What Is Plethysmography In Pulse Oximetry?

What Is Plethysmography In Pulse Oximetry?

You may have heard of the term “plethysmography” when it comes to pulse oximetry, particularly if you use a pulse oximeter for health screening purposes. However, have you ever wondered what it means? We share more with you in this article.


A plethysmograph is used to measure any changes in volume within the body or a particular organ. We all know that pulse oximeters measure SpO2 levels and pulse rate. It does so with the help of a photo-plethysmograph (PPG), which is a type of plethysmograph that makes use of optical techniques. This allows the oximeter to detect any change in the volume of arterial blood through the fingertip or some other body part. Sometimes, pulse oximeters are referred to plethysmographs, or “pleth” for short.

Applications of Pulse Oximeters

Now that we know what plethysmographs are and what they are used for, you may be wondering what the obtained readings can tell you about someone’s health. Below are some common applications of pulse oximeters:

  • Any change in the blood volume relationship can be an early indicator of a deeper-rooted illness.
  • Irregular heart rhythm can be detected with a plethysmograph. In heart patients, it is important to observe the waveform generated by the plethysmograph, especially if they are having discomfort. As the heart’s job is to move blood and nutrients throughout the body, any unaccounted for irregularities can be a sign of something wrong.
  • Athletes and health enthusiasts can also make use of pulse oximeters to keep track of their SpO2 levels before and after working out. This can help them determine if any changes need to be made to their routine, such as if they are overexerting themselves or if they can hype up the intensity of their workouts.
  • Patients who have recently undergone surgery or any other procedures that required sedation are often monitored with a plethysmograph to avert and catch any complications early.
  • … and many more!

Get Pulse Oximeters with Plethysmograph for Health Screening Purposes

Are you looking for a pulse oximeter that is easy to use and provides accurate readings? If so, look no further than LOOKEE® Tech as your one-stop shop. Our Premium Fingertip Pulse Oximeter comes with an alarm, plethysmograph and perfusion index and can be clipped comfortably onto your fingertip. It fits a wide range of finger sizes, from children above three years old all the way to adults. Two batteries as well as a case and lanyard are provided so you can start using your pulse oximeter immediately upon receiving it!

Additional features include a dual color OLED screen for easy reading and cutting edge sensors to ensure the accuracy of your readings. Our products are FDA approved and authorized by Health Canada so you can shop with confidence knowing you are getting only the best. If you have any more questions regarding our pulse oximeters and plethysmographs, please feel free to contact us.