What Should Every Biological Physicist Know?

Is there a common core of knowledge that every medical or biological physicist should know? Oakland University has a Medical Physics PhD program, and we define our knowledge core through our PhD qualifying exam. Students take three exams in theoretical physics, mathematical methods, and biophysical sciences (or, more succinctly, physics, math, and biology). If you would like to see what sort of questions we ask on this exam, go to https://sites.google.com/view/bradroth/home/medical-physics-graduate-program/qualifying-exams?authuser=0, where you can download copies of all exams for at least the last decade. If you look closely, you will find questions from Intermediate Physics for Medicine and Biology every year.

A "Citation Index" for Intermediate Physics for Medicine and Biology

Who does Intermediate Physics for Medicine and Biology cite most? I went through the index of our book and tallied the number of entries for various scientists. (Disclaimer: this is the number of pages listed in the index, which is not necessarily the same as the number of times cited.) Most are authors of leading textbooks. Here is a list of scientists who Russ Hobbie and I cite a dozen or more times.

Bioelectric Phenomena,
by Robert Plonsey.

16 Robert Plonsey: Emeritus Professor of Biomedical Engineering at Duke University and author of several textbooks including the classic Bioelectric Phenomena

16 William Press: first author of my favorite book on numerical methods, Numerical Recipes. His unfortunate coauthors didn't make the list because we usually cited the book as “Press et al.”

16 Robert Resnick: Prolific textbook coauthor, including the excellent Quantum Physics of Atoms, Molecules, Solids, Nuclei, and Particles

15 Mark Denny: Author of the delightful book Air and Water.

From Clocks to Chaos,
by Glass and Mackey.

14 Leon Glass: Leading researcher at McGill University studying nonlinear dynamics as applied to biology and medicine. Coauthor of the influential book From Clocks to Chaos.

13 Jose Jalife: Leading researcher in cardiac electrophysiology at the Upstate University of New York, and co-editor of the often-cited book Cardiac Electrophysiology: From Cell to Bedside.

13 Brad Roth: Humble, I’m not.

13 John Wikswo: Physics Professor at Vanderbilt University known for his research in biomagnetism and electrophysiology.

12 Frank Attix: Author of the textbook Introduction to Radiological Physics and Radiation Dosimetry, a standard for medical physics.

Textbook of Medical Physiology,
by Guyton and Hall.

12 Arthur Guyton (1919–2003): Author of the much-cited book Textbook of Medical Physiology (with coauthor Hall in recent editions).

Weight Control

How do we add material to each edition without making Intermediate Physics for Medicine and Biology a lot larger? Answer: The web. We no longer need the tables that occupied many pages in the Appendices of earlier editions. You can now find all that data online, for instance at http://physics.nist.gov/PhysRefData/XrayMassCoef/t ab2.html. Also, we deleted sections of previous editions that we did not feel were essential. Deleted text—some dating back to the first edition—is available on the book web site: https://sites.google.com/view/hobbieroth.

For the curious, the 1st (1978) edition had 557 pages and the 2nd (1988) edition had 623 pages. After the 2nd edition the page size became larger making comparisons difficult. The 3rd (1997) edition had 575 pages and the 4th (2007) edition has 616 pages. Like many Americans our weight is creeping up, but we fight a constant battle to keep the book from becoming super-sized.

A Bridge Between Biologists and Physicists

Peter Kahn reviewed the third edition of Intermediate Physics for Medicine and Biology in the American Journal of Physics (Volume 67, Pages 457–458, 1999). Kahn wrote

Hobbie’s book presents a wealth of material. Clearly the target audience is physics students interested in biological processes, although biology students with strong backgrounds in physics and mathematics will benefit greatly from reading the book. It will prove useful as a text for those wishing to help advanced physics undergraduates and graduate students appreciate the important role that physics plays in understanding biology. It will be of value to biologists, physiologists, and neurobiologists as a reference. And, maybe, it will be a bridge over which biologists and physicists can initiate and maintain a dialogue.

Page Proofs

This week is a major anniversary for the fourth edition of Intermediate Physics for Medicine and Biology. One year ago this Tuesday, the page proofs arrived. Russ Hobbie and I painstakingly checked 632 pages of text, figures, tables, and equations, equations, equations (I estimate about 2000 of them). The job took over our lives for two weeks, but we finished before Thanksgiving, bringing to an end the process of preparing the 4th edition that had begun five years earlier.

I Heartily Recommend This Book

In the Jan/Feb 1999 issue of the IEEE Engineering in Medicine and Biology Magazine, Cynthia Paschal reviewed the third edition of Intermediate Physics for Medicine and Biology. She wrote

This third edition of Hobbie’s fine text incorporates the best of the previous editions with some new topics and examples. As before, every chapter includes numerous figures, graphs, tables, and logically developed equations... I heartily recommend this book as the sole text for a year-long intermediate undergraduate course in biophysics. The text is also useful for an introductory biophysics graduate course.

