10 Health

Health care is replete with applications of physics. The earliest uses of X-rays for radiographs have evolved into sophisticated 3-dimensional time-resolved tomographic systems using X-rays, magnetic resonances, and positron emission. Ultrasound images organ tissues and developing fetuses and, with the Doppler effect, monitors blood flow in arteries and veins. Sensitive electrical measurements monitor heart, brain, and muscle activity. These tools for health monitoring and disease diagnosis are matched by tools for treatment, including radiation treatment and radiofrequency hyperthermia for cancer, a “gamma knife” for local excision of problem tissues in the brain. Fiber optics and associated tools permit direct imaging and non-invasive procedures inside the body. Meanwhile, optical and electron microscopes provide imaging at the cellular level…now at the point of tracking single molecules. Microfluidic technologies are rapidly evolving for rapid-throughput processing of cells and cell constituents. Mass spectrometers, nuclear magnetic resonance, x-ray crystallography, and other tools advance the understanding of biomolecules and potential drug treatments. Meanwhile, testable physical models evolve to describe all scales of biological processes, from fundamental enzymatic control of reactions to cell membrane processes to the mechanics of cell division and cell motion…all the way up to the dynamics of heart beats and lung function, coordination of muscle activity for movement, etc. Physical devices are key to devices that can maintain or restore biological function: eyeglasses and hearing aids help with our senses, pacemakers and other implants keep the heart and other organs functioning, and prosthetic devices help with movement. Special technologies help first responders care for and transport people who are injured or who suddenly succumb to acute medical conditions like heart attacks. Personal monitoring devices can be worn like clothing or placed around our homes and workplaces, helping us sustain and optimize our well-being. And all of these technologies translate to the care of animals. Now a big challenge is to make the tremendous array of physics-enabled medical monitoring, diagnostics and treatments more affordable, more widely distributed, and capable of reaching people all over the world.