15636 results about "Membrane configuration" patented technology

A surgical access device is adapted to facilitate access through an incision in a body wall having an inner surface and an outer surface, and into a body cavity of a patient. The device includes first and second retention members adapted to be disposed in proximity to the outer surface and the inner surface of the body wall, respectively. A membrane extending between the two retention members forms a throat which is adapted to extend through the incision and form a first funnel extending from the first retention member into the throat, and a second funnel extending from the second retention member into the throat. The throat of the membrane has characteristics for forming an instrument seal in the presence of an instrument and a zero seal in the absence of an instrument. The first retention member may include a ring with either a fixed or variable diameter. The ring can be formed in first and second sections, each having two ends. Couplings can be disposed between the ends to accommodate variations in the size of the first retention member. The first retention member can also be formed as an inflatable toroid, a self-expanding foam, or a circumferential spring. A plurality of inflatable chambers can also provide the surgical access device with a working channel adapted for disposition across the body wall. A first retention member with a plurality of retention stations functions with a plurality of tethers connected to the membrane to change the shape of the membrane and the working channel. A stabilizing platform can be used to support the access device generally independent of any movement of the body wall.

A biointerface membrane for an implantable device including a nonresorbable solid portion with a plurality of interconnected cavities therein adapted to support tissue ingrowth in vivo, and a bioactive agent incorporated into the biointerface membrane and adapted to modify the tissue response is provided. The bioactive agents can be chosen to induce vascularization and / or prevent barrier cell layer formation in vivo, and are advantageous when used with implantable devices wherein solutes are transported across the device-tissue interface.

A membrane for implantation in soft tissue comprising a first domain that supports tissue ingrowth, disrupts contractile forces typically found in a foreign body response, encourages vascularity, and interferes with barrier cell layer formation, and a second domain that is resistant to cellular attachment, is impermeable to cells and cell processes, and allows the passage of analytes. The membrane allows for long-term analyte transport in vivo and is suitable for use as a biointerface for implantable analyte sensors, cell transplantation devices, drug delivery devices, and / or electrical signal delivering or measuring devices. The membrane architecture, including cavity size, depth, and interconnectivity, provide long-term robust functionality of the membrane in vivo.

A percutaneously inserted bistable heart valve prosthesis is folded inside a catheter for transseptal delivery to the patient's heart for implantation. The heart valve has an annular ring, a body member having a plurality of legs, each leg connecting at one end to the annular ring, claws that are adjustable from a first position to a second position by application of external force so as to allow ingress of surrounding heart tissue into the claws in the second position, and leaflet membranes connected to the annular ring, the body member and / or the legs, the leaflet membranes having a first position for blocking blood flow therethrough and a second position for allowing blood flow therethrough. The heart valve is designed such that upon removal of the external force the claws elastically revert to the first position so as to grip the heart tissue positioned within the claws, thereby holding the heart valve in place. The body member and claws may be integrated into a one-piece design. The heart valve may be used as a prosthesis for the mitral valve, aortic valve, pulmonary valve, or tricuspid valve by adapting the annular ring to fit in a respective mitral, aortic, pulmonary, or tricuspid valve opening of the heart.

Abstract of the DisclosureThe preferred embodiments provide a membrane system, particularly for use on an electrochemical sensor, wherein the membrane system includes an affinity domain that dampens the effects of target interferant(s) on the sensor. The affinity domain can be layer, surface, region, and / or portion of the membrane system formed using sorbents that have an affinity for the target interferant. The sorbents can be adapted to adsorb the interferants, for example using adsorbents such as chromatography packing materials. The sorbents can also be adapted to absorb the interferants by imprinting a molecular structure on the material that forms the affinity domain such that target interferants bind to the imprinted surfaces at the molecular level.

An implantable analyte-measuring device including a membrane adapted to promote vascularization and / or interfere with barrier cell layer formation. The membrane includes any combination of materials, architecture, and bioactive agents that facilitate analyte transport to provide long-term in vivo performance of the implantable analyte-measuring device.

