Abstract: A breath monitor device useful for monitoring the inhaling and exhaling of patients and particularly patients on a breathing apparatus, the device being constructed to have a sensor element positioned in the path of the breath flow to respond to the breath and to the constituants thereof, the breathing apparatus including structure for supporting the sensor element, and a control circuit connected to the sensor element including a circuit portion for amplifying responses produced by the sensor element, a circuit portion for establishing threshold conditions for indicating whether the individual patient being monitored is inhaling or exhaling and that the patient is using the oxygen being breathed at a set minimum rate, a control panel connected to the control circuit including a first indicator for indicating when the patient is inhaling, a second indicator for indicating when the patient is exhaling, and a control element adjustable to establish minimum safe breathing rate conditions including an alarm devic
Type:
Grant
Filed:
September 15, 1980
Date of Patent:
January 4, 1983
Assignee:
Marie C. Kercheval
Inventors:
Edward A. Wittmaier, Joseph A. Kretschmer
Abstract: A fume detector including a gas sensor having a heater element and a variable impedance element associated therewith whose impedance decreases in the presence of toxic gases or fumes, or a decrease of free oxygen in an atmosphere being monitored. A load resistor in series circuit with the gas sensor and a pair of series connected potentiometers in parallel circuit with the gas sensor and the load resistor form a Wheatstone bridge. A first voltage comparator connected to one of the potentiometers and a reference voltage provides a signal when the supply voltage decreases below a predetermined level. A second voltage comparator connected to the other potentiometer and a junction between the gas sensor and the load resistor provides a signal when the gas sensor fails in the open circuit condition. A third voltage comparator connected across the bridge provides a signal when a toxic gas condition exists.