PPG

Last modified by Iris Spruit on 2024/07/26 15:51

Contents

Introduction

A photo plephysmogram (PPG) measures the blood volume pulse using optical methodology. The pulse is usually measured at the finger tip or ear lobe. The pulse is established by measuring the infrared reflectance which results from a varying blood flow.

Availability, Support and Use-case

For availability of PPG equipment within your unit, contact your lab coordinator. PPG equipment from BIOPAC can also be borrowed from SOLO through the Helpdesk or by contacting labsupport@fsw.leidenuniv.nl.

Protocol

Below, a general protocol of measuring PPG with BIOPAC is described. Note that an adequate training is required before working with physiological data acquisition equipment and collecting such data from participants. If you are uncertain about the procedure, please contact your supervisor or lab coordinator. 

Setup

Equipment

PPG can be measured with the BIOPAC PPGED-R (wireless) module or the OXY100E (wired). Note that the PPGED-R outputs the raw pulse signal, while the OXY100E outputs a pre-conditioned waveform. BIOPAC advices to only use the pulse waveform outputted by the OXY100E for the calculation of hear rate (see product sheet OXY100E).

Transducer

PPGED-R
A pulse transducer (BN-PULSE-XDCR) is used to measure pulse, usually at the finger tip. The PPGED-R transmitter can be attached to a BioNomadix velcro strap with size 33 cm (BN-STRAP-33), which can be tied around the wrist of the participant.

OXY100E
An ear or finger clip SpO2 transducer (TSD124B/TSD124D) is used to measure pulse. Currently, only an ear clip transducer is available at SSH Leiden. 

Materials

For SSH researchers, supplies can be picked up at SOLO 1B11 in PdlC or 2.5.01 in Sylvius, see lab supplies for more info.

  • PPG equipment (see Setup)
  • Gloves
  • Incidin OxyWipe

Placement

Always wear disposable gloves (see gloves protocol) when you place the finger pulse transducer or ear clip. After use, remove the gloves and dispose of them.

Skin preparation is not required.

Placing the finger pulse transducer:

  • Put on disposable gloves.
  • Put the pulse transducer around the tip of one of the middle fingers. Make sure the transducer is placed firmly against the skin, without being too tight for the participant. 

Placing the ear clip on the participant:

  • Make sure the participant does not wear earrings.
  • Put on disposable gloves.
  • Place the ear clip on one of the earlobes.

Note that the ear clip should be properly placed on the earlobe. Make sure the light shines through the earlobe, not under it. When the participant has small earlobes, attaching the clip can be difficult. Try carefully stretching the earlobe a bit with one hand, while placing the ear clip with the other hand. Make sure you always communicate with the participant about what you are doing and ask them to indicate when it hurts.

Cleaning up

  • Put on disposable gloves.
  • Remove the finger pulse transducer or ear clip from the participant.
  • Disconnect the pulse transducer the ear clip from the PPGED-R transmitter or OXY100E module.
  • Gently clean pulse transducer or the ear clip with Incidin Oxywipe (make sure the wipe is not too wet) and if necessary the lead. Let it dry before using it again.

Tips & Tricks

  • When an ear clip is used, do not let the participant move much with their head, to make sure the ear clip stays properly attached. 
  • Check the pulse signal before starting actual data collection.

More information