Welch Allyn, Inc.

Samuel G. Dawson

Kerry O Banke

Edward D Suszynski

John W Stevenson

Thomas K Gregory

John Archie Mossman

An improved medical thermometer is disclosed that provides an accurate estimate of a patient's temperature in substantially reduced time as compared to prior thermometers of this kind. This improved performance is achieved by configuring the thermometer to include a hollow, thin-walled metallic probe tip sized for secure attachment to the remote end of an elongated base. This defines an elongated cavity within the probe tip, and a thermistor is bonded to the probe tip within that cavity. The cavity is configured to be substantially longer in the direction of the probe's longitudinal axis than it is in a transverse direction, to inhibit the conduction of heat along the probe tip to the elongated base. The temperature of the thermistor, therefore, closely follows the temperature of any surface that contacts the metallic tip.

Medical thermometer

An improved prediction-type medical thermometer that provides an accurate estimate of a patient's temperature in substantially reduced time as compared to prior thermometers of this kind. This improved performance is achieved by using a special hollow probe tip having a low heat capacity and incorporating a resistive heater that is actuated only upon removal of the probe from a base housing. In particular, a processor measures an initial temperature upon the probe's removal and applies to the heater an initial electrical signal having prescribed parameter, e.g., pulse duration, that varies according to the initial temperature measurement. This warms the probe to a prescribed temperature at or near about 93.degree. F., after which the processor applies a sequence of pulses to the heater, to controllably regulate the probe's temperature to the prescribed value.

Detecting the temperature of water moving from a solar collector to a hot water storage and detecting the temperature of the water in the hot water storage by thermistor devices, comparing the resistance differences of the thermistor devices and providing a voltage proportional to the differences and comparing the voltage with a reference voltage providing a first output difference signal. Comparing the first output signal in a differential amplifier device with a second reference voltage providing an output for opening and closing a switch circuit to a pump when the temperature differential exceeds or is less than a given amount. Also detecting by a third thermistor the temperature of the water in the solar collector and then comparing the resistance of the third thermistor relative to a standard resistance providing a control voltage to the second differential amplifier. This provides an output signal that also opens or closes the pump switch circuit in response to the temperature of the water in the solar collector falling below a given temperature. The system also selectively changes the second reference voltage in response to the switch to the pump being opened and closed, so that the pump is energized at or above a given water temperature differential between the solar collector and the hot water storage, and is de-energized when the temperature differential is a lesser amount.

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La Mesa, CA, United States of America

Kerry O Banke