FEBRUARY 2012: Electronic devices are increasingly being seen in the field of medicine for diagnosis, therapy and rehabilitation. Medical electronics and electromechanical equipment have become indispensable for the better service of patients not only in hospitals but also outside the hospitals. The service quality of hospitals is often judged by the state of the equipment they have at their disposal.
Consider a few cases to understand the reach and impact of medical electronics on patient care. Surgeons use three-dimensional (3D) body registration systems and high-resolution imaging for cutting into invisible areas. Also, implanted insulin pumps with a closed loop-feedback are capable of automatic fine-tuning of drug delivery, thus cut-ting down the need for diabetics to opt for regular self-tests. Unlike oral psychiatric drugs, implanted stimulators and drug delivery devices focus only on affected parts reducing the risk of collateral damages and side effects.
Today, electronic therapeutic and diagnostic instruments and techniques are blended innovatively for overall improvement in healthcare and devising potential cure for a large number of hitherto incurable diseases. With growing popularity of medical electronics, there is now a growing concern about quality, safety, reliability, cost, liability and regulatory issues.
Design, repair and maintenance
Medical electronics engineering ranges from model-driven embedded software design to PCB design and manufacture, and a large number of inter-related sub-sectors too. It covers a very wide range of technologies including radio frequency, analogue semiconductors, digital and microprocessor chips, digital signal processors, sensors, actuators, electromagnetics, optoelectronics and photonics, displays, embedded software, power supplies and antennae.
The rapid advancement in information technology and healthcare consciousness has accelerated the scope for medical electronics. Fast growth in medical electronics is further influencing various demographic trends like consumers’ expectations of more household medical electronic equipment, enhanced portability of complex imaging and monitoring systems, further miniaturisation of implantable equipment with lower energy consumption, and functional integration of equipment and applications in wireless and network technology.
A large number of hospitals are equipped with high-tech medical equipment but lack trained manpower. This results in long down-time and early classification of equipment as defunct. Rou-tine preventive maintenance is required to ensure proper working condition of equipment and applications. The need for special skills to repair and maintain these equipment is realised as hospital technicians normally do not have the expertise and in many cases require special technical skill for rectification.
Quality, safety and reliability
Designing and manufacturing medical electronics equipment for compliance with product safety standards is no easy task. The best way to ascertain a product’s compliance with its governing standard is to get type testing done on sample products by a third-party test house or recognised test lab after the design phase and before the product is launched in the market.
Once a newly designed product has undergone proper compliance testing, the dielectric withstand or hipot test is one of the primary safety tests routinely performed as part of the final production process. This test has long been required on medical electronics products as well as most other electrical devices and appliances before these exit the manufacturer’s production floor. The intention of the test is to stress a product’s insulation beyond what it would encounter in normal use. The end goal is to ensure that patients or caregivers never serve as a current path to ground due to faulty insulation or faulty grounding within the product.
Medical device manufacturers’ concerns are changing due to tighter governmental quality requirements, regulations of agencies worldwide and current legal climates. When designing semiconductor products for medical original equipment manufacturers (OEMs), quality and reliability considerations are paramount and the stakes are high. Enhanced product flows to catalogue processes bring extended product lifetimes as well as well-defined and improved change-control processes.
To meet the demands of the medical market, dedicated and controlled manufacturing lines effectively eliminate facility-to-facility variations, extend qualification practices, improve product traceability, and enhance production testing rigours. Enhanced product flows can also save manufacturers cost and time-to-market by offering an alternative to upscreening, which is commonplace in high-reliability markets. Another way to address these concerns is to adopt portions of ISO13485 (a quality management system) for medical devices as they apply to the semiconductor industry.
With advancement in technology, new medical electronics devices are emerging in all healthcare segments. In hospitals these devices include handheld smart phone-sized ultrasound systems, digital stethoscopes and digital X-ray systems. Outside hospitals there are medical devices that ensure seamless vital sign monitoring with wireless connectivity between the hospital and home. In homes, available today are healthcare systems for daily activity monitoring, blood coagulation test, continuous glucose measurement and insulin delivery.
The latest medical systems deliver faster and more accurate diagnostic information, thus improving quality of life and reducing healthcare costs. A common requirement for all these devices is operation from a battery, small form factor, and a portable and lightweight design with intuitive user interface.
With devices like injectors or inhalers, the pharmaceutical sector is now looking for more electronics integration. This integration can allow it to develop new ways of administering drugs. Injected drugs can be inhaled and delivered through the lungs for improved efficiency, thanks to electronics-assisted devices.
