Abstract:
An system, including an implant for placement within a hollow body organ. The system includes a member having an undeployed shape for delivery within a hollow body and one or more deployed shapes for implantation therein. The member has sufficient rigidity in its deployed shape to exert an outward force against an interior of the hollow body so as to bring together two substantially opposing surfaces of the hollow body. The system includes an external means in communication with the member, the external means is remote from a patient, the external means comprises a means for remotely adjusting the shape of the member, and a means of powering the implant.

Description:
[0001]    This case is related to the following commonly assigned and concurrently filed U.S. applications Ser. No., all of which are hereby incorporated herein by reference: 
         [0002]    U.S. Ser. No. [ ] (Attorney Docket Number END6514USNP) titled DEVICES and METHODS FOR ADJUSTING A SATIATION AND SATIETY-INDUCING IMPLANTED DEVICE; U.S. Ser. No. [ ] (Attorney Docket Number END6515USNP) titled Sensor Trigger; U.S. Ser. No. [ ] (Attorney Docket Number END6516USNP) titled AUTOMATICALLY ADJUSTING INTRA-GASTRIC SATIATION AND SATIETY CREATION DEVICE; U.S. Ser. No. [ ] (Attorney Docket Number END6517USNP) titled OPTIMIZING THE OPERATION OF AN INTRA-GASTRIC SATIETY CREATION DEVICE; U.S. Ser. No. [ ] (Attorney Docket Number END6518USNP) titled POWERING IMPLANTABLE DISTENSION SYSTEMS USING INTERNAL ENERGY HARVESTING MEANS; U.S. Ser. No. [ ] (Attorney Docket Number END6519USNP) titled WEARABLE ELEMENTS FOR INTRA-GASTRIC SATIETY CREATION SYSTEMS; U.S. Ser. No. [ ] (Attorney Docket Number END6520USNP) titled INTRA-GASTRIC SATIETY CREATION DEVICE WITH DATA HANDLING DEVICES AND METHODS; U.S. Ser. No. [ ] (Attorney Docket Number END6521USNP) titled GUI FOR AN IMPLANTABLE DISTENSION DEVICE AND A DATA LOGGER; U.S. Ser. No. [ ] (Attorney Docket Number END6522USNP) titled METHODS AND DEVICES FOR FIXING ANTENNA ORIENTATION IN AN INTRA-GASTRIC SATIETY CREATION SYSTEM; U.S. Ser. No. [ ] (Attorney Docket Number END6523USNP) titled METHODS AND DEVICES FOR PREDICTING INTRA-GASTRIC SATIETY CREATION DEVICE SYSTEM PERFORMANCE; U.S. Ser. No. [ ] (Attorney Docket Number END6524USNP) titled CONSTANT FORCE MECHANISMS for Regulating Distension Devices; U.S. Ser. No. [ ] (Attorney Docket Number END6525USNP) titled A METHOD OF REMOTELY ADJUSTING A SATIATION AND SAFETY-INDUCING IMPLANTED DEVICE. 
     
    
     FIELD OF THE INVENTION 
       [0003]    The present invention relates generally to obesity treatment and, more particularly, to the treatment of obesity by implanting a force producing device into a gastric lumen to create pressure on the inside surface of the lumen to reduce the effective volume of the lumen inducing a prolonged sense of satiety and/or and earlier feeling of satiation in the patient, and adjusting the device remotely or automatically. 
       BACKGROUND OF THE INVENTION 
       [0004]    Obesity is a medical condition affecting more than 30% of the population in the United States. Obesity affects an individual&#39;s personal quality of life and contributes significantly to morbidity and mortality. Obesity is most commonly defined by body mass index (BMI), a measure which takes into account a person&#39;s weight and height to gauge total body fat. It is a simple, rapid, and inexpensive measure that correlates both with morbidity and mortality. Overweight is defined as a BMI of 25 to 29.9 kg/m 2  and obesity as a BMI of ≧30 kg/m 2 . Morbid obesity is defined as BMI≧40 kg/m 2  or being 100 lbs. overweight. Obesity and its co-morbidities are estimated to cost an excess of $100 billion dollars annually in direct and indirect health care costs. Among the co-morbid conditions which have been associated with obesity are type 2 diabetes mellitus, cardiovascular disease, hypertension, dyslipidemias, gastroesophageal reflux disease, obstructive sleep apnea, urinary incontinence, infertility, osteoarthritis of the weight-bearing joints, and some cancers. These complications can affect all systems of the body, and dispel the misconception that obesity is merely a cosmetic problem. Studies have shown that conservative treatment with diet and exercise alone may be ineffective for reducing excess body weight in many patients. 
