1769 results about "Elastance" patented technology

An embodiment of the invention provides a method for detecting and treating a tumor using tissue localized volumetric impedance measurement. The method includes providing an impedance measurement apparatus having a plurality of resilient members deployable with curvature and configured to sample tissue impedance through a plurality of conductive pathways. The apparatus is configured to be coupled to at least one of an energy delivery device, a power supply, a switching device or logic resources. The apparatus is then positioned at a selected tissue site and the impedance array deployed to define a sample volume. The impedance array is then utilized to make impedance measurements through a plurality of conductive pathways. Information from the impedance measurements is then utilized to determine a tissue condition of the sample volume. Energy is then delivered from the energy delivery device to ablate or necrose at least a portion of the tumor.

Apparatus and methods for endoscope assemblies having working channels with reduced bending and stretching resistance are disclosed. In one embodiment, an endoscope assembly includes a sheath having a body portion adapted to at least partially encapsulate an endoscopic insertion tube, and a working channel attached to the body portion and extending along at least a portion of the body portion. The working channel includes a component for reducing the resistance of the assembly to bending and stretching. In alternate aspects, the working channel may include a cut, a gap, a sliding portion, or an expansion section. Endoscope assemblies having a working channel in accordance with the invention advantageously reduce the articulation and stretching resistance of the assembly during articulation of the endoscope assembly. Also, because the axial forces (tension and compression) within the working channel are reduced, the working channel can be fabricated out of a relatively hard, inelastic material, thereby reducing the friction within the working channel and improving the physician's ability to perform a medical procedure.

A tubular sleeve is provided for enabling a physician to impart a preselected shape in an implantable tubular device, such as a cardiac lead, a catheter, or some other tubular structure. The sleeve may be deformed by the surgeon before or at the time of implantation to customize the shape of the tubular device to the particular anatomical structures to be encountered by the device. To retain the deformation imparted by the physician, the sleeve may be composed of a heat-sensitive shape-memory material or an elastomeric material provided with a plastically deformable rib.

The virtual intelligence shoe with a podiatric analysis system provided with a portable pair of shoe-like body types thereof, into two of which a miniature electronic module and an enclosed sensor mat are permanently embedded in the shoe-like with a mechanical air package enclosing the electronic module to serve as a shock absorption. A miniature electronic module comprises a transmitting circuit with pressure resistance, shoe temperature and warning buzzer for full memory capacity, which receives the variable pressure and temperature voltage signals, convert them into resistance (ohm) and Celsius, respectively. The electrical signals can be emitted in an infrared light signal. An enclosed sensor mat constitutes a thin, flexible, planar, resilient, and dielectric material that arrays seventy-four positions at strategic geometrical pattern to produce the precision of collecting data exerted by a foot or feet continuously and instantaneously in static and dynamic event during the full weight bearing in various activities. The conjunction of a pair of shoe-like body types, a digital foot scanner, a portable infrared light-receiving unit and a central integrator (servers) form a podiatric analysis system for enabling accurate information. An obtained information of each individual can be stored and analyzed for diagnostic means with respect to the foot or feet maladies. The virtual intelligence shoe with a podiatric analysis system is an unconventional, which can ultimately be used by anyone and capable to produce consistent foot or feet information to implement the changes in the foot or feet biomechanics by altering the shoes, orthoses or other modes. In a preferred form, a pair of shoe-like body types is virtually applied to any type of foot or feet maladies and worn daily as if they were conventional shoes under various terrain conditions.

A constriction device that constricts body tissue is viewable under X ray fluoroscopy. The device includes an elongated sleeve. The sleeve includes opposed opened ends and is formed from expandable or elastic material to receive therein, when in an expanded condition, body tissue to be constricted and to constrict the body tissue therein when released from the expanded condition. At least a portion of the sleeve includes X ray opaque material rendering the device visible under X ray fluoroscopy.

Either an endoscopic or open bipolar forceps includes a flexible, generally tubular insulating boot for insulating patient tissue, while not impeding motion of the jaw members. The jaw members are movable from an open to a closed position and the jaw members are connected to a source of electrosurgical energy such that the jaw members are capable of conducting energy through tissue held therebetween to effect a tissue seal. A knife assembly may be included that allows a user to selectively divide tissue upon actuation thereof. The insulating boot may be made from a viscoelastic, elastomeric or flexible material suitable for use with a sterilization process including ethylene oxide. An interior portion of the insulating boot may have at least one mechanically interfacing surface that interfaces with a mechanically interfacing surface formed between the shaft and a jaw member or with a mechanically interfacing surface disposed or formed on the shaft or a jaw member.

