Abstract: A polarographic sensor for blood oxygen monitoring is defined by respective anode and cathode electrode wires fixedly maintained in conventional fashion. The end cross sections of the wires are carried on a surface, and overlying this surface is a capillary pore ultrafiltration membrane. The microscopic capillary pores, which have diameters less than 12 micrometers each, pass water therethrough and thus allow the blood, which passes on the side of the membrane opposite the anode and cathode, to act as its own electrolyte.

Abstract: A pair of compressible, hinged opposing arms enclose a bladder chamber, which in turn is coupled to the catheter. As the arms are compressed together, successive pivot fulcra close, in turn first pinching and closing, and then opening the bladder to create negative differential pressure against the catheter, and promoting flashback.

Abstract: A device for simulating the pressure readings obtained from the arm of a living subject whose blood pressure levels are being determined by an oscillometric blood pressure monitor, includes a pulse pressure chamber for generating pressure pulses at a rate equivalent to a preselected pulse rate. The input to the pressure chamber is attached to the pressure cuff of the monitor and the output is connected to the pressure transducer of the monitor. In order to balance the pressure across the chamber and to apply the full cuff pressure to the monitor transducer, a normally-open valve is connected across the pressure chamber. This valve, however, is closed when the chamber creates a pressure pulse so that the pulse is added to the applied cuff pressure at the monitor transducer. A processor generates electrical signals that control the amplitude of the pressure pulses created by the chamber, depending on preselected values for simulated systolic, mean arterial and diastolic pressures.

Abstract: An adaptive monitor and method for rapidly determining blood pressure, selects an initial cuff pressure to be applied to an artery of the test subject and then measures the amplitude of pressure pulses caused by the pumping of blood by the subject's heart. The cuff pressure is incrementally increased while the pulse amplitudes are monitored in order to obtain blood pressure readings by the oscillometric method. If the pulse amplitudes decrease for increases in pressure above the initial value, it is taken as an indication that mean arterial pressure is below the initial cuff pressure. Thus the cuff pressure is substantially decreased to a new initial value and the process is restarted.

Abstract: In the formation of a chemically sensitive field effect device, prior to formation of the gate membrane, an aluminum pad is disposed over the gate, and a polyimide layer is disposed thereover. Photoresist and etching steps produce openings in the polyimide to form a gridwork which is anchored to the device on the periphery of the gate. The aluminum layer is etched completely away, forming a void defined by the suspended polyimide mesh on one side, and the gate insulator on the other. Polymeric membrane is formed in the void by insertion in liquid form.

Abstract: Semiconductor chips carrying chemically sensitive field effect devices are encapsulated by tape automated bonding techniques, wherein one tape layer has a beam lead pattern disposed thereon which terminates in the chip bonding pad pattern over an opening in the tape. A tape layer for sealably covering the beam lead pattern and the chip has openings which are respectively coincident with the chemically selective membrane systems of the field effect devices.

Abstract: A thermodilution catheter assembly for use in determining cardiac output includes a special connector for joining the catheter to the output computer. Catheter size indicator links housed in the connector automatically communicate the size of the catheter to the computer when the connection is made. As an optional feature, the connector additionally includes means to automatically energize the computer when the connection is made.

Abstract: Provided is a method as well as apparatus for a catheter catheter-balloon assembly wherein the catheter balloon is mounted on the catheter by means of adhesive and, in the preferred mode, an annular internal rib protrusion of the catheter balloon is provided for forming a sharply defined boundary of adhesive thereby aiding in the even and symmetrical inflation of the catheter balloon.

Abstract: A pneumotachograph including a housing having first and second ports which, during the course of respiration, alternate as input and output ports and which provide a path for generally linear flow of the respiratory gases. A pair of pitot tubes are disposed along the top of the path and are positioned generally at right angles thereto. A pair of baffles or flow deflectors are disposed in the path in alignment with the axes of the pitot tubes. Each of the baffles is positioned at an angle of approximately 45.degree. to the axis of its associated pitot tube and to the path of flow. The baffles may be held in the flow path by a rigid connection or alternatively, they may be retained there by a resilient connection such that the pitot tube measurement is linearized.In another embodiment, the baffles may actually be merged into a single baffle thus leaving an annular opening between itself and the housing with the opening of the gap being approximately the same distance as the distance between the pair of tubes.

Abstract: Method and apparatus for enhancing the reflection coefficient of a surgical instrument for use in conjunction with an apparatus for pulse-echo ultrasound imaging of an area of the body, by means of a diffraction grating disposed on the surgical instrument.