         [0005]    Bariatrics is the branch of medicine that deals with the control and treatment of obesity. A variety of surgical procedures have been developed within the bariatrics field to treat obesity. The most common currently performed procedure is the Roux-en-Y gastric bypass (RYGB). This procedure is highly complex and is commonly utilized to treat people exhibiting morbid obesity. In a RYGB procedure, a small stomach pouch is separated from the remainder of the gastric cavity and attached to a resected portion of the small intestine. This resected portion of the small intestine is connected between the “smaller” gastric pouch and a distal section of small intestine allowing the passage of food therebetween. The conventional RYGB procedure requires a great deal of operative time and is not without procedure related risks. Because of the degree of invasiveness, post-operative recovery can be quite lengthy and painful. Still more than 100,000 RYGB procedures are performed annually in the United States alone, costing significant health care dollars. 
         [0006]    In view of the highly invasive nature of the RYGB procedure, other less invasive procedures have been developed. These procedures include gastric banding, which constricts the stomach to form an hourglass shape. This procedure restricts the amount of food that passes from one section of the stomach to the next, thereby inducing an early feeling of satiation and/or a prolonged feeling of satiety. A band is placed around the stomach near the junction of the stomach and esophagus. The small upper stomach pouch is filled quickly, and slowly empties through the narrow outlet to produce the feelings of satiety and satiation. In addition to surgical complications, patients undergoing a gastric banding procedure may suffer from esophageal injury, spleen injury, band slippage, reservoir deflation/leak, and persistent vomiting. Other forms of bariatric surgery that have been developed to treat obesity include Fobi pouch, bilio-pancreatic diversion, vertical banded gastroplasty and sleeve gastrectomy. As aspects of some of these procedures, including RYGB, involve stapling a portion of the stomach, many bariatric procedures are commonly referred to as “stomach stapling” procedures. 
         [0007]    For morbidly obese individuals, RYGB, gastric banding or another of the more complex procedures may be the recommended course of treatment due to the significant health problems and mortality risks facing the individual. However, there is a growing segment of the population in the United States and elsewhere who are overweight without being considered morbidly obese. These persons may be 20-30 pounds overweight and want to lose the weight, but have not been able to succeed through diet and exercise alone. For these individuals, the risks associated with the RYGB or other complex procedures often outweigh the potential health benefits and costs. Accordingly, treatment options should involve a less invasive, lower cost solution for weight loss. Further, it is known that modest reductions in weight may significantly decrease the impact of co-morbid conditions including, but not limited to type 2 diabetes mellitus. For this reason as well, a low cost, low risk procedure with effective weight loss results would provide significant benefit to both patients and health care providers. 
         [0008]    Accordingly, it is desirable to have a low risk, minimally invasive procedure for treating obesity. It is desirable to have a procedure in which a treatment device can be easily and safely implanted into the gastric cavity of a patient to reduce the effective volume of the cavity. Additionally, it is desirable to have such a device that can assume an initial deploying configuration, and then be transformed into a second operable configuration within the gastric cavity. Further, it is desirable that the device apply outward pressure against the wall of the gastric cavity in the operable configuration in order to create a sensation of fullness within the patient. Further, it is desirable to have a method of treating obesity by reducing the effective volume within the gastric cavity. Additionally, it is desirable to have a method of treating obesity which includes applying pressure against the inside surface of the gastric cavity to create a feeling of fullness. It is desirable that the obesity treatment method be low cost and minimally invasive so as to be beneficial to a large number of obese patients. Further, it is desirable that the obesity treatment be easily and safely reversible. Additionally, it is desirable to adjust the device over time to accommodate individual patients and extend the durability of the treatment effect. The present invention provides an implantable obesity treatment device and method of treating obesity which achieves these objectives. 
