公开(公告)号：US20200253500A1

公开(公告)日：2020-08-13

申请号：US16784235

申请日：2020-02-06

Applicant: IMEC VZW ,  STICHTING IMEC NEDERLAND

Inventor： Hyunsoo HA ,  Nick VAN HELLEPUTTE ,  Seokho YUN ,  IIhwan KIM ,  Hyung Jun Kim ,  Chung Kun CHO

IPC: A61B5/053 ,  A61B5/08 ,  A61B5/0245 ,  A61B5/00

Abstract: A measurement unit for measuring a bio-impedance of a body, the measurement unit comprising a current generator circuit, a readout circuit, and a baseline cancellation current circuit, wherein the current generator circuit is configured to amplify a reference current to form a measurement current to be driven through a body to generate a measurement voltage representing the bio-impedance; wherein the readout circuit comprises a Instrumentation amplifier (IA) which has a transconductance stage and a transimpedance stage, wherein the IA is configured to: produce a first current in the transconductance stage, the first current being proportional to the measurement voltage, receive a second current from the baseline cancellation current circuit, produce an output voltage in the transimpedance stage, the output voltage being proportional to a difference between the first current and the second current and representative of the measured bio-impedance; wherein the baseline cancellation current circuit is configured to amplify the reference current by a factor to form the second current and deliver it to the IA, wherein the factor is such that that the absolute value of the difference between the first and the second current is below a threshold such that a baseline of the first current is cancelled by the second current.