Apparatus and method for using a portable thermal device to quantify pain perception

A hand-held device for assessing a patient's perception of pain, the device comprising:

• a housing portion configured to be held in a user's hand;
• and
• a stimulus portion coupled to the housing portion, the stimulus portion configured to deliver a thermal stimulus to a skin surface of a patient, the stimulus portion comprising:
• a thermoelectric unit (“TEU”) having a first side and a second side, the TEU configured to receive an electrical current signal and to vary a temperature of the first side of the TEU in response to the received electrical current signal, the first side of the TEU being configured to be placed in proximity to the skin surface of the patient to deliver the thermal stimulus;
• a temperature sensor disposed in proximity to one of the first side and the second side of the TEU and configured to generate a sensed temperature signal;
• a heat sink comprising a first heat sink portion and a second heat sink portion, the first heat sink portion formed of one of a copper material and an aluminum material, the second heat sink portion formed of the other of the copper material and the aluminum material, a first side of the first heat sink portion in thermal contact with the second side of the TEU, a second side of the first heat sink portion in thermal contact with a first side of the second heat sink portion, the second side of the first heat sink portion having a first surface area, the first side of the second heat sink portion having a second surface area, the second surface area being larger than the first surface area;
• the housing portion comprising:
• a source of electrical power;
• a switching circuit configured to deliver the electrical current signal from the source of electrical power to the TEU;
• and
• a processor, the processor configured to:
• receive electrical power from the source of electrical power;
• receive the sensed temperature signal from the temperature sensor;
• and
• cause the electrical current signal to be delivered to the TEU to cause the thermal stimulus to be delivered to the skin surface of the patient, the processor configured to change a direction of the electrical current signal delivered to the TEU via the switching circuit to produce the thermal stimulus, the thermal stimulus comprising a rapidly increasing temperature portion followed by a rapidly decreasing temperature portion.