         [0009]    Currently, gastric distension devices are known in the art such as the commonly owned and pending U.S. patent application Ser. No. 11/469564, filed Sep. 1, 2006, pending U.S. patent application Ser. No. 11/469,562, filed Sep. 1, 2006, all of which are incorporated herein by reference in their entirety. Exemplary non-limiting examples of adjustable implantable distension devices (e.g., satiation and satiety inducing gastric implants), optimal design features, as well as methods for installing and removing them are described in commonly owned and pending U.S. patent application Ser. No. [ ], filed on even date herewith and entitled “Devices and Methods for Adjusting a Satiation and Satiety-Inducing Implanted Device” [Atty. Docket No. END6514USNP, pending U.S. patent application Ser. No. [ ], filed on even date herewith and entitled “Powering Implantable Distension Systems Using Internal Energy Harvesting Means” [Atty. Docket No. END6518USNP], pending U.S. patent application Ser. No. [ ], filed on even date herewith and entitled “Methods and Devices for Fixing Antenna Orientation in an Intra-Gastric Satiety Creation System” [Atty. Docket No. END6522USNP], all of which are hereby incorporated herein by reference in their entirety. In such gastric distension devices referred to as gastric coils, it is necessary to add or remove fluid to control the dimensions of the coil, and therefore modulate the distension of the stomach with associated effects. One effect of a gastric coil is to more rapidly induce feelings of satiation defined herein as achieving a level of fullness during a meal that helps regulate the amount of food consumed. Another effect of the coil is to prolong the effect of satiety which is defined herein as delaying the onset of hunger after a meal which in turn regulates the frequency of eating. By way of a non-limiting list of examples, positive impacts on satiation and satiety may be achieved by an intragastric coil through one or more of the following mechanisms: reduction of stomach capacity, rapid engagement of stretch receptors, alterations in gastric motility, pressure induced alteration in gut hormone levels, and alterations to the flow of food either into or out of the stomach. Positive changes in satiety and satiation alter eating habits leading to weight loss. In most cases, the adjustment of fluid volume or pressure requires either a transcutaneous or an endoscopic approach, neither of which is preferable to the patient. 
         [0010]    Adjustments to adjustable systems typically require an office visit. In view of current trends of increased patient mobility, particularly in homogeneous population such as in the U.S., as well as the increasing prevalence of medical tourism, where patients travel to distant countries for an operation as a cost savings measure, repeat return visits to the site of operation may be cost and time prohibitive. Further, if it is determined that there is not a need for an adjustment, the patient will have wasted time and money resources. Accordingly, there is a need for a device and method to affect adjustments without necessitating a patient visit to a remote location. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a perspective view of a U-shaped satiety inducing coil; 
           [0012]      FIG. 2  is a schematic view illustrating an external port for percutaneously adjusting an implanted coil; 
           [0013]      FIG. 3  is a cross-sectional view of a gastric lumen, taken along line A-A of  FIG. 2 , showing a first embodiment for percutaneously adjusting the implanted coil; 
           [0014]      FIG. 4  is a cross-sectional view taken along line B-B of  FIG. 3 , showing the adjustment wire of the first embodiment in greater detail; 
           [0015]      FIG. 5  is a detailed view of the coil and adjustment wire of  FIG. 4 , showing offset positions for the adjustment wire; 
           [0016]      FIG. 6  is a cross-sectional view of a gastric lumen showing a second embodiment for percutaneously adjusting an implanted coil; 
           [0017]      FIG. 7  is a cross-sectional view similar to  FIG. 6 , showing the coil in an expanded position following the severing of a first suture connection; 
           [0018]      FIG. 8  is a cross-sectional view of a gastric lumen showing a third embodiment for percutaneously adjusting an implanted coil; 
           [0019]      FIG. 9A  is a more detailed view of the suture and winch of  FIG. 8 ; 
           [0020]      FIG. 9B  is a cross-sectional view taken along line C-C of  FIG. 8 , showing an adjustment device for the winch of  FIG. 8 ; 
           [0021]      FIG. 10  is a cross-sectional view of a gastric lumen showing a fourth embodiment for percutaneously adjusting an implanted coil; 
           [0022]      FIG. 11  is a cross-sectional view of the coil of  FIG. 10 , taken along line D-D; 
           [0023]      FIG. 12  is a cross-sectional view similar to  FIG. 10 , showing the coil being activated by a light source; 
           [0024]      FIG. 13  is a cross-sectional view of a gastric lumen showing a fifth embodiment for percutaneously adjusting an implanted coil; 
           [0025]      FIG. 14  is a cross-sectional view taken along line E-E of  FIG. 13 ; 
           [0026]      FIG. 15  is a cross-sectional view of a gastric lumen showing a sixth embodiment for percutaneously adjusting an implanted coil; 
           [0027]      FIG. 16  is a cross-sectional view taken along line F-F of  FIG. 15 , showing a device for changing the fluid level within the implanted coil; 
           [0028]      FIG. 17  is a cross-sectional view of the gastric lumen showing a 7 th  embodiment for an adjustable implanted coil; 
           [0029]      FIG. 18  is a cross-sectional view of a gastric coil device; 
           [0030]      FIG. 19  is a detail view of individual links of a gastric coil device; 
           [0031]      FIG. 20  is a detail view of individual links of a gastric coil device; 
           [0032]      FIG. 21  is a detailed cross-sectional view of the individual links of a gastric coil device; 
           [0033]      FIG. 22  is a cross-sectional view of a gastric coil device being filled with a fluid; 
           [0034]      FIG. 23  is a cross-sectional view of a gastric coil device being fully expanded; 
           [0035]      FIG. 24  is a cross-sectional view of a gastric lumen with the gastric coil device being fully expanded; and 
           [0036]      FIG. 25  is a side view of a gastric lumen being acted upon by the gastric coil device. 
