The Doppler fetal heart rate monitor is a handheld ultrasound transducer that uses the Doppler Effect to provide an audible simulation of the heart beat and displays the number of beats per minute.
To achieve this, acoustic waves are sent to the heart of a fetus inside the mother’s womb. Part of the energy bounces back; however, because the heart is beating, the bounced waves will be affected by the Doppler Effect, which changes their frequency.
An ultrasonic probe is a key component in the system. The probe contains an oscillator to generate ultrasound frequency followed by an amplifier to condition the sine wave in the order of volts.
|VF3xx: ARM® Cortex®-A5 based Microprocessors with 1.5MB SRAM, LCD, security, 2x Ethernet, L2 switch||ARM Cortex-A5 266MHz, 1.5M SRAM, Display, dual 10/100 ETH, dual CAN, PMU, <1W|
|Keypad or Touch Screen|
|TSSMCU: Freescale Touch-Sensing for MCUs||Xtrinsic Touch-Sensing software, converts S08 and ColdFire V1 MCUs into touch sensors|
|CRTOUCH: Freescale Touch-Sensing Platform, a Ready Play Solution||Resistive screen controller with basic gesture recognition, and up to four capacitive touch-sensing electrodes|
|MC34712: 3.0A 1.0MHz Integrated DDR Switch-Mode Power Supply||Li-Ion battery charger, DDR switch-mode power supply (3.0A, 1MHz)|
|MC34713: 5.0A 1.0MHz Integrated Single Switch-Mode Power Supply||Li-Ion battery charger, single switch-mode power supply (5A, 1MHz)|
|MC34716: 1.0 MHz Dual Switch-Mode DDR Power Supply||Li-Ion battery charger, dual switch-mode DDR power supply (5A, 1Mhz)|
|MC34717: 5.0A 1.0MHz Integrated Dual Switch-Mode Power Supply||Li-Ion battery charger, dual switch-mode power supply (5A, 3.3V)|