Fiber-Optic “Nerves” Enable Sensitive Surgery Tools

Can you make a robot come to feel? That was the question posed to Johnson Space Heart engineer Toby Martin.

It wasn’t a coronary heart that NASA required to give its Robonaut, though—it was tactile sensing for the robot’s hands.

“It did not have an autonomous greedy ability,” Martin claims of the initially model of NASA’s robot astronaut. A manage methods professional, he was tasked in 2004 with on the lookout for a way to give it that capability. “First we had to determine out how to feeling when it’s greedy a little something,” he claims. “We required the hand to be capable to seize an item and alter finger forces and positions and tensions to decide up irregular objects.”

At minimum just one enterprise that responded to Martin’s request for proposals, Clever Fiber Optic Techniques (IFOS) Company, was no stranger to NASA. Much of the Silicon Valley, California-centered company’s funding to develop its original engineering had occur from two Compact Small business Innovation Study (SBIR) contracts with Langley Study Heart a decade previously.

NASA’s SBIR and Compact Small business Technology Transfer (STTR) systems make relatively little investments in promising technologies that could prove helpful to the Space Agency’s missions and also demonstrate industrial possible.

For the Langley undertaking, the enterprise had proposed establishing “smart surfaces” for aerospace materials and other purposes by producing what IFOS phone calls “optical nerves.” These are optical fibers with reflective micro-buildings referred to as fiber Bragg gratings imprinted in just their cores at intervals. A product known as an optical interrogator sends light-weight along the fiber, and every single grating reflects back again a distinct wavelength signature, which modifications slightly if there are modifications to strain or temperature.

“If you extend a grating, the wavelength that arrives back again turns into lengthier, proportional to the strain,” a phenomenon known as red change, explains Richard Black, chief scientist at IFOS. “If the grating is compressed, there’s a proportional blue change.” Equally, a increase in temperature will cause red change, although a drop leads to blue change. The IFOS interrogator can detect modifications in wavelength on the order of picometers to femtometers, the infinitesimal unit used to measure atoms, which it employs to identify strain or temperature transform.

With a collection of fibers attached to or embedded in a floor, every single with quite a few fiber Bragg grating sensors along its duration, the interrogator can watch strain and temperature across the entire floor, a ability that has a multitude of doable purposes across many fields (Spinoff 2002).

For Robonaut’s hand, the enterprise proposed that its engineering could identify the posture of every single finger in real time by measuring the strain that arrives with bending, and if it took readings fast enough, it could even detect vibrations and textures.

Technology Transfer

“I was type of dubious that it would get the job done for our application, but I was intrigued,” claims Martin. “It delivered many of the gains of strain gauges with no some of the negatives, like external electrical sounds and interference. With quite a few gratings for each fiber, the density of sensors that could in good shape into a little room was also a as well as.” Johnson granted the enterprise an SBIR deal to investigate the concept’s feasibility. To stay clear of rebuilding the hands, NASA asked for a glove that in good shape around the existing hands.

At the time, IFOS was nonetheless working with significantly the same interrogator it had produced for Langley, supporting no more than ten sensors. To outfit an entire hand demanding many more sensors, however, the enterprise manufactured a essential transform by establishing a scalable architecture that created an enduring improvement in its sensing capabilities, claims Black.

With Johnson funding, the enterprise took an optical chip principle manufactured for telecommunications purposes, modified it for its massively parallel sensing architecture, and labored with a foundry to customize a photonic spectral processor—a single chip with many waveguides stamped into it. The processor acts like a prism, sending various elements of the spectrum to various photodetectors in an array. The interrogator screens modifications in the ratios of different spectral components simultaneously to enable exact dedication of the sensor wavelengths.

The capability to watch many sensors simultaneously permits for significantly more quickly readings, which is significant for detecting, for instance, the little, rapid vibrations induced by friction with a textured floor.

The glove did not get the job done properly due to misfires induced by wrinkles and other problems, claims Martin. Less than a Stage II SBIR deal, nonetheless, IFOS and the Mechanical Engineering Office at Stanford University produced their personal finger prototype. “We analyzed it and confirmed the experiments the enterprise had run showing it labored,” Martin claims. At the time, both equally the finger prototype and the interrogator ended up far too massive to incorporate into a human-sized hand.

That was as significantly as the undertaking went, but anyone from the Johnson crew pushed Behzad Moslehi, the company’s chief govt and chief engineering officer, to pursue funding for doable health-related purposes by means of the Nationwide Institutes of Wellbeing (NIH), he claims. “I appeared into it, and I located it was the ideal home.”

Gains

IFOS has because located a multitude of doable health-related purposes for its fiber-sensing engineering.

