Four men and one woman reduced to a microscopic fraction of their original size, boarding a miniaturized atomic sub and being injected into a dying man's carotid artery. Fighting their way past giant antibodies, passing through the heart itself, entering the inner ear where even the slightest sound would destroy them, battling relentlessly into the cranium. Their objective . . . to reach a blood clot and destroy it with the piercing rays of a laser gun. At stake . . . the fate of the entire world. —Fantastic Voyage, 1969

Anthony Kalaijakis is the global industry director medical at Hypertronics Corp. He is responsible for Hypertronics' global business development for the medical market. He has led many new medical interconnect product designs, some of which are patented. Kalaijakis can be reached at 978-568-2768 or

The topic of miniaturization in the medical market has been around for many years. In the movie Fantastic Voyage, shrinking the medical team and injecting them into the human body to treat a clot saves the world.

Figure 1: The Activa RC is one of the most innovative deep brain stimulation (DBS) devices available for the treatment of the symptoms of advanced Parkinson's disease and essential tremor. Medtronic DBS Therapy delivers small electrical pulses to precisely targeted areas within one or both sides of the brain to help patients achieve greater control over disabling body movements. (Photo: Medtronic Inc.)
As fantastic as it seemed in 1969, it foreshadowed the future developments in the medical market. Miniaturization in the medical device and equipment market is following the paradigm established by Gordon Moore of Intel in 1965. Known as Moore's law, it theorizes that transistors on integrated circuits double about every two years. The doubling of the density allows for more performance out of less physical space as demonstrated by the downscaling of computing technology and electronics as a whole.

In the consumer marketplace, there are several examples of products scaling down in size. In the early ‘80s, people were fascinated by the first cellular phones which were the size of small appliances. In old episodes of Miami Vice, Crocket is seen talking into what appears to be a television set with a thick antennae sticking out. Today, the mobile telephone has exceeded the functionality of yester year's best personal computers while shrinking to sizes that are approaching too small for human handling.

According to AdvaMed, the Advanced Medical Technology Association, miniaturization is the number one hottest trend and innovation expected in medical technology. Breakthroughs in nanotech will even produce microscopic devices that can deliver treatment to individual diseased cells.

Neurostimulation Application Stories
Figure 2: SynCardia Freedom Driver and biventricular total artificial heart (Photo: Syncardia)
At Minneapolis-based Medtronic Inc., where the mission is to create devices to alleviate pain, restore health, and extend life for millions of people around the world, small devices are the wave of the future.

"The new products under development at Medtronic are either implantable or wearable devices that need to be easily concealed, so all of the components have to become smaller," commented David Warren Lee, senior principal mechanical engineer in the Neuromodulation business at Medtronic. "At the same time, the compact devices that we are developing have higher levels of data acquisition and signal processing so the new standards in medical devices are greater density on a smaller form factor."

A neurostimulator called Activa RC (Figure 1) was recently developed at Medtronic to control the symptoms of Parkinson's disease by delivering Deep Brain Stimulation (DBS) Therapy. Using the technology developed for pacemakers and applying electrical impulses to an area of the brain, the symptoms of the disease, such as tremor, are all but eliminated in many patients. The new technology is smaller and offers more advanced programming than previous models and it is also the first rechargeable DBS device.

Incontinence is one of the fastest growing segments in neurostimulation. Medtronic has a new product called InterStim Therapy that is a safe and effective treatment for this troubling condition using sacral nerve stimulation.

According to Dr. Attila T. Barabas, who specializes in Urologic Surgery in Lancaster, NH, "InterStim therapy is an advancement in patient care that applies neurostimulation to a targeted area in the body near the tailbone called the sacral nerve. It uses sacral nerve stimulation—an intervention that addresses the nerve component of urinary control—by applying mild electrical pulses."

Figure 3: In the Hypertac contact system, the shape of the contact sleeve is formed by wires strung at an angle to the socket's axis. The wire basket design creates a 360° point of contact which ensures signal reliability.
Once the InterStim device is implanted in the patient, the doctor can program the device right in the physcians office. "Adjustments to the stimulation can be made using a hand-held programmer," comments Dr. Barabas. "InterStim therapy allows patients to resume their activity level and lead a normal life. It is also reversible; it can be programmed off at any time."

