3 Jul 2023

5 Cool Things You Didn’t Know About Medical Physics


Physics is everywhere; while some people find joy in understanding the beginnings of the universe, others prefer to focus on some more down-to-Earth science. But do you know how Physics is used in medicine? Check out these 5 facts.

Doctor Hibbert from the Simpsons 'it's hopeless' gif

Fact # 1

Sensitive prosthetic hands make use of the way light bends in different materials. The hands contain bundles of stretchable ‘wave guides’: these are optic fibres with a core with a high refractive index and an elastomer coating with a much lower refractive index. These waveguides are designed to be lossy so that when some light is shone through the fibre, a proportion is radiated out. This proportion increases when the waveguides are deformed, meaning that light sensors can be used to sense the amount of force applied to the hand. In fact, these sensors are so accurate, that the hands can discern if a tomato is ripe or not.

Fact # 2

Antimatter is used in brain scans! PET scans rely on antimatter to produce accurate images of the tissues in the body. They use a beta-emitting Fluorine isotope as a medical tracer, which emits beta-plus particles, called positrons. These are the antiparticles of electrons, so when they interact with the electrons in the body they ‘annihilate’. While this term sounds dramatic, it simply means that both particles turn into energy. This energy is detected and used to pinpoint exactly where the fluorine was to start with.  Since fluorine concentrates in areas of high activity, we can use PET scans to monitor brain function.

Fact # 3

Vibrating crystals are the basis of ultrasound scans! Ultrasound scans are a common non-invasive imaging technique, often used to show parents their unborn children. They work by using ‘ultrasound’, which is a sound that is thousands of times too high pitched to be audible to humans. A piece of equipment called a transducer produces this ultrasound by making a crystal vibrate using something called the ‘piezoelectric effect’. This effect means that when an alternating current is applied to certain crystals, they are squished repeatedly, causing a very high-frequency vibration. This ultrasound vibration is partially reflected whenever it encounters a boundary between substances, like tissue and bone for example. By mapping where the vibrations are reflected, we can produce images of foetuses before they are born! 

Fact # 4

Particle accelerators are used to cure cancer! In an advanced treatment technique called intensity-modulated radiation therapy (IMRT), computer programs are used to precisely shape the field of treatment. A Linear Accelerator or LINAC is used to collide electrons, producing an X-ray beam. As in traditional radiation therapy, the high dose of radiation is able to kill large tumours, preventing them from spreading. This technique delivers a maximal dose of radiation to the target area while reducing the impact on surrounding tissues.

Fact # 5

Researchers are currently working to understand the atomic motion within enzymes. Many pharmaceuticals work by inhibiting the function of enzymes, so understanding exactly how they work could lead to a whole new branch of pharmaceuticals!


Want to learn about more applications of physics? Check out these 8 things you can do with a physics degree>>

Think you have what it takes to be a medical physicist? Find out more about a career in medical physics here>>

Article by Britt Dewing, Stemettes Intern

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