This article reviews a system that is in need of repair in the United States, and engineers are uniquely equipped to help fix it. Although the expenditure per capita on healthcare in the United States is higher than in any other country, the current US healthcare system cannot be sustained, and major improvements are needed. Lives unnecessarily lost each year in the United States due to medical errors are estimated to be as high as 98,000 and injuries over a million. The healthcare system is currently facing many problems and challenges, including rapid changes in medical technology and practice, severe shortages in skilled healthcare workers, and an aging population with increased incidence of disease and disability. The cyber infrastructure will facilitate technology-based, distributed delivery of health services, as well as training and lifelong learning for healthcare workers. It can evolve into an electronic care continuum with pervasive access to global, accurate, and timely medical knowledge for individuals about their health needs in an era of rapid change and expanding knowledge.
Healthcare is the largest industry in the United States. The national expenditure is estimated to be $2.17 trillion in 2006, about 16.5 percent of gross domestic product, and is expected to exceed $4 trillion, or 20 percent of GDP, by 2015.
Although the expenditure per capita on healthcare in the US. is higher than in any other country, the current U.S. healthcare system cannot be sustained, and major improvements are needed. Lives unnecessarily lost each year in the US. due to medical errors are estimated to be as high as 98,000 and injuries over a million. An estimated 30 to 40 percent of healthcare expenditures go to inefficiencies involving duplication, system failures, unnecessary repetition, and poor communication.
In the last decade, intense effort has been devoted to addressing healthcare costs and quality at various levels. Major new initiatives have been proposed by governments and healthcare organizations in the US. and other countries.
A report in 2005 by the National Academy of Engineering emphasized the need for partnership of engineering and health care to meet the six goals of the 21 st century healthcare system identified in 2001 by the Institute of Medicine in Washington, D.C. The IOM said the system must be safe, effective, patient-centered, timely, efficient, and equitable.
The healthcare system is currently facing many problems and challenges, including rapid changes in medical technology and practice, severe shortages in skilled healthcare workers, and an aging population with increased incidence of disease and disability. Until now, attempts to address these problems have added to the complexity and cost of healthcare, and provided, at best, marginal improvements in services.
In short, the U.S. health care system needs to be re-engineered. We mean that literally, because many of the tools and facilities developed in the practice of engineering can be applied to make major improvements to the healthcare delivery system. As in so many other industries, the contributions of engineers can advance the state of the art of medical care.
Applying dynamic modeling of healthcare delivery can analyze the system as a supply chain, without duplication of services. Artificial intelligence-based decision support and risk management systems can aid clinical decisions under uncertainties. Application of Six Sigma and other management tools can improve the quality and process of care.
Engineered devices-the heart pacemaker, the defibrillator, the cochlear implant, and other marvels have improved and extended the lives of millions. Medical device engineering has given rise to the field of biomechatronics, which merges the human with the machine. It is an interdisciplinary field encompassing biology, neurosciences, mechanics, electronics, and robotics.
Biomechatronic devices have been developed that interact with human muscle, skeleton, and nervous systems with the goals of restoring human motor control impaired by trauma, disease, or birth defects. Devices include artificial limbs, such as the Rheo Knee System from Our and Boston Digital Arm System from Liberating Technologies Inc., and neural prosthetic devices in development at the University of Southern California and elsewhere.
Most biomechatronic devices have four components. Biosensors detect the user's intentions. These may be wires that detect electrical activity or solid-state electrode arrays with nerves growing through them. Mechanical sensors measure information about the device. A controller is the interface between the user's nerve or muscle system and the device. It relays and interprets feedback information from the sensors to the user. The actuator is an artificial muscle that produces force or movement.
Future biomechatronics applications may eventually include pancreas pacemakers for diabetics. Initial in vitro studies have shown that circulating insulin concentrations oscillate in regular fashion. Only high-frequency oscillations, every 5 to 17 minutes, were observed, suggesting that they derive from a primary pancreatic source. Researchers also foresee mentally controlled electronic muscle stimulators for stroke and accident survivors, as well as miniature cameras and microphones that can be wired into the brain, allowing blind people to see and deaf people to hear.