The world market for neurostimulation devices is forecast to reach $5.2 billion by 2012 and the vast array of implantable neurostimulators are increasingly being used to improve the quality of life for patients coping with conditions that range from chronic pain to epilepsy to Parkinson's disease and more. "Implantable devices that provide relief of symptoms with electrical nerve impulses are of great value to patient quality of life," commented Dr. Barabas. "Based on the positive response from patients, nerve stimulation seems to have endless possibilities to provide pioneering treatments for many neurological disorders that lack a known cure."

"Consumers who use neurostimulators to control pain, incontinence, or other health care issues want the device to be small and discreet and about the size of an iPod or cell phone," commented Lee. "But unlike cell phones that routinely break over time, our device has to be durable enough to withstand everyday usage. If our device drops on the floor, it still has to work."

Figure 4: Hypertronics mini DO circular connectors reduce the form factor by 30%.
This higher level of durability that applies to medical devices demands extreme robustness in every component, and this especially applies to the connectors. The traditional tuning fork style connector is frequently the cause for failure in everyday consumer electronics. For this reason, companies like Medtronic seek out high quality connector manufacturers.

"The biggest factor about interconnects in medical devices is robustness", commented Lee. "We use the Hypertronics connectors in our external neurostimulator because we needed an extremely durable, very reliable connector. It's a medical device and it has to work."

The exponential decrease in device diameters, dating from the 1960s to current day, parallels the challenges seen in the medical connector space—smaller, lighter, and able to sustain portability.

Each step change provides a technical challenge of scaling down interconnects without compromise to performance of the system. In addition, the human factors of easily connecting and disconnecting must be met as these devices move from the hospital or clinic settings to the home. For example, portable insulin pumps provide for convenience and self regulation; these are great attributes, but wearing a pump is not always aesthetically complementary unless hidden under clothes. Miniaturization of the pump system has scaled the device down dramatically.

Case in Point—Freedom Driver
Another example of a step change in scale is the advances that have been made in pneumatic drivers that power the world's only approved total artificial heart, the SynCardia temporary CardioWest Companion Total Artificial Heart. Since the 1980s, the Total Artificial Heart has been powered by a 400-lb. driver that is the size of a washing machine. Due to the driver's robust size and need for a qualified technician to monitor it, Total Artificial Heart patients who are otherwise healthy, must remain in the hospital while they wait for a matching donor heart. However, in the last decade, the driver has been downsized to a 20-lb. portable driver that has been in use in Europe since 2003, and now a 12-lb. discharge driver under development that is no larger than a woman's purse—the Freedom driver (Figure 2).

Hypertronics worked in parallel with SynCardia Systems Inc. to design an interconnect system for the Freedom driver that delivers reliability for this critical application. Design engineers from both companies collaborated to develop the interconnect solution that ensures signal reliability for this lightweight system.

"With the Freedom driver, for the first time in the U.S., Total Artificial Heart patients will be able to enjoy life at home while they wait for a matching donor heart," said Rodger Ford, CEO and president of SynCardia. "The reliability of the interconnect system from Hypertronics is critical to ensuring that our patients can enjoy their second chance at life."

‘Mini' Scale
As these medical devices migrate from the institution setting to the convenient lifestyle realm, the burden of lighter, smaller, low risk, and absolute performance become unconditional. Similarly, interconnect systems are following suit to the log scale decline in sizes which are creating innovative products of "mini" scale. Component manufacturers that supply products for medical devices need to apply resources to develop mini scale components to meet these needs (Figure 3).

As such, Hypertronics developed the mini circular connector series, reducing the form factor by 30% (Figure 4). "Medtronic was excited to hear about Hypertronics new mini technology because we love the ultra reliability of their current connectors, but size was starting to become a problem," commented Lee.

The growth rate of the medical device market has attracted many investors, creating an exciting environment of innovation and technology expansion. Further, the projection for the future is continued expansion; in 2006, the U.S. market size was $86 billion and it is now over $100 billion.

As the market continues to flourish and investment into research explodes, scientists and engineers can develop newer applications. While the technologies and innovation of the last decade astounded many scientific researchers, the breakthroughs in miniaturization provide opportunities in healthcare that are seemingly as futuristic as those in Fantastic Voyage.

For additional information on the technologies and products discussed in this article, see MDT online at and the following websites: