Pulse oximeters- Application and Maintenance

A pulse oximeter is a painless and reliable way for clinicians to measure a person's blood oxygen levels.

When you breathe, oxygen enters your lungs, passes through thin membranes and enters your blood stream — where it's then picked up by red blood cells and carried around the body to various organs.

A pulse oximeter is a tiny device that usually slides over your fingertip or clips on your ear lobe and uses infrared light refraction to measure how well oxygen is binding to your red blood cells. Oximeters report blood oxygen levels via an oxygen saturation measurement called peripheral capillary oxygen saturation, or SpO2. It has been used extensively to detect COVID early

1. Let’s Learn Health Technology in Health Technology Management Series Topic-Pulse Oximeters Health technology  is defined by the World  Health  Organization as the "application of organized knowledge and skills in the form of devices, medicines, vaccines, procedures, and systems developed to solve a  health  problem and improve quality of lives“

2. PULSE OXIMETRY Health Technology Management Series- By Dr. S.B.Sinha Ex. President Biomedical Engineering Society of India

3. HEMOGLOBIN/HAEMOGLOBIN A Protein that carries oxygen from lungs to tissues throughout the body

4. PULSE OXIMETER A device is used to measure oxygen saturation in the body i.e. how much of the haemoglobin in the blood is carrying oxygen (percentage of haemoglobin that is saturated with oxygen)

5. PULSE OXIMETRY Pulse oximetry, sometimes called the fifth vital sign, is a non invasive method of measuring oxygen saturation (SpO2) by using a light signal transmitted through the tissues. It is one of the most essential monitoring for routine use in anaesthesia and intensive care.

6. PULSE OXIMETRY It also measure the heart rate. Give an idea about tissue perfusion by pulse wave form. If Spo2, specially below 90% may be caused by problems including lung diseases such as COPD, breathing difficulties, circulatory problem such as excessive bleeding or blood circulation problem.

7. PULSE OXIMETRY Pulse oximetry, sometimes called the fifth vital sign, is a non invasive method of measuring oxygen saturation (SpO2) by using a light signal transmitted through the tissues. It is one of the most essential monitoring for routine use in anaesthesia and intensive care. It also measure the heart rate. Give an idea about tissue perfusion by pulse wave form. If Spo2, specially below 90% may be caused by problems including lung diseases such as COPD, breathing difficulties, circulatory problem such as excessive bleeding or blood circulation problem.

8. Normal Reading

9. TYPES OF PULSE OXIMETER, PROBES/SENSORS

10. Working of the Pulse Oximeter Probe of pulse oximeter consists of two diodes which emit equal intensities of red and infrared light sequentially into pulsatile tissue bed with two different wavelengths i.e 940 nm (infrared) and 660 nm (red) respectively. Variable amount of these lights are absorbed by oxygenated and reduced haemoglobin. The Reduced haemoglobin absorbs more red than infrared light and oxygenated haemoglobin absorbs more infrared than red. A photo-detector placed on the opposite side senses the ratio of red and infrared light based on which the proportion of oxygenated and reduced haemoglobin is estimated and displayed.

11. Do’s and Don’ts DO NOT use the Oximeter in environment with inflammable gas such as some ignitable aesthetic agents. Don’t uses the Oximeter while the tested measured by MRI and CT. If the Oximeter gets wet, please stop using it immediately. Keep the Oximeter away from dust, vibration, corrosive substances, explosive materials, high temperature and moisture. DO NOT operate keys on front panel with sharp materials. When it is carried from cold environment to warm or humid environment, please do not use it immediately wipe its surface with disinfectant solution or IPA70% using a soft and lint free cloths

12. Do’s and Don’ts Do not spray any liquid directly onto the device. High temperature or high pressure steam disinfection of the Oximeter is not permitted. Refer to User Manual for instructions of cleaning and disinfection. Use required probe type as per patient category i.e. adult, paediatric or infant The unit shall be fully charged when its kept in Idle state. The battery compartment should be checked time to time for any leakage. Timely replacement of the battery and sensor in case of expiry of the life.

13. USER MAINTENANCE OF PULSE OXIMETER DAILY Cleaning Remove any dust with damp cloth and dry off. Visual Check the main unit and all accessories periodically to make sure that there is no visible damage that may affect patient’s safety and monitoring performance about cables and sensor. Check power cable and connector for any damage or loose contract. Function After switching on the leave the monitor for its self-test.

14. USER MAINTENANCE OF PULSE OXIMETER WEEKLY Cleaning Clean the front panel, basinet by using damp cloth socked in mailed detergent/soap water. Do not use sprit or other chemical. Disinfection as per manufacture’s recommendation. Visual Check all screws and wheels of basinet. Check power cable, sensor and connector for any damage or loose contract. Function After switching on the leave the monitor for its self-test. See the light of the sensor probe.

15. TROUBLESHOOTING OF PULSE OXIMETER Fault Possible Cause Solution 1. The pulse oximeter fail to start/ power failure Batteries are not installed Installed batteries   Batteries discharged Replace the alkaline batteries and charge the Li-on batteries Batteries make improper electrical contact Check that batteries contact the pulse oximeter properly Power supply protection Check that power supply voltage meets the requirement. Main board defective Replace main board or Refer to BME

16. TROUBLESHOOTING OF PULSE OXIMETER Fault Possible Cause Solution 2. LCD displays incorrectly Cables defective Check that LCD cable and connector are undamaged and properly connected.   LCD defective Replace LCD or Refer to BME Main board defective Replace main board or Refer to BME 3. No alarm sound Speaker failure Replace speaker or refer to BME 4. Sensor does not light Light sensor failure Replace sensor or refer to BME

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