PPG Sensors In Modern Technology

PPG sensors for monitoring cardiac functions

PPG sensors, also known as photoplethysmography(PPG) sensor is an essential piece of technology when it comes to monitoring cardiac functions. They are utilized to sense the blood flow rate of a person through low-intensity infrared light. Since many people are suffering from various heart diseases, a PPG sensor is one of the most ideal methods of tracking someone’s cardiac conditions.           

Heart disease has been the leading cause of death all over the world for the last two decades which is why doctors emphasize that prevention is always better than cure. Utilizing a PPG sensor is a great way to track your heart’s health. It allows patients and doctors to spot abnormalities before they get worse.

Though the technology behind PPG sensors was first explored in the 1930s, they managed to remain the most reliable methods for early cardiac disease detection. They have constantly improved in terms of technological applications and nowadays, medical companies have adapted PPG sensors in wearable devices. 

How Do PPG Sensors Work?

As mentioned earlier, PPG sensors utilize low-intensity infrared light that passes through our tissues. It penetrates our bones and is also absorbed by the blood that runs through our arteries and veins. If there is any kind of abnormality or changes within our blood flow, it affects the intensity of light that is passing through. PPG sensors utilize voltage signals which equate to the volume of blood running through our blood vessels. 

PPG Sensors - blood vessel care

PPG sensors represent blood flow changes through a waveform in a graph that has both alternating current (AC) and direct current (DC) components. The AC components are responsible for depicting how blood volume is synchronized with each heartbeat while the DC components come from the optical signals from tissues. 

It represents the blood volumes within the arteries or veins and can detect even the slightest changes in respiration. The field of medicine utilizes PPG technology for different kinds of applications. It allows medical practitioners to assess different aspects of a patient’s physiological integrity. Here are some of the most common applications for PPG technology:


Detecting Blood Oxygen Saturation

“O2 sats” or oxygen saturation specifies the amount of oxygen in your red blood cells. Detecting whether you have a stable or appropriate amount of blood oxygen traveling through your body is necessary when assessing cardiovascular health. 

Assessing Heart Rate and Blood Pressure

When a healthy heart beats properly, it pumps the appropriate amount of blood that your body needs to function properly. This is why knowing whether you have a normal heart rate and blood pressure is necessary when it comes to heart disease prevention.

Determining Cardiac Output

In physiology, the volume of blood being pumped by the heart through the right and left ventricle can be measured per unit time. If you have sufficient cardiac output, this means that you have stable blood pressure that can properly supply oxygen-rich parts of your body. 

PPG sensor - to detect heart issues
Determining Cardiac Output

Measuring Respiratory Rate

A person’s respiration can reflect the overall integrity of their health. Our respiratory rate can be measured by the number of breaths we take per minute. In normal cases, an adult person’s respiratory rate should be at least 12 to 20 breaths per minute when at rest. 

Evaluating Arterial Aging

Commonly experienced by people in their golden years, arterial aging is the degeneration of the large arteries, specifically the media layer. It can also be caused by other factors or specific clinical conditions that may elevate inflammation and oxidative stress. This is why checking the overall state of your arteries is essential in keeping your heart healthy. 

Testing Endothelial Function

A thin membrane that serves as the inner lining of the heart and blood vessels is called the endothelium. It is essentially what controls the enzymes that allow clotting and vascular contractions. Endothelial cells are also responsible for platelet adhesion and immune functions. 

PPG Sensors and Modern Wearable Technology

PPG sensor - Modern Wearable Technology
PPG sensor – Modern Wearable Technology

Now that we’ve established how essential PPG sensors are when it comes to the field of cardiovascular medicine, let’s now discuss how the technology has adapted to 21st-century modern health and fitness trends. Since most people today are becoming more conscious about health and wellness, wearable devices are now built with a PPG sensor that can allow users to track their cardiac functions. 

These wearable technologies can be worn by anybody, from fitness enthusiasts to people with medical conditions that need constant monitoring. Companies have also brilliantly adapted PPG sensors that can fit into accessories such as pins and rings. In this part of the article, we’re giving 2 examples of wearable devices available today, should you wish to purchase your own.

Smart Watches

In today’s fashion trends, having the latest gadgets and technological devices is considered a huge part of one’s style. This is probably the reason why smartwatches became such a big hit among the general public in recent years. It helps people stay digitally connected without the need to pull your phone out of your pocket. 

Smartwatches allow people to track their health and fitness. Many of these devices contain a PPG sensor that helps people track essential cardiac information such as their heart rate and respiration. 

Smart Rings

With the advancements of modern technology, a PPG sensor can now fit into something as tiny as a ring. Smart rings are becoming more and more popular among people nowadays since you can simply wear them on your finger. Many smart rings have been developed to cater to different kinds of users. Smart rings are capable of digitally connecting their users just like smartwatches. 

For the ones built with PPG sensors, they are considered a great way to track their health and possibly even catch early signs of cardiac issues. Some smart rings are even capable of spotting atrial fibrillation and have the ability to send real-time health data to doctors. Since the pandemic outbreak, smart rings have been considered an efficient way to practice remote patient monitoring(RPM). With this kind of function, medical practitioners can receive data about their patients without the need for face-to-face communication.