Abstract: Retroperfusion control apparatus for supplying arterial blood of a patient to the venous side of the patient's heart including a pump having an inlet and an outlet and a piston movable through a pump stroke for moving a liquid from the inlet to the outlet of the pump. A stepper motor is provided which drives the piston. Electronic circuitry is provided for driving the stepper motor and senses the presence of an R wave in a patient to operate the stepper motor in response to the sensed R wave.

Abstract: Disposable pump cassette for a liquid comprising a substantially rigid housing providing a chamber and having upper and lower portions. A flexible substantially cylindrical bladder is vertically disposed in the chamber and has an inlet adapted to receive the liquid and an outlet. The bladder has upper and lower wall portions. The lower wall portion is of a thinner cross section then the upper wall portion. An inlet valve is disposed in the inlet of the bladder and is mounted in the lower portion of the housing. An outlet valve is disposed in the outlet of the bladder and is mounted in the upper portion of the housing. The inlet and outlet valves are disposed in the liquid and provide unidirectional flow of the liquid through the bladder. A substantially incompressible driving liquid is disposed in the chamber and surrounds the bladder. A housing extension is mounted on said housing and is in communication with the driving liquid disposed in the chamber.

Abstract: Retroperfusion control apparatus for supplying arterial blood of a patient to the venous side of the patient's heart including a pump having an inlet and an outlet and a piston movable through a pump stroke for moving a liquid from the inlet to the outlet of the pump. A stepper motor is provided which drives the piston. Electronic circuitry is provided for driving the stepper motor and senses the presence of an R wave in a patient to operate the stepper motor in response to the sensed R wave.

Abstract: A transmission line analyzer for automatically identifying the severities and locations of multiple mismatches generates a ripple waveform which is digitally analyzed by a fast fourier transform method. Foreign and harmonic signals are rejected, and return loss at each mismatch accurately determined.

Abstract: A new microprocessor controlled digital multimeter offers significant advantages to the user. Automatic calibration allows a new reference IC board to be inserted and because of such calibration the multimeter is instantly ready for use.

Abstract: A microprocessor monitor or analyzer used as a test and troubleshooting tool for both the software and hardware of microprocessor based equipment. The analyzer is usable with all microprocessor families having accessible or reconstructible address and data busses up to 16 bits wide each. It has search modes that find and identify the first and last instruction in a program loop. A transfer mode permits stepping forward or backward through programs without setting addresses. It can be used as a passive real time address and data bus monitor or as an interactive break point generator. After a match address is encountered, strobing and storing of the address and data bus content can be delayed by a preset number of machine cycles, instruction cycles, loop cycles (loop being the repetitive execution of the same instruction) or combinations of these delays. After a halt or break, the processor can be stepped in single or multiple step increments according to the above cycles.

Abstract: A new microprocessor controlled digital multimeter offers significant advantages to the user. Automatic calibration and correction routines ensure long term stability and simplify maintenance; self diagnostics greatly help troubleshooting and even warn of impending failures; software implementation of logic design simplifies hardware, improves reliability and adds capabilities such as fast auto ranging and software I/O control; the ability to process data permits averaging, linearization and normalization of input measurements, minimum/maximum storage and limit detection.

Abstract: Apparatus and method is provided to synchronize randomly occuring pulses to the nearest one of a train of clock-pulses. Logic circuitry is provided to shift the synchronization of a pulse from the nearest clock to one clock-pulse earlier or later if said pulse is closely followed or preceded by one or more other pulses to be synchronized, and optimum synchronization of all pulses as a group requires the synchronization of said pulse earlier or later respectively.