>.

In a preferred embodiment, the interconnecting device <NUM> is hollow so as to house various wires, hoses etc. electrically or hydraulically interconnecting the first and second units <NUM>, <NUM> in case the fastening device <NUM> also is a control assembly.

Alternatively or additionally, the interconnecting device <NUM> is made of an elastic material, such as rubber, so that the fastening device <NUM> can adapt to the movements of the patient in which it is implanted.

The artificial stomach <NUM> is fastened to the fastening device <NUM> e.g. by using screws <NUM>, rivets or the like.

The artificial stomach may comprise different material in layers, wherein at least one of said food reservoir, a servo reservoir for controlling the food reservoir and a hydraulic fluid reservoir for controlling the servo reservoir, of said artificial stomach may be provided with at least one layer. The at least one layer may comprise a Parylene layer, or a polytetrafluoroethylene layer, or a polyurethane layer, or a silicon layer, or a metal layer, or a Teflon® layer.

The metal layer may comprise any of gold, silver, and titanium, or a combination thereof.

The artificial stomach may be provided with a plurality of layers. The artificial stomach may comprise an outer surface layer of polyurethane, Teflon®, or polytetrafluoroethylene, Parylene, silicone, metal, or a combination thereof.

The artificial stomach may comprise an inner surface layer of polyurethane, Teflon®, or polytetrafluoroethylene, Parylene, silicone, metal, or a combination thereof.

The artificial stomach may comprise an inner surface layer of polytetrafluoroethylene and an outer layer of silicone.

The artificial stomach may comprise an inner surface layer of polytetrafluoroethylene, an intermediate layer of silicone, and an outer layer of Parylene.

The artificial stomach may comprise an inner surface layer of polyurethane and an outer layer of silicone.

The artificial stomach may comprise an inner surface layer of polyurethane, an intermediate layer of silicone, and an outer layer of Parylene.

The artificial stomach may comprise an outer layer that includes a biocompatible material.

Claim 1:
An artificial stomach (<NUM>) for replacing the normal stomach of a patient who has had his/her stomach surgically removed, comprising:
a food reservoir (<NUM>) adapted to collect food,
an inlet (<NUM>) connected to a first opening of the food reservoir (<NUM>) and further being adapted to upstream connect to the patient's gastrointestinal tract (<NUM>), and
an outlet (<NUM>) connected to a second opening of the food reservoir and further being adapted to downstream connect to the patient's gastrointestinal tract (<NUM>), and
a connector adapted to upstream connect the inlet to the patient's gastrointestinal tract (<NUM>), or downstream connect the outlet to the patient's gastrointestinal tract (<NUM>), said connector comprising a conduit (<NUM>) fixedly attached at a first, proximal end on the outside the artificial stomach and in fluid connection to the food passageway, where the proximal part of the conduit is formed like a tube (<NUM>), and distal to the tube (<NUM>) a bulge (<NUM>) is formed, wherein the connector further comprises at least one of:
a blocking ring (<NUM>) arranged to be pushed against the bulge (<NUM>), the ring (<NUM>) having an inner diameter less than the outer diameter of said bulge but large enough to allow the intestinal/oesophageal wall (<NUM>) to be placed between said ring (<NUM>) and said tube (<NUM>), thereby adapted to stop said intestinal/oesophageal wall from slipping away from the tube (<NUM>); and
a flexible sleeve (<NUM>) arranged to be rolled upon itself and then unrolled to cover part of the tube (<NUM>) and the oesophagus or intestine (<NUM>), which is arranged to be pulled over the second end (<NUM>) of the conduit sufficiently far so as to extend also over the bulge.