Adding wireless connectivity allows doctors to remotely monitor and control the patient’s compliance, preventing over-dosage. Automatic dose counting can also enable the automatic ordering of drugs from the pharmacy. Such promedical electronic advancements provide pharmaceutical companies with new differentiated benefits.
Medical electronics companies are developing innovative products that allow this industry to offer better quality care at reduced costs. Solutions like telemedicine help reduce the length of hospital stay and eliminate the need for frequent visits to a hospital. Early disease detection through modalities like ultrasound can significantly improve diagnosis.
Multi-disciplinary efforts have revolutionised medicine practices and equipment. The medical equipment should be safe, accurate and stable in data measurement, and efficient in emergency situations. Different systems need to be interoperable ensuring the highest efficiency without compromising on accuracy. Their embedded system should be small and compact and provide access to high-quality, affordable and accessible healthcare, anywhere cost-effectively.
Embedded systems can be applied to a broad range of electronic medical equipment such as X-ray machines, ultrasonic diagnosis apparatus, computer tomographs, heart pacemakers and patient monitoring systems.
As medical designs continue to shrink in size, the design challenges and limitations within medical electronics become more pronounced. Miniaturisation continues to have a huge impact on medical electronics because it drives portability and accessibility. Areas like telemedicine and body area networks are completely dependent on the miniaturisation of medical devices. It gives the ability to save and improve lives worldwide because the right equipment can be easily transported whenever and wherever it is needed.
The research and development work of medical electronics engineers leads to the manufacturing of sophisticated diagnostic medical equipment needed to ensure good healthcare. Biomedical engineering combines the design and problem-solving skills of engineering with medical and biological sciences to improve healthcare diagnosis and treatment. Much of the work in biomedical engineering consists of research and development spanning a broad array of sub-fields.
The core healthcare science and research in medical sciences will have ever-increasing interface with technology areas. To meet these challenges, a new breed of medical professionals is required which is conversant with medical as well as engineering aspects. They will be able to fuse together the medical sciences with high-end technologies.
Medical electronics engineers carry out research along with life scientists, chemists and medical scientists to develop and evaluate systems and products such as biocompatible prostheses (artificial devices that replace missing body parts), various diagnostic and therapeutic medical devices ranging from clinical equipment to microimplants, common imaging equipment such as magnetic resonance imaging (MRI) and electroencephalogram (EEG), biotechnologies such as regenerative tissue growth, pharmaceutical drugs and biopharmaceuticals, medical information systems, and health management and care delivery systems.
Most engineers in this speciality need a sound background in another engineering speciality, such as mechanical or electronics engineering, in addition to specialised biomedical training. Some specialties within medical electronics engineering include biomaterials, biomechanics, medical imaging, rehabilitation engineering and orthopaedic engineering.
While up-integration can increase the functionality achieved with a single integrated circuit (IC), redundant support for critical functions becomes less feasible should that IC fail. Similarly, the number of PC board layers needed to route the traces for the device can increase with smaller bond pitches and tiny wafer chip-scale packages. This can require hidden vias on the board, which create through-hole connections that cannot be visually inspected. The good news is that these tradeoffs can be compensated for, if understood and defined early enough in the development process.
Looking into the future
The worldwide medical electronics market grew an estimated twelve per cent in total sales from $139 billion in 2010 to $156 billion in 2011. In the next five years, the market is expected to grow nine per cent a year, reaching $243.2 billion by 2016. Over the last decade, interesting trends have emerged. Rapidly ageing population in developed countries and the need for basic healthcare in developing countries is quickly becoming a challenge for the healthcare industry. This gives enormous opportunities in medical electronics.
Onyx-II (model 9560) fingertip pulse oximeter
Along with the increasing application of network technologies and mobile terminals in the medical sector, the future of medical electronics will be paved with technologies that allow portability, connectivity and data security. Leveraging these technologies, systems will move quickly from the hospital environment to the home, enabling caregivers from doctors to family members to monitor patients’ biological trends and events. For this to happen, secure infrastructure and feature sets in the monitoring systems are the prerequisites.
Knowledge of analogue and processing solutions, dedication to reliability and continued investments in the market will put companies in a leadership position to help manufacturers of medical devices optimise their designs now and in the future. In order to meet the miniaturisation, high integration as well as low-power consumption requirements of portable medical devices, semiconductor vendors are increasing their investment focus on the research and development of electronic components for portable medical devices.
The adoption of electronics technology, however, cannot be achieved in isolation from other technologies like nano-technology, materials, power sources, sensors and micro-fluidics.
The author is in the department of physics, S.L.I.E.T., Longowal, Punjab