Abstract:
A method and apparatus for maintaining a viewing window of a detector substantially clean includes enclosing the detector within a housing, and moving a target surface relative to the viewing window to create an airflow adjacent the viewing window. The housing can include an aperture through which the viewing window of the sensor views the target surface. Motion of the target surface creates an airflow velocity adjacent the viewing window for maintaining the viewing window substantially clean. To increase the accuracy of the detector, a high emissivity area is provided on an outside surface of the housing which faces the target surface.
Abstract:
A body temperature detector is particularly suited to axillary temperature measurements of adults. The radiation sensor views a target surface area of the body and electronics compute an internal temperature of the body as a function of ambient temperature and sensed surface temperature. The function includes a weighted difference of surface temperature and ambient temperature, the weighting being varied with target temperature to account for varying perfusion rate. Preferably, the coefficient varies from a normal of about 0.13 through a range to include 0.09. The ambient temperature used in the function is assumed at about 80null F. but modified with detector temperature weighted by 20%.
Abstract:
A body temperature detector is particularly suited to axillary temperature measurements of adults. The radiation sensor views a target surface area of the body and electronics compute an internal temperature of the body as a function of ambient temperature and sensed surface temperature. The function includes a weighted difference of surface temperature and ambient temperature, the weighting being varied with target temperature to account for varying perfusion rate. Preferably, the coefficient varies from a normal of about 0.13 through a range to include 0.09. The ambient temperature used in the function is assumed at about 80null F. but modified with detector temperature weighted by 20%.
Abstract:
A radiation detector employs a thermopile having a potentiometer for calibrating the thermopile output to best suit a particular output meter and sensing application. A thermocouple may be connected in series with the thermopile. The output of the thermopile is calibrated to best match a linear function which intersects the thermopile output function at a temperature in the center of a temperature range of interest. A total output signal of the detector is the sum of the thermopile signal and the thermocouple signal, and is indicative of the temperature of a target emitting radiation sensed by the thermopile. The series connection of the thermopile and the thermocouple allow the thermopile hot junction temperature to be referenced to the cold junction temperature of the thermocouple. Thus, the reference temperature may be remote from the thermopile sensor. A filtering lens may be used to prevent short wavelength radiation from reaching the thermopile sensor, improving the linearity of the thermopile response. To improve the response to low emissivity targets, long wavelength radiation may be filtered out at a loss of linearity. Two detectors may be connected differentially to provide a differential output indicative of the temperature difference between two targets. Additionally, a temperature dependent variable resistor may be coupled to the thermopile, providing a variable resistance that combines with the thermopile output response to produce a linearized thermopile output response. Then, the total output signal of the detector for a particular target temperature is independent of fluctuations in local temperature.
Abstract:
A method and apparatus for maintaining a viewing window of a detector substantially clean includes enclosing the detector within a housing, and moving a target surface relative to the viewing window to create an airflow adjacent the viewing window. The housing can include an aperture through which the viewing window of the sensor views the target surface. Motion of the target surface creates an airflow velocity adjacent the viewing window for maintaining the viewing window substantially clean. To increase the accuracy of the detector, a high emissivity area is provided on an outside surface of the housing which faces the target surface.
Abstract:
Tympanic temperature measurements are obtained from the output of a radiation sensor mounted in an extension from a housing. The housing has a temperature display and supports electronics for responding to sensed radiation. The sensor is mounted in an improved extension which is shaped to fit into smaller ear canals, such as a child's ear canal or a swollen adult ear canal. Within the extension, the sensor is positioned in a highly conductive environment and receives radiation from an external target through a tube. Electronics determine the target temperature based on the sensor output signal and a temperature sensor signal.
Abstract:
Body temperature measurements are obtained by scanning a thermal radiation sensor across the side of the forehead over the temporal artery. A peak temperature measurement is processed to compute an internal temperature of the body as a function of ambient temperature and the sensed surface temperature. The function includes a weighted difference of surface temperature and ambient temperature, the weighting being varied with target temperature through a minimum in the range of 96null F. and 100null F. The radiation sensor views the target surface through an emissivity compensating cup which is spaced from the skin by a circular lip of low thermal conductivity.
Abstract:
Body temperature measurements are obtained by scanning a thermal radiation sensor across the side of the forehead over the temporal artery. A peak temperature measurement is processed to compute an internal temperature of the body as a function of ambient temperature and the sensed surface temperature. The function includes a weighted difference of surface temperature and ambient temperature, the weighting being varied with target temperature through a minimum in the range of 96null F. and 100null F. The radiation sensor views the target surface through an emissivity compensating cup which is spaced from the skin by a circular lip of low thermal conductivity.
Abstract:
Tympanic temperature measurements are obtained from the output of a radiation sensor mounted in an extension from a housing. The housing has a temperature display and supports electronics for responding to sensed radiation. The sensor is mounted in an improved extension which is shaped to fit into smaller ear canals, such as a child's ear canal or a swollen adult ear canal. Within the extension, the sensor is positioned in a highly conductive environment and receives radiation from an external target through a tube. Electronics determine the target temperature based on the sensor output signal and a temperature sensor signal.
Abstract:
An infrared detector has a probe having curved surfaces which slide readily into a neonate axilla. The probe is covered by a disposable cover, or a bag completely encloses the infrared detector. The bag has a pleated end surface, through which the detector views the skin, and a flap at a rear surface to close an opening which receives the detector.