Body Area Networking Heats Up in Medical Field

Standards battle brews for wireless chips

By Mark LaPedus, Contributing Editor

For years, chip makers have been waiting for huge growth in the medical market.

So far, though, the medical semiconductor market has yet to see a major boom, but the sector has experienced steady growth. It has become readily apparent that the medical electronics field is complex and fragmented. In medical, chip makers and OEMs alike face long design cycles, funding issues and FDA regulatory headaches.

But one area that is suddenly generating steam – and creating some debate on several fronts – is remote patient monitoring. And seeking to get a piece of the action, Broadcom, IMEC, Qualcomm, TI, Toumaz and others are developing a new class of multi-mode wireless chips for remote monitoring devices. In addition, Intel, Qualcomm and others are backing or developing systems-level products in the arena.

These tiny electronic devices, which can be implanted or worn externally, can remotely monitor the heart, glucose, pulse and other vital data via a PC, and, more recently, through a wireless network. The wireless chips themselves fall into a loosely defined category called body area networks (BANs). BAN has been talked about for years, but the technology is now moving into the limelight.

In fact, as the remote patient monitoring business picks up momentum, there is a wireless standards battle brewing in the BAN arena. The wireless contenders in the BAN field include the emerging IEEE 802.15.6 standard, a low power version of Bluetooth, Wi-Fi and Zigbee. There is no clear-cut winner yet.

“What the (medical) industry is asking for is greater connectivity across different products,” said Ed Hill, director of marketing for the Intelligent Systems Group at Intel Corp. “We believe the industry wants more interoperability – or connected – devices. We also need to make sure these devices are secure.”

For years, Intel has participated in the medical field. In 2006, Intel rolled out the Mobile Clinical Assistant (MCA) reference design, a tablet-like, point-of-care bedside terminal for healthcare. Panasonic and Motion Computing sell products based on the technology.

Intel also has a joint healthcare venture with GE. And Intel also sells its latest and fastest embedded processors for imaging gear and other medical equipment. “New compute platforms will open up new algorithms in medicine,” Hill said.

ISSCC2012_400

Growth seen in medical semis
And it will spur growth in the medical arena. In total, the worldwide medical semiconductor market is expected to increase from $3.8 billion in 2011 to $5.9 billion in 2016, a 9 percent compounded annual growth rate, according to Databeans Inc., a research firm.

However, in 2012, the medical semiconductor market is projected to see flat growth and reach $4 billion, said Susie Inouye, research director for Databeans. The problem is that “there are excess inventories in the worldwide industrial channels,” Inouye said. “There is also a lot of activity in China. There also are a lot of new design starts in Asia.”

“The medical electronics field is diverse,” added Intel’s Hill. “Medical (electronics) is growing fast, but the growth is less than consumer electronics. And the refresh cycles are quite lengthy.”

There are three major areas in the medical electronics field: clinical, imaging and the home. The clinical electronics segment - the largest medical chip market - includes diagnostic lab equipment and other systems. Meanwhile, imaging - the second largest segment - includes magnetic resonance imaging (MRI) and computed tomography (CT) equipment.

Home healthcare is the smallest market, but it is growing the fastest. In the past, the home market was limited to blood pressure monitors, digital thermometers, glucose meters and among others.

The aging population, combined with soaring healthcare costs, is causing a sea of change in the home medical field. To mitigate healthcare costs, there is a movement towards replacing care within hospitals to the patient’s home, said Intel’s Hill.

The trend has given rise to remote monitoring. For some time, medical electronics firms have offered small implantable or worn devices that can remotely send data to a health care provider via a PC.

But the buzz in the arena started last June, when Medtronic Inc. launched its first mobile application for implantable cardiac devices. The software, dubbed CareLink Mobile Application, allows clinicians to access cardiac device diagnostic and patient data directly from their mobile devices. The CareLink Network provides similar information as an office visit for pacemakers, implantable cardioverter-defibrillators (ICDs) and implantable cardiac monitors (ICMs).

Then, in February of 2012, GE Healthcare said it would distribute AirStrip Technologies Inc.’s patient monitoring technology. The deal provides patient monitoring information to physicians via the iPhone and iPad. AirStrip’s platform allows clinicians to monitor the heart, blood pressure, temperature, oxygen saturation, weight and pulse via a wireless network.

