63,895,000,000. That is how many rupees are expected to be spent by healthcare providers in India on devices, telecom services, data centres and information technology (IT) in 2015 alone, according to Gartner.
Medical electronics is a lot more exciting now, with electronic components that resorb after use as well as stents that sense blood flow and temperature that these then transmit for analysis and storage. This article gives you a glance at the electronics behind the scenes—components, devices, standards and other elements that power these innovations to life.
Imaging and diagnostic applications
In the east, China’s Nanjing University is working on an acoustic diode technology that could improve the performance of ultrasound systems. Similar to the usual diodes that allow current only in one direction, this diode allows sound in just one direction, thus eliminating acoustic disturbances caused by sound waves going in both directions.
Another recent addition for those into designing ultrasound systems is the availability of production processes and tools for full-scale capacitive micromachined ultrasonic transducers (cMUTs). These allow ultrasound imaging to enjoy higher lateral and axial resolution, higher speed and even real-time 3D imaging for diagnostic applications for areas such as ophthalmology and dermatology.
On the other side of the planet, University of Michigan’s Wireless Integrated MicroSensing and Systems (WIMS2) Centre has made progress in its work on magnetoelastic sensors. By applying the devices into the circulatory system and bile ducts it is able to detect biliary sludge on a stent in the bile duct or tissue accumulation on arterial stents in cardiology.
EBR Systems has developed an implantable externally-powered grain-sized pacemaker called Wireless Cardiac Stimulation System (WiCS). It allows for bi-ventricular pacing where a traditional pacemaker paces the right ventricle and EBR WiCS electrode paces the left ventricle.
Transforming the data collected above into graphical form can be done using embedded graphics solutions like AMD Embedded Radeon HD 7850 GPU. Based on Graphic Next Core (GCN) architecture that accelerates medical imaging, it provides three times improved performance with detailed medical image visualisation and other advanced graphics-driven capabilities.
Detecting substances
CAP-100 capacitive liquid level sensor from Gems Sensors & Controls allows level sensing through a wide variety of materials. These compact sensors can detect substances like waste, reagent, buffer or diluents, which would be useful for vessels containing bio-hazardous liquids in a sealed container. These can also be calibrated for use as proximity sensors.
Some manufacturers are also looking at making their components more rugged, such as FlexiForce Sustained Stability Series 301 from Tekscan. Made from pressure-sensitive ink, these can withstand and measure force and pressure in a wider range of environments. It is claimed that reducing drive voltage or feedback resistance can extend the range further.
Other novel uses include the use of temperature sensors to ensure the best application of treatments in dermatology. One example is where SynerionVelaShape III uses Exergen’s non-invasive infrared (IR) temperature sensor placed inside the applicator to continuously monitor skin temperature, while allowing the treatment to continue unhindered.
Moore’s Law keeps driving integration
For more integrated components, Honeywell’s HumidIcon digital humidity and temperature sensors integrate multiple functions in a single compact package. These can be used in respiratory therapy, medical incubators and medical micro-environment applications.
Engineers at Georgia Tech Research Institute have designed a sensor that can detect chemical vapour using its package of three sensors and a radio frequency identification (RFID) chip. Current design of the chip requires power from an incoming signal beam to enable sending data out, but researchers hope future models would be able to use ambient energy.
Engineers usually have to face difficulties when building systems out of separate pump motors, gearboxes and drives due to design complications and uncertainty that comes with separate components. With the aim to reduce the cost for engineers at original equipment manufacturers, Watson-Marlow Pumps Group has brought out a brushless DC gear motor with a fully-integrated speed controller that can be used in medical devices.
Building systems enabling better healthcare
The Internet of Things (IoT) is driving the creation of Web-connected medical devices that keep track of your health and medication, prompting your doctor about potential threats or medical events. One such device is Vaica’s SimpleMed+ medication compliance device that uses Telit Wireless Soltuions’ GC864-QUAD V2 for mobile connectivity that allows quad-band connectivity using a mobile network.
In March 2015, Redbend and Telit also announced their partnership that allows designers to avoid IT integration at their end if they use the hosted service to manage their machine-to-machine (M2M) devices.
Also interesting is an electronic patch designed by Sensium that can check a patient’s vital signs every two minutes and wirelessly send it to authorised medical devices. The patch itself is a low-power 915MHz wireless unit that can measure heart rate, respiratory rate and auxiliary temperature.
Maxim Integrated launched a reference design for sensing galvanic skin response (GSR) in mobile medical and fitness applications with improved accuracy. Offered in a wristband form factor, MAXREFDES73# includes body surface temperature readings, Bluetooth communications and a rechargeable battery that lasts up to one week on a single charge.
Google Glass could be helpful
Electronic health records blended with wearable electronics show promise to enable doctors to improve the time they spend with their patients. Texas based Pristine’s app EyeSight lets doctors transmit live video of wounded patients from Google Glass to computers and phones.
There is also Augmedix, a system that would roughly translate information from Glass’s audio-visual stream directly into a patient’s medical record. And Healium is developing an app that would let doctors share patient information through Glass.
There is also some buzz about a helmet-borne system developed by Vijay Varadan and his research team at University of Arkansas. It lets you detect brain injury using a network of flexible sensors. Collected data is then sent through ZigBee and Bluetooth to a receiver.
