Medical

Flexible claw puts non-invasive surgery in surgeons' hands

The FlexDex is a surgical instrument that replicates the full motion of a surgeon's wrist onto a tiny claw, to perform minimally invasive procedures
The FlexDex is a surgical instrument that replicates the full motion of a surgeon's wrist onto a tiny claw, to perform minimally invasive procedures
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FlexDex founders (from left), Shorya Awtar, Greg Bowles and James Geiger
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FlexDex founders (from left), Shorya Awtar, Greg Bowles and James Geiger
The FlexDex system uses a gyroscopic handle that allows the surgeon to angle, twist and rotate their wrist in three dimensions, and the tip of the instrument will follow
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The FlexDex system uses a gyroscopic handle that allows the surgeon to angle, twist and rotate their wrist in three dimensions, and the tip of the instrument will follow
The FlexDex is a surgical instrument that replicates the full motion of a surgeon's wrist onto a tiny claw, to perform minimally invasive procedures
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The FlexDex is a surgical instrument that replicates the full motion of a surgeon's wrist onto a tiny claw, to perform minimally invasive procedures

Minimally invasive surgery often sees robots acting as a surgeon's hands inside the patient's body. Such robots are large and cost several million dollars, and although smaller handheld instruments are out there, their straight-stick design means they're not as dexterous as a skilled surgeon's own hands. A new "needle driver" from a University of Michigan startup, FlexDex Surgical, is designed to precisely mimic the motions of a surgeon's wrist and translate it to a tiny flexible claw, with no electronic or computerized components.

Anchored just above the surgeon's wrist, the FlexDex has a gyroscopic handle that can be rotated, twisted, and angled in three dimensions, while the rest of the device stays still. Those motions are translated through a cable down the length of a metal shaft to the tip, where a two-pronged clamp closely follows those instructions like a tiny robotic replica of the surgeon's own hand.

The pinchable claw and precise rotation lets the FlexDex specialize in internal suturing. For existing devices, a task that fiddly usually requires big, awkward movements on the surgeon's side, but the FlexDex's center of rotation is in the same spot as the human wrist. According to the team, that means its movements aren't inverted like other instruments.

"If I move my hand up, the device tip goes up," says Jim Geiger, co-inventor of the Flexdex. "Wherever I move my hand, the tip of this instrument follows."

The FlexDex system uses a gyroscopic handle that allows the surgeon to angle, twist and rotate their wrist in three dimensions, and the tip of the instrument will follow
The FlexDex system uses a gyroscopic handle that allows the surgeon to angle, twist and rotate their wrist in three dimensions, and the tip of the instrument will follow

The long-used Da Vinci line of surgical robots may be more versatile and provide finer control, but they also come with multi-million-dollar price tags that can keep them out of reach of small or remote hospitals. For a much more reasonable US$500, the FlexDex can help these facilities provide minimally invasive surgery, which is less traumatic and painful than being cut right open, and takes far less recovery time.

"I was amazed by the sophistication of the (Da Vinci) technology," says Shorya Awtar, co-inventor of the FlexDex device. "At the same time, I had a strong instinct that this functionality can be achieved much more simply and cost-effectively. At its price point, this technology would not reach patients across the globe."

So far, the device has been tested in a few different procedures for examining abdominal organs and inside the lungs, but in future FlexDex plans to put it to work treating hernias, and in hysterectomies and prostate cancer removal.

FlexDex founders (from left), Shorya Awtar, Greg Bowles and James Geiger
FlexDex founders (from left), Shorya Awtar, Greg Bowles and James Geiger

"This is the culmination of 10 years of effort and to know that the device is performing exactly as we expected it would, impacting patients' lives in a positive way — it's an amazing feeling," says Geiger. "We always saw the potential, but now it's crystallized."

While similar devices, like Vanderbilt University's mechanical wrist, are in the process of being patented and approved by the US FDA, it could still be a few years before they start appearing on the market. FlexDex Surgical, meanwhile, is already beginning to ship its instruments throughout the US, and the company hopes to eventually expand to the rest of the world. Besides the claw tip, the team is also working on releasing other instruments for the system over the next year.

The researchers demonstrate the FlexDex device in the video below.

Source: University of Michigan

An ergonomic surgical tool for minimally invasive procedures

3 comments
John S. Studer
$500 for a medically certified tool? Amazing! There are many industries that could use a similar tool. There are a large number of technicians that would pay $500 for this tool, and for non-medical use its probably only $100 or less - what about a plastic version? Different sizes? A flexible shaft? Integrated illumination and optics? A plumbers dream!
ljaques
Cool tool, and only $500 for a SINGLE USE! There's no way that instrument could fit into, let alone be run through an autoclave cycle. I cut my hand with a pruning saw last year. The surgeon who stitched up my knuckle gave me the set he opened because they would have thrown them away (scissors, forceps, tweezers), but they threw away the 10ml of lido due to a short shelf life. (darn, thought I might refrigerate it for later use, as I now have a surgical set.) Anyway, I waited 7 hours to be operated on and it took 15 minutes for me to be numbed, cleaned out, and stitched up. The bill was $1,024. <sigh> No doubt the Chiwanese clone of these tools will be sold at a sub $10 price point very soon, salvaged from an operating room, dissected, and made entirely out of plastic. :-/
MD
The problem with a flex shaft is that with increased degrees of freedom it becomes "nontrivial" to define how mush each "joint" moves for a given input. The wrist and arm only have 6 degrees of freedom (7 including a basic grasping function), and more and the "robot" becomes overactuated and in many cases the motion will be undefined.