Also in February, Qualcomm Inc. invested in AirStrip. The two companies are working together to develop wireless chips. And in a related development, Qualcomm, Intel and others recently invested in Sotera Wireless, a startup that is developing “body-worn sensors” for remote monitoring applications.

Despite the momentum in the arena, there are still several challenges in remote monitoring, which impacts the growth of BANs. There is still a question just how doctors are paid – and how insurance providers are involved - in remote monitoring, said Intel’s Hill.

Another challenge is sending critical data like patient information across a wireless network. “Security is an inherit problem,” said Karthik Soundarapandian, systems application manager for health and fitness at Texas Instruments Inc.

Imec-NR photo-BAN-ISSCC paper-21Feb12_400

Standards battle brewing?
Standards also remain a problem. In recent times, the BAN community has worked together to develop a wireless standard – dubbed IEEE802.15.6 – which is geared for the quality-of-service (QoS) levels for personal medical data. The standard is expected to be completed this year.

A variant of Bluetooth - Bluetooth Low Energy (LE) – has also emerged as a competing standard. ZigBee and WiFi are also in the running.

Within the hospital environment, medical equipment may end up supporting multiple protocols, Soundarapandian said. But in terms of using the smartphone as a gateway for remote monitoring, “Bluetooth is the best option today,” Soundarapandian said. “Bluetooth will prevail.”

Another problem is power consumption. Many of BAN-like transceivers use from 20mW to 50mW of power, which is still too high for use in autonomous and semi-autonomous sensor nodes, according to IMEC.

At the recent Integrated Solid-State Circuits Conference (ISSCC) in San Francisco, Alan Wong, head of IC design at U.K.-based Toumaz, presented a paper on one solution to the problem: The company is apparently working on a 1-Volt, 5mA transceiver that supports 802.15.6, Low Energy Bluetooth and proprietary protocols.

Based on 0.13-micron technology, the chip operates in the 2.36-GHz BAN spectrum, specifically allocated for medical devices, and the worldwide 2.4-GHz ISM band. “The network needs to be secure and able to respond immediately,” Wong said.

In a separate presentation at ISSCC, IMEC and Holst Centre described a 2.3-/2.4-GHz transmitter for wireless sensor applications compliant with IEEE802.15.6/4/4g and Bluetooth Low Energy. The transmitter has been fabricated in a 90nm CMOS process, and consumes only 5.4mW from a 1.2-Volt supply at 0dBm output.

This is two to five times more power-efficient than the current Bluetooth-LE solutions, according to IMEC. IMEC’s new transmitter saves at least 75 percent of power consumption by replacing several power-hungry analog blocks with digitally-assisted circuits.

In a somewhat related field, the University of Washington in Seattle and the University of Virginia at ISSCC described a 19uW battery-less energy harvesting chip for body area sensors. Conventional wireless sensors are powered from a battery. In contrast, the two universities propose a chip “powered by energy harvested from human body heat using a thermoelectric generator (TEG).”

The digital section includes a custom digital power management processor, general purpose microprocessor and SRAM. It also has dedicated accelerators for ECG heart rate extraction, atrial fibrillation (AFib) detection, and EMG band energy calculation. A sub-mW 400/433-MHz MICS/ISM band transmitter performs BFSK transmission up to 200kbps.

Besides the wireless front, TI will shortly expand its analog front-end lines for heart monitors, sports, and fitness applications. The ADS1291/2/2R line of AFEs are a family of 24-bit, delta-sigma (ΔΣ) analog-to-digital converters (ADCs).

Based on a proprietary analog process, the parts represent part of TI’s “ECG signal chain.” With the integrated AFEs, “we can take the complexity out of designs,’’ TI’s Soundarapandian said.

Going forward, Ritesh Tyagi, director of product marketing for Renesas Technology America Inc., said the medical field will remain a steady growth market for chip makers, but not the booming business many had hoped. He also warned that vendors must have patience. The IC design cycle can take as much as three years for a new system platform in the medical field, he added.

 


lapedus

Mark LaPedus has covered the semiconductor industry since 1986, including five years in Asia when he was based in Taiwan. He has held senior editorial positions at Electronic News, EBN and Silicon Strategies. In Asia, he was a contributing writer for Byte Magazine. Most recently, he worked as the semiconductor editor at EE Times.