Originally Published MPMN October 2008

BREAKTHROUGHS

Biocompatible Contacts Minimize Mating Risks

Stephanie Steward

Reliability is an obvious concern for such implantable devices as pacemakers and neurostimulators because malfunction or failure can be life threatening. But products that are so tiny or cumbersome that they can be dropped during surgery or misaligned when being connected present equally critical risk factors. With these hazards in mind, Hypertronics has developed a biocompatible contact designed to facilitate easy mating of leads to the implant. The ImplanTac offers the necessary level of reliability for implantable applications while minimizing the potential for damage to the device—and the patient—during implantation.

When implanting a pacemaker, a surgeon mates the device and its leads together during the operation using either set-screw or pin-and-socket contacts. Because the leads monitor and apply electrical energy based on sensory inputs, the connection between the leads and the device must be secure and reliable. However, mating the device and its leads is a process that is prone to risk.

Set-screw contacts require tiny, specialized torque screwdrivers and screws that may be difficult for a gloved surgeon to handle and can even be lost during surgery. Unlike set-screw products, ImplanTac pin-and-socket contacts do not require the use of any mating tools.

The less-complicated socket contacts also offer low insertion force and contact resistance, which make them easier to handle.

Application-appropriate levels of force and resistance are also important because implantable device components mate over such short distances. The components are so small that an improperly designed socket contact can be damaged when mated, according to Tom Kannally, medical industry manager at Hypertronics. “The surgeon can’t always tell if the contact is damaged during surgery,” he says. “And if damage is realized, it can’t be repaired, so a new device needs to be implanted.” Repairing implantable devices is too cost prohibitive and time-consuming to be a realistic option for manufacturers and surgeons, Kannally explains.

The biggest challenge in developing the ImplanTac contacts has been working within the virtually nonexistent real estate of these tiny devices, according to Kannally. Implantable devices often need multiple contacts that tend to be very short and unforgiving of misalignment, he adds. Hypertronics can customize the contacts’ size characteristics and force and resistance features to meet specific application requirements.

Depending on the device, the leads and socket contacts can be made of different biocompatible materials. But Kannally notes that how the materials interact is crucial to making a good electrical connection, and, ultimately, to the device’s functionality and reliability.

Hypertronics Corp., Hudson, MA
www.hypertronics.com

Copyright ©2008 Medical Product Manufacturing News