For the first time in more than 15 years, Cathy Hutchinson took a sip of coffee without the help of a caregiver. Hutchinson, who became a tetrapelegic after suffering a stroke, had assistance in achieving this feat, but she controlled the whole situation with her own mind.

Hutchinson stared down the cup of coffee and with technology monitoring her brain activity, she controlled a robotic arm that brought the cup to her so she could take a sip.

Scientific Breakthroughs for Paralyzed Patients: Woman Controls a Robotic Arm With Her Mind, Surgeons Rewire Mans Nerves to Restore Finger Movement

(Image: Nature YouTube screenshot)

This latest report on mind control of robots, which was published online Wednesday in the journal Nature, comes from scientists at Brown University, the Providence VA Medical Center in Rhode Island, Harvard Medical School and elsewhere.

It describes how two people who lost use of their arms and legs because of strokes years before were able to control free-standing robotic arms with the help of a tiny sensor implanted in their brains.

Scientific Breakthroughs for Paralyzed Patients: Woman Controls a Robotic Arm With Her Mind, Surgeons Rewire Mans Nerves to Restore Finger Movement

Image of the sensor compared to a dime. (Image: Nature YouTube screenshot)

The sensor, about the size of a baby aspirin, eavesdropped on the electrical activity of a few dozen brain cells as the study participants imagined moving their arms. The chip then sent signals to a computer, which translated them into commands to the robotic arms.

The computer was taught how to interpret the brain patterns through practice as the paralyzed participants watched the robot arms move and then imagined that they were moving their own arms the same way. Hutchinson succeeded at picking up the coffee, sipping and putting the cup back down four out of six tries.

“The smile on her face … was just a wonderful thing to see,” said Dr. Leigh Hochberg, a researcher with the Providence VA, Brown and Massachusetts General Hospital.

Scientific Breakthroughs for Paralyzed Patients: Woman Controls a Robotic Arm With Her Mind, Surgeons Rewire Mans Nerves to Restore Finger Movement

(Image: Nature YouTube screenshot)

Watch Hutchinson move the robotic arm:

Andrew Schwartz, who is doing similar research at the University of Pittsburgh, said the coffee-sipping was encouraging because it represents an everyday task a paralyzed person might want to do. “I think it’s showing this technology has therapeutic potential,” he said.

But he and others said the technology faces a number of hurdles to widespread use, like reducing its high cost, making it more reliable, and refining the technology. For example, the brain implant now sends signals out with a wire through the skull, and researchers want to develop a completely implanted version that communicates wirelessly.

Learn more about the trial called BrainGate here.

On a similar vein, a separate study was also recently published about an operation on a man paralyzed from the waist down where surgeons were able to connect damaged nerves with undamaged ones, giving him back some function in his fingers.

A terrible car accident in June 2008 left a then 67-year-old man paralyzed no function of either of his hands but some movement in his arms. Now at 71 years old, surgeons from Washington University School of Medicine performed a breakthrough operation to “rewire” his nerves so he can move his fingers.

Medical Daily reports that in the accident, the man crushed his spine at the base of his neck.  The plastic and reconstructive surgery team at Washington University recently published success of the operation in the Journal of Neurosurgery, describing how they cut undamaged nerves in the man’s arms and reconnected them with damaged ones that connected to his fingers.

BBC has more on the operation:

Ida Fox, an assistant professor of plastic and reconstructive surgery at Washington University, told the BBC: “The circuit [in the hand] is intact, but no longer connected to the brain.

“What we do is take that circuit and restore the connection to the brain.”

She said it was a “really novel” and “refreshingly resourceful” way of restoring movement. However, she warned this would never restore normal function. “That isn’t going to happen,” she said.

Watch this video for more from the surgeons on the surgery:

According to the university’s press release, the technique was developed and performed by Dr. Susan Mackinnon, chief of the division of plastic and reconstructive surgery. Mackinnon originally used the surgery to help patients with arm injuries specifically damaging nerves controlling the thumb and index finger. This is the first time it has been used to help reverse the effects of a spinal cord injury. Mackinnon also said that it is not considered an “overly complex” or expensive surgery either.

“It’s not a hand or a face transplant, for example. It’s something we would like other surgeons around the country to do,” Mackinnon said in a statement.

Still, BBC notes that this surgery is not an easy fix. It was only after eight months that the man began to move his fingers and later learned to feed himself and do a little bit of writing with assistance. It is reported that with more therapy, his function should continue to improve.

The Associated Press contributed to this report.