           [0037]      FIG. 26  is a view of a remotely adjustable gastric distension system. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0038]    The present invention pertains to devices and methods for remotely adjusting a satiety-inducing gastric implant. The implant is shaped as an open loop within a gastric lumen to hold the walls of the lumen taut, thereby reducing the effective volume per tissue surface area of the lumen. The stretching of the stomach tissue inhibits gastric motility and delays gastric emptying. When utilized within the stomach, the implant can induce a prolonged hormonal response within the body to reduce the desire to eat. In addition, the implant can bias stretch receptors within the stomach to signal an early sense of satiety. The implant is shaped as a semi-rigid open loop (i.e. U-shaped) that applies an outward radial force in a single plane to flatten the stomach. Alternatively, the device may be shaped as a closed loop D in which the straight line of the D shape is hingedly attached to the loop of the curved part of the D as well as hooped shaped into an “O”. The device would be inserted either collapsed or straight, then formed into a closed loop. The force plane of the implant may change over time due to stomach motions. The implant is preferably installed and removed endoscopically and includes design features that prevent migration and erosion. Although less desirable, laparoscopic, open surgical techniques, or a combination thereof, may also be used to install and remove the implant. Examples of satiety-inducing gastric implants, optimal design features, as well as methods for installing and removing them are described in commonly owned and pending U.S. patent application Ser. No. 11/469564, filed Sep. 1, 2006, and pending U.S. patent application Ser. No. 11/469,562, filed Sep. 1, 2006, referred to and incorporated herein by reference above. 
         [0039]    The implant is preferably inserted trans-orally while deformed, folded, or otherwise placed into a relatively straight position, and is subsequently deployed into a different shape while inside the stomach lumen. The deployed configuration is flexible enough to allow some compression and movement relative to the stomach mucosa to prevent erosion, but rigid enough to prevent unwanted buckling and proximal or distal migration. The implant can be adjusted periodically to relieve the pressure on the gastric walls, or to alter the size or shape of the implant. The size, shape or stiffness of the implant may be adjusted multiple times after implantation as the patient acclimates to the device. The present invention provides for the remote accessing and adjustment of a satiety-maintaining and/or satiation inducing gastric implant. Remote access eliminates the need to intubate the patient endoscopically or pass a needle in order to adjust the implant. 
         [0040]      FIG. 1  illustrates an implant device that may be remotely adjusted in accordance with the present invention. In this embodiment, the implant device is an open loop coil  20 . Coil  20  has a substantially straight configuration during deployment, and a curved, U-shaped configuration once deployed in the lumen. When deployed, coil  20  applies an outward force against the walls of the gastric lumen, keeping the tissue taut, but allowing enough flexibility to prevent damage to the stomach lining. Coil  20  comprises a slightly-curved atraumatic portion  22  and distal ends  24 ,  26  that curve inwardly at a smaller diameter than portion  22 . Ends  24 ,  26  have sufficient stiffness and diameter to prevent proximal and distal migration of the coil after it is placed in the gastric lumen. Ends  24 ,  26  also provide blunt ends to prevent damage of the stomach lining. A plurality of peaks  30  and valleys  32  along the outer surface of coil  20  provide a pathway for the gastric content to travel through to the pylorus, thereby slowing gastric emptying yet preventing a complete obstruction. Peaks  30  and valleys  32  also prevent the erosion of coil  20  into the gastric tissue, by providing a gripping surface for the stomach&#39;s peristaltic movements to propel the device in a circular motion, as indicated by reference numeral  34 . Each of the coil ends  24 ,  26  include a hole  36 ,  40  to aid in the removal and adjustment of coil  20 . Holes  36 ,  40  provide an attachment location for a suture, wire or other flexible material. Additionally, a lumen  42  extends substantially through the length of coil  20 . Lumen  42  is designed to accept a stiffening or movable element to allow for adjustment of the coil. 
