“Biomedical instruments” refer to a very broad class of devices and systems. A biomedical instrument is an ECG machine to many people. To others, it’s a chemical biosensor, and to some it’s a medical imaging system. Current estimates place the worldwide market for biomedical instruments at over $200 billion.
Biomedical instruments are ubiquitous; they are significant to the broader technology and biotechnology sectors; and, finally, they are vital to many medical and scientific fields.
Even though there is a wide variety of instruments, almost all of them can be modeled using the simple diagram below.
All biomedical instruments must interface with biological materials (by definition). The interface can by direct contact or by indirect contact (e.g., induced fields).
1. Basic Sensors and Principles – including biopotential electrodes
2. Electronic Interfacing: including system noise figure, system bandwidth, pre-amplifiers, postamps, instrumentation amps, A/D and D/A converters, aliasing, triggering and signal averaging
3. Computation: including data capture and signal processing
4. Systems: complete system response using specific examples (electromyogram, pressure sensors and blood pressure measurements, flow sensors and blood flow measurements, and chemical biosensors)
Detailed Explanation -
Sensors and Actuators
A sensor must:
• detect biochemical, bioelectrical, or biophysical parameters
• reproduce the physiologic time response of these parameters
• provide a safe interface with biological materials
An actuator must:
• deliver external agents via direct or indirect contact
• control biochemical, bioelectrical, or biophysical parameters
• provide a safe interface with biologic materials
The electronics interface must:
• match the electrical characteristics of the sensor/actuator with the computation unit
• preserve signal-to-noise ratio (SNR) of sensor
• preserve efficiency of actuator
• preserve bandwidth (i.e., time response) of sensor/actuator
• provide a safe interface with the sensor/actuator
• provide a safe interface with the computation unit
• provide secondary signal processing functions for the system
The computation unit must:
• provide primary user interface
• provide primary control for the overall system
• provide data storage for the system
• provide primary signal processing functions for the system
• maintain safe operation of the overall system