Chapter 1: Introduction

Martin Culjat

Center for Advanced Surgical and Interventional Technology (CASIT), University of California, Los Angeles, CA

1.1 History of Medical Devices

The fields of medicine and surgery are as old as the origin of man. There are surviving records of medical procedures and theories dating back thousands of years, from the ancient Egyptians to the Babylonians, Hebrews, Indians, Chinese, and Greeks. Internal diseases were poorly understood and often blamed on supernatural beings and treated by medicine men during religious ceremonies. External injuries and diseases, on the other hand, were often treated surgically with techniques developed independently by multiple civilizations, some using concepts similar to those used currently. Application of dressings to wounds has been nearly universal throughout the history of man, with recorded evidence of the usage of leaves, clay, tar, bark, snow, sand, down feathers, and animal hides (Bishop, 1960). Both cobwebs and heated cautery irons have been used to control bleeding in multiple cultures, and suture needles have been developed using tools such as bone splinters and thorns. Insect jaws have been used as sutures in at least three continents, typically by encouraging a termite to bite through the wound with its powerful jaws and subsequently removing its body. Fracture fixation has been practiced by many civilizations, using materials such as hardened animal hides, clay, and wood. Many other early surgical tools have been discovered across the world, such as bark and feather quills for wound drainage and cleaning by the North American Lakota Indians, as well as bamboo, shells, sharks' teeth, and bones as surgical scalpels in New Britain in the South Pacific. Relatively modern embodiments of surgical tools were used as far back as Roman times, with metal forceps, scalpels, speculas, surgical needles, urinary catheters, and cautery irons discovered in the buried ruins of Pompeii, dating from the first century CE (Greenhill, 1875).

The Middle Ages was a relatively slow period in the advancement of medical tools and interventions. More significant was the increasing study and understanding of anatomy, physiology, pharmacology, surgery, and other fields relevant to medicine. These advances were particularly evident in the Middle East and Europe, where comprehensive texts were written on these topics, often to be lost, rediscovered, and translated. Persian and Arabic physicians were credited with many significant achievements in medicine during the Islamic Golden Age from the eighth century CE until the Mongol invasions in the thirteenth century. In Europe, the birth of universities in the twelfth century and the Renaissance in the fourteenth century likewise encouraged the study and advancement of medicine. Consequently, surgical and patient care techniques slowly began to improve, leading to better patient outcomes. These improvements began to accelerate in the nineteenth century.

Before the nineteenth century, surgery was largely performed without anesthesia, in nonsterile environments, and without the benefit of preoperative visualization of internal anatomy of the patient. The introduction of analgesics such as ether and chloroform in the 1840s was a major advance, as patients were no longer subjected to tremendous pain while conscious, and surgeons were able to perform longer and more complex procedures. Before this time, the best surgeons were often those who could operate the fastest, and surgery was mostly limited to a few procedures, such as bladder stone removal, vessel ligation, leg amputation, and excision of superficial tumors (Tilney, 2011). The acceptance of asepsis, or sterilization, in the late nineteenth century significantly reduced postoperative deaths, which had often occurred at hospitals in as many as 80% of patients. The discovery of the X-ray in 1895 and the subsequent birth of radiology enabled physicians for the first time to study the anatomy of the body. Together, these achievements transformed the surgical discipline and led to a rapid expansion of interventions that could be successfully performed.

