In the game "Operation," players try to remove items from a patient without touching the body's openings. Failure results in a buzzer going off and the patient's nose lighting up. In real life, bungling an operation comes with slightly larger consequences.
If only Operation came with the Chimaera handheld surgical tool. The device, developed by tech and design firm Cambridge Consultants, comes with sensing technologies that guide surgeons to the exact location of the procedure they're performing in the human body, without nicking blood vessels, nerves, or other nearby innards. The tool is specifically designed to work with neurostimulation procedures, wherein a device (essentially repurposed pacemaker technology) applies electrical stimulation directly to the nervous system. This technique has been used to treat Parkinson's, epilepsy, and more recently, for spinal pain management.
The challenge with today's therapies, however, is that they're invasive and unreliable. "It's an implanted device the size of a small hockey puck. Electrodes have to be connected to nerve bundles, connections break, batteries die," says Simon Karger, head of surgical and interventional products at Cambridge Consultants. Karger says that neurostimulation can theoretically treat any condition related to the way the body regulates itself, from migraines and obesity to and incontinence. If someone is in crippling pain, then a large puck-sized implant may still make sense. A number of studies have shown that neurostimulation reduces patient reliance on opioids like oxycodone.
But if a patient just gets a migraine once in awhile? That surgery doesn't seem so necessary all of a sudden.
Fortunately, researchers are developing a miniaturized neurostimulation device—a single battery-free microchip outfitted with electrodes, which is powered by the human body and communicates via wireless power. The big challenge with that technology: there are only a handful of surgeons in the world that can safely access the nerve—deep in the face, behind the eye socket—where it needs to be installed without leaving scars or creating complications.
"Nerve damage is one of the biggest fears of surgeons, and it's almost impossible to determine where a nerve is unless you have perfect anatomical knowledge," says Karger.
That's the problem that Chimaera is designed to address.
The device, a small unit featuring the kind of curved blade used for dissection, combines sensors that can detect nearby structures (like blood vessels) with a 3-D image created by a pre-operative CT scan. A surgeon uses the scan to find the proper path in the body, and Chimaera guides them along that path. The device also alerts the surgeon once they have reached the target nerve.
"We ran a demo of this system where we had non-surgeons who were able to come in and get pretty close to following the target path and deploying an implant on a mannequin," says Karger.
For now, Karger calls Chimaera "the surgical equivalent of a concept car." It won't be commercially available for quite awhile, but when it is, pain management could get a lot easier.