Patent Application
20090222028
The present application relates to methods and devices for fixing antenna orientation in a restriction system.
Obesity is a growing global concern, as the number of individuals classified as overweight, obese, or morbidly obese continues to increase every year. Obesity is associated with several co-morbidities, including hypertension, type II diabetes, and sleep apnea. Morbid obesity, defined as when a person is 100 pounds or more over ideal body weight or having a body mass index (BMI) of 40 or greater, poses the greatest risks for severe health problems. Accordingly, a great deal of attention is being focused on treating patients with this condition. One method of treating morbid obesity is the placement of a restriction device, such as an elongated band, around the upper portion of the stomach. Gastric bands are typically comprised of a fluid-filled elastomeric balloon with fixed endpoints that encircles the stomach just inferior to the esophageal-gastric junction. This forms a small gastric pouch above the band and a reduced stoma opening inferior to the gastro-esophageal junction in the stomach. When fluid is infused into the balloon, the band expands against the stomach creating further food intake restriction or a smaller stoma opening in the stomach. To decrease this restriction level, fluid is removed from the band. The effect of the band is to reduce the available stomach volume and thus the amount of food that can be consumed before becoming “full.”
Food restriction devices have also comprised mechanically adjusted bands that similarly encircle the upper portion of the stomach. These bands include any number of resilient materials or gearing devices, as well as drive members, for adjusting the bands. Additionally, gastric bands have been developed that include both hydraulic and mechanical drive elements. An example of such an adjustable gastric band is disclosed in U.S. Pat. No. 6,067,991, entitled “Mechanical Food Intake Restriction Device” which issued on May 30, 2000, and is incorporated herein by reference. Another method for limiting the available food volume in the stomach cavity is implanting an inflatable elastomeric balloon within the stomach cavity itself. The balloon is filled with a fluid to expand against the stomach walls and, thereby, decrease the available food volume within the stomach.
With each of the above-described food limitation devices, safe, effective treatment requires that the device be regularly monitored and adjusted to vary the degree of affect on food intake. With banding devices, the gastric pouch above the band may substantially increase in size following the initial implantation. Accordingly, the stoma opening in the stomach must initially be made large enough to enable the patient to receive adequate nutrition while the stomach adapts to the banding device. As the patient's body adapts to the implant, the band may be adjusted to vary the stoma size. In addition, it is desirable to vary the stoma size in order to accommodate changes in the patient's body or treatment regime, or in a more urgent case, to relieve an obstruction or severe esophageal dysmotility or dilatation. Traditionally, adjusting a hydraulic gastric band required a scheduled clinician visit during which a Huber (non-coring) needle and syringe were used to penetrate the patient's skin and add or remove fluid from the balloon. More recently, devices have been developed which enable non-invasive adjustments of the band. An external programmer communicates with the implant using telemetry to control the stoma diameter of the band. During a scheduled visit, a physician places a hand-held portion of the programmer near the implant and transmits power and command signals to the implant. The implant in turn adjusts the stoma diameter of the band and transmits a response command to the programmer.
One problem that can arise is giving stability to various housings in a restriction system, such as an antenna housing for communicating with an external device. Specifically, it can be difficult to provide orientational stability to an antenna housing once it is implanted as the tissue underneath the skin does not provide a flat surface for mounting and the housing may shift locations as the patient loses or gains weight, or even during movement by the patient. As a result, it can be difficult to align an external device with the antenna housing to enable wireless communication.
Accordingly, there remains a need for improved methods and devices for substantially fixing the orientation of an antenna housing implanted in tissue.
Various methods and devices are provided for substantially fixing the orientation of a housing, such as an antenna housing, within tissue. In one embodiment, a restriction system is provided having a first housing with a reservoir formed therein for receiving fluid. The first housing can be configured to be anchored to tissue. The system can also include a second housing spaced apart from and in fluid communication with the first housing. The second housing can have an antenna therein configured to wirelessly communicate with an external device. The system can also include a restriction device in fluid communication with the first and second housings and adapted to form a restriction in a pathway, and a constraining element coupled to the first and second housings and configured to limit rotational movement of the first and second housings relative to one another. In an exemplary embodiment, the constraining element is configured to substantially prevent rotation of the first and second housings along an axis extending between the first and second housings.
