The population is aging and medical costs are soaring, creating a greater need for home-based healthcare solutions. These pressures have led to an increase in the number of healthcare devices on the market as smaller, portable, and less expensive homecare technologies replace larger, costlier equipment.
The numbers are daunting. According to the World Health Organization (WHO), the worldwide number of people age 50 and older was 650 million in 2006. WHO expects this total to reach 1.2 billion by 2025. In the U.S. alone, those age 65 or older now constitute an increasing share of the population, a number that is expected to rise steadily in the future.
The healthcare market is big business. According to the U.S. government, the U.S. spends $2.5 trillion on healthcare, representing 18% of the nation’s gross domestic product (GDP). ABI Research forecasts that 59 million wearable home health devices will be used by 2014 and that the total number of wearable devices will be 420 million by then, when devices for sports and fitness applications are counted.
The Freedonia Group puts the present market value of home healthcare medical equipment at well over $7 billion, when technologies for respiratory therapy, intravenous (IV) injections, dialysis, patient monitoring, wheelchairs, walking assistance, medical furniture, and safety devices are considered.
Today’s devices give patients a lower-cost and hassle-free option for monitoring and in some cases treating their health conditions right in their own homes. There’s less of a need to have them travel to a hospital, medical clinic, or doctor’s office. Healthcare is becoming more decentralized.
Portable home healthcare medical gadgets include blood glucose, blood pressure, and heart rate monitors, digital thermometers, pulse oximeters, wheezometers for patients with asthma and other respiratory disorders, fall and movement detection devices for the elderly and disabled, and digital scales for weight monitoring and management. Therapeutic devices for sleep apnea are available as well. And, many home fitness devices are being updated to include health measurement and management functions.
IC ADVANCES
Facilitated by Internet connectivity, advances in semiconductor IC performance and integration levels are driving innovations in home healthcare. Paradoxically, these semiconductor IC advances are saving thousands of lives and pushing the number of people living longer even higher, placing still greater demands on healthcare and increasing the need for more medical innovation.
Designers can take advantage of sensors, microcontroller units (MCUs), microprocessors, DSPs, analog front ends, memory devices, power ICs, and transmitters and receivers. FPGAs also are implementing many functions. These solutions all achieve a high level of functional integration.
Many IC functions are driving the home healthcare trend, particularly processors and advanced sensors. For example, DSPs are enabling a new class of monitoring products thanks to their high computational performance levels.
Advanced accelerometers like the Analog Devices ADXL345 iMEMS tri-axis digital accelerometer, found in millions of games, navigation devices, cell phones, automotive applications, and other consumer products, ensure the accuracy of home digital blood pressure meters. They sense and ensure the correct position of the arm (where the cuff is placed) relative to the patient’s heart for maximum accuracy.
Pulse oximetry is one of the more recent functions to invade the home healthcare monitoring scene. It’s considered the fifth vital sign after blood pressure, heart rate, respiratory rate, and temperature. It measures the amount of oxygen bound to hemoglobin, an essential part of the red blood cells that deliver oxygen from the lungs to the tissues.
A pulse oximeter (Fig. 1) can be designed using a number of conventional ICs, according to ON Semiconductor. The company purchased AMI Semiconductor, a leading manufacturer of advanced custom ICs for medical applications, three years ago. Some semiconductor IC manufacturers supply the entire signal chain of functions needed for home healthcare applications.
“We developed the AD5933 impedance analyzer chip for measuring parameters such as body fat and blood coagulation. Its output can be linked to a home telehealth terminal for communications with a physician,” explains Paul Errico, worldwide strategic marketing manager for the Analog Devices Healthcare Group. “This is just one of the ICs needed for an entire signal chain (Fig. 2) in portable home healthcare products that we can supply.”
“We’re trying to enable the solutions for present and future home healthcare applications needs, which include not only the data measurement part of the signal chain, but also the connectivity part between home patients and their medical providers,” says Steve Dean, medical marketing director at Texas Instruments.
DESIGN CHALLENGES
The home healthcare equipment market poses challenging requirements to design engineers. These include the need for low power and thus longer battery life, robust and powerful data processing, friendlier and simpler user operation, wireless connectivity, and low end-user costs. And, semiconductor IC manufacturers are rising to these challenges.
The integrated Texas Instruments CC430 platform (Fig. 3) includes the MSP430 MCU, the CC1101 RF transceiver system-on-a-chip (SoC) IC, and intelligent peripherals, all within a 9.1- by 9.1-mm, 64-pin, quad-flat no-lead (QFN) package. The unit features 128-bit security encryption and 433-, 865-, and 915-MHz communications, the last two of which are user-selectable. TI also says that the MSP430 is the industry’s lowest power-dissipation MCU. It operates from 2.2 to 5.5 V and dissipates a mere 330 µA (at 3 V and 1 MHz). In the standby mode, current drain is a measly 0.1 µA.