Sensor system with pressure application
Embodiments of the present disclosure relate to sensors for applying pressure to a patient's tissue. According to certain embodiments, the sensors may include one or more deformable elements that hold the optical components of the sensor against the tissue with an appropriate amount of pressure. In additional embodiments, such sensors may include a rigid one-piece sensor body that incorporates a deformable element to facilitate fine-fitting of the sensor against the tissue.
1. A sensor, comprising:
a conformable sensor body having a tissue-contact surface;
an emitter and detector disposed on the tissue-contact surface in a reflectance configuration; and
a deformable element disposed on the sensor body on a surface opposing the emitter and the detector, wherein the deformable element comprises a material having a deformation point, and wherein the deformable element is configured to cause a portion of the sensor body to protrude against a patient's tissue when the sensor is applied to the patient's tissue and when a force is applied to the deformable element that exceeds the deformation point of the material such that the pressure applied by the sensor body is non-uniform across the tissue-contact surface and is highest in the area of the sensor body proximate to the emitter and the detector.
2. The sensor of claim 1 , wherein the sensor is configured to be applied to a patient's forehead.
3. The sensor of claim 1 , wherein the sensor is disposed on an interior portion of a hat.
4. The sensor of claim 1 , wherein the sensor is disposed on an interior portion of a headband, or semi-rigid or rigid head-gear.
5. The sensor of claim 1 , wherein the sensor is disposed in a window of a hat or a headband such that the sensor is visible to an observer when the hat is applied to a patient.
6. The sensor of claim 1 , wherein the deformable element is adapted to cause the sensor body to apply sufficient pressure to the patient's tissue to overcome venous pressure but not arterial pressure.
7. The sensor of claim 1 , wherein the deformable element covers less than 20% of the opposing surface sensor body.
8. The sensor of claim 1 , wherein the deformable element comprises a foam, wherein when the foam is compressed with a biasing force, the tissue-contact surface has a generally planar configuration and wherein when the biasing force is removed, the tissue-contact surface has a generally non-planar configuration.
9. The sensor of claim 1 , wherein the deformable element is not capable of resuming an un-deformed conformation after being deformed.
10. The sensor of claim 1 , wherein the sensor comprises a photoplethysmography sensor.
11. A sensor, comprising:
a conformable sensor body having a tissue-contact surface;
an emitter or a detector disposed on the tissue-contact surface in a reflectance configuration; and
a deformable element disposed on the sensor body on a surface opposing the emitter and the detector, wherein the deformable element is configured to cause the sensor body to assume a first non-planar configuration, wherein the first non-planar configuration is stable in the absence of a biasing force, and wherein the deformable element is configured to cause the sensor body to assume a second non-planar configuration when a force above a predetermined threshold is applied to the deformable element, and wherein the force above the predetermined threshold strains the deformable element past a deformation point of the deformable element such that the sensor body is not capable of resuming the first non-planar configuration after the sensor body assumes the second non-planar configuration.
12. The sensor of claim 11 , wherein the deformable element comprises a thermoplastic dome or button.
13. A sensor, comprising:
a conformable sensor body having a tissue-contact surface;
an emitter and detector disposed on the tissue-contact surface in a reflectance configuration; and
a deformable element on the conformable sensor body on a surface opposing the emitter and the detector, wherein the deformable element is in a first configuration, and wherein the deformable element assumes a second configuration when a force above a predetermined threshold is applied to the deformable element, and wherein the deformable element is not capable of resuming the first configuration after the deformable element assumes the second configuration.
14. The sensor of claim 13 , wherein the sensor comprises a photoplethysmography sensor.
15. The sensor of claim 13 , wherein the deformable element comprises a thermoplastic dome or button.