Abstract: A cannula assembly suitable for rapid, closed-chest cannulation of the cardiopulmonary system to an extracorporeal bypass machine through punctures in the femoral veins and arteries is disclosed. The assembly comprises a conduit made of a smooth, flexible, thin-walled material and capable of longitudinal insertion through these vessels by use of an associated "introducer" and conventional guide wire. The conduit has adequate hemodynamic flow capacity and sufficient unsupported hoop strength to resist collapse from suctional and vasoconstrictive forces during use.

Abstract: A compact, hand-held instrument by which to permit a physician to accurately and controllably implant, dispense, and inflate an inflatable membrane at a predetermined target area within the tissues of a patient. In a preferred embodiment of the invention, the inflatable membrane is a genitourinary prosthesis, and the targeted area lies within the corpus spongiousum surrounding the urethra to enable a patient to overcome urinary incontinence by means of increasing both localized tissue volume and passive occlusive pressure upon the urethral mucosa. The instrument includes a trocar assembly having a plurality of telescoping trocar members which may be either retracted for dilating a tunnel through the urethral tissues of the patient or expanded for placing, dispensing and inflating the membrane at the end of the tunnel. The membrane is percutaneously infused with and inflated by material (e.g.

Abstract: Apparatus and methods are provided for determining the concentration of a gaseous component in a fluid. A solid body of a natural or synthetic high polymer, which is permeable to the gaseous component, is exposed to the fluid, the polymer is exposed to infrared radiation, and the infrared absorption by the gas in the polymer is measured. In the preferred embodiment, a sensor is provided for making in vivo measurements of the concentration of CO.sub.2 in the blood. The sensor includes an optical fiber which is nonpermeable to CO.sub.2 and substantially transparent at the CO.sub.2 absorption wavelength range, and a solid body of polymeric material at the distal end of the fiber which is substantially transparent to the absorption wavelength range and permeable to CO.sub.2. An incident infrared signal is transmitted down the fiber, passes through the body, is reflected off the distal end of the body, and the intensity of the return signal is measured by a detector.

Abstract: Apparatus for positioning a sensor probe in vivo, including a probe advancement mechanism and a mating interconnection for positioning a distal end of a sensor probe a predetermined distance from the distal end of an indwelling catheter. The advancement mechanism includes a plurality of telescoping elements. The distal tip of the probe is moved from a retracted position within the advancement mechanism where the probe is maintained sterile and protected from breakage, to an advanced position wherein the distal tip of the probe is advanced through the catheter to a predetermined position with respect to the distal tip of the catheter at which the sensor measurement is made.

Abstract: A venous reservoir including a blood collecting chamber with heat seamed peripheral edges incorporating fillet-defining beads for enhanced blood flow and debubbling. Flow diverters are provided vertically between lower inlet tubes and upper air vents, and laterally between the inlet tubes and an outlet tube. The diverters are vertically spaced and upwardly inclined toward the vent within the flow path of the blood between the inlet and outlet tubes for an enhanced upward directing of entrapped air toward the vents and groove extensions thereof within the chamber.

Abstract: An electrosurgical technique of achieving coagulation involves conducting a predetermined ionizable gas in a jet to the tissue at a predetermined flow rate sufficient to clear natural fluids from the tissue and to substantially expose the tissue stroma. Electrical radio frequency energy is conducted to the tissue in ionized conductive pathways in the gas jet. To achieve fulguration, the electrical energy is conducted as arcs in the ionized conductive pathways. To achieve a non-contact type of electrosurgical desiccation, the electrical energy is conducted as a non-arcing diffuse current in the ionized conductive pathways.

Abstract: A catheter having a relatively soft body formed of a hydrophobic elastomer and a tip portion coated with a water insoluble hydrophilic polymer grafted thereto to impart, in the dry state, rigidity to the tip portion. In use the hydrophilic coating absorbs or adsorbs water with resultant softening of the coating so as to render the tip portion soft. A method of facilitating placement of a catheter utilizing a transitorily rigidified tip portion is taught.

