By Dr. Chad Kennedy, Chair and Professor Biomedical Engineering Technology, College of Engineering and Information Sciences, DeVry University Phoenix
Often we hear about how Big Physics will pave the way to human understanding of our Universe and the underlying fundamental constituents that create everything from subatomic particles and atoms to the Stars and Galaxies in which we live. Pretty heavy stuff! However, many people wonder what have these grand multi-million dollar experiments contributed to human kind today. Though there is a decade’s long delay from Big Physics to applied physics, some of the greatest contributions of Big Physics do translate to Big Medicine.
For example, many of us think the advent of LASERs (Light Amplification by Stimulated Emission) in medicine came from doctors. However early research was done be physicists, followed by a team of engineers, such as Biomedical Engineers, and finally the medical community. Several successful types are the CO2 Laser used for general surgical procedures and the excimer laser. The excimer laser advanced refractive eye surgery such as LASIK (Laser-Assisted in Situ Keratomileusis) to become a preferred type treatment for many people over the age of 25, myself included.
But what about subatomic particles, such as electrons, protons and neutrons, are those discoveries used in medicine? What about non-particle radiation, such as the baffling duality photons that can act both as a wave or a particle depending upon how we observe and use them? Lost yet? Well, don’t be. We have been using some of these types of radiation for more than a century and have progressed to using almost all of them in medicine in the last few decades.
Pictures Using High Energy Photons
Although photons have no mass and travel at the speed of light we have been using them in medicine since the advent of the light bulb. In fact, the light bulb emits exactly that, photons of visible light so that we can light an operation room (OR) even without daylight. Imagine medicine without lights. “Sorry ma’am, we can’t perform that double bypass surgery until sun up!” Now that may have been obvious, but all X-ray machines, Computed Tomography (CT) Machines, Image Guided Radiation Therapy (IGRT) Machines and Gamma radiation therapy machines also use photons. The difference is the amount of energy that these photons have. X-rays and Gamma rays have a thousand to a million more times energy than the light with which you and I use to read this sentence. With that comes the power to see into the inner structures of our bodies and also focus that energy to disrupt and destroy cancer tumors without a single cut being made.
High-powered particle generators are required to create these high energy photons. In X-rays, Fluoroscopy machines and CT scanners, high speed electrons are generated to crash into X-ray producing targets. Typically, Tungsten is used for larger imaging and IGERT systems. This crashing interaction between the electrons and tungsten generates the X-rays which are then focused on the patient to either image and/or treat them in the case of IGERT systems. Even higher energies, such as gamma rays are used for specifically treating cancer. For example the TrueBeam™ radiotherapy device developed by Varian Medical Systems uses a high energy gamma ray generator and complex beam focusing system to target singular or multiple irregular cancer tumors. Since gamma radiation can be lethal in large doses, the system only focuses the dose at the tumor site, keeping the rest of the healthy tissue relatively untouched.
Big: Proton Therapy
Proton accelerators have been part of Big Physics for many decades and are now making a splash in Big Medicine. Protons are those positively charged cousins of the electrons that typically reside in the nucleus with the neighboring neutrons. Now protons have been making their big debut in medicine with extremely large proton treatment suites being built at select locations around the United States and the World. Still at the forefront of medical physics, proton accelerator suites, like the new Hitachi proton beam therapy system built at the Mayo Clinic Hospital, house at least four treatment rooms with a central proton accelerator system. Set to open in 2016, this massive undertaking require physicists, contractors and multiple engineering disciplines from civil, structural, mechanical, electrical and biomedical with a budget of about $200 million. Since protons typically exist in the nuclei of atoms, extremely large amounts of energy are required to free the protons from the nuclear grasp. The energy of a proton beam varies from 70-230 MeV, depending upon how deep the tumor in the tissue is that you wish to treat. These energy requirements explain why separate power supply and backups had to be designated just for these systems.
Bang: Matter-Anti Matter Imaging
The biggest “Bang” known to man other than the initial Big Bang that took place perhaps 13.6 billion years ago is a matter-antimatter annihilation event. Notice, I did not write explosion. This event is so energetic that both particles involved, a Positron and an Electron are literally annihilated into pure energy. The mass of both particles is completely gone leaving two beams of gamma rays that speed off in opposite directions. So what does this have to do with medicine? If you have ever undergone a Positron Emission Tomography (PET) procedure, you have had many of these events occur in your body! PET scanners are often used to diagnose the spread and treatment of diseases such as cancer and Alzheimer’s. What is interesting is that the application of this theory of interaction is leading the actual science of understanding. Exactly how this transformation occurs is still unclear, however the consistent behavior observed is what this imaging technique relies on. Sources that generate this radiation, such as F-18 labeled glucose called fluorodeoxyglucose (FDG), are called Radioisotopes. These “radiotracers” are injected (at safe dosage levels) and attach to specific chemical structures in the body so that we can visually “trace” where cancer tumors are and whether or not they have spread.
Medicine: BMETS fill the gap
All of this “Big Medicine” technology drives the need for highly-skilled people trained to understand, build and support these medical innovations. According to the US Bureau of Labor Statistics, the fields of Biomedical Engineering Technology and Biomedical Engineering are growing at roughly 31%* and 62%*, respectively, through the next decade, which is much faster than average. This growth is fueled by the increasing:
- Baby boomer population that needs medical intervention
- Reliance on medical technology
- Retirement rates of people currently in the Health Technology Management field
As more people retire in health technology management, there are growing job opportunities for students interested in taking their career in a direction that can help make a difference in the lives of others through technology. By pursuing degrees such as Biomedical Engineering Technology – full disclosure: this program is offered by DeVry University where I teach.
When you have a family member who needs to have radiation therapy to cure their previously incurable cancer or to see if a broken bone healed properly, thank your physicists and biomedical engineers for developing and designing these marvels of medicine. Especially thank your hospital’s biomedical medical engineering technologists (BMETs) and healthcare technology managers (HTMs) who keep this high-tech equipment operating correctly.
Dr. Chad Kennedy is a futurist, technology expert, Professor and Chair of BMET in the College of Engineering and Information Sciences at DeVry University. He has more than 20 years of experience in the engineering industry, serving in roles at various organizations, including NASA’s Johnson Space Center in Houston. In 2006, Kennedy helped develop the Biomedical Engineering Technology (BMET) program at DeVry University’s Phoenix campus, where he is a professor.Tags: biomedical engineering, biomedical engineering technology, biomedical imaging, chad kennedy, DeVry University, healthcare technology, medical physics, medical technology