Low Power Blood Pressure Meter Demonstration
A blood pressure meter, or sphygmomanometer, is a device that is used to measure blood pressure. The meter is used with an inflatable cuff for restricting blood flow and a pump to inflate the cuff. Digital blood pressure meters typically measure both systolic and diastolic pressures by an oscillometric detection method, using a piezoelectric pressure sensor.
The Microchip Blood Pressure Meter Demonstration was implemented using the system-on-a-chip PIC24FJ128GC010 MCU. The features of this MCU are:
eXtreme Low Power (XLP) technology
18 nA Deep Sleep mode
240 nA Watch Dog Timer operation in Deep Sleep modes
180 µA/MHz Run mode
16-bit Delta-Sigma Analog-to-Digital Converter (ADC): 2 differential channels
12-bit 10 Msps pipeline ADC: 50 channels
Two 10-bit 1 Msps Digital-to-Analog Converter (DAC)
Two operational amplifiers
Three voltage references
Charge Time Measurement Unit (CTMU)
USB with Device/Host/OTG support with active clock tuning (no crystal required)
Segmented LCD driver with charge pump
This reference design helps to develop a low-cost, low-power, handheld or portable blood pressure meter with user interface.*
Measures both systolic and diastolic pressures
Measures heart rate
Low overall BOM cost due to
eXtreme Low Power (XLP) operation
Measure While Inflating (MWI) algorithm used to reduce patient discomfort
Utilizes the PIC24FJ128GC010's integrated Pulse-Width Modulation (PWM) module to drive the air pump's motor in fast or slow speed mode
Integrated LCD controller generates the data and timing control required to directly drive a static or multiplexed LCD panel
High-pass filter implemented with one of the PIC24FJ128GC010 MCU's integrated operational amplifiers
MCP1802 LDO converts the 5V or 6V main input voltage to 3.3V VDD
Energizer® Application Support (from the makers of Energizer batteries) did extensive testing of Microchip's Low-Power Blood Pressure Meter demonstration. From that
Contact your local sales representative to see a working demonstration of the Blood Pressure Meter demo.
Development Made Easy
Start with the free download of the application note, schematics and 'C' source code that can easily be modified to your specific application needs. To download, see the Resources section.
*Microchip medical reference designs and demos are intended for evaluation and development purposes only. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use.