Wednesday, November 29, 2006

The Latest on Robotic Tools with a Sense of Touch

Filed under: Surgery

Allison Okamura, a researcher of human-machine interaction at Johns Hopkins University, presented promising research which may provide new robotic tools for surgeons with a sense of touch:

"The surgeons have asked for this kind of feedback," says Allison Okamura, an associate professor of mechanical engineering at Johns Hopkins. "So we're using our understanding of haptic technology to try to give surgeons back the sense of touch that they lose when they use robotic medical tools."

"The sense of touch is important to surgeons," Okamura says. "They like to feel what's happening when they're working inside the body. They feel a 'pop' when a needle pokes through tissue. They can feel for calcification. Their sense of touch helps tell them where they are within the body. In robotic procedures and other types of minimally invasive surgery, surgeons insert long tools between their hands and the patient. This approach has definite medical benefits, but for the surgeon, there's a loss of dexterity and haptic information. It's like operating with chopsticks that have grippers on the end."

To address this, Okamura's team is experimenting with several techniques that could give some of those sensations back to the surgeons. One option is to attach to the robotic tools force sensors capable of conveying to the human operator how much force the machine is applying during surgery. Another idea is to create mathematical computer models that represent the moves made by the robotic tools, and then use this data to send haptic feedback to the operator.

Both approaches have advantages and drawbacks. Force sensors may be highly accurate, but they are expensive and would have to be made of sterile, biocompatible materials in order to be used in medical robots. Computer models could be less expensive but might not respond quickly enough. "I'm exploring both approaches to see which produces the best results," Okamura says. "The most important thing is that the haptic feedback sent to the human operator must feel right because the fingers aren't easily fooled."

Okamura's team has already published a journal article describing an early version of this visual haptic feedback project and is continuing to refine the system.

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replies: 2 comments
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Haptics and force-feedback are very badly needed in robotic endoscopic surgery. There is a problem guaging tissue forces and during suturing during the learning curve lots of sutures get broken while learning to cinch down the knots. As far as expense- with the most popular robot where this would be used at $1.4 M a few extra dollars is not so significant.

link to a podcast about the future of surgical robots and endoscopy and the coming radical transformation:
http://docinthemachine.com/2006/11/23/docinthemachine-futurevision-surgery-podcast-2/


Posted by: Steven F Palter, MD
on November 29, 2006 08:24 AM GMT

i'm not really a medical kind of guy, but i was thinking of just putting some sensors connected to a sort of clamp thingy on the finger... the more pressure the sensor in the mechanical arm "feels" the more pressure the clamp on the finger exerts... i guess, that's easier rather than covering the mechanical arm with some sort of mechanical "skin"...


Posted by: Carlo Ang
on November 29, 2006 08:25 AM GMT