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Industrial Research And Consultancy Centre
Patent
A Portable Low-Voltage Low-Power ppm-level Resistive Sensor Measurement System with Square-Wave Current Generator
Abstract

This invention is a portable, low-power system designed to accurately measure resistive sensors, which are used in various applications like monitoring pressure, temperature, and soil moisture. The system is particularly useful for new flexible sensors found in wearable devices and electronic skin that measure body temperature and blood pressure. Traditional sensor systems face challenges like high power consumption, interference from offset voltages, and difficulty in achieving both high resolution and a wide range. This new system overcomes these issues by using a low-power microcontroller, an auto-programmable current generator, and an active half-bridge circuit to ensure accurate, sensitive, and energy-efficient measurements.

Problem Statement

Resistive sensors are commonly used in medicine, agriculture, and various scientific fields to measure different parameters. However, the circuits used to reduce noise and improve accuracy often consume more power than the sensors themselves. This new technology aims to create a portable, low-voltage, and low-power system for accurately measuring resistive sensors. It features a square wave current generator, a specialized circuit for enhancing signal quality, and a digital filter to ensure high-resolution measurements while keeping power consumption low.

Uniqueness of the Solution
  • Reduced Power Consumption: A simple low-power microcontroller is sufficient to generate the required voltage. 
  • Enhanced Range of Measurement: The amplitude of the square wave current is auto-programmable, offering maximum resolution for the sensor's baseline resistance. 
  • Active Half Bridge: It utilizes an active half-bridge circuit instead of a conventional Wheatstone bridge, improving linearity, sensitivity, and power supply rejection ratio. 
  • Auto Calibration: The system automatically adjusts the gain of the instrumentation amplifier (INA) and the amplitude of the square wave to ensure maximum sensitivity for the resistive sensor.
Prototype Details

Prototype has been developed. 

Current Status of Technology

The demonstration and testing has been done in lab environment.

Technology readiness level

4

Societal Impact

This innovation enables advanced wearable health monitoring devices, improving personal health management. It facilitates more efficient agricultural and industrial monitoring systems, enhancing productivity and resource management.

Applications or Domain
  • Healthcare: Enables precise monitoring of body temperature and blood pressure through flexible, wearable sensors
  • Agriculture: Enhances agricultural productivity by accurately measuring soil moisture and environmental conditions
  • Industrial Automation: Pressure and temperature sensing
  • Consumer Electronics: Smart clothing and wearable devices

Geography of IP

Type of IP

Application Number

202121001693

Filing Date
Grant Number

514420

Grant Date
Assignee(s)
Indian Institute of Technology Bombay
**This IP is owned by IIT Bombay**