Abstract: A method of dehydration of bulky hydrogel samples of polyvinyl alcohol (i.e., PVA) and a method of preparation of prosthetic nuclei for vertebral discs are given. A method of gamma irradiation sterilization of PVA gel samples which does not incur the side effects of discoloration and of increased crystallinity (i.e., further reduction of water content) is also given.A method of dehydrating bulky hydrogel samples of polyvinyl alcohol (i.e., PVA) so that no significant distortion in the samples results, comprises:(a) subjecting the sample to a solvent system comprising at least one organic solvent which(1) has a solubility for PVA which is less than the solubility of water for PVA and(2) is miscible with waterfor a length of time generally from about 2 to about 10 days so that the dehydration rate of the hydrogel samples is sufficiently slow so as not to cause any distortions on the dehydrated samples.

Abstract: A design and method of manufacture is disclosed for an electrosurgical electrode with a silicone coating. The coating resists the buildup of eschar. The silicone material is thick enough in the flat area of the blade to withstand the electrosurgical voltage without breakdown. The electrosurgical current path is primarily through the blade edges and tip. The flat of the blade remains insulated under most conditions. The relatively thick coating also provides high tear strength and added durability. The composition of the electrode coatings may include silicone elastomers in the form of adhesives, dispersions, or liquid rubbers. The coating composition may also contain adhesion promoters, heat stabilizers, plasticizers, release enhancers, crosslinking agents, and colorants. Several methods of manufacture are illustrated by way of examples.

Abstract: A stent delivery device is disclosed that includes an inner tube having a distal portion which carries the stent on the delivery device. At least part of the inner tube is formed from a spirally wound wire. A movable outer tube is used to constrain the stent in a radially contracted state on the distal portion of the inner tube. A substantially straight elongate wire is configured inside the spirally wound wire and bonded at the distal and proximal portions of the wound wire. The outer tube may have at least one side port adjacent to the distal portion in communication with the annular space between the outer tube and the inner tube allowing radiopaque fluid to be injected through the annular space and out the side port in the vicinity of the stent.

Abstract: Apparatus monitors RF return current to maximize the AC signal of impedance at two return electrodes. A transformer with driving and driven windings isolates ESU and patient. At ends of the driving winding are signal and ground terminals joined to the return electrodes with capacitors returning current. An AC coupling capacitor at the signal terminal has a timing circuit in sync to the voltage wave and relative to impedance of the return electrodes. Microprocessing the voltage at the signal terminal of the driving winding watches impedance and determines if the RF return current path is adequate. Voltage detection within the timing circuit has a voltage shaping circuit. A voltage comparator after the voltage detection forms a square wave. A current detection circuit and a coupling capacitor allow AC flow to the driving winding. Current shaping circuit in the current detection circuit has a voltage comparator at the output to form a square wave.

Abstract: A sealed airtight container and a method for forming the same produces an increased resistance between the seal and a flange on the container to pressure differences between the inside of the container and the outside environment. The container includes a body having a hollow interior with sidewalls, a bottom, and having a planar opening at one end. The opening in the hollow interior is surrounded by an outwardly extending flange. A multi-layer peelable cover is sealed to the flange surrounding the opening. The cover and the flange are deformed towards the bottom of the container from the plane of the opening to be sealed.

Abstract: A medical device is disclosed for the treatment of a body lumen by radiation. The device includes a catheter for insertion into a body lumen, a radiation source, and a wire for advancing and removing the radiation source into and from the catheter.

Abstract: A space correction apparatus is provided for a knee prosthesis comprising a body and two pairs of parallel runners extending on both sides of the body in a direction perpendicular to the plane of the body and of which the spacing of the front and back parts can be adjusted independently. This apparatus makes it possible to measure the spacing between the resected parts of the tibia and the femur in the extension position and to reproduce the spacing in flexion position so as to perform resections of the femur in this latter position.

Abstract: A minimally invasive retractor and dissector for internal surgical use on a patent's body has a tubular support for passing into the patient's body. A proximal end on the tubular support located outside the patient's body is in position to provide assess for the surgeon. A distal end on the tubular support located inside the patient's body to provide access within the patient for surgery. A control is located at the proximal end of the tubular support. One or more articulated members are movably positioned relative to the distal end of the tubular support so each of the articulated members allows movement relative to the distal end. A rotator connects to the proximal end of the tubular support for movement relative to the control. An instrument moves independently of the tubular support when the articulated members and the distal tips cooperatively function on the tissue.

Abstract: An apparatus for correcting a spinal column having damaged vertebrae comprises a fastener (which is preferably a pedicle screw) having a receiving slot for holding a distracting or compressing bar. The bar is positioned within the slot in a manner permitting adjustment and is then locked in a fixed position, both functions achieved by a special two-part locking element which first holds and then rigidly locks the bar and fastener together. A method for correcting a spinal column having damaged vertebrae is also given.

Abstract: An apparatus for delivering laser energy to a target through a radiation-transmitting waveguide having a distal end terminating in a tip which is in contact with the target during delivery, while protecting the tip from heat damage, which apparatus comprises a waveguide for transmitting laser radiation and having a distal end terminating in a tip adapted to be placed in contact with the target to deliver laser energy directly to the target at the site of contact, and means for delivering a controlled small amount of liquid to the target adjacent to the tip, which small amount is just sufficient to limit the temperature at the target to not more than the failure temperature of the tip. An apparatus assembly for performing ILC incorporating a waveguide and a method for protecting the tip of a waveguide from damage is also disclosed.