         [0041]    Referring now to  FIGS. 2-4 , to percutaneously adjust coil  20  a port  44  is inserted through an abdominal wall  50  of the patient and into the interior of a gastric cavity  46 . Port  44  is preferably a PEG tube that is sized to allow mechanical, electrical or fluid communication with the implanted coil. Port  44  may be implanted prior to, during or after the implantation of coil  20 . For a one time adjustment of coil  20 , port  44  may be inserted and removed during a single procedure. Alternatively, port  44  may be inserted and retained within the abdominal wall in a semi-permanent manner to allow for multiple adjustments of the implant over a period of time. 
         [0042]      FIG. 3  shows a first embodiment for adjusting coil  20  through port  44 . In this embodiment, an adjustment wire  52  is housed within a sheath  54 . The adjustment wire and sheath extend through lumen  42  of coil  20 . Wire  52  is securely attached at one opening of lumen  42  to one of the distal ends  24 ,  26  of coil  20 . The other, free end of wire  52  extends through sheath  54  outside the opposite opening of lumen  42 . To adjust coil  20 , a knob  56  is disposed on the external side of port  44 , as shown in  FIG. 4 . The free end of wire  52  extends through port  44  and is attached to knob  56 . Wire  52  may be pulled externally through sheath  54  by turning knob  56  in a first direction. As knob  56  turns, pulling on wire  52 , the wire tension is passed back into lumen  42  to the attached end of the wire. The tension on wire  52  shortens the length of the wire within lumen  42 . When adjustment wire  52  is offset from the bending moment of coil  20  towards the inner diameter  110  of the coil, as shown in  FIG. 5 , pulling on the wire draws the ends  24 ,  26  of coil  20  closer together. As the coil ends are drawn together, the diameter of coil  20  decreases, thereby reducing the force of the implant against the gastric walls. Alternatively, when adjustment wire  52  is offset from the bending moment of coil  20  towards the outer diameter  111  of the coil, as shown by the dashed lines  58  in  FIG. 5 , pulling on the wire causes ends  24 ,  26  of coil  20  to move apart, thereby expanding the size of the coil and increasing the force against the gastric cavity walls during implantation. 
         [0043]    The length of wire  52  within coil lumen  42  may be increased by turning knob  56  in an opposite direction to push on the wire. As wire  52  is pushed, an additional length of wire  52  is forced through sheath  54  and into lumen  42 . When wire  52  is offset towards the inner diameter  110  of coil  20 , pushing additional wire into lumen  42  allows the ends  24 ,  26  of the coil to move apart. As ends  24 ,  26  move apart, coil  20  expands, increasing the coil&#39;s force against the gastric walls. Likewise, when wire  52  is offset towards the outer diameter  111  of coil  20 , pushing additional wire into lumen  42  will reduce the tension within coil  20 , allowing ends  24 ,  26  of the coil to move closer together, thereby reducing the diameter of the coil. After wire  52  is adjusted, knob  56  is locked into position to secure the wire and prevent a subsequent change in wire tension. 
         [0044]      FIG. 6  shows a second embodiment for percutaneously adjusting an implanted coil  20  through port  44 . In this embodiment, a plurality of pieces of flexible material  60  extend through the open loop of coil  20 . Flexible material  60  may, for example, be strands of suture material. Each of the suture strands  60  is attached at one end to hole  36  and at the opposite end to hole  40  to constrain coil  20  in a compressed configuration. Suture strands  60  have differing lengths to create different degrees of compression within coil  20 . Initially, the shortest piece of suture is held tautly between the coil ends to compress the coil into a minimum size. To expand the size and shape of coil  20 , a tool may be passed through port  44  to selectively sever one or more of the sutures  60 . Alternatively, a tool may be passed trans-esophageally to cut sutures  60 . The sutures are preferably severed in the order of increasing length, with the shortest suture cut first, to gradually expand the size of the coil. As each suture is cut, coil  20  expands until the next shortest suture is taut between coil ends  24 ,  26 .  FIG. 7  shows coil  20  in an expanded shape after the shortest one of the sutures  60  has been cut, and the next shortest suture is held tautly between coil ends  24 ,  26 . Any number of sutures  60  may be cut until coil  20  obtains the desired size. Multiple sutures may be cut in a single adjustment procedure. Alternatively, individual sutures may be cut over a period of time to gradually expand the size of coil  20 . 
