Method and circuit for storing and providing historical physiological data

1. An oximeter sensor, comprising:

a light emitting element configured to emit light;

a light detector configured to receive the light, wherein the sensor is configured to operate in transmittance mode and the light emitting element is positioned relative to the light detector to facilitate operation in the transmittance mode;

a pressure switch that is sensitive to pressure present due to placement of the sensor on a patient, the pressure switch having a status indicative of sensor contact with the patient; and

a memory storing data relating to whether the status is indicative of adequate contact with the patient.

2. The oximeter sensor of claim 1 , comprising a sensor body capable of positioning on patient tissue such that the sensor body is in contact with an external surface of the patient and compresses the patient tissue.

3. An oximeter system, comprising:

a sensor configured to be placed externally on a patient comprising:

a light emitting element configured to emit light;

a light detector configured to receive the light; and

a pressure switch that is sensitive to pressure present due to placement of the sensor externally on the patient, the pressure switch having a status indicative of sensor contact with the patient;

a monitor communicatively coupled with the sensor, the monitor configured to receive information relating to the status of the pressure switch; and

a sensor memory storing data relating to whether the status is indicative of adequate contact with the patient.

4. The oximeter system of claim 3 , wherein the sensor is configured to operate in transmittance mode.

5. The oximeter system of claim 3 , wherein the sensor is configured to compress tissue of the patient between components of the sensor.

6. An oximeter monitor, comprising:

a drive circuit configured to provide signals to circuitry of an oximeter sensor;

a circuit configured to receive information from a pressure switch of the oximeter sensor, the information relating to a status of the pressure switch on the sensor, the pressure switch being sensitive to adequate contact pressure present due to placement of the oximeter sensor on a patient; and

a data circuit configured to receive data relating to whether the status is indicative of adequate contact with the patient from a memory of the oximeter sensor.

7. A method of monitor operation, comprising:

providing signals to circuitry of an oximeter sensor;

receiving information from a pressure switch of the oximeter sensor, the information comprising a status of the pressure switch that is indicative of oximeter sensor contact with a patient; and

receiving data relating to whether the status is indicative of adequate contact with the patient from a memory of the oximeter sensor.

8. The method of claim 7 , wherein the status of the pressure switch is indicative of an adequacy of compression pressure applied by a body of the sensor on the patient.

9. A method of oximeter sensor operation, comprising:

projecting light from a light emitting element;

receiving the light with a light detector;

sensing a pressure with a pressure switch, the pressure being resultant from placement of the sensor on an external surface of a patient; and

providing a status signal originating from the pressure switch, the status signal being indicative of contact between the oximeter sensor and the patient; and

storing data relating to whether the status is indicative of adequate contact with the patient.

10. The method of claim 9 , wherein sensing the pressure with the pressure switch comprises sensing an adequacy of compression pressure applied by a body of the sensor on the patient.

11. A method of manufacturing an oximeter sensor, comprising:

coupling a light emitting element configured to emit light to the oximeter sensor;

coupling a light detector configured to receive the light to the oximeter sensor;

coupling a pressure switch to the oximeter sensor, the pressure switch being sensitive to pressure present due to placement of the oximeter sensor on a patient, wherein actuation of the pressure switch provides an indication of contact between the oximeter sensor and the patient; and

providing a memory storing data relating to whether the status is indicative of adequate contact with the patient.

12. The method of claim 11 , wherein actuation of the pressure switch provides the indication via an extrinsic probe.

13. The method of claim 11 , wherein actuation of the pressure switch provides the indication via electrodes.

14. The method of claim 11 , wherein the oximeter sensor is configured to operate in transmittance mode and the light emitting element is positioned relative to the light detector to facilitate operation in the transmittance mode.

15. An oximeter sensor, comprising:

a light emitting element configured to emit light;

a light detector configured to receive the light;

a pressure switch that is sensitive to pressure present due to placement of the sensor on a patient, the pressure switch having a status indicative of sensor contact with the patient; and

a memory storing data relating to whether the status is indicative of adequate contact with the patient.