Smart Energy Efficiency: The Insight I Got from my Radiology Clinical Posting.

Teletherapy Simulation Room, College of Medicine, University College Hospital and University of Ibadan, Ibadan.

 In med school, we rotate from one department to another, spending approximately two months in majority of the rotations/postings. I have enjoyed quite a few of them---Internal Medicine I, Surgery I,Ophthalmology, and most recently Radiology.

We spent just one week in this department, learning the various equipment that use radiation and sound waves to diagnose patients (to identify the cause of the symptoms of their disease conditions) and the principles underlying each of these imaging modalities as we call them in medicine. Believe me there's a lot of physics behind their working mechanisms; and this one thing should make you very cautious: the inevitable exposure to dangerous radiations such as x-rays, gamma rays, alpha particles, neutrons and so on which can cause cancer, loss of hair on the skin, cataract (leading to blindness). But hey, the partial comfort here is that there are high occupational safety measures taken before one starts working with those rayey and wavy guys.

On the other hand, my intent of sharing this with you is to lay bare an insight I had during the clinical posting. While we were being taught in a practical demonstration in the CT (Computerized Tomography) suite one day by one of the resident radiologists something caught my attention. He talked about the principle by which the X-ray machine and CT machine generate x-rays used for imaging patients (the William Roentgen experiment of cathode rays-electrons- hitting the anode to give off an unknown radiation---of course we were taught this superficially in secondary school and in a more broad perspective in our first year in the university when we did the basic sciences---and an enormous amount of heat). In fact, 99% of the total electrical voltage used to accelerate the electrons from the cathode to the anode are converted to heat and only 1% generate the x-rays. Resources are spent in the form of cooling units to cool the machine to prevent its breakdown from such enormous heat generated. I could hear myself saying to me: "this is a waste of resources and may be a lack of deeper consideration".

In this current age of ours when technology has woven its webs and threads into virtually every tunnel of our endeavour; in this age that has given birth to ingenious technological applications from the science of thermoelectricity (conversion of heat energy into electrical energy); and I thought: "we should harness the potential of this weapon of thermoelectricity to stop this waste in x-ray machines.

Dance floor tiles generating electricity for the hall. Image credit to Newlaunches

And so my insight, and I'm throwing it as a challenge to those out there in the thermoelectric science and technology industry, is this: we can devise a way to turn this wasted 99%-generated heat energy into other useful forms of energy. One way could be to couple the area in the machine where this heat is generated with a new thermoelectric material invented by researchers at the Ohio State University. The material engineered at the nanoscale level (one-billionth of a metre) consists of an element thallium which has been integrated into a compound lead telluride; it works by using heat to generate electrons that act as the fuel which it uses to generate electricity. This has already been demonstrated in cars by researchers at the California Institute of Technology. Another way is to create an entirely different method that could be more efficient than the Ohio State University material because the thallium-lead telluride technology is pending patent registration.

Smart floors of the future. Image credit to taringas

As technology expands we become more efficient in everything we do, including the generation, use and recycling of energy because energy can neither be created nor destroyed but can be converted from one form to another. A UK company, Pavegen, invented floor tiles that generate electricity by people walking on them: they were installed in some railway stations in London during the 2012 Olympic games, which were powered by the millions of people walking on them to board trains to the various games venues. Also, American students at Harvard University (one a Nigerian) recently invented a football, Soccket ball, that generates electricity from the kinetic energy it acquires after being played for minutes. So, I believe this efficiency can equally be replicated in this case of x-ray-generating machines such that we wouldn't be wasting resources again to waste a very useful resource.