Throughout history, war was a major catalyst for advances in medicine and surgery, allowing physicians and surgeons to practice and popularize experimental tools, drugs, and techniques, many of which still benefit the global population at present. The introduction of firearms and canons in the Battle of Crécy in 1346 and machine guns in the 1870 Franco-Prussian War underscored the need for improved battlefield care, as these weapons led to more severe wounds, more rapid infections, and deaths due to tetanus (Tilney, 2011). The Crimean War in the 1850s highlighted the poor conditions on and off the battlefield, where large armies were used and the wounded were cared for in overcrowded, unsanitary conditions. During this war, five out of six deaths resulted from cholera, dysentery, and malaria, and above-knee amputations had a 90% mortality rate because of infection. Typhus, typhoid, and dysentery caused two-thirds of deaths in the American Civil War, and many others died from wound infections. However, this period of warfare also saw the introduction of nursing teams, the foundation of the Red Cross, improved surgical techniques, and the occasional use of analgesics and antisepsis. World War I saw significant improvements in asepsis, successful abdominal and plastic surgery techniques, the introduction of blood transfusions, and large-scale immunization of soldiers against typhoid. World War II led to improved burn management, use of blood banking and intravenous fluids, a better understanding of pharmaceuticals, and the standardization of care. Introduction of plastic fluid bags, tubing, and tools following World War II was a major development in asepsis, as contamination from patient to patient was virtually eliminated.

In the twentieth century, advancements in antibiotics, pharmaceuticals, and anesthesia improved outcomes for patients worldwide and brought modern medicine to a more global population. At the same time, innovations in materials, manufacturing, electronics, and computing accelerated the use of technology in medicine and led to the birth of the medical device industry. Some notable technological advances in the twentieth century include electrocardiology (ECG) (1903), stereotactic surgery (1908), endoscopy (1910), electroencephalography (EEG) (1929), dialysis machines (1943), disposable catheters (1944), defibrillators (1947), ventilators (1949), hip replacements (1962), artificial heart (1963), diagnostic ultrasound (1965), balloon catheters (1969), cochlear implants (1969), laser eye surgery (1973), positron emission tomography (PET) (1976), magnetic resonance imaging (MRI) (1980), surgical robotics (1985), and intravascular stents (1988) (Challoner, 2009).

Recent technological innovations have spawned entirely new approaches to surgery. For example, traditional open surgeries that are associated with large incisions and extensive patient trauma have recently began to give way to minimally invasive techniques, such as laparoscopy. In these procedures, small “keyhole” incisions are made on the patient's body, significantly reducing trauma and recovery times. Precision tools have been developed to operate through these small openings and allow clinicians to perform an array of tasks from outside of the body. Interventional devices, such as catheters, are now commonly fed deep into the vasculature from needle incisions in the skin to deliver medication, measure pressure, or widen obstructed blood vessels. Some techniques, such as tissue ablation, can now be performed either laparoscopically, with a catheter, or even noninvasively from outside of the skin surface. Many minimally invasive procedures have already began to move toward robotic control or automation.

Implantable devices have also continued to mature. The use of new biocompatible and nonthrombogenic materials and coatings has led to vast improvements in a range of implant technologies, from coronary stents to hip replacements and cardiac assist devices. Computer-aided design, finite-element modeling, and precision machining have enabled implant designers to better customize implantable devices for individual patients or conditions. Likewise, miniaturization of electronics, improved battery technologies, and advanced telemetry systems have enabled the implantation of robust sensing and stimulation systems, such as cardiac pacemakers, deep brain stimulators, and cochlear implants.

Some of the greatest changes in modern medicine have occurred in the field of imaging. Improvements in 3D imaging techniques, such as computed tomography (CT) and MRI, have given clinicians an unprecedented view of patients' internal anatomic and pathophysiologic processes. In addition to facilitating diagnosis, imaging techniques have been adapted to guide interventions, facilitating more targeted and less invasive delivery of therapy. A current trend is an increased use of image fusion, or the combination of multiple imaging technologies. These techniques merge data from disparate sources such as ultrasound, MRI, CT, and PET, to give a more complete picture of a patient's disease state. Image fusion can be used as a preoperative, intraoperative, or postoperative tool in fields such as neurosurgery and prostate surgery.

All of these technological advances have led to rapid worldwide growth in the medical device industry. At present, the global medical device industry has estimated worldwide sales greater than $300 billion (Zack's Equity Research, 2011). The US medical device market is the world's largest market, with an estimated value greater than $105 billion in 2011 (Espicom Healthcare...