Abstract: Apparatus for hypodermically implanting a genitourinary prosthesis comprising an extensible, inflatable tissue expanding containment membrane to be located in the proximal periurethral tissues to add bulk to these tissues and thereby overcome urinary incontinence by means of localized, controlled tissue volume increase. Hypodermic positioning, injecting and inflating instruments are also disclosed for implanting the containment membrane and for percutaneously infusing the membrane with biocompatible fluid or suspended particulate matter. The containment membrane functions as an envelope for retaining the fluid or particulate matter therewith in while controllably and advantageously increasing localized tissue volume and simultaneously preventing the migration of such fluid or particles. Accordingly, an increased passive occlusive pressure may be applied to the patient's urethra to achieve continence.

Abstract: A stent for the anastomosis of a vessel comprises an integral solid of biologically compatible material which is adapted to melt from a solid into a fluid in response to heat energy or body temperature into the fluid which flows through the vessel. Preferably the stent is formed of frozen material, and has a temperature which is substantially less than the temperature of the vessel upon insertion. Upon melting, the biologically compatible material naturally integrates with the fluid normally conducted by the vessel. The stent may be advantageously formed of frozen blood plasma or other blood fluid which is compatible with the blood normally conducted by an artery or a vein. When used in conjunction with thermal bonding techniques, the stent aligns the ends of the vessel for thermal bonding without the necessity for taking the time-consuming circumferentially-spaced stay sutures.

Abstract: Prosthesis for repair of inguinal hernias and femoral hernias are provided, together with techniques for implanting the prostheses. The inguinal prosthesis has three panels which radiate from a common elongate core. The core serves as a replacement for the inguinal ligament and the panels are attached to selected musculature and ligamentous tissue. One of the panels is sutured to Cooper's ligament, a second panel is sutured to the conjoined tendon and the third panel is sutured to the exterior oblique aponeurosis. A prosthesis for repair of femoral hernias also is provided and is in the form of an umbrella-shaped device having a top panel and a stem which is attached to the face and extends generally perpendicular from the top panel. The prosthesis may be implanted in a relatively simple procedure in which the femoral ring, through which the hernia has occurred is exposed surgically from below.

Abstract: An electrical connector achieves improvements in connecting a patient plate to an electrosurgical generator. The connector is preferably of the lever operated type, and electrical contacts are connected on the lever and connected within a passageway internally in a housing of the connector. A tongue portion of the patient plate is inserted in the passageway. Upon closure of the lever, the contacts on the lever extend into the passageway above the lower contacts to mechanically contact and retain the tongue portion between the contacts and to electrically contact the tongue portion by which to conduct current to the patient plate. A recess is formed in the lower marginal area of the passageway and a retaining structure on the lever member extends into the passageway to deform the tongue portion into the indention.

Abstract: A medical electrode comprises a sensor element formed of an electrically conductive material and having a substantially flat, electrically conductive surface portion for engagement with the skin of a patient, and an elecrically conductive coating applied to a selected portion of the flat surface portion. The coating is applied such that the area of the flat surface portion other than the coated selected portion is substantially free of the conductive coating. This defines a predetermined pattern on the flat surface portion of the sensor element, consisting of the portion having the conductive coating applied thereto and the portion substantially free of the conductive coating. A backing member has a substantially flat, adhesively coated surface and is affixed to the sensor element such that the adhesively coated surface is exposed about a substantial portion of the periphery of the sensor element.

Abstract: A steerable guidewire has an elongate main wire having a tapered distal portion and a helical coil mounted about the distal portion. The distal end of the coil extends beyond the distal tip of the tapered distal portion of the main wire. An inner helical coil is disposed within the outer coil is secured at its proximal end to the distal tip of the tapered distal portion of the main wire and at its distal end to the distal end of the outer coil. The device does not have a separate safety wire, the inner coil serving as the sole safety connection between the main wire and the outer coil. The omission of the conventional safety wire and the use of the dual coil construction provides a tip which is equally flexible in all directions. Gradual selected transitions in stiffness may be achieved by varying the spacing of the individual turns of the inner and outer coils.

