Medical Technology, the application of science to medicine to provide practical solutions to problems normally raised by clinicians with defined medical needs. The products of this technology are engineered and manufactured to facilitate a number of rapidly developing techniques in medicine and to provide safe, reliable performance in clinical practice. While most of the developments have been made and applied in developed countries, medical technology has had far less of an impact in developing countries, as their health-care services are more dependent on locally chosen personnel and less on expensive medical devices. In developing countries the importance is also on prevention of disease rather than its diagnosis and treatment. Traditional medicine and medical techniques are encouraged, health care is regarded as a local matter and is better suited to the rural areas of the country where the majority of the population live.
II. DEVELOPMENT OF MEDICAL TECHNOLOGY
The revolutionary medical discoveries made in the 19th and 20th centuries in human anatomy and physiology, causes of disease, drugs, and therapeutic procedures transformed medical practice, which had been generally restricted to folklore medicine, often guided by religious and cultural beliefs. With the rise of modern empirical science, medicine became multi-disciplinary, and aimed at the prevention and treatment of disease and the maintenance of health. For example, purpose-made incubators to aid the survival of newborn and premature infants were already in use in Europe before the end of the 19th century. However, although the impact of this technology was initially small, demand for this type of intensive care grew; with the development of successful methods for providing respiratory support and an advanced monitoring system, prenatal and infant mortality rates in most Western societies fell dramatically throughout the 20th century.
III. DIAGNOSTIC TOOLS
Devices to monitor body functions include the air pump sphygmomanometer for measuring blood pressure; the stethoscope, for listening to sounds within heart and lungs; disposable pressure transducers, for the measurement of intervascular pressure; and, from the 1980s on, digital technology for improvements in signal processing, screen displays, and reliability. The stethoscope and the sphygmomanometer, both 19th-century inventions, are still to be found in the doctor’s surgery, although there will now also be, in hospitals, an electrocardiograph machine, a portable ultrasound scanner, a computerized tomography scanner, and other high-technology medical test equipment.
Since the discovery of X-rays by Wilhelm Conrad Roentgen, their application has expanded the field of radiology, which has played a significant role in medical diagnostics and, ultimately, in health-care and medical treatment. Skin damage as a result of careless use of X-rays led to the early recognition of their harmful effect on human tissue. From this knowledge, and from developments in dose measurement, specialized therapy systems have been developed alongside methods of administering radiation therapy, including improvements in higher resolution; more sensitive detectors; better tube design; direct digital detectors; and film-less radiology.
IV. ADVANCED SURGICAL TECHNIQUES
Many devices come from parallel technologies; for example, video camera, television monitor, and computer can be combined with a rod lens telescope to form a high-definition endoscope video system to help surgeons see inside the patient’s body. These individual devices have been developed as a single practical solution in answer to the clinician’s needs for a system to assist in non-invasive or minimally invasive surgery. Other devices, such as the microscope, originally developed in the 17th century and re-engineered recently with the use of specially adapted lasers, enable the surgeon to perform microsurgery. This is high-precision work such as repairing a detached retina or reattaching the nerves and blood vessels of severed limbs. Great advances in microsurgery have enabled heart surgery, notably heart transplantation, to save the lives of thousands of people who formerly would have died.
Medical technology is now helping to avoid the need for major surgery. Kidney and gallstones can be broken up in vivo by directing high-energy sound waves at the body (lithotripsy). Major surgery and lengthy rehabilitation for knee injuries can be avoided using arthoscopic surgery. Owing to advances in surgical techniques and drugs, transplants and implants are increasingly successful, with minimal rejection rates and patients regaining a good quality of life for many years. Similarly, continuing development of drugs has helped to lower the risk of second and third heart attacks, without the need for cardiovascular surgery. Cancer treatment with chemotherapy and irradiation, new forms of medication made available through gene therapy, and a greater understanding of the human immune system are rapidly advancing fields. Even though cures for AIDS and many forms of cancer have not yet been found, strides are being made in prolonging life in patients as well as in preventing these diseases.