An integrated seal and electrical contact system for medical implantable pulse generators (IPGs) has been engineered to help large and small OEMs accelerate the development process, reduce device volume, and improve functionality.

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 dis- tal cap completes the standard IS-4 footprint.
The SYGNUS™ system combines electrical contacts with pre-tested silicone seals, resulting in a densely-spaced connector “stack” that can accommodate IPG leads with diameters ranging from 0.90–3.20mm. The system’s contact elements consist of housings made from medical grade MP35N® and Platinum-Iridium Canted-coil™ springs. The spring contacts exhibit low insertion force, provide multi-point contact and conductivity, and compensate for both misalignment and mating surface irregularities.

The implantable-grade silicone seals in the stack provide dielectric isolation for the prevention of signal leakage that can result in false positives and other potential device malfunctions. The combined stack is engineered to provide resistance to fatigue caused by multiple lead insertion cycles. In addition, the minimum “pitch” of the system (a measurement of the space from the centerline of one contact to another — roughly 2 mm), gives OEMs the ability to shrink overall package volume and build greater contact density into smaller spaces within the IPG connector cavity.

The stackable configuration of the connector system makes it completely scalable. The number of contacts and seals it contains can be specified to meet unique application and industry requirements, such as the recently ratified IS-4 and DF-4 standards for cardiac health management devices. In these applications, a proximal cap serves as the datum, and a distal cap completes the footprint.

Each electrical contact is force and resistance tested, and each sealing component is packaged to “critical clean” standards. The system is designed to be a “plug-and-play” solution for lead interfaces in implantable devices used for cardiac rhythm management therapies (resynchronization, defibrillation) and neuromodulation (spinal cord stimulation, deep brain stimulation, and functional electrical stimulation). Due to its small size, the system is also being considered for use in devices designed to treat obesity, hearing loss, and sleep apnea.

Makers of IPGs cite reliability, safety, and ease of implementation as primary reasons for specifying the integrated seal/contact system. Since it eliminates the need for dual sourcing of seals and contacts and pre-testing of individual components, the system enables manufacturers to focus resources on therapy improvements and increased device functionality.

This technology was done by Bal Seal Engineering, Foothill Ranch, CA. For more information, Click Here  or call 800-366-1006.