Abstract: A balloon dilatation catheter adapted for use in angioplasty techniques has two balloons at the distal end of the catheter, one inside the other with a separate inflation lumen for each balloon. The catheter enables dilatation of stenoses of different sizes and the dilatation of arteries of different sizes without requiring catheter exchanges.

Abstract: A control module for regulating the flow of gases in a suction drainage apparatus. The drainage apparatus includes a collection container in communication with a body cavity to receive body fluids (including liquids and gases) therefrom and a suction source for creating a negative pressure within the collection container and removing the gases of the body fluids. The control module includes a serial arrangement of chambers and a plurality of flow control means in a unitary compact structure which fits within a recess provided in the collection container. The control module is adapatable to different sizes and types of collection means and does not add appreciably to the overall size of the device. Baffle means are provided to prevent the loss of the indicator liquid from the air leak indicator means if the device is tipped in any direction.

Abstract: This invention relates to a novel and improved chest drainage apparatus characterized by a bottle housing a fluid collection chamber and a fluid inlet connectable to receive fluid and air from a chest cavity to be drained, air inlet and exhaust ports downstream of the fluid inlet open to the atmosphere within the air space above the fluid collected, and a U-tube between the fluid inlet and the air exhaust port capable of collecting and retaining an amount of fluid effective to provide a visual indication of any air flow into the system; a subassembly including an air chamber containing a check valve effective when connected to receive air from the exhaust port of the bottle to prevent the backflow thereof into the system; and a negative pressure relief valve connected to the air intake port automatically operative to limit the negative pressure, if any, in the air space above the fluid to a predetermined maximum.

Abstract: An autotransfusion system for collecting and salvaging blood from a patient's body cavity and for returning it to the patient includes a collection bottle which is detachably connected by an arrangement of ports and an adapter to a source of suction as well as to a conduit from the patient. When the bottle is connected to the system the suction draws the blood into the bottle. When the bottle has been filled and it is desired to return the blood to the patient or for further processing before returning it to the patient the container is easily detached and may be connected to an intravenous delivery set. During reinfusion blood may continue to be collected by the system by replacing the original container with another container. The system may be operated by suction from commonly available fittings in hospital environments or may be connected to a thoracic drainage system to utilize the suction from that system to operate the autotransfusion device.

Abstract: A two-stroke pumping device for developing pulsatile fluid flow includes a housing with an internal resilient flexible element. The flexible element defines a pair of chambers within the housing, including a pumping chamber and a driving chamber. The pumping chamber is connected to a source of the fluid to be pumped and the driving chamber is connected to a pneumatic source adapted to create a pressure differential across the flexible element. The device includes a means responsive to the flexure of the element in one of the strokes to terminate that stroke and begin the other stroke. The flexible element oscillates to generate repetitive ejection and filling strokes. The pneumatic source may be a source of negative or positive pressure.

Abstract: This invention relates to a novel and improved chest drainage apparatus characterized by a bottle housing a fluid collection chamber and a fluid inlet connectable to receive fluid and air from a chest cavity to be drained, air inlet and exhaust ports downstream of the fluid inlet open to the atmosphere within the air space above the fluid collected, and a U-tube between the fluid inlet and the air exhaust port capable of collecting and retaining an amount of fluid effective to provide a visual indication of any air flow into the system; a subassembly including an air chamber containing a check valve effective when connected to receive air from the exhaust port of the bottle to prevent backflow thereof into the system; and a negative pressure relief valve connected to the air intake port automatically operative to limit the negative pressure, if any, in the air space above the fluid to a predetermined maximum.

Abstract: A pulse width modulation technique regulates the output power of each cycle of a radio frequency surgical signal of an electrosurgical generator. The delivered power of the surgical signal is determined by multiplying the sensed current and the sensed voltage of the surgical signal. An error signal is established by the difference of the actual delivered power with respect to a selected desired output power. The error signal is operatively utilized to modulate the pulse width of each driving pulse which creates the cycles of the surgical signal. Limits on the sensed voltage and sensed current signals are established to limit the output characteristics of the surgical signal. A minimum current limit signal is utilized to limit the maximum output voltage into relatively high impedances. A minimum voltage limit signal is utilized to limit the maximum output current into relatively low impedances.