There are various devices for measuring heart rate. Up until now it has been difficult and expensive to obtain devices which are relatively non-intrusive and allow automatic logging of a participant’s heart rate directly with other experimental data timed with stimulus presentation.
Recently we have developed a simple heart rate monitor using an ear clip (generally the least intrusive method for pulse monitoring) and a simple interface box (based on an Arduino microcontroller) which connects via USB (optionally wireless) to the controlling computer for the experiment.
The interface box can be configured to present the current heart rate as a number (beats per minute) over a serial interface (which requires installation of a special device driver in Windows), or simply present a key press or joystick button press every time a pulse beat is detected.
We also have a range of standard heart rate monitors. The original CatEye PL6000 ear clip monitors are no longer available to buy, but we have three remaining working ones. We also have Sigma and Polar chest strap monitors – these are much more intrusive to use as the participant has to fit the strap under their clothing. All of these are stand-alone monitors with no computer connection. The researcher has to manually note the heart rate at required times to synchronise with their other data collection.
With the interface box we can also use a finger clip monitor which provides a blood oxygen reading in addition to heart rate. This is a moderately cumbersome device that encloses the end of the little finger, obviously this is can be a problem if the participant is required to do something with their hands during the experiment.
We are developing a version of the interface box with a built in display and data recording capability as a relatively low cost replacement for the CatEye PL6000 devices which will also be capable of connecting to a controlling computer.