         [0045]    In an alternative embodiment, sutures  60  may be comprised of a plurality of bioabsorbable materials that gradually degrade over time. The degradation period of the materials can vary between the various suture pieces, so that the sutures dissolve at different rates. The degradation rate can be controlled by cross sectional area for example. The length of the degradation period corresponds to the length of the suture piece, so that the pieces dissolve in the order of increasing length to gradually expand the size of the coil. In this embodiment, coil expansion can be accomplished without penetrating the gastric cavity through port  44 . 
         [0046]      FIG. 8  shows a third embodiment for percutaneously adjusting a coil  20  through port  44 . In this embodiment, a winch  62  is embedded in one of the coil ends  24 ,  26 . A first end of a suture material  64  is wound around winch  62 , as shown in greater detail in  FIG. 9A . A second end of the suture is securely attached to the other one of the coil ends  24 ,  26 . Suture  64  is held between the coil end and winch  62  to maintain coil  20  in a compressed configuration. To expand the size of coil  20 , winch  62  is turned in a first direction to increase the suture length between the winch and coil end. Alternatively, to reduce the size of coil  20 , winch  62  is turned in a second direction to reduce the suture length and draw coil ends  24 ,  26  closer together. As shown in  FIG. 9B , a torsional cable  66  extends from winch  62  through port  44  to operate the winch. Cable  66  is housed within a sheath  68  and attached at an external end to knob  56 . When knob  56  is turned, cable  66  moves within sheath  68  to turn winch  62 , and thereby adjust the length of suture material  64  extending between the coil ends. 
         [0047]      FIG. 10  shows yet another embodiment for percutaneously adjusting an implanted coil. In this embodiment, the implant is a coil  70  formed as a composite of multiple layers of a shape memory polymer or metal. This shape memory polymer or metal (Nitinol is not a polymer) may, for example, be Nitinol, a nickel-titanium alloy. The polymer layers are activated by exposure to an environmental element which effects a change in the shape of the polymer. The shape change in the polymer produces a corresponding change in the size or shape of coil  70 . In the embodiment shown in  FIGS. 10 and 11 , coil  70  comprises three different polymer layers which each extend the circumferential length of the coil. Coil  70 , however, can be made up of any number of different polymer layers depending upon the desired degree and rate of coil expansion. Each of the different polymer layers has a different activation point for expansion. The different activation points allow for successive activation of the layers, thereby producing a gradual change in the size of the coil. These layers may also be comprised of a bimetallic material so that when exposed to varying temperature the elements will expand or contract. Further, the elements may be comprised of bladders with a ferrofluidic material that changes shape (enlarges) in the presence of a magnetic field. 
         [0048]    As shown in  FIG. 12 , one way in which the polymer layers in coil  70  may be activated is by exposure to specific light frequencies. In this embodiment, a light source  76  producing a beam of a specific frequency is passed into gastric cavity  46 , either transesophageally through an endoscope, or through port  44  as shown. The light source is applied to coil  70  to activate one of the polymer layers. As the light beam penetrates coil  70 , one of the layers within the coil expands to increase the diameter of the coil. Each of the different polymer layers may be activated by a different light frequency, so that a gradual expansion of coil  70  can be accomplished. In an alternative embodiment, coil  70  may be made up of shape memory polymers that are activated by exposure to a magnetic field. In this embodiment, the size of the coil may be changed by passing a current through port  44  to create a magnetic field adjacent to the coil. The magnetic field causes one or more of the polymer materials in the coil to expand, thereby changing the shape of the coil. In yet another embodiment, the shape memory polymers may be thermally activated to affect a change in the coil shape. A current may be selectively applied to heat one or more polymer layers until the desired coil shape is achieved. Additionally, a shape memory polymer that is sensitive to Ph levels could be employed. When the Ph level of the stomach is low as is the case during fasting, the device could be in a small configuration. As the Ph level of the stomach raises during eating, the device would expand and send an early sense of satiation. 