The constraining element can have various configurations. In one embodiment, the constraining element can be substantially rigid in a first plane of motion and flexible in a second plane of motion that differs from the first plane of motion. For example, the constraining element can be a sheath disposed around at least a portion of the first and second housings. In one embodiment, the sheath can be sealed with a hermetic coating. The system can also include a connector, such as a catheter, extending through the constraining element between the first and second housings. The connector can be configured to allow fluid flow therethrough between the first and second housings. Alternatively, the constraining element can include a lumen extending therethrough and configured to allow fluid flow between the first and second housings. The constraining element can also include other features, such as an outer layer formed from a compliant material, such as keratin and silicone.
In another embodiment, a restriction system is provided having a fill port with a needle-penetrable septum and a reservoir formed therein and configured to receive fluid. An antenna housing can be coupled to the fill port and it can have an antenna therein configured to wirelessly communicate with an external device. The system can also include a constraining element extending between the fill port and the antenna housing. The constraining element can be substantially rigid in a first plane of motion and flexible in a second plane of motion that differs from the first plane of motion. For example, the constraining element can prevent rotation between the antenna housing and the fill port. The constraining element can have various configurations, as discussed above.
Exemplary methods are also provided for constraining movement of a housing in tissue, and in one embodiment the method can include implanting a first housing in tissue. The first housing can have a second housing spaced apart from but coupled thereto. A constraining element coupled between the first and second housings can substantially prevent rotational movement of the second housing relative to the first housing about an axis extending therebetween such that the second housing is maintained in a substantially fixed orientation in the tissue. The method can also include positioning an external device above a tissue surface, and activating the external device to communicate with an antenna disposed within the second housing. In one embodiment, implanting the first housing in tissue can include anchoring the first housing to tissue. The first housing can contain fluid therein and the constraining element can include a lumen extending therethrough such that the fluid can flow between the first and second housings. The fluid can also flow through a catheter extending through the lumen in the constraining element. The method can also include implanting a restriction device coupled to at least one of the first and second housings. The restriction device can form a restriction in a pathway. In a further embodiment, the second housing can include a sensor that measures the pressure of fluid in the restriction device.
The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the present invention is defined solely by the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention.
Various exemplary methods and devices are provided for limiting movement of an antenna housing associated with a restriction system to allow for alignment and communication with an external device. In certain exemplary embodiments, the antenna housing is constrained relative to another housing, such as an injection port 30, that is anchored to tissue. In particular, a constraining element can be coupled to the housings and it can limit or substantially prevent movement of the housings relative to one another, preferably in at least one plane of motion. Since housings tend to shift once implanted in tissue, the ability to control movement between the housings can be particularly advantageous to allow for effective wireless communication with an external device.
While the present invention can be used with a variety of restriction systems known in the art,
The fluid injection port 30 can also have a variety of configurations. In the embodiment shown in
As indicated above and as shown in
Various pressure sensors known in the art can be used, such as a wireless pressure sensor provided by CardioMEMS, Inc. of Atlanta, Ga., though a suitable MEMS pressure sensor may be obtained from any other source, including but not limited to Integrated Sensing Systems (ISSYS), and Remon Medical. One exemplary MEMS pressure sensor is described in U.S. Pat. No. 6,855,115, the disclosure of which is incorporated by reference herein for illustrative purposes only. It will also be appreciated that suitable pressure sensors may include, but are not limited to, capacitive, piezoresistive, silicon strain gauge, or ultrasonic (acoustic) pressure sensors, as well as various other devices capable of measuring pressure.
