Back to results
US 2016/0235313 A1Published application
Optical receiver chain for components of a photoplethysmograph signal
AssigneeTexas Instruments Incorporated
InventorsAjit Sharma, Sriram Narayanan, Srinath Mathur Ramaswamy, Arup Polley, Seung Bae Lee, Wen Li
Life of this patent
Estimating the term…
Abstract
The circuitry of an optical receiver reduces the ambient DC component and the pleth DC component to leave a pleth signal with substantially only a pleth AC component. The circuitry also provides gain control and can provide transmit power control to change the range of the pleth AC component to occupy a desired input range of an analog-to-digital converter.
Claims20
Circuitry for an optical receiver, comprising:
- a photo detector to:
- receive ambient light that has an ambient intensity and, in response thereto, output a first signal on at least one first line having a first magnitude that represents the ambient intensity;
- and
- receive pulsed light that has a pulsed intensity and, in response thereto, output a second signal on the at least one first line having a second magnitude that represents the pulsed intensity without the ambient intensity, the second magnitude of the second signal having a pleth DC component and a pleth AC component;
- and
- a demodulation circuit coupled to the photo detector to:
- sample and hold the first signal, and output a third signal on at least one second line whose magnitude represents the first magnitude of the first signal;
- and
- sample and hold the second signal, and output a fourth signal on the at least one second line whose magnitude represents the second magnitude of the second signal, the magnitude of the fourth signal having a pleth DC component that represents the pleth DC component of the second signal, and a pleth AC component that represents the pleth AC component of the second signal.
6 more elements
A method of operating circuitry for an optical receiver, the method comprising:
- receiving ambient light that has an ambient intensity and, in response thereto, outputting a first signal having a first magnitude that represents the ambient intensity;
- receiving pulsed light that has a pulsed intensity and, in response thereto, outputting a second signal having a second magnitude that represents the pulsed intensity without the ambient intensity, the second magnitude of the second signal having a pleth DC component and a pleth AC component;
- sampling and holding the first magnitude of the first signal, and outputting a third signal having a magnitude that represents the first magnitude of the first signal;
- and
- sampling and holding the second magnitude of the second signal, and outputting a fourth signal with a magnitude that represents the second magnitude of the second signal, the magnitude of the fourth signal having a pleth DC component that represents the pleth DC component of the second signal, and a pleth AC component that represents the pleth AC component of the second signal.
2 more elements
Dependencies are inferred from the claim text.