Abstract: An intravascular device for pumping blood includes a catheter comprising a membrane chamber located between a proximal end and a distal end of the catheter. An inflatable membrane is disposed within the membrane chamber. The intravascular device includes a first one-way valve and optionally a second one-way valve configured to permit blood flow in a first direction. The first one-way valve may be positioned proximal to the membrane chamber, and the second one-way valve may be positioned distal to the membrane chamber. Methods related to intravascular devices and their respective use are provided.

Abstract: An intravascular device for pumping blood includes a catheter comprising a membrane chamber located between a proximal end and a distal end of the catheter. An inflatable membrane is disposed within the membrane chamber. The intravascular device includes a first one-way valve and optionally a second one-way valve configured to permit blood flow in a first direction. The first one-way valve may be positioned proximal to the membrane chamber, and the second one-way valve may be positioned distal to the membrane chamber. Methods related to intravascular devices and their respective use are provided.

Abstract: An intravascular device for pumping blood includes a catheter comprising a membrane chamber located between a proximal end and a distal end of the catheter. An inflatable membrane is disposed within the membrane chamber. The intravascular device includes a first one-way valve and optionally a second one-way valve configured to permit blood flow in a first direction. The first one-way valve may be positioned proximal to the membrane chamber, and the second one-way valve may be positioned distal to the membrane chamber. Methods related to intravascular devices and their respective use are provided.

Abstract: The invention described is a procedure whereby a small balloon catheter can be placed in a patient's body, expanded and collapsed as needed and then a second, larger balloon catheter placed over the smaller one. There is also disclosed a balloon catheter system for performing the above-noted procedure.

Abstract: A dual tubular member intra-aortic balloon assembly (1) has an inflatable balloon (4) bonded, at its proximal end, to an outer tubular member (2), and at its distal end, to an inner tubular member (3). The inner tubular member is composed of metal, being axially rigid yet bendable along its length. A flexible forwardly projecting extension (12) is attached to the inner tubular member for guiding the relatively stiff balloon assembly over a guide wire (9) through a tortuous arterial path, without causing buckling or misplacement of the guide wire. The junction between the inner tubular member and the flexible tubular member extension is embedded within a flexible tip (10) which reinforces the juncture to prevent balloon failure due to bending stress at the same time, enables a tighter balloon wrapping by eliminating the enlarged junction of the inner tubular member and flexible tip within the balloon membrane.

Abstract: A method and apparatus are disclosed for tracking instantaneous changes in blood pressure. The invention is utilized in an oscillometric blood pressure measuring apparatus of the type measuring pulsatile perturbations in a patient's blood pressure at a plurality of different measurement pressures of a sphygmomanometer cuff, to derive a blood pressure model for the patient, the model being stored in the apparatus as a series of pulsatile perturbations and the associated cuff pressures. A characteristic curve is generated so as to approximate the stored model in the vicinity of a predefined index value of cuff pressure. The pressure of the cuff is maintained within a predetermined range, r, of the index value, while changes in the index value are tracked by sensing a pulsatile perturbation in the cuff pressure, deriving the corresponding value for cuff pressure from the characteristic curve, and utilizing the derived pressure as a new estimate for the index value.

Abstract: A water separator adapted for use in a gas monitor includes a gas inlet port, a gas outlet port, a two-stage gas/water separator section, and a fluid reservoir. The two-stage gas/water separator section includes a first portion defining a first chamber which communicates with the gas inlet and gas outlet ports via a connecting conduit, a second portion defining a second chamber which communicates with the first chamber and the fluid reservoir, and an intermediate portion interposed between the first and second portions and defining a constricted passage between the first and second chambers. The second chamber has a frusto-conical shape in longitudinal cross section.

Abstract: Disclosed herein is a circuit for automatically selecting between an ECG heartbeat signal source and a pressure/pulse signal source depending on which of the two sources is the most periodic between three successive heart beats. A pair of microprocessor internal timers commence a count-up cycle in response to a first detected heart beat from each of the two respective sources, after which count-down cycles are started in response to the next successive detected heart beats. The counting of the timers is then stopped in response to the third successive detected heart beats from the two sources and a comparison is provided to determine which of the two sources is most periodic, and should be used to trigger a heart rate monitor.

Abstract: Improved plotting and printing apparatus has a writing surface for supporting a printing medium and which has an opening for exposing the underside of the medium. A transparent plate is mounted to the supporting surface so as to permit placement onto that surface of a printing medium such as a plural leaf form set whose area is larger than that of the plate so that one portion of the medium extends across the opening under the plate and can be printed on by a printer positioned under the surface opposite the opening, while another portion of the medium lies on the surface beyond the plate so that it can be written on from above the surface.

Abstract: A wrapping system for an intra-aortic balloon in which a wrapping guide is provided which restrains the proximal end of the envelope from rotating as the distal end is rotated thereby providing a uniform wrap of the envelope from its distal to its proximal end. A wrapping wire is provided for rotating the envelope distal end and the wire extends through at least a part of the catheter to which the envelope is attached. A wrapping knob is coupled to the proximal end of the wrapping wire, whose distal end can be detachably coupled to the distal end of the envelope, and the knob is constructed to permit only a predetermined number of rotations in both wrapping and unwrapping the envelope.