As discussed above, the system can include a constraining element coupled between first and second housings and configured to limit movement between first and second housings. This will allow the port 30, for example, to be anchored to tissue and the antenna housing 60 to be maintained in a substantially fixed orientation relative to the port 30. As a result, the antenna housing 60 can be maintained in a position substantially parallel to a tissue surface, thus allowing optimal communication between the antenna 62 and an external device. In an exemplary embodiment, the constraining element can be in the form of a sheath 100 extending between and optionally disposed around at least a portion of the injection port 30 and the antenna housing 60. The sheath 100 can be constructed to limit movement, e.g., rotational/torsional movement, between the housings preferably about an axis extending therebetween. Movement can be completely prevented, or merely limited in one or more directions or planes of motion. In an exemplary embodiment, as shown in
The sheath 100 can be formed from a variety of materials, and it can be rigid or flexible, but in the preferred embodiment the sheath 100 is at least semi-rigid to limit movement between the injection port 30 and the sensor housing 60. For example, the sheath 100 can be formed from an elastomeric material. In addition, the sheath 100 can be formed from a hermetic or near-hermetic material as the sheath 100 can also be configured to form a seal around the injection port 30 and the sensor housing 60. This seal can be configured to substantially eliminate transport of materials both into and out of the sheath 100 in order to provide protection to the components housed within the sheath 100, including the components housed in the injection port 30 and the sensor housing 60. A hermetic seal can be achieved with a variety of hermetic materials, such as laser welded titanium. A person skilled in the art will appreciate that the sheath 100 can be formed from any material that has the ability to form a hermetic seal using any known technique for forming a seal, including AuSn brazing, anodic bonding, seam welding, or impulse welding. A near-hermetic seal can be achieved using a variety of near-hermetic materials to form the sheath 100, such as materials configured to slow the ingress of moisture through the sheath. A near-hermetic seal can also be achieved through the use of a coating formed around the sheath. A person skilled in the art will appreciate that a variety of materials can form a near-hermetic seal, including but not limited to silicones, metallized LCP, parylene-C, PDMS, and PEEK. Moreover, a person skilled in the art will appreciate that a variety of technologies can be used to form a coating around the sheath 100, including nanoreinforced moisture barrier coatings and self-aligned nano-particle engineered surfaces. In addition, the sheath 100 can also be formed from a keratin. This can be advantageous as keratin is less likely to react or be rejected by the body as it is a substance found in the body, it is less susceptible to humidity, it can be gamma sterilized, and can be injection molded to form the various components of the sheath 100. Keratin has also been shown to accelerate tissue healing as it can cooperate with the body's healing mechanisms. A person skilled in the art will appreciate, however, that the sheath 100 can be formed from any material that can be implanted in the body and that can provide limitation of movement between the housings as described above.
As discussed above, the first and third portions 100a, 100c of the sheath 100 can have any configuration that allows the sheath to fit around and/or mate to the injection port 30 and the antenna housing 60, and the sheath 100 can be formed in a variety of ways. For example, the first portion 100a of the sheath 100 can be overmolded to encompass a portion of the injection port 30, but preferably not the entire injection port 30. Specifically, at least the septum 34 extending across the injection port 30 will not be encompassed by the sheath 100 as the septum 34 is configured to provide access to the fluid reservoir formed within the housing of the injection port 30. The sheath 100 can, however, be needle-penetrable to allow fluid to be introduced into an injection port 30 fully encapsulated by the sheath 100. In an exemplary embodiment illustrated in
The second portion 100b of the sheath 100 can also have a variety of configurations. In an exemplary embodiment, the second portion 100b includes a lumen 102 extending therethrough that is configured to allow for fluid flow between the injection port 30 and the antenna housing 60. In one exemplary embodiment, the lumen 102 can contain a catheter 50, as shown in
As previously indicated, the second portion 100b of the sheath 100 is also preferably adapted to limit movement between the port 30 and the housing 60. While various techniques can be used to limit movement, in an exemplary embodiment the second portion 100b can be configured to provide rigidity in any or all planes or axes of movement. In one exemplary embodiment, the second portion 100b of the sheath 100 is configured to limit movement about an axis A (
In an exemplary embodiment, as shown, the second portion 100b of the sheath 100 can have a shape that allows for bending between the port 30 and the housing 60 but prevents rotation therebetween. As best shown in
In use, the restriction system 10 shown in
After implantation, it is necessary to be able to communicate with the restriction system, for example, to transmit power to the restriction system and/or communicate data to and from the restriction system. Since the sheath 100 limits or prevents movement of the housing 60 containing the antenna 62 relative to the injection port 30, an external device placed on the skin surface above the housing 60 will be aligned with and can thus communicate with the antenna 62. For example, the sheath 100 can prevent rotational movement between the port 30 and the housing 60 along an axis extending therebetween, while allowing for bending in a plane of motion substantially perpendicular to the axis extending between the port 30 and the housing 60. This prevention of rotational movement will allow the antenna 62 and the external device to be substantially parallel to one another as the sheath 100 prevents the antenna 62 from rotating away from the surface of the tissue.
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.
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.
It is preferred that 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.
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.
