Circulatory System

Defibrillator

ECG Unit

Heart Pump

Hermatology Analyzer

Pulse Oximeter

Sphygmananometer

MRI

Usage: By clipping the patient's finger with the sensor

Portable: Yes (depending on model)

Parts:

• Light emitting diodes
• Light collecting diodes

Oxygenated blood absorbs light at 660nm for red light, while deoxygenated blood absorbs light preferentially at 940nm for infra red. The finger clip of a pulse oximeter consists of 2 light emitting diodes (LEDs), functioning at the 2 wavelengths mentioned above, and 2 light collecting sensors.

The 2 light collecting sensors measure the light emerging from the tissue, and using the data obtained for the relative absorption of light by the Haemoglobin and Oxyhaemoglobin in the blood, the oxygen saturation rate is displayed on screen.

• The oximeter is a relatively cheap device, and has a variety of uses in operation theatres, intensive care units and when attending to patients outdoors.
• Portable
• Work continuously to produce quick results

• Not highly accurate - Oximeters are setup to measure oxygenated and deoxygenated haemoglobin, and measurement errors might result in the presence of dyshemoglobinmoieties, such as carboxyhaemoglobin and methemoglobinemia. These 2 compounds reflect and absorb red light as well.
• Medical conditions such as low blood flow, hypothermia, hypotension reduce the pulsability of capillary blood, and the device might not function correctly