FYS4250Fysisk institutt - Rikshospitalet

Image: Grimnes, Høgetveit. Biomedical Engineering Education & Advanced Bioengineering Learning: Interdisciplinary Concepts. ”A sensor is a mediator able to convert one or more measurands or physical variables into an equivalent signal variable of another type of quantity within a frame of a given unity” Pallàs-Areny, Webster, Sensors 2001 What is a sensor?

Image: Grimnes-Høgetveit. Biomedical Engineering Education & Advanced Bioengineering Learning: Interdisciplinary Concepts. - Sensor system: ”comprises the total signal path from the measurand to the observer and includes all sensing, conditioning and real-time processing elements in the path” - Electrode: ” An electrode is an electrochemical cell converting charge carriers from ions to electrons or vice versa. An electrode is only a half- sensor in the way that two electrodes are necessary in order to apply a current or read a potential difference in living tissue” - Probe: A ”probe is a broader concept than a sensor. A probe is often comprising multiparameter sensors (e.g. temperature) and may be held by the operator and be equipped with switches and level adjustment facilities. Example: Ultrasound probe” Source: Grimnes-Høgetveit. Biomedical Engineering Education & Advanced Bioengineering Learning: Interdisciplinary Concepts. More definitions....

Pressure transducer and Wheatstone bridge Image: Grimnes-Høgetveit. Biomedical Engineering Education & Advanced Bioengineering Learning: Interdisciplinary Concepts.

FYS4250Fysisk institutt - Rikshospitalet Piezoelectric transducer C=εA/x

FYS4250Fysisk institutt - Rikshospitalet Photomultipliers

Membrane potential Nernst equation for potassium K (Nor - Kalium): across a cell membrane with active channels pumping K ions into the cell.

Dipoles in the axon

Neural velocity

The heart

Atrioventricular- block

Ectopic beat

Tachycardia flutter= increased regular frequency

flimmer (norsk) = fibrillation (eng) = = uregelmessig rytme

Ischemia

Metal / electrolyte = electron / ion transitions

Ag / AgCl Non-polarizable electrode

Electrode polarization + skin + deeper layer

Stimulation electrodes

FYS4250Fysisk institutt - Rikshospitalet

FYS4250Fysisk institutt - Rikshospitalet Einthoven triangle

FYS4250Fysisk institutt - Rikshospitalet Wilson central terminal

FYS4250Fysisk institutt - Rikshospitalet Augmented leads

FYS4250Fysisk institutt - Rikshospitalet ”Driven right leg”

FYS4250Fysisk institutt - Rikshospitalet Biopotentail amplifiers

FYS4250Fysisk institutt - Rikshospitalet

FYS4250Fysisk institutt - Rikshospitalet

FYS4250Fysisk institutt - Rikshospitalet The circulatory system

FYS4250Fysisk institutt - Rikshospitalet Typical blood pressures

FYS4250Fysisk institutt - Rikshospitalet Invasive blood pressure measurement

FYS4250Fysisk institutt - Rikshospitalet Harmonic analysis, Fourier

FYS4250Fysisk institutt - Rikshospitalet Heart sounds

FYS4250Fysisk institutt - Rikshospitalet Stethoscopes, spektrogram

FYS4250Fysisk institutt - Rikshospitalet Non-invasive blood pressure

FYS4250Fysisk institutt - Rikshospitalet Ultrasound measurement

FYS4250Fysisk institutt - Rikshospitalet Bloodpressure, oscillometric

FYS4250Fysisk institutt - Rikshospitalet Non-contact tonometry

Indicator-dilution method

Elektromagnetic flowmeter

Electromagnetic flowmeter waveforms

Quadrature-suppression flowm.

Plethysmography

Plethysmography curve

Figure 1 Airways with larynx, trachea, bronchi and alveoles

Figure 2 Lung volume parameters Equation 1 ComplianceC = ΔV / ΔP [L/Pa, L/cmH2O]

Equation 2 Poiseuille [Pa/m 3 /s = pressure / flow rate]

Figure 6 Laplace cylinder model P=T/r

Figure 10 Rebreathing circle with one-directional valves 1 and 2

Figure 13 IR absorption spectra for some anaesthetic agent vapours. Datex Ohmeda Division, Instrumentarium Corporation

Figure 14 Multigas spectrophotometric gas analyzer with rotating filter wheel

pH-measurement

pCO 2 (Severinghaus) electrode

pO 2 (Clark) electrode

Fluorescent dye sensor

pH-sensitive dyes

Pulsoxymetry light absorption