Abstract: A redundant alarm system including a central controller that interfaces with a first alarm, a second alarm, a visual indicator and an acoustic sensor. When an alarm condition exists, the controller activates the primary alarm causing the primary alarm to generate an audible first alarm signal. The audible first alarm signal is transmitted from the primary alarm to the acoustical sensor. The acoustical sensor detects the audible first alarm signal and transduces the audible first alarm signal into a first feedback signal that is relayed to the controller. If the controller does not receive the first feedback signal from the acoustical sensor within a predetermined time after activating the primary alarm, the controller activates the secondary alarm and the visual indicator.

Abstract: A sleep analysis system for analyzing a sleep episode of a subject based on measured values of a plurality of parameters characterizing that subject. Portions of the measured parameter signals are classified as significant events, and the significant events are segregated based on parameter signal criteria and time correlation as a basis for the analysis.

Abstract: The invention relates to an oxygen sensor which measures the concentration of oxygen based upon ultrasonic sound waves traveling through a binary gas. The measured sound-wave delay through the gases determines the concentration level for oxygen within the transducer chamber. The invention includes an L-shaped housing where a transmitter/transducer is attached to one end of the housing and the receiver/transponder is positioned at the junction between the two substantially straight portions of the L-shaped housing. A straight transducer chamber is thereby provided, while simultaneously provided a housing design which minimizes reflected standing waves for detection by the receiver/transponder. The invention includes a sonic baffle positioned at the opposite end of the L-shaped housing from the transmitter/transducer which minimizes standing waves thereby improving the performance of the gas detection device.

Abstract: A tocodynamometer for measuring intra-amniotic pressure through the abdominal wall of obstetric patients, including a force transducer resiliently mounted in a housing, a precompressed coil spring between the housing and an outer backplate, and an attachment on the outer backplate for fastening thereto a belt tensioner for holding the apparatus against the patient adjacent the uterine wall.

Abstract: Apparatus for monitoring respiration and heartbeat and for processing electrical signals representative thereof, including circuits for developing a phase-shifted and amplitude-offset respiration signal for comparison with an original respiration signal for compensating for signal drift, and circuits for logically combining signals representative of the presence of respiration and heartbeat for eliminating certain false indications which may occur when only heartbeat exists.