Plethymographs

Plethymographs

The IR Plethysmographs use an infrared photoelectric sensor to detect changes in tissue blood volume. The MLT1020PPG features a velcro strap, the MLT1060EC has a spring clip suitable for readings from a finger or toe and the MLT1020EC features an ear clip. The IR Plethysmographs can be connected to any Bridge Amp, or directly to a Pod port of a PowerLab.

Item# Description U.S. List Price Quantity
77-0293 Plethymograph, from Ear, Model MLT1060EC
77-0071 Plethymograph, from Finger, Model MLT1020FC
77-0072 Plethymograph, from Finger, Toe or Forehead, Model MLT1020PPG
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The IR Plethysmographs use an infrared photoelectric sensor to detect changes in tissue blood volume. The MLT1020PPG features a velcro strap, the MLT1020FC has a spring clip suitable for readings from a finger or toe and the MLT1060EC features an ear clip. The IR Plethysmographs can be connected to any Bridge Amp, or directly to a Pod port of a PowerLab.


Operation:

The velcro strap and finger clip models use reflected infrared light and work best where the light can reflect from the bone beneath the tissue. They are especially good for the finger or forehead (directly over the centre of the eyebrow is an excellent location). The ear clip, on the other hand, uses infrared light transmitted through the tissue, and so works best on fleshy areas such as the earlobe. The amplitude of the signal depends primarily on the volume of blood in the capillary bed directly beneath the sensor, so it may be necessary to move the sensor around to find the best signal. The clips should attach to fleshy areas with no problems. When using the model with the Velcro strap to attach to a finger or toe, take care that the strap is firm, but not so tight as to restrict blood flow. If you are taking measurements where the Velcro strap is too short to be useful (such as from the leg or head), then you can lightly wrap an elastic bandage around the sensor and body part to hold the sensor in place. Ambient light may affect the output: if it does, a covering of black, opaque material over the sensor and location should remove such interference.

Note: The IR Plethysmographs are normally used with AC coupling in the Input Amplifier dialog box (in LabChart software) turned on.

Application:

The IR Plethysmographs can be used to record changes in blood volume as the arterial pulse expands and contracts the microvasculature.
Specifications77-029377-007177-0072
Amplification Input Amplifier8-pin DINSee product page for complete specificationsSee product page for complete specifications
Connector6 to 9 V DC8-pin DIN8-pin DIN
ExcitationMLT1060EC6 to 9 V DC6 to 9 V DC
Model1 kΩ nominalMLT1020FCMLT1020PPG
Output Impedance5 to 50 mV (typical finger application at rest)1 kΩ nominal1 kΩ nominal
Output15 to 50 mV (typical finger application at rest)5 to 50 mV (typical finger application at rest)
PackageData Acquisition11
Product Family0.6 x 0.6 x 0.24 inData AcquisitionData Acquisition
Sensor Size English15 x 15 x 6.3 mm0.6 x 0.6 x 0.24 in0.6 x 0.6 x 0.24 in
Sensor Size Metric950 nm15 x 15 x 6.3 mm15 x 15 x 6.3 mm
Wavelength8 g950 nm950 nm