The redesign of a surgical-assist device, the Embrace Heart Stabilizer, shows that even an inherited design can be improved with input from several disciplines. CardioVation Ethicon Inc, a division of Johnson & Johnson, wanted to improve the device which allows beating-heart bypass surgery, so it turned to design firm Strategix Vision Inc, Bozeman, Mont., (strategixvision.com). The challenge for the design firm was to take suggestions from surgeons on the OEM's design team, add its own ideas, and work them into a newer device.

The Embrace isolates the work area from the motion of the beating heart so surgeons can perform delicate coronary surgeries without the considerable drawbacks that come from stopping the heart, a widely used procedure. A traditional coronary bypass requires that doctors position a heart so as to stabilize the coronary arteries, a task usually preceded by hooking the patient to a heart-lung bypass machine to keep that person alive and then stopping the heart. But such surgery is extremely invasive, high risk, and involves taking the patient close to death. “Stopping the heart leads to enormous patient stress,” says Strategix's Design Director Kent Swendseid. “For example, to provide more time for surgery the patient is chilled and then suffers from oxygen deprivation. Chilled blood also affects the brain. In many cases, the trauma of opening the patient's ribcage to access the heart is not the worst part of the ordeal. So the concept of working on a beating heart is a breakthrough.”

After a few weeks of sketching, discussions, and prototyping, the Strategix team presented several alternatives to CardioVation which decided which combination of features would work best. “For example, using suction on the end tabs to hold them in place on a heart was an existing idea and the end effector was similar. But the internal mechanisms changed through the cycle,” he adds.

“We had to package the design into something that was an ergonomic improvement for surgeons and fit what CardioVation calls its brand statements,” says Swendseid. For example, part of the company identity includes being a developer of products that are easy to use in the OR. And to some extent, the original design was deemed too difficult to use. “The mechanism that clips to the retractor started as a kind of pliers-grip device that also stiffens the gooseneck by squeezing two levers together. But it took too much effort, about 40 lbs. It could be repositioned only a few times because of the high force. Surgeons also thought the original design was too large. An open chest looks enormous, but there can be a lot going on there, so space is at a premium,” he says.

The redesign includes two different control handles. One clamps the device to the chest retractor, and the other operates the trunk and end effector. Now surgeons can reposition the device on the retractor without loosening the end effectors held in place by suction.