         [0049]      FIGS. 13 and 14  illustrate another embodiment for adjusting an implanted gastric satiety-enhancing or satiation inducing device. In this embodiment, the implant is an open loop coil  80  having an inner core  82  and an outer covering  84 . Inner core  82  is composed of a stiffening material that is biased to expand outwardly into a maximum size and shape. An exemplary stiffening material for inner core  82  is Nitinol. Covering  84  is molded over inner core  82  to compress and constrain the inner core into a reduced diameter configuration. Covering  84  is comprised of one or more bioabsorbable materials that gradually erode off of the exterior of inner core  82  following implantation within the gastric cavity. Cover materials may erode at different rates. As covering  84  is slowly absorbed away from coil  80 , the energy stored in compressed inner core  82  is released, allowing the coil to expand in size within the gastric cavity. When covering  84  is completely eroded off of inner core  82 , coil  80  assumes a maximum size within the cavity. In this embodiment, coil  80  can be adjusted without outside intervention through port  44 . The Nitinol may be preshaped such that the coil will expand with one segment eroding off and alternatively contracting with an additional segment eroding off. 
         [0050]    In a slight modification to the embodiment shown in  FIGS. 13 and 14 , a stiffening material may be inserted into a coil to alter or constrain the shape of the coil. In this modification, the coil is comprised of a biodegradable material having a lumen extending the length of the coil. The stiffening member is inserted into the coil lumen prior to implantation. After implantation, the coil is slowly absorbed into the gastric cavity, leaving the stiffening member which expands and assumes a larger size within the cavity. An exemplary stiffening material for this alternative embodiment is Nitinol. 
         [0051]      FIG. 15  illustrates yet another embodiment for adjusting an implanted gastric coil. In this embodiment, a coil  90  includes a plurality of fluid-filled sacs  92  spaced along the length of the coil. Each of the sacs  92  is in fluid communication with the other sacs through a channel  94  that extends the length of the coil. Fluid is injected into or removed from sacs  92  to vary the size of coil  90 . Coil  90  is biased into a small diameter configuration when sacs  92  are empty. As fluid is injected into sacs  92  through channel  94 , the volume of each sac expands, causing the sacs to force the coil to expand outwardly and increase the force of the coil against the gastric cavity walls. Likewise, when fluid is removed from sacs  92 , the force against the rigid portion of coil  90  is decreased, allowing the coil to relax into a smaller diameter configuration. As shown in  FIG. 16 , fluid may be manually added to or removed from sacs  92  through a syringe  96  injected into channel  94  via a port  100 . Alternatively, a fluid reservoir with a control valve may be connected to channel  94 , and fluid periodically injected into or removed from the channel based upon a signal. 
         [0052]    A sensor  102  may be located within coil  90  to measure the fluid pressure within sacs  92  and channel  94 . The signal from sensor  102  can be used to control fluid exchange with channel  94 . In addition to fluid pressure, sensors may be located within coil  90  to measure clinically relevant parameters such as conditions within the gastric cavity or from within the coil itself. These measurements may be used to provide feedback either automatically or manually regarding operation of the coil. This feedback may be used to make adjustments to the coil. For example, a sensor could measure changes in the stomach pH, pressure, or internal device strains indicating that the patient was eating. The sensor could then generate a signal to increase the size of the coil in order to induce satiation sooner. When the readings returned to a previous level, indicating the patient was finished eating, the coil could be returned to a previous size. In one embodiment, this rate at which the coil returns to a previous size may be fast or slow, but is optimized to prolong feelings of satiety. A sensor within coil  90  could also be used to record operational data for the coil. This data could be retrieved from the coil during a medical checkup. 
         [0053]      FIG. 17  illustrates yet another embodiment for adjusting a gastric coil device. In this embodiment, a plurality of rigid links  105  are rotatably coupled by a plurality of pivot pins  106 . At either end of the coil are fixation segments  115  that prevent the passage of the device through either the esophagus or pylorus. Each fixation segment  115  may be comprised of a single deformable material and geometry that could be selectively straightened for insertion, but could be reshaped after insertion as shown to prevent migration of the coil out of the gastric cavity. Methods for inserting a coil with device features to prevent migration have been previously described. Alternatively, fixation segments  115  may also be comprised from a series of rigid links  105 . Rigid links  105  comprising fixation segments  115  may be tethered to separate regions of the device so as to prevent migration. Methods for deploying a coil that requires tethers to establish fixation segments  115  are described in the previously incorporated applications. As illustrated in  FIG. 18 , a lumen  107  preferably runs through the entire length of the device. Inside the lumen  107 , an elongated balloon  108  is placed. The balloon is preferably made out of a material with a geometry that deforms under moderate pressures exerting loads along at least a portion of lumen  107 . Balloon  108  should be able to maintain the desired pressure over time, should not degrade due to exposure to the gastric environment, and should be constructed of a material that is biocompatible. Examples of candidate materials include but are not limited to silicone, polyether polyester urethane, polyether polyester copolymer, and polypropylene oxide. The balloon is in fluid communication with a fill port  109 . Numerous fill ports configurations for devices such as laparoscopic adjustable gastric bands are well known in the art and may be used for this application. Additionally, the sensor  102  could be in fluid communication with the balloon  108 . 