A combination of a patient core temperature sensor and the dual-wavelength optical sensors in an ear probe or a body surface probe improves performance and allows for accurate computation of various vital signs from the photo-plethysmographic signal, such as arterial blood oxygenation (pulse oximetry), blood pressure, and others. A core body temperature is measured by two sensors, where the first contact sensor positioned on a resilient ear plug and the second sensor is on the external portion of the probe. The ear plug changes it's geometry after being inserted into an ear canal and compress both the first temperature sensor and the optical assembly against ear canal walls. The second temperature sensor provides a reference signal to a heater that is warmed up close to the body core temperature. The heater is connected to a common heat equalizer for the temperature sensor and the pulse oximeter. Temperature of the heat equalizer enhances the tissue perfusion to improve the optical sensors response. A pilot light is conducted to the ear canal via a contact illuminator, while a light transparent ear plug conducts the reflected lights back to the light detector.

A catheter has a stylet formed of a shape-retentive and resilient material having a preformed curved shape at its distal end resulting in the catheter sheath having the preformed curved shape. The catheter sheath has a plurality of electrodes at its distal end for contacting selected biological tissue for imparting ablation energy thereto. The catheter sheath also has an axially mounted tendon for causing deflection of the distal end. The stylet material permits straightening the catheter sheath during insertion into the patient and advancing the electrodes to the target tissue. Upon removal of the straightening forces, such as by entry into a chamber of the heart, the stylet material resumes its preformed curved distal shape thereby forcing the catheter distal end with the electrodes into the same preformed curved shape. The operator may place the curved distal end into contact with the target tissue and axially move the tendon as desired to gain greater control over the bend in the distal end of the catheter sheath to adjust the radius of curvature of the distal end to obtain greater contact of the electrodes with the heart tissue. Preferably, the stylet is formed of nitinol.

A respiratory mask assembly for delivering breathable gas to a patient includes a frame and a cushion. The cushion has a non-face contacting portion structured to be connected to the frame, a face-contacting portion structured to engage the patient's face, and a central portion that interconnects the non-face contacting portion and the face contacting portion. The frame may be structured to allow a forehead support to assume multiple positions, to compensate for replacement cushions that may have a different profile, shape or size. The cushion is structured to compensate for variations in strap tension, treatment pressure and / or movement of the patient. Headgear may be provided with a strap assembly in which one or more straps is provided with selectively adjustable elasticity or extensibility that may be automatically changed in dependence of treatment pressure and / or treatment type.

A flat interface nerve electrode is provided along with a method for its use. The electrode provides a plurality of conductive elements embedded in a non-conductive cuff structure, which acts to gently and non-evasively redefine the geometry of a nerve through the application of a force so as to apply pressure to a nerve in a defined range, namely from 2 to 40 mmHG and more preferably from 15 to 30 mmHG and most preferably from 15 mmHG to 20 MMHG. This range is selected to minimize the reduction of blood flow within the tissue, which preferably is at least 70% of the initial value, more preferably 90% of the initial value. The cuff has an opening, which is elongated relative to the diameter of the nerve to which it is applied. Preferably, the cuff is constructed from an elastic bio-compatible material having top and bottom beam members configured to define a nerve opening. The cuff is open at one side and has a connection at the other side which results in a spring force being applied through the surfaces of the nerve opening to the subject nerve. During implantation the open sides of the cuff are closed so as to capture the nerve in the cuff. As the nerve is reshaped, specific nerve axons become more easily addressed through the epineurium by the embedded conductive elements.

Method and apparatus for controlling a ventilator are described. The invention can be used to control mechanical ventilators as well as respiratory assist devices such as CPAP machines. The apparatus receives input data indicative of patient's oxygen level. A controller determines PEEP, or CPAP, and FIO2, on the basis of data indicative of the patient's oxygen level. In an alternative embodiment, the apparatus further receives input data indicative of patient's carbon dioxide levels, respiratory elastance and airway resistance, and barometric pressure. The controller further utilizes the said input data to determine the optimal values of tidal volume and breathing frequency for a next breath of the patient, and uses the respiratory elastance and airway resistance data to determine any necessary adjustments in the I:E ratio. The controller also applies safety rules, detects and corrects artifacts, and generates warning signals when needed.

An active bodily ring having a housing adapted to be sutured to a bodily component and a loop disposed in the housing, the loop capable of actively expanding and compressing during the bodily components normal function. The housing defines a first chamber and a second chamber, the first chamber containing the loop and the second chamber providing a region capable of being sutured to the bodily component. In one embodiment, the housing can be a crimped-fabric housing. In another embodiment, the housing can be a woven-fabric housing having elastic properties. The housing can be made from polyester.

