Emitter arrangement for physiological measurements
A noninvasive physiological sensor for measuring one or more physiological parameters of a medical patient can include a bump interposed between a light source and a photodetector. The bump can be placed in contact with body tissue of a patient and thereby reduce a thickness of the body tissue. As a result, an optical pathlength between the light source and the photodetector can be reduced. In addition, the sensor can include a heat sink that can direct heat away from the light source. Moreover, the sensor can include shielding in the optical path between the light source and the photodetector. The shielding can reduce noise received by the photodetector.
1. An emitter for a noninvasive, physiological device configured to transmit optical radiation towards a tissue site, said emitter comprising:
a support structure;
a top-emitting diode positioned on a first surface of the support structure, said top-emitting diode configured to directly emit first optical radiation in a first direction towards a tissue site of a user, wherein the first direction is perpendicular to the first surface; and
a side-emitting diode positioned on a second surface of the support structure, said side-emitting diode configured to directly emit second optical radiation in a second direction towards the tissue site of the user, wherein the second direction is parallel to the second surface, wherein the second surface is perpendicular to the first surface.
2. The emitter of claim 1 , wherein the second optical radiation is emitted at a power between 40 mW to 100 mW and at a wavelength between 1600 nm to 1800 nm.
3. The emitter of claim 1 , wherein the side-emitting diode is larger than the top-emitting diode.
4. The emitter of claim 1 , wherein the side-emitting diode comprises a super luminescent light emitting diode.
5. The emitter of claim 1 , wherein the side-emitting diode comprises a laser diode.
6. The emitter of claim 1 , wherein the first optical radiation is emitted at a wavelength of 900 to approximately 1350 nm.