Physiological signals and medical quackery

Chapters three and four deals primarily with physiological signals and the instrumentation used to detect them.  Much of biomedical engineering is concerned with detecting signals commonly produced inside the body and translating these signals to form visual representations of physiological processes.  Bioengineering has led to modern medical devices such as x-ray machines and MRI scanners thus revolutionizing the way clinicians diagnose and treat patients.  Bioengineering has brought medical practice out of the dark ages by transforming the hospital from a passive repository for sick people into a dynamic interdisciplinary sanctuary for patients who now have a real chance for recovery.   

Unlike the previous chapter, chapters three and four are much easier for the novice to absorb−Valentinuzzi appears less concerned with referencing his own research and more involved in providing a general overview of signals and signal pick-up.  Although in chapter two Valentinuzzi discussed cardiovascular physiology ad nauseam, he still felt the need to briefly revisit related concepts.  Valuntinuzzi however keeps things brief in chapters three and four, especially the math and physics.  This part of the book feels more appropriately like a primer and would probably be suitable as a complementary excerpt for an advanced high school or introductory post-secondary biomedical engineering class.     

My only recommendation for chapters three and four would be to make them more relevant to everyday life.  For example, when I taught sports medicine, my students would often ask questions about what dietary supplements to take and how to take them.  As a former athlete, I once bought into the dietary supplement hype.  It wasn’t until I became a teacher when I learned that vitamins and supplements are at best, a marketing gimmick.  At worst, these substances can even have serious health consequences.  Like myself, many of my student-athletes were ardent users of dietary supplements−so I designed my lessons to be more germane to my students’ interests by sharing peer-reviewed research on diet and nutrition and teaching them how to discern between credible sources and misinformation.  

Similarly, I believe Valentinuzzi should have discussed how biomedical engineering can be used to disillusion victims of medical quackery in addition to explaining technical details.  Valentinuzzi defines and illustrates diamagnetic and paramagnetic substances by explaining: 

[d]iamagnetic substances are expelled from a magnetic field, i.e., they are displaced from the points of greater intensity to those of lesser intensity… Paramagnetic substances are sucked in by a magnetic field, i.e., they are displaced from the points of lesser to the points of greater intensity. 

In other words, diamagnetic substances are repelled by a magnetic field whereas paramagnetic substances have an affinity for a magnetic field.  Valentinuzzi however fails to mention the practical application of these properties.  For example, magnet therapists use magnets to promote circulation because they claim that the iron in our hemoglobin allows magnets to attract blood to the surface of our body.  This is a reasonable hypothesis; however, oxygenated hemoglobin is diamagnetic so theoretically magnets would have the opposite effect.  Additionally, the magnets typically used in magnet therapy do not create a strong enough magnetic field to have any significant physiological effect.  Unfortunately, many people fall victim to false claims and although Valentinuzzi does a great job sharing technical knowledge about biomedical engineering, the novice would have also benefited from practical information about quackery.