US 12,484,826 B2
Low-power contactless physiological sensor
Xicai Yue, Bristol (GB); David Attwood, Bristol (GB); and Janice Kiely, Bristol (GB)
Assigned to University of the West of England, Bristol, Bristol (GB)
Appl. No. 17/787,143
Filed by University of the West of England, Bristol, Bristol (GB)
PCT Filed Dec. 18, 2020, PCT No. PCT/GB2020/053268
§ 371(c)(1), (2) Date Jun. 17, 2022,
PCT Pub. No. WO2021/123794, PCT Pub. Date Jun. 24, 2021.
Claims priority of application No. 1918862 (GB), filed on Dec. 19, 2019.
Prior Publication US 2023/0027668 A1, Jan. 26, 2023
Int. Cl. A61B 5/277 (2021.01); A61B 5/00 (2006.01); A61B 5/302 (2021.01); G01D 5/24 (2006.01)
CPC A61B 5/277 (2021.01) [A61B 5/302 (2021.01); A61B 5/7207 (2013.01); G01D 5/2405 (2013.01); A61B 5/6801 (2013.01); A61B 2560/0209 (2013.01); A61B 2562/0214 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A system-on-chip contactless physiological sensor comprising:
a capacitive-sensor electrode having a first capacitance;
an amplifier device connected to the capacitive-sensor electrode, the amplifier device having an inverting input and non-inverting input, the capacitive-sensor electrode and the amplifier device at least in part forming an amplifier circuit for the physiological sensor which has a gain determined by the values of a second capacitance of an artefact-reducing capacitor and a third capacitance of a bridging capacitor which spans the amplifier device between the inverting input and an output of the amplifier device; and
the artefact-reducing capacitor being connected in series between the capacitive-sensor electrode and the inverting input of the amplifier device;
wherein the second capacitance is less than the first capacitance;
wherein there is no impedance boosting input between the capacitive-sensor electrode and the inverting input of the amplifier device, and wherein the gain of the amplifier device is determined by the formula:

OG Complex Work Unit Math
where C1 is the first capacitance, C2 is the second capacitance, and C3 is the capacitance of the bridging capacitor.