Blood Pressure Monitor

Overview

A health boom has seen a rapid increase in household healthcare equipment, typified by blood pressure monitors or sphygmomanometers. In addition to the widely-seen upper arm blood pressure monitor, demand for the easy-to-use wrist blood pressure monitor is also increasing, so smaller set size and longer battery life has become essential. Also, communication functions for connecting with personal computers or mobile phones via USB or Bluetooth are being enhanced so that measured data can be shared and retrieved anywhere, ubiquitously.

Low power consumption is essential for achieving longer battery life, and for reducing the number of batteries in order to have smaller set sizes. A common method is to use an inverter circuit to convert pressure sensor input to frequency and then use a timer to calculate blood pressure. Also, a PWM (Pulse Width Modulation) timer for pressurizing the measurement cuff, and a UART (Universal Asynchronous Receiver Transmitter) for handling communication functions, are required on chip.

Renesas has a comprehensive rich MCU lineup for use in blood pressure monitors. In particular within this lineup, the low power 78K0/Lx3 and the R8C/Lx Series with on-chip LCD driver control circuit incorporate on-chip peripheral functions required by blood pressure monitors. They also achieve a reduction in number of external components and cost by integrating a built-in on-chip oscillator (OCO), watchdog timer (WDT), and real-time clock (RTC).