Robotics, meanwhile, can improve clinical procedures and provide innovative approaches to clinical problems. Robots can serve as carriers, porters, and helpers. The precision and repeatability of robotic systems can aid physicians in performing surgery. Robots are also suitable for noninvasive and minimally invasive surgery.
The first robotic-assisted surgery dates back to the mid-1980s. A robot, the Puma 560, was used to place a needle for a brain biopsy using CT guidance. Further advances led to the development of the commercial da Vinci Surgical System, which was used in 1998 in Germany to perform the first robotic-assisted heart bypass. The first unmanned robotic surgery took place in May 2006 in Italy.
Future surgical robots will be lighter, smaller, simpler, and cheaper. They will be integrated, with other smart instruments, in hospital operating rooms to form plug and play systems.
Diagnostic applications of medical robots include capsular endoscopy for noninvasive diagnosis of the gastrointestinal tract. That is, there may one day be camera pills for detecting colon polyps.
Robots are being explored as an adjunct to physical therapy. Other applications include robotic legs, arms, and hands, both as prosthetic devices and as exoskeletons. Engineering challenges for future robotic devices include designing them to become autonomous with a sense of their environment. Autonomous wheelchairs and robotic-assisted walking devices, for example, could provide home care, help the elderly move around, or guide blind people. Portable surgical robotics, coupled with advanced telecommunications and telepresence facilities, will provide healthcare and telementoring services in remote areas, war zones, and, possibly, future human space missions.
A Family of Digital Humans
The Visible Human Project, which dates back to the late 1980s, is the first major effort to create a detailed digital data set of cross-section photographs of the human body, in order to facilitate anatomy visualization applications. The activity was carried out by the U.S. National Library of Medicine. Since then a number of digital human projects have been initiated. These efforts include the Defense Advanced Research Projects Agency virtual soldier, the NASA digital astronaut, the University of Calgary CAVEman, the Physiome Project, and the virtual physiological human.
The Virtual Soldier project aims at producing complex mathematical models to create physiological representations of individual soldiers, which can help in the automatic diagnosis of battlefield injuries, prediction of soldier performance, evaluation of nonlethal weapons, and virtual clinical trials.
The goal of the digital astronaut project is to predict the effect of various events on humans during a space mission, including the effectiveness of multiple simultaneous countermeasures designed to maintain an appropriate standard of health.
The CAVEman is a 4-D human atlas that has more than 3,000 distinct body parts catalogued by the computer. It is built upon data from basic anatomy textbooks, and shows every vein, artery, and internal organ of a human male. The project is intended to help medical researchers investigate the genetics of various diseases, and new approaches to targeted treatments.
The Physiome Project is a worldwide effort organized by the International Union of Physiological Sciences and funded by the National Institutes of Health and other organizations. It aims at creating a complete digital representation of the human being, from DNA through the whole body function, in order to provide better understanding of the integrative functions of cells, organs, and organisms. This is being attempted through the development of computational models, data bases (linking experimental information and computational models from several sources), and a numerical simulation framework that enables the integration of multiple physics and spatiotemporal scales in modeling a physiological human system.
Related to the Physiome Project is the Virtual Physiological Human, which is a major multidisciplinary project initiated by the European Commission aimed at developing an integrated system of high-fidelity models of human physiology and pathology at multiple levels (from molecular and genetic to tissue and organ). It also includes computational, solid body models of the human anatomy, along with data and algorithms for coupling the different models.
This ambitious project is expected to help in creating a new environment for better healthcare. The project can also serve developers of products that exchange forces with the human body, including cars, sporting gear, and body armor.
Management and Modeling
As vast as the possibilities of engineered devices may be, there is more that engineering can offer to the practice of health care.
Management technologies developed for complex engineering systems can be used to improve the quality and reduce the cost of healthcare services. The engineering world is familiar with product lifecycle management, product data management, earned value management, and risk management. The concepts are not foreign to medicine, but may deserve wider application.
Computer-based modeling and simulation already provide a realistic and economical set of tools to improve and maintain the skills of health care providers, adding a valuable dimension to medical education, training, and research. In training simulations, the learners can practice tasks and processes in life-like circumstances using digital models, with feedback from observers, peers, and video cameras. They can review and practice procedures as often as required to reach proficiency, thereby ensuring patient safety and decreasing overall healthcare costs.