A ventilation system is controlled by detecting the resistance and elastance of the patient's respiratory system and adjusting the flow supplied by the ventilator accordingly. In one embodiment, the resistance is detected by controlling the ventilator to superimpose at least one forced single oscillation on the flow and observing the reaction of the respiratory system. In another embodiment, the elastance is detected by controlling the ventilator to supply a pressure which has the effect of temporarily occluding the respiratory system, waiting until the respiratory system has reached equilibrium, and observing the resulting state of the respiratory system. The detection techniques of these two embodiments can be used together.

An adaptive optic for refractive lens exchange or cataract patients. The intracapsular implant comprises an elastomeric monolith with an equilibrium memory shape that imparts to the capsular sac's periphery the natural shape of the capsule in an accommodated state. In one embodiment, the monolith carries a recessed deformable central lens portion having an ultralow modulus that allows for high accommodative amplitude in response to equatorial tensioning. In a preferred embodiment, the adaptive optic defines an anisotropic modulus with a plurality of on-axis, rotationally symmetric elastomer block portions each having a different Young's modulus. The invention further provides composite materials for enhancing deformation of lens curvature, including the use of auxetic polymeric materials and negative stiffness materials. In preferred embodiments, at least a portion of the lens is fabricated of a shape memory polymer that provides a memory shape and a temporary shape with a reduced cross-sectional shape for introduction into the patient's eye.

A nasal dilator capable of introducing separating stresses in nasal outer wall tissues has a truss of a single body with a resilient member secured therein and a pair of spaced-apart end surfaces which, when forced toward one another from initial positions to substantially reduce direct spacing therebetween by a spacing reducing force external to said truss, results in restoring forces in the truss tending to return to the original direct spacing between the end surfaces. A resilient member, which is symmetrical with respect to a centerline of the truss that is perpendicular to the long axis of the truss, has a spring rate which continuously diminishes from the centerline to the end surfaces. An adhesive on the end surfaces adhesively engages exposed surfaces of nasal outer wall tissues sufficiently to keep the truss attached to the nasal wall surfaces while subjecting them to the restoring forces.

Methods and devices for measuring the size of a body lumen and a method for ablating tissue that uses the measurement to normalize delivery of ablational energy from an expandable operative element to a luminal target of varying circumference are provided. The method includes inserting into the lumen an expandable operative element having circuitry with resistivity or inductance that varies according to the circumference of the operative element, varying the expansion of the operative element with an expansion medium, measuring the resistivity of the circuitry, and relating the resistivity or inductance to a value for the circumference of the operative element. In some embodiments the sizing circuit includes a conductive elastomer wrapped around the operative element. Other embodiments of the method apply to operative elements that include an overlapping energy delivery element support in which the overlap varies inversely with respect to the state of expansion, and which is configured with sizing electrodes that sense the amount of the overlap.

An elastic structure is introduced percutaneously into the left ventricle and attached to the walls of the ventricle. Over time the structure bonds firmly to the walls via scar tissue formation. The structure helps the ventricle expand and fill with blood during the diastolic period while having little affect on systolic performance. The structure also strengthens the ventricular walls and limits the effects of congestive heart failure, as the maximum expansion of the support structure is limited by flexible or elastic members.

An implantable lead having at least one electrode contact at or near its distal end prevents undesirable movement of the electrode contact from its initial implant location. One embodiment relates to a spinal cord stimulation (SCS) lead. A balloon may be positioned on the electrode lead array. The balloon is filled with air, liquid or a compliant material. When inflated, the balloon stabilizes the lead with respect to the spinal cord and holds the lead in place. The pressure of the balloon is monitored or otherwise controlled during the filling process in order to determine at what point the filling process should be discontinued. An elastic aspect of the balloon serves as a contained relief valve to limit the pressure the balloon may place on the surrounding tissues when the epidural space is constrained.

An intracardiac device for restoring the functional elasticity of the cardiac structures, in particular for the treatment of cardiomyopathies and or valvulopathies, by storing energy from the cardiac structures and ceding energy to the cardiac structures during the cardiac cycle, has an elongated shape, is at least partially wound in coils and is attachable to a cardiac structure; the coils are selected in material, number and dimension so as to allow an elastic elongation of the intracardiac device higher than 10% of the rest length of the intracardiac device and are exposed, in use, to the blood flow.

In one embodiment, an impact and torque-absorbing module for a low profile lower limb prosthesis comprises two support members telescopingly engaged to permit axial and rotational motion therebetween. A resilient element resists axial displacement of the two support members, and a torque resisting cuff resists rotational displacement of the two support members. Precompression of the resilient element can reduce the size of the shock module making it more compact. The resilient element can also be replaced allowing adjustment of the shock absorption.