Abstract: A wrapping system for an intra-aortic balloon in which a wrapping guide is provided which restrains the proximal end of the envelope from rotating as the distal end is rotated thereby providing a uniform wrap of the envelope from its distal to its proximal end. A wrapping wire is provided for rotating the envelope distal end and the wire extends through at least a part of the catheter to which the envelope is attached. A wrapping knob is coupled to the proximal end of the wrapping wire, whose distal end can be detachably coupled to the distal end of the envelope, and the knob is constructed to permit only a predetermined number of rotations in both wrapping and unwrapping the envelope.

Abstract: A cardiac valvular prosthesis comprising an occluder disc, a supporting ring pivotally supporting said disc, and a suturing ring arranged on an outer portion of said supporting ring and adapted to facilitate suturing to the annulus of a cardiac valve to be replaced, said occluder disc having a hydrodynamic shape, an eccentrically positioned rotational axis far from the obturation plane of the disc, and hinges located in the central area of said disc, said occluder disc being pivotable between an open position disposed at an angle which is 90.degree. with respect to the supporting ring and a closed position wherein said disc is disposed at an angle of approximately 15.degree. with respect to said supporting ring.

Abstract: Apparatus and method for providing hypothermia or effecting hemostasis to prevent hemorrhaging in organs or regions of the human body and the like. In one application described herein, the apparatus provides hypothermia to the heart during, for example, cardio-pulmonary bypass. The apparatus comprises a unitary preferably disposable coolant fluid circuit, including a length of flexible tubing having a heat exchange portion and a flexible, inflatable bag through which a sterile coolant fluid passes. The inflatable bag is connected to the flexible tubing by a double lumen. The tubing is provided with appropriate fittings proximate to its juncture with the double lumen to allow introduction of coolant fluid. The heat exchanger portion of the coolant fluid circuit is located within a preferably disposable container which contains refrigeration means for reducing the temperature of the coolant fluid.

Abstract: A device which is adapted to transmit electrical energy between an electrical instrument and a living body such as a human body. The device includes a support which has an outer face adapted to be placed in engagement with a surface such as a human skin surface, while the support has an outer periheral edge surrounding the latter outer face thereof and the support being formed inwardly of its outer peripheral edge with an opening extending at least partly into the support from its outer face. An electrically-conductive gel is situated in the latter opening and is at least partly exposed at the outer face of the support so as to be capable of engaging and making electrical contact with the surface which is engaged by the outer face of the support. At least one carbon yarn has a portion situated in this gel for making electrical contact therewith, and an insulation covers the yarn at the region of its portion which is situated in the gel.

Abstract: Improved blood pumping apparatus is disclosed which includes a smooth avalvular deflatable section through which blood flows, said section mounted within a rigid avalvular airtight housing, gas being introduced and withdrawn from the housing by suitable control means, the action of the gas causing the blood chamber to inflate and deflate with consequent non-traumatic pulsatile ejection of blood from said chamber. The apparatus is simple, reliable, inexpensive and can aid the blood pumping function in many ways. For example, apparatus is disclosed to provide pulsatile flow to the blood being pumped by a heart-lung machine, or to provide pulsatile flow to the coronary arteries during coronary artery perfusion, or to be utilized as an arterio-venous fistula to decrease the afterload of the left ventricle and preserve the systemic diastolic pressure while increasing coronary perfusion.

Abstract: The surface of optical substrate are coated with a polymerized monomer of the formula: ##STR1## wherein R is selected from the group consisting of straight and branched alkane or alkylene of up to 10 carbon atoms, R' is selected from the group consisting of hydrogen and lower alkyl, and R" is a monovalent cation. The polymer may be linear, an interpolymer, or a cross linked polymer. The polymeric coating is capable of permitting steam, fog, water vapor, etc. to permeate its matrix and render the coated optical substrate anti-fog when subjected to such conditions.

Abstract: A circuit for charging an electrical storage device, such as a capacitor, from a source of energy via an induction coil interconnected between the source of energy and the storage device. Current from the source of energy builds up a magnetic field within a primary winding of the coil. A sensing circuit detects a desired maximum value of the magnetic field and then operates a switch to disconnect the primary winding from the source of energy. As the magnetic field starts to collapse, a voltage induced in a secondary winding of the coil enables energy stored in the magnetic field to be transferred to the storage device. When a given minimum value of the collapsing magnetic field is then reached, the primary of the induction coil is reconnected to the source of energy to repeat the above cycle. The minimum of the magnetic field is relatively close to the desired maximum, to permit only a partial magnetic field drop before commencing the next cycle.

Abstract: A device to be inserted in a blood vessel in order to aid the pumping of blood in only one direction within that vessel which comprises a gas inflatable and deflatable chamber mounted on support means and divided into an occluding section and a pumping section in direct communication with each other, such that it is necessary to deliver gas directly only to the occluding section, thereby enabling the occluding and pumping sections to be mounted on the support means in any order which further enables the device to be inserted from either above or below the vessel and which also permits thinner and therefore more easily insertable support means when the sections are mounted for insertion from below.