Division Aids Medical Systems Power Designers

Nov 8, 2006 3:55 PM

Microchip Technology has formed the Medical Products Group (MPG) to address the emerging challenges of the medical electronics market through close partnerships with medical device makers. According to the FDA, aging baby boomers are driving a "consumerization" of therapeutic and diagnostic medical devices, as more medical care is being done in the home. This trend is fueling the development of smarter and easier-to-use consumer medical devices, the largest portion of the $100 billion medical device market, which is growing at an annual rate of 15%, overall.

Microchip's broad portfolio of 8-bit and 16-bit PIC microcontrollers, 16-bit dsPIC digital signal controllers, analog and interface semiconductors, KEELOQ security products and non-volatile memory semiconductors is ideally suited for medical applications. Microchip offers high-performance microcontroller architectures with application-optimized peripherals and an easy migration path to re-use code in whichever microcontroller best fits the application. Additionally, Microchip offers low-risk development with all of its semiconductor products through a full suite of development tools and software, including the free MPLAB Integrated Development Environment.

"With the creation of the Medical Products Group, we are bringing Microchip's unique advantages to a market that is large and growing," said Dan Termer, vice president of Microchip's Vertical Markets Group. "Advances in semiconductors are enabling unprecedented innovation in medical devices, and Microchip is playing a vital role in enabling this trend."

Microchip's semiconductors are designed to be horizontal and general purpose, enabling them to address a wide range of applications. Specific medical application examples include: Implanted Devices (cardiac rhythm management, neural stimulation, drug delivery, bariatric therapy); Portable Devices (diagnostic imaging, oxygen therapy, patient monitoring); Home-Use Devices (vital-sign monitoring, disease management, rehabilitation, compliance monitoring, medical information terminals); and Security (authentication of consumables, data confidentiality).

According to Steve Kennelly, manager of the MPG, several medical applications involving motorized equipment utilize essentially the same techniques as conventional motor control methods (see Figure). The main difference is that medical sensors, such as the air pressure sensor used in a Continuous Positive Airway Pressure system, are in the feedback loop. In that particular application, referred to as positive airway pressure therapy, the airway of a patient suffering sleep apnea is prevented from collapsing through the application of constant air pressure through a face mask.

Another class of medical application applies electrical impulses directly to the patient. In these applications, one example of which is a muscle stimulator, the microcontroller would ensure the current and voltage of the applied signals are maintained within minimum and maximum limits.

Yet another application for microcontrollers is in the battery management of portable medical devices. Fanie Duvenhage, Product Marketing Manager of Microchip’s Security, Microcontroller and Technology Development Division, stated that here again power management and battery charging techniques for medical devices, such as PWM current charging, would be similar to those employed by more conventional applications. However, the specifications and safety requirements for medical applications would be more stringent.

Microchip has developed a comprehensive online Medical Design Center to assist with the development of these and other applications. The center is divided into four main medical-design categories: Data Acquisition, User Interface, Processing and Connectivity. Each section contains application notes, design guides, reference manuals, user guides, Tips n' Tricks documents, and detailed product and development-tool information to assist engineers in designing medical applications.

One unique characteristic of the microcontroller is its ubiquitous presence, and medical applications for this product reveal an important aspect of Moore’s Law. That is, a broader range of physical—and thus medical—applications is available when each new generation of fabrication process is used to shrink device size rather than simply increase computing power.

Some medical applications for microcontrollers, such as dialysis machines, employ motor drive techniques similar to those in more conventional applications.