Exelys, LLC

Alesis Corporation

Alesis Studio Electronics, Inc.

Other

Alesis Semiconductor, Inc.

Keith E Barr

Marcus Ryle

David Brown

Alan Zak

Frank J Thomson

Peter J Celi

Carl Lafky

A system and method for obtaining ECG signals from an ambulatory patient are disclosed herein. The system is configured to be inexpensive, small, and robust for outpatient monitoring. The system is configured to be a low power consuming device. The system provides options for a variety of settings and real-time access to the ECG signals being recorded during the recording period.

Portable cardiac monitor including a range limiter

Portable cardiac monitor

An electronic inclination sensor is provided for the determination and display of surface inclination and the direction of such inclination. The information regarding the inclination and direction of inclination can be displayed such that an end user can readily and easily comprehend and use the information without additional interpretation. Further, when the inclination is displayed in decimal values, a large range of inclination angles can be displayed with significant accuracy.

Inclination sensor

An improved technique for a laser rangefinder includes a pulsed laser sending out a repetition of light pulses and the received signal (light pulse and noise components combined) being analyzed by continuous averaging of successive received signal discrete time sequences, each sequence beginning with the onset of transmitted laser light. Also, a circuit generates high potentials for the laser diode driving circuitry that simultaneously drives the laser diode, having at least one of several beneficial characteristics: It is conveniently synchronous with the light pulse send/receive process to reduce the effects of noise on the receive section. It is energy efficient in converting low battery potentials to higher voltages. Finally, it utilizes a minimized number of components, leading to high product economy.

Method for improving the received signal to noise ratio of a laser rangefinder

A data transmission system comprising a transmitter and a receiver that use a single external word clock to generate all needed clocks locally using a clock generator and a phase locked loop. Data words are transmitted on a transmission line based on a single transition of the word clock. The transmitter and receiver may each be incorporated on a single chip.

Serial data transmission system using minimal interface

An apparatus and method for interconnecting digital and analog circuitry on separate substrates within a single integrated chip package attenuates logic level signals on one substrate, transmits the attenuated signals to another substrate, and amplifies the attenuated signals back to logic level signals.

Low noise method for interconnecting analog and digital integrated

A method and apparatus for decreasing the supply current to peak output current ratio of a fully complementary cascode amplifier. The amplifier has two shunt portions coupled to a pair of differential input signals and to an output portion which, in turn, is coupled to a pair of output terminals. Based on the relative magnitudes of the input signals, the first shunt portion selectively diverts current from the output portion while the second shunt portion selectively supplies current to the output portion.

Fully complementary folded cascode amplifier

A method for synchronously operating two or more rotary head digital audio tape recorders without having to dedicate a separate timing track. The present invention synchronizes the machines in three steps. First, the slave unit reads the time code value from the data stream and compares this time code to the master's time code, examining the difference in time code values and adjusting the transport speed so that the values are approximately equal. Next, the slave's capstan motors are slowed down (or sped up) so that the slave and master units are within one drum revolution of each other. Finally, the slave's microprocessor adjusts the speed of the entire system to skip individual samples until the master and slave units are synchronized.

Method for synchronizing digital audio tape recorders

A method and apparatus for recording multiple channels of digital audio data onto one-half inch tape using a rotary head recorder. The tape format includes sector spaces and a write timing sector to provide reduced susceptibility to errors arising from head misalignment, provides improved punch-in and punch-out capabilities using overdub identification values recorded within each channel of audio information, and provides a unique time code word that facilitates accurate high-speed scan and search operations, as well as multiple device synchronization. Each pair of audio tracks terminates with a write timing sector that serves as an absolute location marker for the rotary head, and allows the digital audio system to determine precise head location with respect to the tape.

Format for recording digital audio onto magnetic tape with enhanced

A digital audio interface protocol carries multiple channels of digital audio information serially between a transmitting digital audio tape recorder and a plurality of receiving recording units. Using a three stage process, the circuitry of the present invention allows the receiving VCO's to 'lock on' to the sampling rate of the serial digital data stream without any explicit sampling information. In a first stage, the VCO frequency is adjusted until a sync pattern is properly received. In a second stage, the VCO frequency is adjusted to oscillate a preselected number of times between sync pattern occurrences. In a third stage, the VCO phase is adjusted to match the phase of the serial data stream.

Method and apparatus for providing a digital audio interface protocol

The present invention is directed to a microphone in which all elements having mass which can affect the output of the microphone have a resonant frequency outside the frequency range of interest. The present invention utilizes a relatively stiff diaphragm having low density, which is at the same time thin. The diaphragm is designed to have a resonant frequency outside the range of interest. The diaphragm and the sensor are a single assembly in the preferred embodiment of the present invention. The assembly comprises a diaphragm made of a ceramic material having the properties of stiffness and low density. The sensor is a piezo electric disk coupled to the diaphragm. The sensor/diaphragm assembly is mounted in a housing so as to have a reference air space behind the assembly. The sensor is metallized to provide electrical conductivity. The reference air space is kept separate from the atmosphere and the resonant frequency of the assembly and air space is higher than the selected frequency range.

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Los Angeles, CA, United States of America

Keith E Barr