Abstract: A method for measuring pressure within a heart includes the steps of: (1) providing a passive wireless pressure sensor having a characteristic impedance and a deflectable surface, the characteristic impedance changing in response to deflection of the deflectable surface; (2) inserting the sensor to a location within the body of a patient at which the sensor can detect pressure within the heart; (3) affixing the sensor relative to the heart; (4) interrogating the sensor with an electromagnetic field; (5) receiving a signal from the sensor corresponding to a sensed pressure; and (6) leaving the sensor in situ so that future pressure measurements can be made.

Abstract: A low profile adaptor is disclosed for use with a gastrostomy feeding tube which has been inserted by means of conventional endoscopic procedures or with a replacement feeding tube inserted through the patient's stomach. The tube is cut to the approximate length by the surgeon. The adaptor comprises an anti-reflux valve assembly having a stem which can be plugged into the open end of the feeding tube. The valve assembly contains a seal which functions as a one-way valve to prevent reflux of gastric contents but which permits the introduction of feeding solution into the feeding tube. A clamp is placed around the feeding tube and the valve stem and locked into place to secure the valve assembly to the feeding tube at a location flush with the patient's skin. A silicone cover is placed around the clamp to protect the patient from skin irritation caused by the clamp, and also to protect the clamp and valve assembly from contamination.

Abstract: An interface circuit for use between a radio control transmitter equipped with joysticks and a standard serial input port of a personal type computer. The interface circuitry includes a microcontroller operated as a reformatter for signals received from the remote control transmitter and a transistorized converter circuit connected between the output of the microcontroller and computer to convert the voltage level of signals output from the microcontroller in reformatted form.

Abstract: An interface circuit for use between a radio control transmitter equipped with joysticks and a standard data bus of a personal type computer. The interface circuitry includes a microcontroller operated as a reformatter for signals received from the remote control transmitter and a number of integrated circuit latch and buffer circuits connected between the output of the microcontroller and the data bus of a computer to convert the signals output from the microcontroller to the data bus on a direct basis.

Abstract: An interface circuit for use between a control point equipped with joysticks and switches and a standard serial input port of a personal type computer. The interface circuitry includes an analog to digital converter, a microcontroller operated as a reformatter for signals received from the analog to digital converter and a transistorized converter circuit connected between the output of the microcontroller and the serial input of the computer to convert the voltage level of signals output from the microcontroller in reformatted form.

Abstract: A circuit providing a joystick interface to a computer. The circuit plugs into the cartridge slot of the computer and receives power from the computer. The circuit includes an analog interface circuit, a read only memory (ROM) containing both a machine language program to drive the analog interface circuit, and a machine language application program. The analog interface circuit includes an analog-to-digital converter, a clock circuit, and a decoder. The circuit of the present invention also includes a tri-state bus interface circuit to communicate the state of input switches to the computer.

Abstract: A circuit arrangement for comparing a clock pulse train against a standard pulse train. The circuit includes an exclusive OR gate to which are inputted the pulse train to be tested, and a latch at the output of the gate, operated only upon a mismatch of the two pulse trains. Provision is also made to prevent operation of the latch within certain adjustable tolerance parameters as to pulse width and position of the pulse train.