Within the last decade, modeling and simulation. technology has been implemented successfully in training that addresses a variety of procedures across medical and healthcare specialties.
Current healthcare modeling and simulation activities cover a broad spectrum ranging from health care management to biomedical, molecular, pharmacologic, and disease modeling, to simulations of clinical, emergency, and operating room procedures, and multilevel simulation of the human anatomy and physiology. There have been simulations of patient flow-outpatient scheduling, inpatient scheduling, and admissions-to reduce waiting times and ensure the best use of expensive resources. Biomedical simulations include simulation of transmission and control of diseases.
Simulation of clinical and robotic procedures is used in training to improve surgical skills. It makes it possible for a surgeon to rehearse on a model of the patient to plan a surgery. A virtual operating room was developed by researchers from Old Dominion University and Eastern Virginia Medical School to serve as a platform for incorporating human factors in the simulation, and identifying sources of error in the medical service system, without putting the patient at risk.
Several multidisciplinary activities have been devoted to the integrative, multilevel modeling and simulation of human anatomy and physiology.
The concepts of hierarchical models and network representation of complex engineering systems comprising distributed, functionally interrelated, and communicating components can be applied to the human body. All the biological components of the body, from individual genes to entire organs, work together as a complex system to promote normal development and sustain health. Network representations can be used to understand the array of intricate and interconnected pathways in the human that facilitates communication among genes, molecules, and cells.
Future advances in high-fidelity models of human physiology and systems biology, and the discovery of indicators of physiological or disease processes (for instance, that genes can indicate diseases before systems do) can significantly enhance disease prognosis and prediction of response to therapies.
The engineering applications of nuclear and radiation phenomena date back to the second half of the 20th century. Nuclear medicine, a branch of medical imaging and treatment that uses the nuclear properties of matter in diagnosis and therapy, is a major contributor to the vitality and health of society. Nuclear imaging differs from most other imaging modalities in that the tests primarily show the physiological function of the system being investigated as opposed to the anatomy, as in X-ray computed tomography or magnetic resonance imaging.
Nuclear imaging equipment typically uses gamma cameras, with a gamma-ray detector, and an image reconstruction technique, such as positron emission tomography or single photon emission computed tomography, or SPECT. These nuclear imaging scanners are capable of detecting areas of molecular biology detail, even prior to anatomic change.
Recently, functional magnetic resonance imaging, usually called fMRI, has become a major way to assess brain function, and it has effectively replaced the PET scan for functional brain imaging. Following fMRI, Denis Le Bihann in Paris has demonstrated a diffusion tensor imaging technique, which observes anisotropic diffusion along nerve channels. A representation of nerve fiber distribution is obtained in the living brain, which enables the mapping of the structural aspects of brain anatomy. Further improvements in medical imaging may focus on sharpened resolution, laser-based patient positioning, and autonomous 3-D image reconstruction and interpretation.
Nuclear therapies include the old radiation therapy, in which ionizing radiation is used to control malignant cells as part of cancer treatment. Newer procedures include radioisotope therapy, delivered through infusion into the bloodstream or ingestion; radio surgery, which allows noninvasive brain surgery by means of directed beams of ionizing radiation, without opening the skull; and proton therapy, which has the ability to accurately target and kill tumors by directing protons to the tumor site.
Through developments in radiopharmaceuticals and other technologies, nuclear medicine is gradually developing toward the stage of molecular imaging and therapy procedures. Imaging on the molecular level may one day show precise details of a disorder and provide new information for diagnosis. Molecular therapy would directly target molecules in diseased tissue and bypass normal tissue to avoid the toxic side effects of many current therapies. The aim is to create safe, painless, and cost-effective techniques to image the body and treat diseases.
Neural Prosthetic Devices
Neural prosthetic devices are the result of biomechatronics research, which attempts to find artificial extensions to the body that restore, or supplement, functions of the nervous system lost during disease or injury. Neural prosthetics allow disabled persons to control their own bodies and lead fuller, more productive lives, and can be divided into three categories: sensory, motor, and cognitive prosthetics.
Sensory prosthetics restore a sensory function, through delivering input to the nervous system. They include auditory, visual devices, and prosthetics for pain relief.