Disclosed herein are biointerface membranes including a macro-architecture and a micro-architecture co-continuous with and bonded to and / or located within at least a portion of the macro-architecture. The macro- and micro-architectures work together to manage and manipulate the high-level tissue organization and the low-level cellular organization of the foreign body response in vivo, thereby increasing neovascularization close to a device-tissue interface, interfering with barrier cell layer formation, and providing good tissue anchoring, while reducing the effects of motion artifact, and disrupting the organization and / or contracture of the FBC. The biointerface membranes of the preferred embodiments can be utilized with implantable devices such as devices for the detection of analyte concentrations in a biological sample (for example, from a body), cell transplantation devices, drug delivery devices, electrical signal delivering or measuring devices, and / or combinations thereof.

An implantable analyte-measuring device including a membrane adapted to promote vascularization and / or interfere with barrier cell layer formation. The membrane includes any combination of materials, architecture, and bioactive agents that facilitate analyte transport to provide long-term in vivo performance of the implantable analyte-measuring device.

There is described a prosthetic valve to be inserted into a body lumen, the valve having leaflets that are spread apart during forward flow of fluid to create an orifice, and the leaflets coming into contact with each other during reverse flow of fluid, thereby impeding the reverse flow of fluid, the valve comprising: a hollow, cylindrical stent having an inner surface and an outer surface, and having a first and a second open end; and valve means formed from a single tubular membrane, the membrane mounted to the stent, the membrane having a graft portion internally folded and bonded to itself at a plurality of points to form pouches such that the leaflets extend from the pouches, and a sleeve portion on an outer surface of the stent to secure the membrane thereto.

The present invention relates generally to systems and methods for increasing oxygen availability to implantable devices. The preferred embodiments provide a membrane system configured to provide protection of the device from the biological environment and / or a catalyst for enabling an enzymatic reaction, wherein the membrane system includes a polymer formed from a high oxygen soluble material. The high oxygen soluble polymer material is disposed adjacent to an oxygen-utilizing source on the implantable device so as to dynamically retain high oxygen availability to the oxygen-utilizing source during oxygen deficits. Membrane systems of the preferred embodiments are useful for implantable devices with oxygen-utilizing sources and / or that function in low oxygen environments, such as enzyme-based electrochemical sensors and cell transplantation devices.

Systems and methods of use involving sensors having a particle-containing domain are provided for continuous analyte measurement in a host. In some embodiments, a continuous analyte measurement system is configured to be wholly, transcutaneously, intravascularly or extracorporeally implanted.

The present invention relates to a method and a device for transporting a molecule through a mammalian barrier membrane of at least one layer of cells comprising the steps of: ablating the membrane with an electric current from a treatment electrode; and utilizing a driving force to move the molecule through the perforated membrane.

An implantable analyte-measuring device including a membrane adapted to promote vascularization and / or interfere with barrier cell layer formation. The membrane includes any combination of materials, architecture, and bioactive agents that facilitate analyte transport to provide long-term in vivo performance of the implantable analyte-measuring device.

The filter device captures embolic material in a blood vessel and is placed in the blood vessel via a guide wire. The guide wire has a proximal end, a distal end and a stop near its distal end. The filter device includes an expandable frame of frame struts having a closed, radially compact form and an open, radially expanded form. The frame, in the radially expanded form, has frame struts forming a pair of facing frustoconical frame structures. Filter material is attached to one of the pair of frustoconical frame structures. In one embodiment, the filter material is a perforated membrane. The guide wire extends through the expandable frame and the expandable frame is freely movable over the guide wire (likewise, the guide wire is freely movable within the frame), both rotatably and longitudinally, except distally beyond the stop near the distal end of the guide wire. This mobility of the guide wire with respect to the expandable frame enables to guide wire to be guided by the operator through the blood vessel.

The present invention provides a biointerface membrane for use with an implantable device that interferes with the formation of a barrier cell layer including; a first domain distal to the implantable device wherein the first domain supports tissue attachment and interferes with barrier cell layer formation and a second domain proximal to the implantable device wherein the second domain is resistant to cellular attachment and is impermeable to cells. In addition, the present invention provides sensors including the biointerface membrane, implantable devices including these sensors or biointerface membranes, and methods of monitoring glucose levels in a host utilizing the analyte detection implantable device of the invention. Other implantable devices which include the biointerface membrane of the present invention, such as devices for cell transplantation, drug delivery devices, and electrical signal delivery or measuring devices are also provided.

A multifunctional membrane is provided. The multifunctional membrane is suitable for use in an analyte sensor. In a particular application, the multifunctional membrane may be used in connection with an amperometric biosensor, such as a transcutaneous amperometric biosensor. Some functions of the membrane are associated with properties of membrane itself, which is comprised of crosslinked polymers containing heterocyclic nitrogen groups. For example, the membrane, by virtue of its polymeric composition, may regulate the flux of an analyte to a sensor. Such regulation generally improves the kinetic performance of the sensor over a broad range of analyte concentration. Other functions of the membrane are associated with functional components, such as a superoxide-dismutating / catalase catalyst, either in the form of an enzyme or an enzyme mimic, that can be bound to the scaffold provided by the membrane. The effect of any such enzyme or enzyme mimic is to lower the concentration of a metabolite, such as superoxide and / or hydrogen peroxide, in the immediate vicinity of the sensing layer of the biosensor. Lowering the concentrations of such metabolites, which are generally deleterious to the function of the sensor, generally protects or enhances biosensor integrity and performance. The membrane is thus an important tool for use in connection with analyte sensors, amperometric sensors, biosensors, and particularly, transcutaneous biosensors. A membrane-covered sensor and a method for making same are also provided.

A system, method and apparatus for performing a renal replacement therapy is provided. In one embodiment, two small high flux dialyzers are connected in series. A restriction is placed between the two dialyzers in the dialysate flow path. The restriction is variable and adjustable in one preferred embodiment. The restriction builds a positive pressure in the venous dialyzer, causing a high degree of intentional backfiltration. That backfiltration causes a significant flow of dialysate through the high flux venous membrane directly into the patient's blood. That backfiltered solution is subsequently ultrafiltered from the patient from the arterial dialyzer. The diffusion of dialysate into the venous filter and removal of dialysate from the arterial dialyzer causes a convective transport of toxins from the patient. Additionally, the dialysate that does not diffuse directly into the patient but instead flows across the membranes of both dialyzers provides a diffusive clearance of waste products.

A liquid-filled balloon may be positioned between a workpiece, such as a semiconductor structure covered with a photoresist, and a lithography light source. The balloon includes a thin membrane that exhibits good optical and physical properties. Liquid contained in the balloon also exhibits good optical properties, including a refractive index higher than that of air. Light from the lithography light source passes through a mask, through a top layer of the balloon membrane, through the contained liquid, through a bottom layer of the balloon membrane, and onto the workpiece where it alters portions of the photoresist. As the liquid has a low absorption and a higher refractive index than air, the liquid-filled balloon system enhances resolution. Thus, the balloon provides optical benefits of liquid immersion without the complications of maintaining a liquid between (and in contact with) a lithographic light source mechanism and workpiece.

An artificial intervertebral disc and disc nucleus are described herein having chambers and dampening members. The dampening members may be within or outside of the main body of the device. The chambers may be filled with a suitable liquid, gas, or both, and separated by valves to regulate flow of fluid between chambers, within a dampening member, between the main body and dampening member, or all of the above. Chambers may be filled with responsive hydrogels, EPAM, or other suitable materials, and the device may have activation plates or members, a strain gauge, a pressure sensor, or other means for detecting changes in the materials and / or triggering desired changes in the materials in order to mimic the behavior of a healthy native disc or disc nucleus. A control system may be in communication with the device for receiving feedback and delivering stimuli to initiate desired changes in the fluids or other materials. Membranes may be of variable permeability and may be metallized to ensure as low permeability as possible. Dampening members may be filled during manufacture with carbon dioxide or other suitable gas which may be in a supercritical state and allowed to return to ambient temperature and gaseous state or by other means. Methods of manufacture, delivery of the artificial disc and related structures, and methods of treatment are also described.

