Ensuring proper connection of leads into implantable cardiac devices can be challenging, especially for small start-ups whose specialty may not focus on this area. As a result, one company is offering a solution that can be completely integrated easily into a device to help satisfy the requirements of this component and enable a faster time to market.

In this cross-sectional view of the SYGNUS system, silicone isolation seals separate metal housings that contain a small canted-coil spring element. A proximal cap serves as the datum, and a distal cap completes the standard IS-4 footprint.

For years now, manufacturers of pacemakers, defibrillators, and other implantable pulse generators used in cardiac rhythm management have been feeling extraordinary pressure from shareholders and funding sources to move more quickly from prototype to design and build. As a result, many of these device makers have begun seeking new solutions that will enable them to integrate or “systemize” in order to make the most of precious time and capital.

One area in which an increasing number of OEMs have identified opportunities for integration is the connector cavity–the small enclosure at the top of the IPG where power is transmitted through multi-channel connections as therapy-delivering signals from the battery and electronics to the lead. Until recently, producers of IPGs had little choice but to undergo the costly, iterative, and time-consuming process of purchasing electrical contacts and designing, creating, and testing their own isolation seals for this critical interface.

A new “plug-and-play” connector technology, slated for formal introduction in

Bal Seal Engineering’s SYGNUS system is supplied with pre-tested seals and contacts that fit together in a “stack.” The contacts employ canted-coil spring technology for multi-point conductivity.

October 2010, may make that process obsolete–at least for smaller OEMs and startup companies focused on emerging therapies.

The concept behind this new technology is relatively simple: Take a proven electrical contact platform and package it with isolation seals that can guard against fluid infiltration and prevent signal cross-talk. Then, test the components for insertion and extraction forces, conductivity, electrical resistance, seal isolation, and other criteria, so that a manufacturer can confidently integrate the entire connector system into its device design and move closer to the holy grail of market introduction.

An example of this new approach, which effectively pairs seals and contacts in a pre-tested, compact, and scalable package, has been developed by Bal Seal Engineering Inc. Billed as the “world’s first seal-integrated contact system” and marketed under the tradename Sygnus, Bal Seal’s solution is built around its canted-coil spring technology. The Sygnus system combines the tiny springs made from platinum-iridium, metal housings of MP35N, and implantable-grade silicone isolation seals in an interlocking configuration that forms a tight connector “stack” to accommodate a lead with a diameter of 3.2 mm, or 0.125 in. Since the seal/contact combo is engineered to the recently-ratified IS-4 standard for cardiac health management devices (a proximal cap serves as the datum, and a distal cap completes the footprint), the company says Sygnus gives manufacturers the ability to dedicate resources to therapy and function improvements, rather than component development.

Shown here in a configuration that meets the IS-4 standard for cardiac applications, the SYGNUS Implantable Contact System was developed by Bal Seal Engineering in answer to increased demand for seal/contact integration.

“There has definitely been a growing need for this kind of solution,” says Bal Seal Business Development Manager Bill Nissim. “To some companies, especially those facing venture capital deadlines and clinical trial windows, choosing a system like [Sygnus] provides a level of freedom that could mean the difference between success and failure. Likewise, from a patient’s perspective, it might be one of the factors that determine whether or not a breakthrough therapy ever makes it to market.”

CHM device makers who have recently tested and adopted the new packaged seal/contact technology cite reliability, safety, and ease of implementation as primary reasons for their choice. And in a move that mirrors their cardiac counterparts, designers of active implantables used in the delivery of neurostimulation and sensing therapies are now eyeing the same kind of “stack” solution–engineered to even smaller, more contact-dense specifications–for the very same reasons.

For now at least, this move toward systemization (especially of the contact/seal variety) is more prevalent among small, agile manufacturers whose organizations don’t afford the vertical integration common to the industry giants. But it may not be long before even the heavy-hitters discover the benefits of specifying pre-packaged, pre-tested connecting solutions for their devices.

Mark D. Halloran is the marketing communications manager at Bal Seal Engineering Inc., a company that custom-engineers sealing, connecting, conducting, and shielding solutions. He can be reached at 949-460-2187 or