Platform can revolutionize medical device design

Typical point-of-care instruments today can remind you of IBM mainframes of the 1970s, said Charles G. Sodini, the LeBel Professor of Electrical Engineering at MIT, at his DesignMed keynote address Wednesday September 28. He hopes to change that and is working through the Medical Electronic Device Realization Center (MEDRC) at MIT to revolutionize medical device design.

Sodini began his address by citing industries already disrupted by microelectronics, including watches in 1970, calculators in 1980, computers in 1990, communications in 2000, and consumer devices in 2010. Looking ahead, he said, he sees similar disruption in medical applications, with microelectronics revolutionizing medical device design through 2020.

One goal of MEDRC is to change the face of how engineers design medical devices and look at markets. Now, Sodini said, there is little interaction between medical-device companies and microelectronics companies. Each entity prepares product project definitions separately.

In pursuit of that improvement, Sodini said that MEDRC provides precompetitive medical electronic device solutions involving strong interaction among medical device and microelectronics companies as well as physicians and clinicians. The goal is to derive precompetitive technology results that industrial members can turn into products.
He sees MEDRC as well situated at the MIT campus. “Boston has the most hospitals per unit area that we know of, and that’s good for medical research.” He also said that MIT has 30 years experience with the microelectronics industry, interacting with industry over the long haul, and MEDRC will leverage MIT’s industry experience to strengthen relations with medical-device community.

Sodini said that the MEDRC will make use of the MIT portfolio over a wide range of areas. “I am a chip guy, he acknowledged, “but we are not talking just chips.” MEDRC, he said, will address issues including biocompatible packaging, energy saving and power management, and communication of bits to end users.

The medical world is segmented by disease, Sodini said, with each device being very specialized for one disease and serving a relatively small market size. One of MEDRC’s goals is to establish a platform that can serve multiple vertical markets with each market defined by a specific disease.

Sodini cited several applications MEDRC is addressing or will address in the future: wearable products such as cuffless blood-pressure devices, minimally invasive monitors, point-of-care instruments (including lab on a chip), data-communications techniques (including body-coupled body-area networks in which the body itself is the communications medium), and imaging systems (including smart ultrasound devices that reduce technician training requirements). He noted that the GE Vscan ultrasound system is almost as small as a cell phone. But he added that such systems require a trained and therefore expensive technician, who serves as the feedback loop manipulating probe. The goal is to have an ultrasound machine able to guide the technician so that less training is required.

Epilepsy and Parkinson’s disease are examples of different diseases that could be addressed by a platform approach to medical-device design, Sodini said. A physician working with epilepsy wants to know how many seizures a patient has each month, and self-reported data is noisy and unreliable. In contrast, a wearable EEG monitor could count seizures and enable the physician to adjust medication based on reliable data.

In contrast, a physician treating a Parkinson’s patient wants to adjust medicine based on reliable measurements of motion changes. The physician treating epilepsy and the one treating Parkinson’s require an electrical sensor and an accelerometer, respectively, but despite the different sensor requirements, each could take advantage of the same packaging, power management, and data-communications technologies.

Sodini provided details on the specific example of noninvasive monitoring of intracranial pressure—the hydrostatic pressure of cerebrospinal fluid. ICP monitoring can be essential after a severe head injury—after a traumatic head injury the brain can swell, driving IC pressure up and cerebral blood flow down, leading, he said, to what clinicians call “poor outcomes.” Traditionally, he said, measuring ICP is very invasive, requiring surgical penetration of the skull. MEDRC, however, has developed a minimally invasive alternative that employs a transcranial Doppler technique. The wearable device is built from off-the-shelf parts, including an Imasonic capacitive 2-D 16×16 ultrasonic transducer array. He noted that ultrasound waves in the body behave much like millimeter waves in space and can be steered to the desired target using phased-array techniques, thereby minimizing the power required to generate the ultrasound signal.

Sodini  also described a wearable heart monitor that can make mechanical, electrical, and optical measurements—ballistocardiogram (BCG) electrocardiogram (ECG), and photoplethysmography (PPG) measurements, respectively. (BCG relates to the body’s mechanical recoil in response to a heartbeat, while PPG is an optical technique that can measure blood oxygen saturation). The device is worn on the ear, which, he said, is a great anchor that can support everything from eyeglasses to Bluetooth headsets.
The heart monitor is definitely a prototype, mostly housed in an old-fashioned hearing-aid package. But the goal, said Sodini, is to get the device into the clinic to learn how well it can deliver the data doctors need to serve their patients. With the use model sufficiently developed in the clinic setting, industry can pick up where MEDRC leaves off and provide the integration that can lead to the mass production of high-quality cost-effective devices that lead to commercial solutions.

(Originally posted October 3 at

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