An apparatus for accurately infusing fluids into a patient at specific rates over an extended period of time. The apparatus is of a low profile, laminate construction having a stored energy source in the form of a distendable membrane, which in cooperation with the base of the apparatus defines one or more fluid reservoirs each having a fluid inlet and a fluid outlet. The apparatus further includes a novel, conformable ullage made of formable materials. The conformable ullage uniquely conforms to the shape of elastomeric membrane as the membrane returns to its less distend configuration and in so doing can move between a central chamber and a toroidal chamber formed in the cover of the apparatus. This arrangement will satisfy even the most stringent medicament delivery tolerance requirements and will elegantly overcome the limitations of materials selection encountered in devices embodying solely rigid ullage construction. Additionally, the infusion cannula of the apparatus is connected to the base in a novel manner which permits expeditious subdermal delivery to the patient via a cannula which extends generally perpendicularly relative to the base.

The invention provides intrafallopian devices and non-surgical methods for their placement to prevent conception. The efficacy of the device is enhanced by forming the structure at least in part from copper or a copper alloy. The device is anchored within the fallopian tube by imposing a secondary shape on a resilient structure, the secondary shape having a larger cross-section than the fallopian tube. The resilient structure is restrained in a straight configuration and transcervically inserted within the fallopian tube, where it is released. The resilient structure is then restrained by the walls of the fallopian tube, imposing anchoring forces as it tries to resume the secondary shape.

This invention relates to an elastomerically recoverable PTFE material that includes a longitudinally compressed fibrils of ePTFE material penetrated by elastomeric material within the pores defining the elastomeric matrix. The elastomeric matrix and the compressed fibrils cooperatively expand and recover without plastic deformation of the ePTFE material. This invention was used for various prosthesis, such as a vascular prosthesis like a patch, a graft and an implantable tubular stents. Furthermore, this invention discloses a method of producing the elastomerically recoverable PTFE material which include the steps of: providing the specified ePTFE, defined by the nodes and fibrils, to meet the desired end use; longitudinally compressing the fibrils of the ePTFE, the pore size sufficiently enough to permit penetration of the elastomeric material; applying the elastomeric material within the pores to provide a structurally integral elastomerically recoverable PTFE material defining an elastomeric matrix. The elastomeric material is applied to the ePTFE by dip, brush or spray coating techniques. The compression step and the application steps are interchangeable to produce the desired properties for the end use material. Finally, the elastomeric material is dried within the pores of the longitudinally compressed ePTFE to solidify the elastomeric matrix.

An endovascular graft which is configured to conform to the morphology of the vessel to be treated and which is made from an inflatable structure having a proximal end with a proximal inflatable cuff and a distal end with a distal inflatable cuff. At least one elongated inflatable channel is disposed between and in fluid communication with fluid tight chambers of the inflatable cuffs which may contain rupture discs therebetween which can be configured to rupture at different pressures. A thin flexible barrier disposed between the inflatable cuffs and the elongated inflatable channel of the frame so as to form a tubular structure defining a longitudinal channel to confine a flow of blood or other fluid therethrough. The graft may also have an expansion member attached to the proximal end of the graft which is preferably made of linked expandable rings of pseudoelastic shape memory alloy which is self expanding and prevents axial displacement of the graft once it is deployed.

Conductive elastomeric circuits are used in various simulated physiological structures such as tissues and organs, enabling feedback to be provided indicating whether a simulated task is being performed correctly. For example, a surgical trainer has a simulated human tissue structure made of an elastomeric composition, at least one reinforcing layer of a fibrous material, and at least one flexible electrical circuit. The surgical trainer preferably includes multiple areas for practicing surgical skills, each with evaluation circuits for providing feedback regarding that skill. Conductive elastomers are also incorporated into other types of medical training simulators, to similarly provide feedback. In another embodiment, a simulated organ has a conductive elastomeric circuit in the periphery of the simulated organ, enabling feedback to be provided to evaluate whether a person is properly manipulating the organ in response to a manual applied pressure.

In accordance with the invention, there are provided medical devices for providing a fluid passage between two areas in the body. An embodiment of the present invention relates to a stent comprising a tubular member comprising a distal transition region and a proximal transition region adapted to provide the ability for the stent to accommodate the dynamic urinary tract anatomy that stretches and relaxes. The distal transition region and the proximal transition region is adapted to exhibit a physical property that provides both longitudinal elasticity, allowing for stretch and recoil, as well as radial elasticity, allowing for bending and recovery.