Howtosignalprocessing
- Which type of sensor is used in plethysmography?
- How does a finger plethysmography work?
- What does a PPG sensor measure?
- What is plethysmography in pulse oximeter?
Which type of sensor is used in plethysmography?
An electrical sensor designed to measure blood volume changes during the cardiac cycle was used together with an infrared optical sensor for detection of erythrocyte-bound hemoglobin. Both sensors demonstrated sensitivity to changes in pulse volume (plethysmography).
How does a finger plethysmography work?
It uses a probe which contains a light source and a detector to detect cardio-vascular pulse wave that propagates through the body. The PPG signal reflects the blood movement in the vessel, which goes from the heart to the fingertips and toes through the blood vessels in a wave-like motion [32], as shown in Fig.
What does a PPG sensor measure?
Photoplethysmography, known most commonly as PPG, utilizes an infrared light to measure the volumetric variations of blood circulation. This measurement provides valuable information about the cardiovascular system.
What is plethysmography in pulse oximeter?
Photo plethysmography measures changes in volume of the finger. The larger the blood volume in the finger (vasodilation), the more light is being absorbed by the finger. Thus, less light passes through the finger and the current generated by the photodetector is smaller.