Motor prosthetics are devices that support the function of, and deliver output from, the autonomous nervous system. They include the heart pacemaker and bladder control implants.
To date, success has been realized in the development of cochlear prosthesis, which bypasses damaged hair cells in the auditory system by direct electrical stimulation of the auditory nerve, and deep brain stimulation, which has been useful for some patients in reducing the motor symptoms associated with Parkinson's disease. Also, an international team supported by the Defense Advanced Research Projects Agency and led by the Applied Physics Lab of Johns Hopkins University has developed a prototype of the first fully integrated prosthetic arm that can be controlled naturally and provide sensory feedback. It allows a level of control beyond the current state of the art for prosthetic limbs.
Future challenges include developing motor prosthetics for conscious control of movement, as well as neurally controlled limbs that will perform, look, and feel like natural limbs. For example, improving walking for individuals with stroke (by eliminating "foot drop"), restoring hand and arm function in individuals with quadriplegia, restoring standing and walking for individuals with paraplegia, and controlling bladder and/or bowel function in persons with incontinence.
Cognitive prosthetics aim at re storing a cognitive function by replacing circuits within the brain damaged by stroke, trauma, or disease. Work has begun at the University of Southern California on developing a prosthetic device that can mimic the function of the part of the brain responsible for the formation of memories.
IT for Health
The synergy between information technology and medical services has opened new possibilities in care delivery and healthcare system performance. Health information technology consists of tools and facilities used to manage and process data, information, and knowledge to inform the decisions of providers and patients. Electronic records can make health information available when and where it is needed. E-prescribing computerized order entry by physicians-can minimize medical errors and improve safety.
Since information technology is considered pivotal to improving the quality and reducing the cost of healthcare, several public and private programs have been directed to building the infrastructure for it. They include the Nationwide Health Information Network planned by the office of the IT coordinator of the U.S. Department of Health and Human Services. Four prototype architectures of NHIN were completed in January 2007 by consortia led by Accenture, Computer Sciences Corp., IBM, and Northrop Grumman. The next step is to connect the prototypes and the state and regional health information exchange efforts in trial implementations that will make up the networks of networks of the NHIN.
Information technology can also help in personalized healthcare, where the best treatment and prevention are provided for each patient, based on highly individualized information. IT is also a key enabler of both cybermedicine (the application of the Internet and networking technologies to medicine and public health), and telehealth (the remote delivery of health-related services via telecommunications technologies).
Toward a Healthy Future
Emerging and breakthrough medical engineering, and spinoff technologies provide the engineering profession with new opportunities and challenges for re-engineering healthcare. We see the possibility of a digital convergence of genomics, multilevel modeling and simulation, robotic devices, new materials, ultra wideband optical networks, integrated distributed sensing and actuation, and healthcare information that promises a new pervasive healthcare landscape.
The realization of smart engineering healthcare systems requires, among other things, the accelerated development of novel medical devices, as well as the creation of an ambient intelligent environment that enhances innovation, stimulates discovery, and facilitates incorporation of new technologies. An engineering health care cyber infrastructure is needed to encompass the acquisition, generation, fusion, dissemination, and application of information pertaining to biomedical and engineering healthcare technologies.
Novel medical devices range from molecular and biophotonic imaging machines to minimally invasive and noninvasive surgical devices; from tools for microsurgery to intracellular nanosurgery instruments; from camera pills to labs on chips and nanodevices that can roam the bloodstream to prevent infections.
The ambient intelligent environment will enable the integration, interoperation, and networking of the devices through the use of high-confidence software systems. It will enhance the safe device operation through the use of natural, intuitive, multimodal human-device interfaces.
The cyberinfrastructure will facilitate technology based, distributed delivery of health services, as well as training and lifelong learning for healthcare workers. It can evolve into an electronic care continuum with pervasive access to global, accurate, and timely medical knowledge for individuals about their health needs in an era of rapid change and expanding knowledge.
For More Information
Readers interested in pursuing the subject covered in this article will find links to more information at http://www.aee.odu.edujintelligentenghlth.
The Web site, created as a companion to Mechanical Engineering magazine's November Feature Focus, contains links to material on healthcare technologies and has continuously updated information feeds. There are also links to other online services and features of the Center for Advanced Engineering Environments at Old Dominion University.