Abstract: A system for encapsulating semiconductor chips, such as chips carrying chemical sensitive field-effect devices, includes lamination of a sheet of dry film photoresist material onto the surface of the chip, placement of a photomask over the chip in a predetermined alignment, and then exposure of the photomask to light so that light passes through certain light-transmitting portions of the mask onto the chip. The photoresist material is then developed to remove the material from over the gate regions of each of the field-effect devices to define windows in the material through which the gate regions are exposed. Chemical sensitive membrane systems may then be applied to the windows of the devices to cover the gate regions.

Abstract: A standard articulated B-scan arm provides positional and directional information for a transducer at its end, based on relative angular displacements of the separate arm segments. A real time scanner, preferably one having a fixed transducer and a fixed oscillating mirror, is freely attachable or detachable from the scan arm. The probe itself is operable either in a real time sector scan or in a static B-scan mode.

Abstract: An apparatus for producing information indicative of the mean blood pressure of a living creature through indirect measurement comprising an inflatable cuff, a pump connected to the cuff, a deflating valve connected to the cuff, measuring apparatus connected to the cuff adapted to measure cuff pressure and pressure oscillations occurring in the cuff caused by the heartbeat of the living creature and control apparatus connected to the pressure measuring apparatus, pump and deflating valve. Deflation of the cuff occurs in pressure increments, with processing being done at each given decrement to evaluate plural successive pulsations for purposes of artifact rejection and identification of a true pulsation.

Abstract: A method for producing information indicative of the mean blood pressure of a living creature through indirect measurement, practiced in a system comprising an inflatable cuff, a pump connected to the cuff, a deflating valve connected to the cuff, measuring apparatus connected to the cuff adapted to measure cuff pressure and pressure oscillations occurring in the cuff caused by the heartbeat of the living creature and control apparatus connected to the pressure measuring apparatus, pump and deflating valve. Deflation of the cuff occurs in pressure increments, with processing being done at each given increment to evaluate plural successive pulsations for purposes of artifact rejection and identification of a true pulsation.

Abstract: A roller-switch and cam, located at an intermediary joint of a plural arm overhead assembly, delays the unlocking of a brake at a next adjacent joint until the joint at which the cam and switch are located has diverged a predetermined angle from alignment.

Abstract: A pair of toroidally wound cores are maintained in a generally parallel, vertical, spaced apart relationship by a tubular insulating member passing through the toroid centers. The tubular member insulates the windings from a coupling loop which passes through the tube and which closes outside the toroidal windings. One winding is the primary of the isolation circuit, connecting the source of signals through a FET device to ground, and the other winding is secondary winding, which is also connected to ground through a FET, and which is coupled to a utilization device through a low pass filter. The FET devices are synchronously pulsed at a frequency above the signal frequency and the filter pass band.

Abstract: A disposable gas sensor, such as for monitoring pO.sub.2 in blood or administered gases, includes a housing, a passageway therein for blood or gas, a membrane-anode-cathode polarographic assembly, and a temperature sensing element. The temperature sensing element penetrates the housing and includes a removable thermistor, which is matable with the housing for thermal contact with a metallic element, and which in turn is in direct contact with the fluid being monitored.

Abstract: Transcutaneous electrical nerve stimulation is applied to the patient, as though electrocardiograph monitoring is not being practiced. The EKG signals are preprocessed through a selective sample and hold module, which performs amplification, comparison with selective frequency and amplitude standards (as by differentiation) and temporary holding of EKG signals at such time as the transcutaneous nerve stimulating pulses are occurring, as sensed against the frequency and amplitude criteria. In the absence of transcutaneous stimulation signals, EKG signals are coupled directly through for conventional EKG processing.

Abstract: A curved faced, disc shaped transducer and an oppositely facing, circular angularly disposed mirror form the transmission and reception path of a mechanical sector scan imaging system. The transducer and mirror are mounted on a common axis, and a shaft upon which the mirror is affixed oscillates about that axis. Through a belt drive mechanism, a motor provides the oscillating motion, in turn scanning the ultrasound beams through the subject by virtue of the mirror motion. An optical encoder records positional information from the motor, for coordination of the mirror oscillation with transducer signals, and thereby for the assembly of a composite image.

Abstract: A sample of whole blood is stained with an acridine orange reagent, and is analyzed rapidly, a cell at a time, in a flow cytometry system having a sample stream dimension in the range of expected red cell dimensions. Red florescence and forward scatter data is utilized first to discriminate a cell from noise, and then to distinguish platelets from reticulocytes and red cells. The red cell and reticulocyte data is subjected to a correction such as rotational coordinate shift, and the shifted data are, by means of statistical procedures, utilized to determine threshold criteria separating red cells from reticulocytes, and to enumerate the cells on that basis.