Abstract: A sensor system for determining the pH or carbon dioxide concentration of a liquid medium comprising, in combination, a pH-insensitive fluorescent indicator and a PH-sensitive fluorescent indicator which act in concert or a single fluorescence indicator which emits fluorescent signals of different wavelengths in different carriers, which system(s) produce diverging signals, the ratio of which provides an accurate and stable determination of the parameter being measured. A method for determining pH and CO.sub.2 concentration is also disclosed.

Abstract: An extracorporeal blood circuit comprises a generally cylindrically shaped blood reservoir; a generally cylindrically shaped oxygenator arranged coaxially and adjacently below said reservoir; and a generally cylindrically shaped heat exchanger attached coaxially and adjacently below said oxygenator. The reservoir encloses an upper defoamer and multiple filter element adapted to receive cardiotomy blood within the interior of said upper element and to discharge treated blood to said reservoir; and a lower defoamer and filter element adapted to receive arterial blood within the interior of said lower element and to discharge treated blood to said reservoir; and has a lower blood outlet. The oxygenator has an inlet adapted to integrally receive blood directly from the outlet of said heat exchanger and an outlet adapted to return the oxygenated blood to the patient.

Abstract: The present invention discloses an improved fenestrated tracheostomy tube which includes a tubular outer cannula which has a distal end for insertion within the trachea and a proximal end which remains outside of the patient. The outer cannula has a generally circular longitudinal radius of curvature and has an upper wall portion with a longitudinal center along its uppermost surface. The tube includes a disposable inner cannula having a distal end and a proximal end which is adapted to fit closely within and to be removably inserted into the outer cannula. The outer cannula has a plurality of slotted fenestrations through the upper wall portion arranged so that each fenestration is slightly spaced from the longitudinal center and forms an acute angle away from the longitudinal center in the direction of the distal end of the outer cannula. With the foregoing fenestration arrangement, the inner cannula is readily inserted into the outer cannula free from interference with the fenestrations.

Abstract: A device for releasably holding an object, particularly a prosthetic heart valve, comprising a handle member integral with a key member which releasably engages a holder member having an interacting engaging screw which controls and limits the movement of integral cooperating fingers for holding and releasing said object; and a package assembly for storing under sterile conditions a holder member of said device attached to a prosthetic heart valve comprising a clam shell mechanism for releasably holding said holder member and valve.

Abstract: A unitary device for the treatment and collection of blood from two different sources during a surgical procedure comprises a hollow housing made of a rigid, preferably transparent, material, first and second blood inlets in the housing, a first blood treatment element inside the housing comprising a layer of porous defoaming material and a layer of non-woven depth filter material, and a second blood treatment element inside the housing comprising a layer of porous defoaming material and free of any depth filter material. The novel device also includes internal walls for providing two blood flow paths therein, one through the first inlet, the first blood treatment element, a blood collection reservoir defined within the device and a treated blood outlet in the bottom wall of the housing, and the other through the second inlet, the second blood treatment element, the blood collection reservoir and the blood outlet.

Abstract: A device for transferring high energy electromagnetic radiation from a laser to an optical fiber, which comprises a cone-shaped coupler having a wide proximal end and a narrow distal end, wherein the proximal end is in the form of a convex surface which acts as a focussing lens adapted to receive radiation from a laser and to transmit said radiation into and through said optical fiber and the distal end is attached to the input end of the optical fiber to form an integral assembly therewith, said cone-shaped coupler having a taper angle .theta. defined by the equation ##EQU1## wherein N.A. is the numerical aperture of the fiber material and .mu. is the refractive index of the material of the coupler at the wavelength of the incident radiation. A process for removing an obstruction by laser surgery using said device is also disclosed.

Abstract: An ultrasonic sensor for non-invasive detection of air bubbles in a liquid flowing through a tube comprises two half-housings capable of being assembled together and two mutually opposed ultrasonic transducers, one installed in each of the half-housings. For acoustic coupling of the tube to the two mutually opposed ultrasonic transducers, each half-housing contains a chamber closed off by a flexible membrane and filled with a fluid highly transmissive of sound. The fluid displaced by the tube inserted between the two half-housings forces the membrane up in the form of a bulge on either side of the tube. In this way, an excellent contact is obtained between the chamber filled with sound-transmissive fluid and the tube. The membrane may be embedded into the side walls of the half-housings and cylindrically arched along the same.

Abstract: An apparatus for directing laser energy to a vascular occlusion comprises a catheter and a plurality of optical fibers disposed in an annular array about a central axis at the outer wall of the catheter. The distal end of each fiber is beveled at an angle and is oriented away from the central axis and perpendicular to a plane formed by the central axis and the center of the distal end of the respective fiber, whereby the output of the fibers are directed toward the central axis and converge at a common focal point.

Abstract: A device for releasably holding an object, particularly a prosthetic heart valve, comprising a handle member integral with a key member which releasably engages a holder member having an interacting engaging screw which controls and limits the movement of integral cooperating fingers for holding and releasing said object; and a package assembly for storing under sterile conditions a holder member of said device attached to a prosthetic heart valve comprising a clam shell mechanism for releasably holding said holder member and valve.

Abstract: A prosthetic heart valve comprising a stent having an annular base and a plurality of legs extending upwardly from said base; a valve element circumscribing said stent and attached thereto, said valving element comprising a number of cooperating valve leaflets equal to the number of said legs; and a layer of biologically-compatible material secured to said stent and positioned between said stent and said leaflets, said layer having a smooth, non-abrasive outer surface and covering all of the surfaces of said stent that, in the absence of said layer, would contact the mobile portions of said leaflets during the normal function of the valve.

Abstract: Prosthetic heart valves comprising an annular, right cylindrical, metal stent covered with fabric to which a glutaraldehyde-stabilized pericardial valving element formed of three leaflets, each having a plateau on a truncated triangle extending higher at the center than at the edges, and formed as a cylinder having a diameter substantially equal to the diameter of the stent, and having a low profile is disclosed.