PROGRESS 5 : METHODOLOGY

Block diagram

The following is the experimental set up for acquisition of pulse wave. Heart activities are senses from subject through the PPG sensor. PPG signals are taken from individual persons using Biokit at a sample rate of 1000 samples/second. The frequency response for PPG it is 0.05-10Hz. It is obtained by using reflection type PPG sensor, these signal are amplified using a PPG amplifier and are interfaced with the PC using DAQ (NI USB-6009).

 The NI USB-6009 is a USB based data acquisition (DAQ) and control device with analog input and output and digital input and output. The main features of NI USB-6009 are as follows :

·         Analog input (AI): 8 inputs with referenced single ended signal coupling or 4 inputs with differential signal coupling. Software-configurable voltage ranges: ±20V, ±10V, ±5V, ±4V, ±2.5V, ±2V, ±1.25V, ±1V. Max sampling rate is 48kS/s (48000 samples per second). 14 bits AD converter.

·         Digital input (DI) and digital output (DO): 12 channels which can be used as either DI or DO (configured individually). These 12 channels are organized in ports, with Port 0 having lines 0... 7, and Port 1 having lines 0... 3. Input low is between -0.3V and +0.8V. Input high is between 2.0V and +5.8V. Output low is below 0.8V. Output high is above 2V (with open-drain and push-pull as options). (USB-6008 has only open-drain output.)

·          On-board voltage sources (available at individual terminals): 2.5V and 5.0V

·         Power: USB-6009 is powered via the USB cable.

·         Application software: LabVIEW: Windows, Mac, Linux. The present document gives an example of how to use USB-6009 in LabVIEW.