5 Types of Biomedical Instrumentation Systems

We have the following five types of biomedical instrumentation/measurement systems:

1. Direct/Indirect
2. Invasive/Non-invasive
3. Contact/Remote
4. Sense/Actuate
5. Dynamic/Static

Direct/Indirect

In biomedical instrumentation we may have the sensing system measuring a physiological parameter directly, such as the average blood flow in an artery or indirect measurement where a parameter related to the physiologic parameter of interest such as ECG recording at the body surface which is related to propagation of the action potential in the heart but isn’t a measurement of the propagation waveform.

You may also read: The Instrumentation for Recording ECG Signals

Invasive/Non-invasive

An example of invasive biomedical measurement is the direct electrical recording of the action potential in nerve fibers using an implantable electrode system. An imaging system measuring blood flow dynamics in an artery such as ultrasound color flow imaging of the carotid artery is case of non-invasive biomedical measurement.

Also read: Ultrasound Scanning Techniques

Contact/Remote

A contact biomedical measurement is whereby you have the biosensor contacting the tissue for example a strain gauge attached to a muscle fiber can record deformations and forces in the muscle. An example of remote/non-contact biomedical measurement is an MRI or ultrasound imaging system that measures the internal deformations and forces without contacting the tissue.

Sense/Actuate

A sensor is used to detect bioelectrical, biochemical, or physiological parameters. An actuator delivers external agents via direct or indirect contact and/or controls biochemical, bioelectrical or biophysical parameters. An automated insulin delivery pump is an example of a direct, contact actuator. Non-invasive surgery with high intensity, focused ultrasound is an example of a remote, non-invasive actuator.

Also read: What is a Biosensor?

Dynamic/Static

Static instruments measure the temporal averages of physiological parameters. Dynamic or real-time instruments have a time response faster or equal to the physiologic time constants of the sensed parameter, for instance, a real-time, ultrasound Doppler system can measure the changes in arterial blood velocity over a cardiac cycle.

You may also read:

• 4 Classifications of Biomedical Measurement Instruments
• The Introduction to Biomedical Instrumentation
• Key Performance Requirements of Effective Biomedical Instrumentation Systems
• Key Points to Note when using a Biomedical Instrumentation System