Abstract: An apparatus and method for igniting plasma in a surgical system is disclosed. A corona discharge is generated on a surgical handpiece which is used to ignite a plasma arc for surgical operations. The advantages include greater reliability and repeatability of plasma arc ignition. The apparatus comprises a handpiece incorporating an active electrode, a passage for ionizable gas, and a corona return electrode. The corona return electrode has a terminus on the holder and near the distal end of the holder. The corona return electrode is electrically connected to the return path of the electrosurgical generator. A non-uniform electric field is generated between the active electrode and the corona return electrode of sufficient strength so that a corona is formed near the active electrode. A separate return electrode may be on the patient, or the apparatus may be configured for bipolar electrosurgical operation by carrying the return electrode on the handpiece.

Abstract: A surgical system has a multiple electrode electrosurgical capability in combination with a gas plasma capability for delivery of electrosurgical energy to the tissue or bodily fluids of a patient. The system includes a holder, a source of electrical energy, electrodes connected to the source of electrical energy, one or more passages carried on the holder for transporting ionizable gas, and a source of ionizable gas of a selectable flow rate. The gas passages may include at least one electrode extending toward the operative site. The gas passages may include a part that creates a vortex in the gas flow. The electrodes may be coaxially placed in the gas passages. The system may also be configured such that two electrodes are each shrouded by the ionized gas so that the electrosurgical energy is conducted to the tissue or bodily fluids of the operative site by passing along conductive pathways in the ionized gas from each electrode. There may also be a dielectric barrier between the conductive pathways.

Abstract: A prostatic stent and method of manufacture. The stent has an elongate body defining a passage therethrough and includes a distal section, a mid-section and a proximal section. The elongate body has a length sufficient to extend distally from a bladder neck to a position somewhat short of the external sphincter. The proximal section has a shape conforming to the neck of the urinary bladder.

Abstract: A prosthesis having attachment portion for insertion into or attachment to a patient's bone without bone cement. Parts of the attachment portion on the prosthesis are attached to the bone are covered with a mantle of synthetic resin material and which has a roughened outer surface with bone fragments or calcium phosphate fragments embedded therein.

Abstract: A process for preparing coating compositions of a commingled hydrogel of a polyurethane-polyurea polymer hydrogel and a poly(N-vinylpyrrolidone) polymer hydrogel; a process for making materials composed of a polymeric plastic or rubber substrate or a metallic substrate, with a coating of the commingled hydrogel thereon; and a process for making medical devices with a coating of the commingled hydrogel thereon, are disclosed. The coating compositions tenaciously adhere to the substrate materials and medical devices to which they are applied due to bonding of a tie coat to a reactive substrate surface and due to the commingling of the two hydrogel components. The coating compositions and coated materials and medical devices are non-toxic and biocompatible, making them ideally suited for use in applications such as for catheters, catheter balloons and stents.

Abstract: A bipolar electrosurgical scissors has an improved coagulation capability. Both poles of electrosurgical energy are exposed on the exterior surfaces of each shearing member so that the scissors can be used to coagulate tissue using only one shearing member. There may be two or more electrically conductive regions on the exterior surface of each shearing member. The conductive regions may be formed by laminating, depositing, or inlaying electrically conductive material on the exterior surfaces. The conductive regions are electrically insulated from each other. In one embodiment, the shearing surfaces are also electrically conductive and are each connected to the same electrical pole. In another embodiment, the conductive material that forms one of the conductive regions on each exterior surface also extends through the shearing member to also form a conductive shearing surface.

Abstract: A centralizer for the stem of a cementable prosthetic orthopedic implant that is implanted into the medullary canal of a bone has a hollow annular body with a tapered interior surface for receiving a tapered stem of the implant. The centralizer has four fins spaced around the exterior surface of its annular body with the fins extending radially outwardly in a direction generally perpendicular to the longitudinal axis extending along the stem in a proximal-distal direction. The annular body of the centralizer has a proximal and a distal end surface spaced a predetermined distance apart with the fins having a base adjacent the body extending over a substantial portion of the predetermined distance. Adjacent fins are offset from neighboring fins in a proximal-distal direction so that when the proximal-distal dimension of the annular body is maintained, it generates a wavelike structure for the centralizer body.

Abstract: A method and apparatus for preparing a planar surface on the distal femur prior to implantation of a femoral knee prosthesis has a femoral plate with an opening therein for exposing both condyles of the femur. A guide with a central aperture is used to align the femoral plate on the distal femur. The guide is releasably secured to the femoral plate and an intramedullary guide rod is placed through the aperture therein and into the intramedullary canal of the femur. After alignment with the intramedullary canal, the femoral plate is pinned to the femur and the rod and guide are removed. A milling guide having two bores, one adjacent each condyle, is then placed on the femoral plate and an end mill is used to mill a planar surface on at least one of the condyles.

Abstract: An endoprosthesis for a shoulder joint that provides for an adjustable distance between the head portion and the shank portion is provided. The head portion of the endoprosthesis is connected through a threaded connection to the proximal end of the shank portion such that the distance between the head portion and the shank portion can be varied. In operation, the head portion is screwed into the shank portion until the desired distance is obtained.

Abstract: A catheter for use in angioplasty and other medical procedures is disclosed. The catheter features a flexible-wire mesh tip movably attached at a distal end of the catheter, the tip being expandable from a contracted position which it is first in when the catheter is deployed inside the lumen of a vessel, to stretch open the lumen and eliminate a flow obstruction therein, such as is caused by plaque deposits; the tip subsequently being returnable to its contracted position inside the catheter when the catheter is withdrawn from the lumen of the vessel. Radio frequency energy may additionally be used to weld the source of the flow obstruction to the wall of the lumen leaving a conduit of sufficiently expanded diameter to allow resumption of normal flow in the vessel.