US 11,986,275 B2
Optical vital signs sensor
Alphonsus Tarcisius Jozef Maria Schipper, Stramproy (NL); Paulus Henricus Antonius Dillen, Eindhoven (NL); and David Antoine Christian Marie Roovers, Eindhoven (NL)
Assigned to Koninklijke Philips N.V., Eindhoven (NL)
Appl. No. 16/337,218
Filed by KONINKLIJKE PHILIPS N.V., Eindhoven (NL)
PCT Filed Sep. 29, 2017, PCT No. PCT/EP2017/074918
§ 371(c)(1), (2) Date Mar. 27, 2019,
PCT Pub. No. WO2018/060508, PCT Pub. Date Apr. 5, 2018.
Claims priority of application No. 16191324 (EP), filed on Sep. 29, 2016.
Prior Publication US 2019/0290146 A1, Sep. 26, 2019
Int. Cl. A61B 5/024 (2006.01); A61B 5/00 (2006.01); A61B 5/026 (2006.01); A61B 5/0295 (2006.01); A61B 5/1455 (2006.01)
CPC A61B 5/02416 (2013.01) [A61B 5/0261 (2013.01); A61B 5/0295 (2013.01); A61B 5/14552 (2013.01); A61B 5/7203 (2013.01); A61B 5/7207 (2013.01); A61B 5/7225 (2013.01); A61B 5/681 (2013.01); A61B 5/6824 (2013.01); A61B 2560/0204 (2013.01); A61B 2562/0238 (2013.01)] 5 Claims
OG exemplary drawing
 
1. An optical vital signs sensor configured to measure or determine vital signs of a user, the optical vital signs sensor comprising:
a photoplethysmographic (PPG) sensor having a light source configured to generate light which is directed towards a skin of the user and a photo detector unit configured to detect light,
wherein said light being indicative of a reflection of light emitted in or from the skin of the user, and
wherein an output signal of the PPG sensor has a sampling rate, an amplitude, a number of pulses per sample and a duty-cycle;
a pre-processing unit coupled to an output of the PPG sensor and being configured to convert an output signal from the PPG sensor having a first sample frequency and a first number of pulses per sample into an output signal having a second sample frequency and a second number of pulses per sample in order to neutralize or equalize any changes in sample frequency or the number of pulses per sample, wherein the pre-processing unit includes:
a scaler which receives a number of pulses per sample from a sensor control unit and which is configured to multiply the output signal of the PPG sensor by a factor inversely proportional to the number n of pulses in a sample; and
a down sampler which adapts the sampling rate of the output signal of the PPG sensor to a desired sampling rate (SR) which the down sampler receives from the sensor control unit;
a processing unit coupled to the pre-processing unit and being configured to execute at least one processing algorithm for generating a control output based on an output signal of the pre-processing unit; and
the sensor control unit coupled to the processing unit and configured to control an operation of the PPG sensor by adapting the sampling rate (SR) and/or the number (n) of pulses per sample based on the control output of the processing unit.