In: Nursing
Bedside monitors in the intensive care unit (ICU) have ECG, pulse oximeter, respiration and periodic blood pressure using a programmed sphygmomanometer (i.e. this measures blood pressure at a pre- programmed desired interval, e.g. 15min). (i) Describe the biophysical principles underlying pulse oximetry including tissue absorption characteristics. (ii) Describe the instrumentation required to for the ICU monitor, from sensors to display. Use a block diagram with each block representing the hardware or data processing element. (iii) One of the most difficult problems with the current ICU bedside monitor is the large number of wires/cables/leads/hoses etc. which get tangled. This problem can be exacerbated by having one or more intravenous (IV) lines also in the patient. How can a better system be designed? Outline the changes in the block diagram already done in part (ii) above. (iv) List two sources of noise in the measurement of arterial O2 saturation for 1CU patients.
1.Principles of pulse oxymetry
Oximeters work by the principles of spectrophotometry: the relative
absorption of red (absorbed by deoxygenated blood) and infrared
(absorbed by oxygenated blood) light of the systolic component of
the absorption waveform correlates to arterial blood oxygen
saturations. Measurements of relative light absorption are made
multiple times every second and these are processed by the machine
to give a new reading every 0.5-1 second that averages out the
readings over the last three seconds.
2.please see image attached
3.please see image attached
4.sources of noise
A.patient motion,
B.some types of lighting,
C.intravenous dyes,
D.skin pigmentation and
E.nail polish.