BIOPAC® Systems, Inc. Logo

PPG setup and calibration

To record a pulse waveform using the PPG100C, follow these setup and calibration details:

Connections

Plug the transducer into the amplifier but do not connect it to the subject yet.

red lead into VSUP+ port
black lead into GND port
blue lead into INPUT port

PPG100C swithc settings to record puilseSwitch Settings

Hint: Using the 3.0 Hz LP setting and the 0.5 Hz HP setting in conjunction will make it easier to find the rate of the pulse waveform (these filters can be applied in software as well).

Gain: 10 (lowest Gain option) = top position
LP: 3.0 Hz = top position
HP (first bank) : 0.5 Hz HP = top position
HP (second bank): 0.05 Hz HP = top position

Set Up Acquisition

Recommended acquisition sample rate: 100 Hz.

Recording

  1. Start recording in AcqKnowledge.
    • No calibration is necessary—simply make sure the correct channel is enabled and no other amplifiers are set to the same channel.
  2. Perform Amplifier baseline offset adjustment.
  3. After the amplifier baseline offset adjustment is complete, place the transducer on the finger (e.g., index finger tip) and tighten the Velcro strap (or attach to the ear with adhesive collars).
    • Note: To minimize motion artifact, place the sensor on a hand that will remain mostly immobile.
  4. Check the tension level.
    • If the strap is too tight, blood flow may be constricted, resulting in an almost straight line signal.
    • If the strap is too loose, ambient light could enter the sensor, resulting in no recognizable waveform.
  5. Once you are able to obtain a good recording, it is recommended to increase the gain as much as possible as long as the pulse waveform never goes beyond ±10 Volts.
    • The 0.5 Hz HP filter setting will force the signal to return to baseline faster than with the 0.05 Hz filter.
    • The 10 Hz LP filter will reveal more detail from the waveform than the 3 Hz LP filter.
    • Observe the effect of different filter settings (note that any additional filtering can also be performed in the software, either online or offline).

Sample Results

The following graphs show results of motion artifact and varying tension levels:

Well-placed sensor:

Example of motion artifact (finger):

Example of movement artifact (hand):
Loose sensor:
Tight Sensor:

Associated Applications

Associated Application Notes

Spotlight On
continuous NIR spectroscopy (NIRS) module

fNIR Imaging Systems

fNIR Imaging Systems are stand-alone functional brain imaging solutions for continuous NIR spectroscopy (NIRS). They provide an in-lab cognitive function assessment and eliminate a great many of the drawbacks of a functional MRI. fNIR optical imaging technology measures neural activity and hemodynamic response in the prefrontal cortex. Subjects wear an fNIR sensor (IR light sources […]

View All
Latest News

Alan Macy Answers Proust Questionnaire

BIOPAC co-founder and R&D Director, Alan Macy, was interviewed recently by Roger Durling for the Santa Barbara Independent. The article, “The S.B. Questionnaire: Alan Macy,” provided a background excerpt of the Santa Barbara entrepreneurs’ past as well as his answers to the Proust Questionnaire. The biomedical technology developed at BIOPAC reflects an ambitious understanding of the natural and […]

New Citations | Research in Motion

Physiological researchers have been studying the lower body through examining impacts of training, movement instruction, and innovative research measurements on an individual’s well being. The following articles represent recent developments in physiological research, moving our understanding of lower limbs and the body as a whole forward, one step at a time. The Importance of Form Improper […]

Read All
Request a Demonstration
Request a Demonstration