Abstract: An implantable coronary perfusion assist system to divert blood from large arteries, such as the aorta, to small arteries, such as the coronary arteries where additional blood flow is needed. The assist system includes a shunt graft which is connected to the aorta or another convenient source of oxygenated blood at one end, and to the coronary artery or the atrium at its other end. A pump, preferably of the type employing a trained muscle wrapped around a fluid chamber is connected by a conduit to a bladder disposed in line with the graft, to assist in pumping of blood from the aorta to the coronary artery. The pump action is synchronized to the dastolic phase of the patient's cardiac cycle, and the coronary perfusion is accomplished without increasing the concentration of oxygen in the patient's body.

Abstract: A device for removing stenosis from arteries includes a catheter body for delivering a cutter to the area of the stenosis. A screw is mounted on the distal end of the body for entering and fixedly holding the stenosis. An annular cutting means is moved forward around the screw to cut the stenosis which is held by the screw. The catheter is then removed with the cut stenosis trapped inside the cutter.

Abstract: A heart valve prosthesis and method for replacement of the same are disclosed. The prosthesis includes a sewing ring for permanent attachment to heart tissue, and a valve assembly which is replaceably mounted within the sewing ring in a spaced-apart relationship to define a cylindrical cutting path therebetween. The valve assembly is attached to the sewing ring by interconnecting sutures, but the cylindrical cutting path is otherwise devoid of structure which projects therebetween. Thus, replacement of the valve assembly can be accomplished by insertion of a cutting member, such as a thin scalpel blade, within the cylindrical cutting path, thereby simultaneously facilitating severing of the interconnecting sutures and any tissue ingrowth which may have formed between the sewing ring and valve assembly as the blade is worked around through the cutting path.

Abstract: The present invention includes an implantable medical device with needle sensing means. The sensing means employs the casing of the device, the body of the patient, and the needle in a circuit which activates electrical means for notifying the physician of needle placement. Contact of the hypodermic needle with the desired location in the reservoir completes a circuit which is activated by power means to provide preferably audible feedback.

Abstract: An implantable medical device having a main body, and a port in the main body for receiving a medical instrument percutaneously. A resilient dome is mounted in the device for communicating with the medical instrument, and for flexing from a first rest position to a second position after contact with the medical instrument. The dome provides an extra corporeal response signal resulting from the flexion of the dome from the first position to the second position.

Abstract: A device to be used as a vascular stent comprising a cylindrical open-ended wire component made of a low memory metal such as copper alloy, titanium, or gold, providing a radial support from within a blood vessel after implantation therein. The coronary stent is characterized by its ability to be expanded radially to a larger diameter after initial implantation and means for causing said stent to expand to a larger diameter and a method for transporting, positioning and implantation of such coronary stent transluminally to have said stent act as a permanent prosthesis to assure vascular patency. And method for simultaneous angipolasty and stent implant procedure.

Abstract: An assist device for the heart comprises a continuous flow pump for moving blood through a vessel and a muscle powered device for supplying pulsatility to the flow of blood, to simulate human heart pumping action.

Abstract: A dual chamber pacemaker having an atrial escape interval which is varied on a beat-to-beat basis in response to the measured time from a ventricular event to the next atrial sensed event. Additionally, a portion of the atrial escape interval is bifurcated into a first sensing portion T1 and a second sensing portion T2 wherein atrial sense events occurring during T1 may be ignored by the pacemaker, while atrial sense events falling within T2 are used to compute a new atrial escape interval and are used to resynchronize the pacemaker and are used to inhibit the otherwise scheduled atrial pace event.

Abstract: A battery-powered medical treatment inductor coil generates a pulsed current inducing a magnetic field in the inductor coil for interaction with the patient's body. At the end of a pulse, the magnetic field collapses and an energy recovery circuit returns the energy in the collapsing field to the battery to reduce its average drain thus prolonging battery life.

Abstract: A device to be used as a vascular stent comprising a cylindrical open-ended wire component made of a low memory metal such as copper alloy, titanium, or gold, providing a radial support from within a blood vessel after implantation therein. The coronary stent is characterized by its ability to be expanded radially to a larger diameter after initial implantation and means for causing said stent to expand to a larger diameter and a method for transporting, positioning and implantation of such coronary stent transluminarely to have said stent act as a permanent prosthesis to assure vascular patency. And method for simultaneous angioplasty and stent implant procedure.

Abstract: An electrical apparatus protective interconnect module including a casing having therein a chamber at one end and a socket at the other end for receiving within the socket an electrical apparatus having controls. A power supply is contained within the chamber and provide power to the electrical apparatus received within the socket. Connectors are located between the chamber and the socket for coupling the power supply to the electrical apparatus received within the socket. The casing encloses and restricts access to predetermined controls of the electrical apparatus received within the socket. The module further comprises externally accessible outputs for coupling an electrical signal output of the electrical apparatus, received within the socket, from the casing to external electrodes.

Abstract: A plastic stent for a prosthetic trileaflet heart valve consisting of a cylindrical body portion terminating at one end in three apical, spaced commissure posts, and at the other end, in a skirt comprising three arcuate extensions, each extension being provided with an interrupted channel adjacent the outer edge thereof. An optional metal ring may be mounted over the skirt adjacent the body portion. A cloth cover is secured to the stent by stitching directly through the skirt in the area of reduced thickness resulting from the interrupted channel.

Abstract: An apnea monitor employs dual detectors for determining patient breaths while rejecting cardiac artifacts. The first detector examines a respiration signal at a first sensitivity for apparent breaths. The second detector examines at a second sensitivity to determine if the apparent breath was actually an artifact.

Abstract: A casing for a tissue stimulator includes a box portion for containing the stimulator circuitry and a cover hingeably mounted on the box portion. The cover has a clip for mounting on the user's belt. The box rotates away from the cover approximately 90.degree. to a generally horizontal position wherein the user can manipulate controls on the stimulator.

Abstract: An apparatus for treating a patient which induces an electric current in the body through external application of an electromagnetic field. The apparatus includes means for controlling the magnitude of the induced electric current by sensing the electromagnetic field and automatically controlling its strength. The sensing may be accomplished through time multiplexed use of the field inducing coil or through the use of a separated, dedicated coil.

Abstract: A tissue stimulator of the type which provides short intervals of stimulation followed by longer intervals of rest is provided with a fail-safe system for turning off the stimulator if the stimulation interval exceeds a predetermined maximum interval. A timer times each "on" interval. If the "on" interval exceeds the predetermined maximum, the timer times out and shuts off stimulation.

Abstract: A lead for implantation in the epidural space has an inflatable balloon which is sealed against a first side of the lead so it inflates away from the first side. The balloon contacts walls of the epidural space and urges an electrode on the first side against the dura. A syringe for inflating the balloon has a spring to absorb travel of a plunger actuator when fluid pressure in the balloon exceeds tension of the spring.

Abstract: An ultrasound imaging system particularly adapted for detecting structure which reflects ultrasound at a variety of angles. There is a plurality of ultrasound transducers, which may be a linear array or a two-dimension array with the various horizontal rows of the array offset from one another, but having zero horizontal space or overlapping between adjacent vertical transducers. A sequencer causes one transducer to fire and then listen for an echo; if no echo is heard, the same transducer fires again and an adjacent transducer listens; if there is still no echo, the transducer fires and the next adjacent transducer listens; and so on until a predetermined listening sequence is concluded.