Biomedical Instrumentation (medical pratice)

Question 1

Measurement of body temp

Answer 1

• measurement of elevated body temp is oftent the first sign of a abnormal condition

Question 2

Mercury thermometer

Answer 2

principle of thermal expansion, rises when hot, drops when cool

Question 3

Electronic thermometer

Answer 3

use fo thermocouples or thermistors as the sensing unit, sensing element can be placed in direct or contact the body

Question 4

Ear thermometer

Answer 4

-noncontact probe that senses IR radiaton emitted from the tympanic membrane
-emitted IR is measured witha a pyroceletrical signal
-prone to underestimation

Question 5

Pyroelectricity

Answer 5

is a property of certain materials
- they respond to heat by the generation of an electrical potential
-natural materials such as quartz and bones exhibit pyroelectric behvior

Question 6

measurement of blood pressure

Answer 6

provides rapid information about the health of the cardiovascular system

Question 7

High BP (hypertension)

Answer 7

-heart attack
-atherous derosis
-congestive heart failure

Question 8

Low BP (hypotension)

Answer 8

cause of lacj of blood and oxygen delievery

Question 9

What is blood pressure measured as?

Answer 9

systolic / diastolic pressure

Question 10

Systolic pressure

Answer 10

maximum pressure exerted on the arterial walls during contraction

Question 11

Diastolic pressure

Answer 11

occurs during relaxation of the ventricles

Question 12

Normal blood pressure?
High blood pressure?

Answer 12

120/80
140/90

Question 13

Catherization

Answer 13

-most direct method of measuring blood pressure (invasive, only used when needed)

Question 14

How does catherization work?

Answer 14

catheter is filled with a fluid which transduces the arterial pressure to an external (or internal) pressure transducer

Question 15

Catheter

Answer 15

long, thin, flexible tube gets threaded through the circultaroy system to reach places deep in the body

Question 16

Korotkoff sounds

Answer 16

series of sounds when blood pressure cuff is being inflated and deflated

Question 17

Auscultatory

Answer 17

refers to listening to the sounds within the body
(most common when measuring blood pressure)

Question 18

Korotkoff BP measurement

Answer 18

1. an air filled cuff is wrapped around the patients arm
2. a stethoscope is placed under the cuff and the cuff is inflated to a pressure that exceeds the systolic pressure
3. a fully inflated cuff completely stops the blood flow
   4, as pressure in the cuff is slowly released, operator listens for noise

Question 19

What do Dr listen for when recording blood pressure?

Answer 19

-Appearnace of sounds is the start of systole (or the reapperance)
-Disappearance of sounds the start of diastole

Question 20

Measurement of oxygen saturation

Answer 20

relative measure of the amount of oxygen that id carried (dissolved) in blood
- proper blood O2 + CO2 levels are critcal for maintence of pH and healthy function of cells

Question 21

Lung diseases that cause low O2 levels in the blood (hypoxemia)

Answer 21

-asthma
-emphysema
-severe pneumonia
-pulmonary edema (fluid in the lungs)

Question 22

Is blood oxygen monitored for all patients during surgery and ofeten form patients in recovery?

Answer 22

Yes

Question 23

Ways to measure oxygen saturation

Answer 23

1. Taking an aterial blood sample
2. Pulse oximeter

Question 24

taking an aterial blood sample

Answer 24

• this procedure is more difficult than collection of vrnoud blood sample becasue the arteries in the arm are deeper and the muscular aterial wall is more difficult to punture with a needle
  (Take blood and sample it)
  Very invasive

Question 25

Pulse oximeter parts

Answer 25

Transmission- the device consists of light emitter probe coupled with a photo diode
Recieving- photo dector attached to a fingertip or ear

Question 26

Transmissive oximetry

Answer 26

detectors is on the other side, light goes through the finger

Question 27

Reflectance oximetry

Answer 27

detector is on the same side as the light (reflected)

Question 28

How pulse oximeter works

Answer 28

1. photo diodes emit small light beams at 2 different wavelengths
   - one LED is red adn the other is infared
   -absorbtion of these wavelenghs differs significantly betweeen oxyhemoglobin + its deoxygenated form
   - a ratio is record fo R/IR

Question 29

Infared is absorbed well by?

Answer 29

Oxygenated blood

Question 30

Red light is absorbed well by?

Answer 30

Deoxygenated blood

Question 31

Healthy SpO2?
Mild?

Answer 31

94% to 99%
90% and up

Question 32

Supplementary oxygen should be provided for SpO2 level of

Answer 32

lower than 90%

Question 33

R/IR ratio of ____ equals 100% spO2

Answer 33

0.5

Question 34

Diabetes

Answer 34

usually a chronic disease in which there are high levels of sugar in the blood

Question 35

Insulin

Answer 35

a hormone produed by the pancreas to control blood sugar
-diabetes can be too little insulin and/or a resistance