US 4,183,248 A · Fast response electronic thermometer probe

Abstract

A probe having a temperature sensor mounted in its tip for measuring the temperature of a body into which the probe is inserted, has a heating coil positioned on the shank of the probe near the tip, and a second temperature sensor in the tip area positioned generally between the coil and the first sensor. A control circuit is operative to energize the heater coil in response to differences in the temperature sensed by the two sensors, so that the shank of the probe is heated to track the temperature rise of the tip of the probe upon insertion into a body whose temperature is to be measured. This heat servo thermally isolates the tip from the remainder of the probe, and eliminates long thermal time constants which would otherwise be associated with the flow of heat from the tip area down the probe shank. The time response of the system is then limited only by the tip area of the probe, which is made of high heat conductivity materials and is in intimate thermal contact with the body whose temperature is to be measured. Read-out of the sensed temperature is accomplished by circuitry connected to the tip sensor.

Claims10

Dependent claims

Fast response clinical temperature measurement apparatus of the type having a probe with disposable plastic probe covers, comprising:

an elongate probe member;
a high heat conductivity tip member;
means securing said tip member to an end of said probe;
a disposable plastic probe cover shaped to fit over said probe member and having a tip shaped and sized to conform to said tip member for maintaining close thermal contact between said tip member and a zone of a body whose temperature is to be measured;
a first temperature sensor mounted in close thermal contact with said tip member;
a heater element mounted in thermal communication with said probe end and spaced apart from said first temperature sensor;
a second temperature sensor mounted in a thermal path between said heater element and said first temperature sensor;
and
energization means connected to receive signals from said first and second sensors and to supply energization current to said heater element, said energization means operable during a measurement to supply current to said heater element when the temperature of said first sensor exceeds the temperature of said second sensor by more than a predetermined amount, whereby said heater element supplies heat to the probe member during a measurement to prevent unwanted heat flow from the tip member down the probe member.

6 more elements

Dependencies are inferred from the claim text.

Fast response electronic thermometer probe

Life of this patent

Fast response electronic thermometer probe

Life of this patent

Abstract

Claims10