Date: 05/12/2012

Medical Electronics chips: Precision along the signal chain in a single IC is the focus

More integration of complex functions in single semiconductor chip is driving-down both the size and cost of medical electronic equipments. Leading precision analog and SoC chip maker Analog Devices(ADI) is on the forefront of pushing the boundaries in semiconductor research. Tom O'Dwyer, Director of Technology for Healthcare at Analog Devices Inc, in exclusive interaction with EE Herald shares some of the trends in electronics design specific to healthcare.

Q: Do you see a high level of integration in processing of medical imaging in the medical domain? What about precision in analog solutions in the medical sector? Is cost optimization the primary focus?

Tom: Cost optimization is not really the driver, its more about precision or speed which have been the main drivers over the years. More recently, with focus on specific markets like healthcare, the focus is now on the entire signal chain. It’s not about getting a particular converter to work, but to maintain the analog to digital converter precision using front end sensors, applications, filtering etc.

Q: Will we see a single integrated chip for the medical sector?

Tom: Yes, we are putting much more focus on integration. Earlier, one would evaluate which was the best amplifier or best HD converter for the job, but the challenge now is identifying the process to choose for HD converters at the micron level, for example with 40 volt amplifiers, and getting this all onto a chip – so the challenge is marrying power supply and conflicting needs to develop the entire signal chain.

Q: Too many chips for a board – reduce to fewer chips?

Tom: Our focus is now the entire signal chain on a single chip – not just SoC (system on a chip) but SIP(system in a package).
This is a trend we are seeing as devices get smaller and there is less space for chips. Even the ECG is now reduced to a patch on the body.
Traditionally, we have been big not only in medical imaging like CT ultrasound, digital x-rays, but also in vital signs monitoring like ECG, pulse optometry, respiration and also medical instrumentation like blood analysis. The consumer market is emerging with solutions like glucose meters and advanced hearing aids which are more efficient and are able to kill noise, differentiate between voices and can amplify certain sounds while reducing others.

Q: Are DSPs used for these devices?

Tom: DSPs are typically too high power, so analog implementation is required and specialized processors are developed for this.
We have array of sensors in the signal chain piece, we then have the amplification and filtering stage followed by the HD conversion stage and then the processing stage. The signal chain therefore, has to be developed with the right combination of sensors with filtering to measure temperature, heart rate, etc.
Our new product is called the ADAS 1000 which allows leads to be connected directly to humans -with protection through defibrillators –and can send readings directly to the signal chain.

Q: Is this like ECG on a chip?

Tom: It’s Instrumentation on a chip more than ECG, and includes features like pulse detection for pacemakers. This is a monolithic design at about .18 microns.

Q: What is the market response for this product?

Tom: The ADAS 100 was recently released in July, and we have seen extremely high demand for evaluation boards.
This is a classic case of marrying low and high voltage. We have picked the best node with smaller size for the best compromise between analog and digital components. We had all the blocks, but the challenge was integrating them all into one solution without degrading performance. We are also developing a family of products, with more input channels based on customer requirements, varied base protection etc.

Q: How is the measurement precision compare with other to bench-top ECG devices?

Tom: The precision is much better because we reduce aspects like parasitic as it is now on a single chip.

Q: What are the benefits to customers?

Tom: The benefits are lower cost and size, better performance, and greater power efficiency. Obsolescence is a major factor in the medical sector. Systems could have parts like amplifiers that are no longer available after two years, whereas with this chip we offer support for 15to 20 years. Building with discrete blocks however risks obsolescence.

Q: What other innovations are you seeing?

Tom: Most x-ray machines today are moving from film based to digital x-rays. The quality compared to older machines is far better as there is no additional noise. Traditionally, the life of x-rays are limited to 5 or 10 years but now can be made permanent and also include features like automatic intelligence in detection, analysis of images etc. We call this the physician assist.

Q: What trends are you seeing in the industry (healthcare electronics)?

Tom: In the industry, we see that Innovation and the trend of discrete components moving into SIPs, is causing cannibalization to an extent. Costs are being lowered but there are also more channels, and more sophisticated equipment. The lower prices are beneficial to the consumer.
In the medical sector, regulations for hospitals in particular are an issue for growth. The trend we see in the next few years is that medical devices like hearing aids that don’t fall under the medical sector will drive a market explosion – devices like the personal sound assistant which are not as sophisticated but still functional will drive growth. We call this the consumerism of medical electronics, which is moving from the hospital to the home.
There are several innovative companies and products, which will cause growth in the healthcare market. Sanofi is a company that has a glucose meter that can be plugged into the mobile phone for easy use.
Additional gadgets never designed for medical purposes can now measure pulse, heart rate, etc. and with standardization of USB ports on mobile devices, all one needs now is an app for android for these measurements. In India, we see small affordable gadgets being used in local clinics in remote areas. Other innovations include accelerometer readings in mobile phones that can trigger emergency dialing in case of a fall for senior citizens.
We are working on a single chip solution which is a sensor for pulse that uses high powered LEDs. This is called the ADP 220 and can be used for photo sensing applications like pulse optometry.
Here below is the picture
Smart Phone


Q: Do you leverage ARM products (processor cores) in the medical sector?

Tom: We are a licensee, but we typically play in the front end. The medical sector internally uses DSP, FPGA, etc. and is not standardized to ARM. In the medical electronics domain, body signals are still vector based but ARM is used where possible.

Q: Electronics is now in the grassroots, as more engineers opt for core electronics as a career rather than software. How do you see the potential of India in the coming years?

Tom: India is a major focus market for us. We are investing strongly in the IPDC as we see tremendous potential here. India has matured as a market. Initially, the focus was on software, where MNCs especially in healthcare would have systems designed in the US and software algorithms would be developed in India. Today, there is more maturity in the market, and these companies are more confident as Indian designers now have the expertise and are more willing to get involved in hardware design.

Q: What about China?

Tom: Overall, China is losing its gloss, with issues like wage restrictions. One doesn’t necessarily think of China for digital. It’s mostly software based. However, they have the ability to grow businesses very rapidly.