Non-invasive core temperature sensor

A core temperature sensor for non-invasively measuring a temperature of a core thermal compartment of a human body or other mammal comprising;

• a skin temperature sensor which can be placed in conductive thermal contact with the skin over-laying a portion of the core thermal compartment;
• a heater with a relatively large surface area comprising a first surface facing the skin wherein a central region of the first surface of the heating element is positioned to surround the skin temperature sensor;
• the heater is capable of heating the skin proximate the skin temperature sensor to a minimum of 2 C greater than the temperature of the core thermal compartment and then is capable of rapidly discontinuing heating;
• a relatively thick layer of thermal insulation proximate a second surface of the heater and opposite the first surface of the heater facing the skin;
• a controller attached to the skin temperature sensor which is correlated with time to create a temperature-versus-time dissipation curve when the heating is discontinued by a controller;
• an algorithm for analyzing the skin temperature dissipation curve to determine the intersection of the slopes of the rapid temperature decrease portion of the curve and of the slow temperature decrease portion of the curve.

A method of non-invasively measuring a temperature of a core thermal compartment of a human body or other mammals comprising;

• placing a skin temperature sensor in conductive thermal contact with a skin over-laying a portion of the core thermal compartment;
• placing a heater with a sufficiently large surface area such that a central region of a first surface of the heater is positioned to surround the skin temperature sensor and a layer of thermal insulation is proximate a second surface of the heater opposite the first surface of the heater facing the skin;
• energizing the heater to heat the skin to a temperature greater than core temperature;
• de-energizing the heater to stop heating the skin;
• monitoring a cooling of the skin with the skin temperature sensor and using an algorithm to analyze and interpret the temperature dissipation curve.

A method for measuring a core temperature in a mammalian body, the method comprising:

• energizing a heater and heating an area of a skin covering a peripheral compartment of the mammalian body;
• monitoring the temperature of the skin;
• de-energizing the heater when the temperature of the skin equals or exceeds a pre-specified value;
• monitoring the rate of change in the temperature of the skin;
• identifying a first region of rapid change in the temperature of the skin;
• computing a first slope for the first region;
• identifying a second region of slow change in the temperature of the skin;
• computing a second slope for the second region;
• and
• designating the core temperature as correlating to the temperature of the skin whereat the first slope and the second slope intersect.

An adhesive layer for attaching a skin surface core temperature sensor to the human body comprising;

• a layer of thermally conductive plastic film sized to approximate the size and shape of the core temperature sensor;
• an adhesive material applied to both faces of the plastic film;
• and the adhesive applied to the first face of the plastic film is intended to stick to the core temperature sensor and is a first formulation optimized to stick to and release from a plastic film;
• and
• the adhesive applied to the second face of the plastic film is intended to stick to the patients skin and is a second formulation optimized to stick to release from the patients skin.

An adhesive layer for attaching a skin surface core temperature sensor to the human body comprising;

• a layer of thermally conductive plastic film sized to approximate the size and shape of the core temperature sensor;
• an adhesive material applied to both faces of the plastic film;
• a means for venting air that could be trapped as a bubble between a first face of the attachment means and the core temperature sensor;
• and
• a means for venting air that could be trapped as a bubble between a second face of the attachment means and the patients skin.

A method for attaching a skin surface core temperature sensor to the human body with an adhesive layer comprising;

• a layer of thermally conductive plastic film sized to approximate the size and shape of the core temperature sensor;
• an adhesive material applied to both faces of the plastic film;
• a means for venting air that could be trapped as a bubble between a first face of the attachment means and the core temperature sensor;
• a means for venting air that could be trapped as a bubble between a second face of the attachment means and the patients skin;
• a first step of applying the first face of the attachment means to the core temperature sensor;
• a second step of applying the second face of the attachment means which is now adhesively bonded to the core temperature sensor, to the selected area of the patients skin;
• and
• assuring that air has not been trapped between the adhesive attachment means and the core temperature sensor or skin.