This is one of the oldest and best established areas in biomedical engineering, based on the study of body from a mechanical perspective, including mechanics of movement and posture, effect of trauma or surgery, strength of bones, tendons, etc. An important area related to biomechanics is bio ergonomics: The study of how systems such as chairs, keyboards, steering wheels, tools, etc., can be designed to minimize physical stress on their user's bodies.
Acquiring information about the body, diagnosis and monitoring requires biologically compatible sensors that can be placed in desired locations- often through implantation. Design and fabrication of such sensors using solid-state devices, enzymes and other biochemical agents is one of the extremely important and active areas of biomedical engineering. Recently, interest in using biological systems such as cultured cells, glucose sensors and genetically modified bacteria, a few examples of biosensors, have found great pace.
Bio-MEMS / Nanotechnology:
Micro-electromechanical systems (MEMS) and nanotechnology are the two most promising methods for creating microscopic implants or injectable used for sensing and drug-delivery design. Two prominent applications for these technologies are "lab on a chip" and injectable probes.
Some of modern technologies of diagnosis rely heavily on instruments such as EKG and EEG machines, monitors for blood pressure, heart rate, etc., defibrillators, scanning systems (e.g., MRI, PET, etc.), dialysis machines, ventilators, endoscopes, etc. Research in this area requires centrifuges, electronic instruments and sophisticated tools for extraction and sequencing of DNA. Training engineers to design, manufacture and maintain such systems is a key focus in biomedical engineering.
Medical Imaging and Scanning:
Aside from the issue of developing and implementing scanning devices like X-rays, ultrasound, MRI, CT, PET, scanning presents very complex challenges in image analysis and interpretation. These include registration, segmentation, feature extraction, pattern recognition and object identification of 2D and 3D images. Developing efficient algorithms and platforms for these applications is a major research area for biomedical engineers and computer scientists.
Biomedical Signal Processing and Systems Analysis:
Signals such as blood pressure, heart rate, EEG, respiration, postural sway, etc., are often monitored over time in clinical situations. Analysis of these time-varying signals provides very valuable diagnostic and often prognostic information. A variety of tools such as Fourier analysis, Statistical analysis, Wavelets transformation, Neural networks, etc., have been applied to automate the processing of biological signals in real-time. Recently, there has been great interest in applying tools for nonlinear dynamics and chaos theory (e.g., fractal dimensions, Hurst exponents, entropies, etc.) to interpret complex biological signals. Methods from systems theory- especially system identification are widely used to model biological systems. Signals and systems is one of the most mature sub-areas within biomedical engineering, and are very accessible to students with basic training in engineering.
Implants and Prostheses:
One of the most rapidly growing areas in biomedical is the development of implantable systems. Neural implants for disrupting seizures, Parkinsonian deficits and cochlear problems are now well-established. In the near future, retinal, and even cortical implants for vision problems will become practical. There has also been great success in developing artificial limbs controlled by the nervous system and using neural signals could also control external objects (such as screen cursors, robots and vehicles). Cardiac implants such as pacemakers are very widely used. As understanding of biomechanics, neuroscience and systems biology advances and nano scale devices become more feasible, there is likely to be an explosion in implants for many applications.
With increased longevity and greater mobility in the population, rehabilitation after trauma, surgery and disease (especially stroke & diabetes) is a major medical problem. The standard practice of physical therapy is now being strongly augmented by prosthetics and orthotics in which a patient is provided with artificial limbs or external supports. Started after the Second World War, making and fitting a prosthesis/orthoses has now become a research interest for many organizations and scientists. Gait Analysis is another important area in which problems such as repetitive motion injuries, slips and arthritis are predicted through continuous monitoring and prevented by providing patients with subsequent measures.
When engineered devices or tissues are incorporated in the body, it must meet stringent requirements to allow their integration into the system. The materials used must be compatible with living tissue in many different ways, and must not interfere with the body's normal functioning. This applies to common implants such as replacement joints and stents as well as to more exotic systems such as scaffoldings for engineered tissue. Thus, the study of biologically suitable materials has become a vast and growing field in its own right.
As understanding of cellular and molecular processes in living tissue has grown, it is becoming feasible to create artificial tissues through biomaterials, called tissue engineering. Typically, tissue engineering involves growing cells on an artificially created scaffolding or matrix. This approach has been used to create artificial skin and cartilage. In the future, advances in stem cell research may allow the engineering of many other tissues, and even organs, leading to a revolution in the treatment of diseases such as diabetes, kidney failure, cirrhosis, lung cancer, heart failure, macular degeneration, and others that can be treated through transplantation.
Bioinformatics (Genomics, Biostatistics, Intelligent Diagnostics, etc.):
Broadly, the area of bioinformatics covers all applications of information technology and computer science to biological and medical problems. This includes statistical analysis of epidemiological data, pattern matching, sequence analysis, genomic modeling and the construction, maintenance, mining and use of biomedical databases. This reflects the fact that methods from information and computer science apply more extensively to genetic and molecular analysis than to any other area of biomedicine --- mainly because genetics and molecular processes are inherently about the representation and processing of information within biological organisms. Bioinformatics is arguably one of the most dynamic and significant areas within the biomedical sciences.
With rapid improvements in communications and medical technology, many developed countries are now improvising techniques to provide competent distance medical services (like surgery, diagnostics and community health services). Referred to as Telemedicine, this technology allows patients anywhere to avail specialized medical expertise available only in limited locations such as major hospitals and research centers. Even in Pakistan, basic level of Telemedicine is now emerging in many institutions and holds great promise for scattered rural populations.
Computational and Systems Biology:
The human body can be understood at many levels, from the molecular level upwards. However it is extremely difficult to organize the enormous amount of experimental data available at all levels into a coherent picture. Systems-level thinking has proved to be of enormous value in this regard. Since all these systems are very complex and even the most valuable, nonlinear mathematical analysis cannot be applied in all situations. This leads to the use of computational/numerical techniques. With computers becoming cheaper and faster, computational biology has become one of the most active areas of biology and biomedicine, and is being used to address all kinds of difficult problems from the nature of cognition to the prediction of heart failure. Advances in nonlinear dynamics, information theory and discrete mathematics have contributed enormously in this regard, and provide a fruitful nexus between engineering and biology.
Molecular and Cellular Engineering:
One of the newest and most exciting possibilities in biomedicine is of manipulating living systems at the cellular and molecular level. Many clinical disorders result from genetic variations or faults in the metabolic reactions, responsible for cellular function. It is increasingly possible to fix these problems by altering the molecules involved, even changing the genetic code within cells. Another application for such manipulation is in creating organisms (typically bacteria) that can act as biosensors or produce valuable chemicals. There is even speculation about designing bacteria that can spontaneously assemble organic circuit components, and there is now a well-developed science of DNA computing that seeks to use the natural molecular processes within cells to perform computations --- much like analog computers of old and all living cells.