         [0054]    After insertion into the gastric cavity, the fill port  109  is accessed endoscopically in order to inject or withdraw fluid from balloon  108 . In one embodiment, fill port  109  is releasably connected to a fluid delivery device outside of the patient prior to delivery of the device into the gastric cavity. Balloon  108  may be partially filled prior to introduction into the patient, but not to an extent that would hinder insertion. Once placed in the gastric cavity, balloon  108  may be filled to the desired pressure. After balloon  108  is filled, the fluid delivery device is disconnected from fill port  109 . 
         [0055]      FIG. 19 and 20  are close-up views showing details of individual links  105 . As previously described, the external shape of the coil is ideally shaped to minimize or eliminate acute (pinch points) or long term (erosions) trauma to the gastric wall. 
         [0056]      FIG. 21  is a cross-sectional view highlighting details of lumen  107 . The lumen  107  is widened at both ends of each individual link in area  110  and  111 . These widened areas  110  and  111  abut each other adjacent to pivot pin  106 . As fluid is injected into port  109  and balloon  108  fills, the balloon  108  expands into widened areas  110  and  111  as illustrated by bulge  112  in  FIG. 22 . 
         [0057]    Continued filling of balloon  108  creates opposing forces on widened areas  110  and  111  of lumen  108 . The force provides for a rotational force of individual links  105  about pivot pin  106 , expanding the coil as illustrated in  FIG. 23 . The expanded coil places an outward force on gastric cavity  46 , flattening the gastric lumen  113  as illustrated in  FIG. 25 . As previously described, this distension of the stomach may trigger one of many mechanisms within the metabolic system (e.g., engaging natural stretch receptors of the stomach sooner), sending an early sense of satiation and/or a prolonged sense of satiety to the patient. 
         [0058]      FIG. 26  shows a view of a remotely adjustable gastric distension system where fluid pump  120  is configured to move fluid to and from the balloon  108 . 
         [0059]    The pump may be powered any variety of means such as a battery or a power generation source such as that disclosed in the commonly held application (reference the power generation app). Communication with the implant system may be accomplished by transcutaneous means such as is discussed in the commonly owned application (reference the wearable pack app). 
         [0060]    Communication with the implant system may be accomplished by means of a wireless data transfer system such as is disclosed in the commonly held app (reference the data logger w/GUI apps). Thus it would be possible to completely non-invasively adjust the gastric distension system. Additionally, since involved in the method of adjustment, if the patient had the hand held system at their home, adjustments may be affected over long distance using accepted communications protocols such as telephone, internet, satellite, or kiosk based communication systems. Thus, the patient would be spared the cost and effort of visiting a doctor&#39;s office. 
         [0061]    Information may be communicated both to and from the system remotely. By way of a non-limiting list, examples of clinically relevant information that may be provided to the system include: a new configuration, a new sequence of configurations, rates for changing between configurations, parameter thresholds upon which changes in configurations can be made, and updated information upon which new adjustment algorithms may be based. By way of a non-limiting list, examples of clinically relevant information that may be obtained from the system include: time histories of sensed parameters to be used to alter system settings and device status related to specific component or overall device functions. 
         [0062]    The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device can be disassembled, and any number of the particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the device can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present invention. 
         [0063]    Preferably, the invention described herein will be processed before surgery. First, a new or used instrument is obtained and if necessary cleaned. The instrument can then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument are then placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation kills bacteria on the instrument and in the container. The sterilized instrument can then be stored in the sterile container. The sealed container keeps the instrument sterile until it is opened in the medical facility. 
         [0064]    It is preferred that the device is sterilized. This can be done by any number of ways known to those skilled in the art including beta or gamma radiation, ethylene oxide, steam. 
         [0065]    One of ordinary skill in the art will appreciate further features and advantages of the invention based on the above-described embodiments. Accordingly, the invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. All publications and references cited herein are expressly incorporated herein by reference in their entirety. 
         [0066]    Any patent, publication, application or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.