公开(公告)号：US10739433B2

公开(公告)日：2020-08-11

申请号：US15465484

申请日：2017-03-21

Applicant: TEXAS INSTRUMENTS INCORPORATED

Inventor： Anand Hariraj Udupa ,  Hussam Ahmed ,  Jagannathan Venkataraman ,  Sandeep Kesrimal Oswal ,  Prabin Krishna Yadav ,  Anand Reghunathan ,  Kiran Rajmohan

IPC: G01R35/00 ,  A61B5/00 ,  A61B5/053 ,  G01R27/02 ,  G01R27/16

Abstract: A system may comprise: an excitation current source; a first electrode coupled to the excitation current source; and a second electrode coupled to the excitation current source. The first and second electrodes may be configured to pass an excitation current from the excitation current source through a human body. First and second calibration resistors may be coupled to and positioned between the excitation current source and the first electrode. Third and fourth calibration resistors may be coupled to and positioned between the excitation current source and the second electrode. The system may also comprise a sensor configured to measure voltages across each of the first, second, third, and fourth calibration resistors.

公开(公告)号：US20240027508A1

公开(公告)日：2024-01-25

申请号：US18128912

申请日：2023-03-30

Applicant: Texas Instruments Incorporated

Inventor： Aatish Chandak ,  Aravind Miriyala ,  Midhun Raveendran ,  Anand Hariraj Udupa ,  Raja Reddy Patukuri ,  Prabin Krishna Yadav

IPC: G01R31/00 ,  A61B5/053

CPC classification number: G01R31/002 ,  A61B5/053 ,  A61B2560/0223

Abstract: An example apparatus includes: calibration circuitry configured to determine a second current at a second terminal of a second impedance circuit based on a first parasitic capacitance, a first impedance value, a third impedance value, a first voltage, and a second voltage; determine a third voltage at a second terminal of a second impedance circuit based on the first parasitic capacitance, a second impedance value, the third impedance value, the second voltage, and the second current; and determine a second parasitic capacitance between the second terminal of the second impedance circuit and the second terminal of a fifth impedance circuit based on the second current, the third voltage, a third current at the second terminal of the fifth impedance circuit, and a fourth voltage at the second terminal of the fifth impedance circuit.