With the right semiconductors and development tools, building leading-edge patient monitoring applications can be easier (and quicker) than you think.
In today’s rapidly growing healthcare marketplace, portability and functionality are the name of the game when it comes to medical devices. Healthcare is steadily moving away from hospitals to the point of incident and into the patient’s home. Around the globe, physicians and patients are turning to low-cost telemedicine solutions that give patients the ability to safely and effectively monitor their own health.
Global market trends forecast consistent growth opportunities in patient monitoring applications well into the future. By the year 2020 it’s estimated that there will be more than twice as many people over the age of 60 as there were in 2000. As a result, healthcare costs in the U.S. are expected to grow from $2 trillion in 2007 to $3.1 trillion in 2012.
These growth trends offer significant opportunities in the $2.5 billion medical semiconductor market including consumer medical devices, diagnostic and patient monitoring devices, medical instruments and medical imaging. In 2008 alone, 33 percent of the money spent on medical semiconductors went into consumer medical devices (Databeans 2009).
To meet market demands, medical device manufacturers must look beyond the power-hungry, stationary applications that exist today and create comprehensive portable solutions that meet tight power and cost restraints.
Addressing market trends
With a great deal of today’s healthcare spending being directed toward managing diseases, a tighter connection now exists between physician and patient. Consumer medical devices support this connection through portability by giving patients the ability to take their own measurements, as well as providing physicians the opportunity to take measurements in rural areas.
A major trend in the medical device market is focused on providing greater access to more people through the use of low power, portable tools with greater connectivity. This makes way for the device to be marketed and sold in developing countries and areas where expensive healthcare devices are not currently available.
One approach to portable connectivity and lower cost is on-chip analytics that enable real-time diagnostics; for instance, in a heart rate monitor. This device can detect the patient’s heart rate in real-time using low power, high performance digital signal processing. Digital stethoscope technology – a low-cost alternative to ultrasound, which due to financial constraints is not available in rural areas – is another example where extensive digital signal processing can be used to detect mechanical defects in the heart.
Future paradigms for healthcare delivery
The Continua Health Alliance is a 220-member non-profit organization that is working to connect patients with their healthcare providers by defining guidelines that can be used to develop end-to-end, interoperable systems.
Continua has identified and prioritized various patient-centric scenarios through a process of eliciting, collecting, compiling and analyzing use cases submitted by member companies. Three of these – health and wellness, chronic disease management and aging independently – relate directly to developers of patient monitoring applications.
The issue of connectivity
Connectivity is an important element when developing monitoring applications. While connectivity can take on multiple forms, wireless is the most typical. Continua has adopted various off-the-shelf connectivity standards and specifications for ensuring device interoperability such as Bluetooth, USB, ZigBee and Blutetooth Low Energy (BLE).
While these off-the-shelf options save development time with ready to implement solutions, a number of medical device manufacturers prefer proprietary alternatives due to security and IP protection concerns. These solutions utilize specific frequency bands for use in the medical industry. It is up to the systems or product engineer to select or design the appropriate proprietary protocols for use at these reserved frequencies.
The Wireless Medical Telemetry Service (WMTS) band established by the FCC has dedicated specific frequencies – for example, 1400 MHz and 600 MHz – to be used for remote patient monitoring to avoid interference from TV and radio equipment. The Industrial Scientific and Medical (ISM) bands – the most common being sub-1 GHz and 2.4 GHz – are reserved for international use of wireless technology for industrial scientific and medical purposes. Finally, the Medical Implant Communications Service (MICS) bands reserve frequencies of 400 MHz specifically for usage in implantable medical devices.
Solutions for developers
Today, medical device developers are faced with the challenge of creating very low power, feature-rich, yet compact devices and they have to do so with limited teams and expertise. To address these market needs, semiconductor manufacturers need to provide diverse options that address the full signal chain from the processor, to sensors, to the end user interface.
For instance, for medical device developers creating end-equipments where ultra-low power consumption is the primary concern, developers can take advantage of the ultra-low power MSP430 microcontroller (MCU) from Texas Instruments (TI). Perfectly suited for devices in this market with multiple low-power modes that enable current consumption down to only .1uA, and the integration of high quality analog modules that eliminate external components – thus reducing the bill of materials (BOM) cost – TI’s MSP430 enables smaller medical devices. Two application notes are available to help developers create simple electrocardiogram (ECG) and pulse oximeter solutions using the MSP430. Figure 1 shows a typical medical patient monitoring system block diagram powered by TI’s MSP430 MCU.
Additionally, TI’s Stellaris® ARM® Cortex™-M3 MCUs are well-suited for data acquisition, user interfaces and general embedded processing functionality in patient monitoring and patient diagnostic devices. They offer 32-bit performance, as well as rich connectivity such as integrated USB OTG (On the Go) and Ethernet functionality.
TI also addresses challenges facing medical developers by offering digital, analog and software solutions that they can leverage to create multiple end-products based on the same platform for higher performance ECGs and pulse oximeters, as well as digital stethoscopes. In addition to the functionality, because these are complete hardware solutions, developers can spend more of their time customizing features and integrating specialized functionality to differentiate their products.
Three new medical development kits recently released by TI help reduce development time by up to eight months for medical diagnostic and patient monitoring equipment. The development kits – based on TI’s TMS320VC5505 low power processor – can be built by purchasing an analog front-end module and a C5505 evaluation module. These kits give manufacturers a jump start on designing leading-edge ECGs, digital stethoscopes and pulse oximeters. Figure 2 below shows the ECG analog front-end module.
TI is uniquely positioned in the market – offering a wide range of solutions from low power DSPs and MCUs to high performance processors – to address all types of medical devices, regardless of complexity. Learn more at www.ti.com/medical.
Rajesh Verma is a business development manager for the medical market within TI’s Advanced Embedded Controllers Business Unit. He supports business opportunities worldwide for TI’s MSP430, C2000 and Stellaris Cortex M3 microcontroller families. Prior to that, Verma worked in Motorola’s Mobile Devices division in both technical and marketing roles.
He has a BSEE from the University of Illinois at Chicago, an MSEE from Purdue University and an MBA from Northwestern University’s Kellogg School of Management.
Srikanth (Srik) Gurrapu is the Product Line Marketing Manager for the Low Power Processors Business Unit in Texas Instruments. Srik Gurrapu has been leading the marketing and business development activities for extensive embedded processor solutions featuring C5000, C6000, OMAP and DaVinci technologies for various patient monitoring, diagnostic and therapy applications and portable medical devices.
Srik Gurrapu has a Masters degree in electrical and computer engineering from University Of Kansas.He has been with TI for over 10 years and worked on various technologies in digital communications and audio processing, wireless base stations and embedded processors. He has two patents in embedded processing architectures and is a member of Technical Staff in Texas Instruments.
Fei Gao is currently the product marketing manager of the C5000 Processors group at Texas Instruments. She has been responsible for worldwide marketing and business development activities for a variety of embedded processor solutions, including C5000, OMAP™, Davinci™ and Digital Audio and Video SoCs. She has worked on various applications ranging from low power medical, digital entertainment products to biometrics and portable instrumentation solutions.
Gao holds a Master’s degree in electrical engineering from Texas Tech University. Her research primarily focused on biomedical signal processing in early stage cancer detection. She also holds a dual bachelor’s degree in electrical engineering and computer science from UESTC, China.