The physics behind biomedical devices plays a very wide range of roles in healthcare technology, not all of which are included in this chapter. Human health and well-being is improved due to a variety of medical devices. In such equipment, concepts of physics are applied for design and development. In the healthcare field, medical physicists are found in various departments of hospitals for quality patient care in oncology, radiology, nuclear medicine, audiology, cardiology, physiological monitoring, and others. As the geriatric population progresses, the need for novel solutions to manage age-related diseases increases especially related to nuclear medicine. To combat this, intense design and development in medical devices are important for ontological treatment using radioisotopes in chemotherapy and radiation therapy. This ultimately leads to suboptimal treatment outcomes necessitating long-term care. Physics involved in the above treatment procedures and ontological equipment is very important to decode in the healthcare field.