Photoplethysmography - Research Paper Example

Photoplethysmography “Photoplethysmography (PPG) is a non-invasive method for studies of the skin blood volume pulsations by detection and analysis of the back-scattered optical radiation”(Gailite, p. 1). The PPG method has gained wide clinical use at present because of the lack of complexity and high accuracy of results obtained though this procedure. Heart rate, respiratory rate tissue perfusion etc can be monitored accurately using the PPG method. Moreover, it can be used to evaluate the blood pumping problems at various parts of our body.

This paper briefly analyses various features of Photoplethysmography and its uses. On every cardiac cycle, heart pumps blood to all the organs at a particular rate. PPG makes use of certain light radiations, produced by a pulse oximeter for the evaluation of the blood reaching in each organ and to analyze the functioning of human organs. A light emitting diode (LED) is used in the pulse oximeter in order to illuminate the skin. Pulse oximeter illuminates the skin and measures changes in light absorption by a particular organ and these changes can help the pathologist in analyzing the discrepancies in the functioning of that particular organ.

A photodiode measured the wavelengths of the light transmitted or reflected. Schematic illustration of the time-resolved PPG signal acquisition: from the total detected skin reflectance spectrum (on the left), the intensity-time sections (A-A) are recorded only at the selected laser wavelengths (on the right). (Gailite, p. 1) “Photoplethysmography (PPG) ensures detection of blood volume pulsations by time-resolved analysis of the tissue back-scattered or absorbed optical radiation” (Spigulis, et al, p.1). As mentioned earlier, Photoplethysmography can be used to find out defects in blood pumping at various parts of our body.

As indicated in the above diagram, Photoplethysmography compares the wavelengths of incident and reflected light radiations in order to analyse the functioning of a particular organ of human body. For example, for identifying problems of lower leg, this technique places a small light probe on the surface of the skin just above the ankle.  “After a period of rest the subject exercises the calf pump by moving the foot up and down at the ankle. The PPG probe measures the reduction in skin blood content that is a result of the pumping action of the calf muscles” (Dodds).

The readings at the time of ankle movements and after the ankle movements will be recorded and after the evaluation of these results, the doctor or the pathologist can detect any abnormalities at the lower leg. PPG technique is currently used in many other areas as well. Cardio vascular problems can be detected much earlier with the help of PPG techniques. Most of the cardiovascular problems are detected only at a later stage because of the complexity in the detection procedures. The effectiveness of treatment will be increased if the heart problems detected earlier or at the beginning stages.

PPG procedures are so simple and can be performed at any time and hence anybody who has some heredity of heart diseases or doubts about the functioning of his heart can diagnose the problems with the help of PPG. Continuous monitoring of the functioning of the heart can also be accomplished more accurately using the PPG techniques. PPG can contribute heavily to the development of telemedicine because of the peculiar features of the light radiations used in the PPG techniques. Distant sensing is possible using PPG because of the light radiation’s ability to travel more distances.

PPG can cooperate with the mobile phone technologies and can contribute heavily to the development of telemedicine. Most of the current doctors and the general public are keeping mobile phones always with them and with proper technologies; the doctor can receive signals or data from the distant patient about the functioning of his heart or other body parts. “Contemporary mobile phones are suitable as the PPG monitoring terminals, providing immediate interaction between the patients and caregivers” (Spigulis, et al, p.1). The mobile networks are at present covering almost the entire globe and hence it is easy for the caregivers to receive PPG signal data from the patient’s phone.

However, still this technology has not developed fully because of the difficulties in the “design of the embedded optical contact sensors and development of appropriate methods to enter the measured data into the communication system” (Spigulis, et al, p.1). The following diagram illustrates the typical telemedicine options using mobile phones and PPG. Transmission of the Bluetooth-monitored PPG signals: via the mobile phone network from patient to doctor (Spigulis, et al, p.6) To conclude, PPG is one of the revolutionary pathological methods which help to analyse the functioning of our body parts accurately.

It can be used in the development of telemedicine and the caregivers can evaluate the health conditions of the patients by incorporating the PPG and mobile technologies. Works Cited 1. Dodds S.R. “Photoplethysmography (PPG)”. 2001. Web. 17 February 2011. 2. Gailite, Lasma. “Multi-wavelength Photoplethysmography Method for Skin Microcirculation Assessment”. Web. 17 February 2011. 3. Spigulis, Janis., Erts, Renars., Nikiforovs, Vladimirs and Kviesis-Kipge, Edgars. Wearable wireless photoplethysmography sensors. Web. 17 February 2011.