In 2014, Novartis also announced that its eye-care division, Alcon, would soon license its smartlens technology for all ocular medical uses. This technology involves the use of non-invasive sensors, microchips and other miniaturised electronics that are embedded into the contact lens. A LinkedIn search on Alcon showed the profile of an electronics and software lead engineer at Alcon, which had Institute of Electrical and Electronics Engineers (IEEE) 802.15.6 standard listed. What is that?
LAN, WAN and, now, BAN
After local area network (LAN) and wide area network (WAN), you now have body area network (BAN). Also known as body sensor network, this is effectively a wireless network of wearable computing devices and implantables.
IEEE 802.15 Task Group 6 (BAN) is developing a communication standard optimised for low-power devices and operation on, in or around the human body (but not limited to humans) to serve a variety of applications including medical, consumer electronics, personal entertainment and others.
New memory for wearables
Targeting such wearable devices for applications like hearing aids, pulse meters and activity trackers, Fujitsu has introduced their new 1Mbit serial ferro-electric random access memories (FRAMs). The new FRAM memory delivers 77 per cent reduction in surface mount area, apart from contributing to longer battery life by minimising power consumption during write operations. The FRAM developed by Cypress is immune to corruption by magnetic fields and radiation, thus allowing for its use in medical wearables for capturing data instantly with complete security.
Maxim’s newly-designed gamma resistant non-volatile memory based on 1-wire technology allows calibration of consumable medical sensors, tools and accessories to their host medical instrument in the field.
Meeting standards
Got an amazing idea for a wearable device that you believe will change the world? Figured out all the hardware and software design, too? If you want to see your device enter the market and start selling, you have to ensure that it meets medical standards. Do not despair though, because Shreekant Pawar, co-founder and CMO at Diabeto, has just the advice you need.
“When we were developing Diabeto, in the early stages, we were completely unaware of medical standards; we did not even know what standards were. Only when we developed the first prototype, one investor asked us if our design was according to the standards. Just like us, many medical devices start-ups are completely unaware about the prevailing medical standards,” says Pawar.
He explains that, broadly there are two types of standards, namely, vertical and horizontal. Typically, a vertical standard is specific to a product or a device, while a horizontal standard applies to a wide range of devices. International Organization for Standardization (ISO) 13485 and ISO 14971 are examples of the most important horizontal standards that are widely used.
ISO 13485 is optional, but is considered the de facto standard for companies that sell in Europe. One good thing about ISO 13485:2003 is that, it is made specifically for medical devices and is accepted worldwide, except the USA. The US FDA follows a different system. Having said that, there is 90 per cent overlap between ISO 13485 and the US FDA system.
ISO 14971 covers risk management. Your device needs to pass all possible scenarios or operation modes in which there is a failure situation.
Pawar explains that, “As a medical device designer, one needs to be absolutely clear with two documents/standards, IEC 60601-1 and IEC 60601-1-2. If your device adheres to these documents, you would be what they usually call 601 compliant. The 601 standard is primarily for electrical safety and electromagnetic compatibility (EMC). If your medical device is using an external power supply, or even a step-down transformer, it needs to be 601-compliant as well. For EMC, testing needs to be rigorous to ensure that your device not only functions but also keeps functioning even with electromagnetic interference.”
“There are two main safety approvals for power supplies. Information Technology Equipment (ITE) IEC 60950-1 and Medical Electrical Equipment (MEE) IEC 60601-1. There is also ISO 13485 certification, which states requirements for a comprehensive system of manufacturing of medical devices,” says Chris Jones, product marketing director of Artesyn Embedded Technologies. IEC 60601-1 is a safety standard for medical electrical equipment, whose third edition includes general requirements for safety as well as essential performance.
The software and firmware that goes in your medical device programming is also regulated. These are broadly classified by two testing approaches that are driven by simple code and complex code. For simple code, refer IEC 60601-1 Annex H, and for more complex code driven firmware, check IEC 62304 document.
“Making your medical device is a complicated and time-consuming process, and care should be taken to befriend these standards right from the prototype-design phase. Once the device is designed keeping standards in mind right from day one, the process becomes simpler, linear and cascading,” adds Pawar.
Securing your body
Of course, with wireless access comes the possibility of hacking. This could be especially painful now that the devices are on your body.
Barnaby Jack was someone who had already demonstrated how it was possible to hack a diabetic’s insulin pump to deliver a fatal dose as well as how to hack a pacemaker from 15 metres away and get it to deliver an 830-volt jolt to the user. Unfortunately, he was found dead under suspicious circumstances a week before his scheduled demonstration at a major black hat convention with cyber security experts at Caesar’s Palace. So, how can this problem be solved?
The knee-jerk response would be what former US vice president Dick Cheney’s doctors did. They disabled his pacemaker’s wireless connectivity to thwart possible assassination attempts. More thought-out approaches include mobile medical device benchmark initiative that was implemented by Centre for Internet Security, whose resulting benchmarks are recommended as guidance for device makers to harden a device’s security.
Indeed, there are embedded cryptographic co-processors that come with processors like Cortex-M4 based STM32F479 to power applications requiring high security. A cryptographic co-processor is a hardware module specialised for encryption and related processing to prevent unauthorised retrieval of data. However, can chips like these solve the problem single-handed? Probably not. Jack had also added that many hospitals are using out-of-date software as they are afraid of running foul of regulations such as those formulated by the FDA. As a result, it is known that malware is rampant on hospital networks.
It looks like healthcare technology advances have gotten us to the stage where you do not need to worry that much about contracting a biological infection, but you do need to worry a lot about infecting yourself (and your devices) with malware.