The present invention relates generally to systems and methods for increasing oxygen generation in electrochemical sensors in order to overcome the oxygen limitations. The preferred embodiments employ electrode systems with at least two electrodes in relatively close proximity to each other; wherein at least one electrode is configured to generate oxygen and at least one other electrode is configured to sense an analyte or a product of a reaction indicative of the concentration of analyte. The oxygen generated by the oxygen-generating electrode is available to the catalyst within a membrane system and / or the counter electrode, thereby enabling the electrochemical sensors of the preferred embodiments to function even during ischemic conditions.

A protective enclosure is disclosed for an interactive flat-panel controlled device. The protective enclosure is watertight, crush-resistant, and impact-resistant. While providing protection, the protective enclosure simultaneously allows smooth and accurate interaction with the interactive flat-panel controlled device. The protective enclosure has a protective membrane that permits RF and touch screen stylus inputs, as well as capacitance, such as from a finger, to be transmitted accurately to the flat-panel control. The hardness and texture of the protective membrane allows a stylus or finger to glide smoothly along the surface of the membrane without catching or sticking. The protective enclosure is further adapted to allow infrared and other communication signals while the device is secured inside the case. Further, electrical connections can be made through the case without affecting the protection afforded the electronic device inside.

A microfluidic system for performing chemical reactions or biochemical, biological, or chemical assays utilizing a microfabricated device or “chip.” The system may include, among others, an integrated membrane fabricated from a chemically inert material whose permeability for gases, liquids, cells, and specific molecules, etc. can be selected for optimum results in a desired application.

A photolithographic apparatus, system and method employing an improved refractive medium. The photolithographic apparatus may be used in an immersion lithography system for projecting light onto a workpiece such as a semiconductor wafer. In one embodiment, the photolithographic apparatus includes a container containing a transparent fluid. The fluid container is positioned between a lens element and the wafer. The container is further characterized as having a substantially flexible and transparent bottom membrane contacting an upper surface of the wafer and overlapping at least one side edge of the wafer such that a fluid filled skirt is formed extending beyond the edges of the wafer.

There is described a prosthetic valve to be inserted into a body lumen, the valve having leaflets that are spread apart during forward flow of fluid to create an orifice, and the leaflets coming into contact with each other during reverse flow of fluid, thereby impeding the reverse flow of fluid, the valve comprising: a hollow, cylindrical stent having an inner surface and an outer surface, and having a first and a second open end; and valve means formed from a single tubular membrane, the membrane mounted to the stent, the membrane having a graft portion internally folded and bonded to itself at a plurality of points to form pouches such that the leaflets extend from the pouches, and a sleeve portion on an outer surface of the stent to secure the membrane thereto.

The present invention provides an aortic valvuloplasty catheter which, in one preferred embodiment, has a tapered distal balloon segment that anchors within the left ventricle outflow track of the patient's heart and a rounded proximal segment which conforms to the aortic sinuses forcing the valve leaflets open. In addition, this embodiment of the valvuloplasty catheter includes a fiber-based balloon membrane, a distal pigtail end hole catheter tip, and a catheter sheath.

The present invention relates generally to devices for measuring an analyte in a host. More particularly, the present invention relates to devices for measurement of glucose in a host that incorporate a hydrophilic electrode domain and / or a cellulosic-based interference domain.

Described are devices, methods, and kits for non-invasively measuring glucose. In general, the devices comprise skin patches for placement on a skin surface and measurement devices for measuring glucose collected in the patches. The patches may include an adhesive material, a collection layer, an interface layer, and a sweat-permeable membrane. The sweat-permeable membrane is configured to act as a barrier to epidermal contaminants and glucose brought to the skin surface via diffusion. In this way, non-correlatable skin surface glucose will not be measured. The patches may further include components to induce a local sweat response. The measurement device typically includes a display, a processor, and a measurement mechanism. The methods typically include the steps of wiping the skin surface with a wipe containing at least one solvent for removing glucose, placing a patch on a skin surface, and measuring glucose collected in the patch. Kits comprising the patch and measurement device are also described.