Shortly just after the Robonaut undertaking, as the enterprise was checking out health-related purposes, Intuitive Surgical Inc. acquired just one of IFOS’ fiber-optic sensor methods to examine its use on dexterous surgical robots. A handful of yrs later on, IFOS created quite a few instrumented grasper assemblies with haptic sensing for a health-related application Samsung was evaluating. Moslehi claims he sees the health-related robot industry as an possibility for the company’s upcoming, by means of strategic partnerships with other businesses.

Closer to commercialization are instrumented biopsy needles that surgeons can use in conjunction with both equally MRI and ultrasound equipment. Stanford has been collaborating with IFOS by means of its engineering and health-related educational institutions to appraise and test the engineering on animals in the MRI ecosystem.

Resources used in real-time MRI-guided surgery—where the surgeon is either reaching into the MRI device or operating remotely from a manage room—must not respond to magnets or use energy, Black claims. “Optical-fiber sensors are suitable for the type of sensing we’re carrying out.” But this sort of a needle is virtually invisible in the MRI image.

“We arrived up with a way to measure the shape of a biopsy needle in real time, down to the idea of the needle, and superimpose the exact shape around the blurry artifacts from an MRI,” he claims. This lets surgeons see what they’re carrying out.

The instrument can also measure forces on the idea, which relate to tissue hardness. This delivers another clue for surgeons, as tumors are normally more durable than the bordering tissue. The crew is operating on giving haptic feedback, this sort of as a joystick for distant medical procedures that vibrates according to strain on the needle.

A catheter for sucking up fluids all through medical procedures would get the job done significantly the same way.

The enterprise has properly analyzed the engineering on pigs but has nevertheless to go by means of clinical trials and Food and drug administration acceptance, so the working area is nonetheless a techniques off. IFOS is also operating with Civco Healthcare Options to develop needles with optical fiber sensing.

Meanwhile, at the University of Calgary, another crew is operating on a identical product for MRI-guided neurosurgery, known as NeuroArm. IFOS offered the crew an interrogator and outfitted a pair of surgical forceps with its fiber-optic sensors.

Sleep centers at Stanford and at the University of California, Los Angeles, are collaborating with IFOS on a product to watch snooze apnea with a real-time strain profile of the airway, and the enterprise has a proposal pending with NIH for identical engineering to watch male incontinence.

In all these purposes, fiber-optic sensing permits for a thinner probe or surgical instrument and uniquely superior-resolution, multi-dimensional mapping.

In another undertaking, the enterprise is developing on its robotic-hand working experience to get the job done with the NIH and George Mason University to develop a robotic prosthetic hand that brings together IFOS’ fiber-optic sensors with ultrasonic imaging engineering that senses the activation of finger-precise muscle mass in the forearm. This lets the person manage the fingers with superior precision.

Extra-latest NASA get the job done will also probably lead to industrial purposes in medicine and beyond. Less than latest Compact Small business Technology Transfer (STTR) funding from Goddard Space Flight Heart and Johnson, IFOS and Stanford are collaboratively establishing specialized photonic built-in circuits (Photos), in this case for a “lab-on-a-chip” product to watch concentrations of biochemicals this sort of as protein and creatinine in animals and human beings, which includes astronauts. The engineering is identical to digital built-in circuits, with a light-weight source and different optical tools densely interconnected in just a chip more compact than a fingernail.

“It’s like a miniaturized, specialized photonic computing product or signal processor,” claims Moslehi. “And it operates at the pace of light-weight.”

IFOS is presently operating with quite a few PIC foundries to fabricate the optical chips, which could obtain a multitude of employs.

Black notes that, although the interrogator used in the Robonaut get the job done was desktop-sized, the just one now getting used for surgical products is 50 % the dimensions of a shoebox. The enterprise is operating to lessen that to the dimensions of a smartphone.

In the early days, claims William Cost, IFOS’ strategic systems supervisor, “the expense to construct a superior-efficiency interrogator was a major limiting element, but IFOS is continuously operating to lessen costs.” IFOS not too long ago accomplished beta screening and will quickly start a spouse and children of interrogators priced beneath $ten,000, a fraction of the price tag of its initially interrogators, he claims, noting that he expects these new products and solutions to open up new purposes for fiber-optic sensing beyond the health-related industries. They will enhance IFOS’ other superior-efficiency interrogators for acoustic and vibration measurements.

Moslehi claims NASA in distinct, as properly as other Federal organizations, has been instrumental in giving the funding essential to develop the company’s engineering improvements into products and solutions because the commencing. “Certainly, in the early days when IFOS was nonetheless run out of a garage in Silicon Valley, NASA funding was what helped us consider off and develop this engineering,” he claims.

Several of the initiatives because then, meant for use in spaceflight, rocket screening, atmospheric reentry, and other serious environments, have held that engineering sturdy, trustworthy, and chopping-edge.

To understand more about other technologies you use in daily lifestyle that originated with NASA, be sure to take a look at Spinoff.

Resource: NASA