Abstract: An imaging apparatus with a flexible light guide which a surgeon can easily manipulate within the patient to control the field of view. Specifically, a scintillator receives radiation rays and converts these radiation rays into light signals at a position inside the body. A flexible bundle of optical fibers optically connected to the scintillator, channels the light signals from the scintillator to a position sensitive light signal detector located outside the body. The position sensitive light signal detector creates a digital signal to relay the position information about the detected event to a computer which accumulates these digital signals, converts these digital signals into images and displays the images.

Abstract: An electrode assembly for acquiring physiological signals, comprising a flexible substrate having a bottom surface and a top surface, means forming a plurality of electrodes at the bottom surface of the substrate and each electrode having a bottom surface facing away from the substrate, an electrical connector fixed to the substrate and having a plurality of connector elements, a plurality of flexible conductors fixed on the substrate and connecting the electrodes to the connector elements, a layer of conductive adhesive on the bottom surface of each electrode; and an adhesive layer on at least a portion of the bottom surface of the substrate.

Abstract: A device for indicating that a refrigerator door is open, includes a housing which is mountable on a refrigerator in the vicinity of the refrigerator door during the use of the device. A transducer is mountable at the refrigerator door gasket for changing an electrical parameter in response to the movement of the refrigerator door from its closed position to an open position. Circuitry disposed in the housing senses the change in the electrical parameter of the transducer to produce an alarm after a preselected time delay.

Abstract: An N-path filter has a number N of parallel resistive-capacitive filter sections. A switching arrangement connects each filter section periodically into an input signal path through the filter. The switching arrangement also triggers a sample and hold network to sample the filtered input signal for a portion of the time each filter section is connected into the input signal path through the filter and then hold the sampled, filtered input signal. The sampling time is preferably selected to be an initial portion of the time each filter section is connected as the signal path through the filter when variations in the charging rates of the capacitors in the filter sections have the least effect. The sampled N-path filter technique thus reduces the need to match the filter section components.

Abstract: A discontinuity detector detects a sudden change or discontinuity in a medium moving relative to the detector such as a liquid plug in a gas flowing along a conduct, an air bubble in a liquid, or a change form one liquid or gas to another. It has a sensor which senses the discontinuity and a circuit which compensates for gradual changes in the medium or sensor, but responds to the sensed discontinuity. The preferred circuit also determines that the sensor is functioning properly and is properly set up for sensing the discontinuity. The preferred circuit is an analog-to-digital delta modulator which periodically resets a clock pulse counter until a discontinuity is sensed. The clock pulses then increment the counter to a higher-than-normal count to signal the discontinuity. The preferred embodiments are intended for detecting discontinuities in patient gas or liquid supplies in a medical diagnostic or therapeutic instrument.

Abstract: A system for measuring the flow rate of electrolytic fluids includes a flow cell which has a cylindrical flow channel receptive of the fluid flow to be measured and a pair of spaced apart electrodes configured to conform to the cylindrical surface of the flow channel and to be flushed therewith. The electrodes are electrically conductive and inert to the fluid of the flow and a channel is configured to effect contact of the electrodes with the fluid flow for a desired range of flow measurement. A monopolar pulse train is applied across the electrodes to effect a cell impedance across the electrodes which is inversely proportional to the rate of flow.

Abstract: A jet ventilator control system produces a periodic pulse signal either asynchronous or synchronous with a patient's pulse rate. It is proportional in frequency to the number of jet ventilation pulses to be applied to the patient per unit time and is digitally programmable to adjust the delay and duty cycle of the pulse signal within the period defined by the produced pulse. The duration and duty cycle adjusted pulse signals effect the application of jet ventilation pulses corresponding thereto to the patient.

Abstract: A delta modulator has its feedback loop components selected to put the delta modulator into slope overload in response to the QRS wave of an EKG signal for detecting the same.

Abstract: A process and apparatus for measuring the catheter fluid pressure of a patient wherein a pressure transducer is used to convert the pressure into an electrical signal and a pressure indicator indicates the pressure corresponding to the electrical signal. A turnable active filter is disposed in the signal path between the transducer and the pressure indicator and the frequency parameters of the filter are adapted to that of the catheter in real time.