The Pulse coupler operates with photoplethysmograph transducers which detects changes in blood flow by passing light through the finger and picking it up with a photo-sensor. Infra-red and normal light are used. PsychLab provides two transducers, PT1 and PT2 for measuring peripheral pulse from the finger or ear. Heart Rate may be obtained from this measure, but it is more reliable when measured using EKG.
Pulse gain and filtering may be adjusted in two steps from the computer control program. Additionally a manual gain control with 4 steps is provided. The amplitude of the resulting wave-form may be quantified off-line in a similar fashion as described here for respiration, using PsychLab slope detection system (WAVE) to obtain both Heart Rate and relative pulse volume.
The Pneumotrace transducer is positioned around the lower chest to produce this measure. Respiration is a difficult measure when the subject is at all active or involved in speech. The graph shows a period of respiration, with the waves automatically detected, from which respiration rate can be calculated.
Respiration gain and filtering may be adjusted in two steps from the computer control program. Additionally a manual gain control with 4 steps is provided.