The Nobel Prize

Last week the 2007 Nobel Prize winners were announced. Congratulations to these distinguished scientists. In the 4th edition of Intermediate Physics for Medicine and Biology, Russ Hobbie and I discuss many Nobel Laureates and their research:

1. Felix Bloch and Edward Purcell shared the 1952 Nobel Prize in Physics for their discovery of nuclear magnetic resonance (p. 519).
2. Alan Hodgkin and Andrew Huxley won the Nobel Prize in Physiology or Medicine in 1963 for their research on nerve action potentials (p. 154).
3. The Nobel Prize in Physiology or Medicine was shared in 1979 by a physicist, Allan Cormack, and an engineer, Godfrey Hounsfield, for the development of computed tomography (p. 455).
4. Erwin Neher and Bert Sakmann received the Nobel Prize in Physiology or Medicine in 1991 for the invention of the patch clamp technique for studying ion channels (p. 238).
5. For his work elucidating the structure of potassium channels (p. 240), Roderick MacKinnon shared the 2003 Nobel Prize in Chemistry with Peter Agre.
6. Paul Lauterbur shared with Sir Peter Mansfield the 2003 Nobel Prize in Physiology or Medicine for the development of magnetic resonance imaging (p. 527).

Medical and biological physics is truly interdisciplinary: it involves Nobel Prize-winning work in physics, chemistry, and physiology and medicine.

Distances and Sizes

The Machinery of Life,
by David Goodsell.

One of the things Russ Hobbie and I added to the 4th edition of Intermediate Physics for Medicine and Biology is an introductory section about distances and sizes in Chapter 1 (pages 1–3). Our goal is to introduce the relative sizes of different biological objects (cells, bacteria, viruses, etc.). We try to provide something similar to what you would find in Morrison’s book Powers of Ten or in Goodsell’s book The Machinery of Life. The section also serves as a nice way to introduce many of the topics developed in more detail later in the book, and allows students to practice the valuable skill of making back-of-the-envelope estimates, such as estimating the number of hemoglobin molecules in one red blood cell. We hope you like it.

Medical Physics: The Perfect Intermediate Level Physics Class

In 2001, Nelson Christensen of Carleton College published an article in the European Journal of Physics (Volume 22, Pages 421–427) titled “Medical Physics: the Perfect Intermediate Level Physics Class.” The primary textbook for his class was the 3rd edition of Intermediate Physics for Medicine and Biology. Below is the conclusion to his paper.

A medical physics course should be looked upon as a beneficial addition to the undergraduate physics curriculum. The course should be considered as an ideal addition to the intermediate level physics curriculum, as it covers almost all of the major subjects that physics undergraduates should see. Students are often bored by lack of direct applications or good examples when covering physics subjects. In our class we talked about physics within the context of medical applications. For every physical topic there was a medical application; students loved it.

The interdisciplinary nature of a course like medical physics offers other advantages. A course like this provides an opportunity for keen pre-medical students to return to physics. A number of the pre-meds are genuinely interested in physics, but lack a good opportunity or reason to take an upper-level physics course. The differing backgrounds of the physics and pre- medical students presented an additional benefit in that a fantastic environment for stimulating discussions was created. The students would share with one-another their expertise.

Finally, there can be no denying that medical physics and biomedical engineering are evolving at a breakneck pace. There are opportunities available in abundance in these fields. Students are interested in medical physics for a number of reasons. There are equally good reasons for the faculty to provide a course in medical physics. This is exciting physics and exciting science!

Teaching from Intemediate Physics for Medicine and Biology

How can you structure a class using the 4th edition of Intermediate Physics for Medicine and Biology? At Oakland University, we offer two classes—Biological Physics and Medical Physics—as part of our undergraduate medical physics major. Biological Physics covers the first ten chapters of the book, and Medical Physics covers the last eight chapters. Below is the information about these classes in our undergraduate catalog (Note: PHY 102 and 152 are the second semesters of the non-calculus and calculus based introductory physics classes, and MTH 155 is the second semester of introductory calculus).

PHY 325 Biological Physics (4 credits)
Applications of physics to biology, including biomechanics, fluid dynamics, statistical mechanics, diffusion, bioelectricity, biomagnetism, feedback and control.
Prerequisite: PHY 102 or 152, and MTH 155

PHY 326 Medical Physics (4 credits)
Applications of physics to medicine, including signal analysis, imaging, x-rays, nuclear medicine and magnetic resonance imaging.
Prerequisite: PHY 102 or 152, and MTH 155