Teaching

Design of Medical Instrumentation: BME100

Biomedical Engineers need to be able to design safe and effective instrumentation meeting the needs of medical professionals for monitoring and treating their patients. Biomedical researchers depend on the availability of reliable instrumentation to interface with their systems. The consumer industry is tapping into a growing market for personal monitoring devices for health and fitness tracking.  The course BME100:  Design of Medical Instrumentation seeks to introduce students to the concepts involved in the realization of such instrumentation.The basis of the design elements remain the same:  linear system approximations, an understanding of basic electronics and the interface between electronics and living systems, sensor design and application. However he technical environment in which the engineer operates is constantly and rapidly evolving. Computers are becoming faster, smaller, and more powerful. Smart phones are ubiquitous. The fundamental science behind all these devices progresses at ever increasing speed. 

 

It is with this background in mind that the course is taught a flexible and evolving way. It is built around the following basic topics:

  • Linear systems: transfer functions and frequency response
  • Electrodes for biopotential recording
  • Basic electronics including operational amplifiers and the instrumentation amplifier
  • Transducers for temperature, displacement, pressure, force, and flow
  • Optical transducers and blood oxygenation measurement
  • Computer interfaces and data acquisition
  • Product development and regulation
  • Safety

Students have the opportunity to relate these topics to current engineering practice by

  • Relating their learning to material in the scientific and professional literature
  • Participating in a group project to discover the engineering involved in the development of an existing commercial product

When the course moved to online format in the last part of the Spring 2020 semester, the labs went online too and became demonstrations.

 

Electrical Circuits and Linear Systems BME 93

A basic understanding of electrical circuits and linear systems is essential for a biomedical engineer who wants to design effective solutions for various needs, whether monitoring a cell culture, producing an acoustic or visual implant, or even designing a structural, load bearing implant.

This course introduces  the students to the concepts of voltage and current, amplification, resonance, filtering and methods for analysis and design of electrical circuits and devices. The systems involved are often linear, or can be approximated as such. That is, the response of a device to the sum of two inputs is the same as the sum of the responses of the system to each input separately. For example, a properly functioning weigh scale is a linear system.  If you have two sacks of flour, weigh them separately and find that the first sack weighs 1 pound, and the second sack weighs 2 pounds, then what will the scale show if you put both sacks of flour on the scale at the same time? Of course the answer is 3 pounds.  And that is the essence of linearity: no more, no less. 1lb + 2lb = 3lb.

Even though the idea itself is very simple, its use in practice involves many methods that have been developed over a long time. And some of the results are not intuitive at all. One example is the reciprocity theorem. The box in the figure below labelled NR is some circuit containing a network of passive linear components such as resistors, capacitors and inductors. The reciprocity theorem states that i2 = i1

The reciprocity theorem i2 = i1

One of the goals of the course will be to enable students to understand and use results like this. The course will be taught using an interactive textbook from zyBooks.