December 18, 2014Quadriplegic successfully uses mind-controlled robotic arm

Quadriplegic Jan Scheuermann gave the mind-controlled robotic arm a big thumbs up at the end of her trial period (Photo: Journal of Neural Engineering/IOP Publishing)

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In 2012, a quadriplegic woman managed to move a robotic arm, using only her thoughts, to a level of proficiency that allowed her to eat a chocolate bar using said arm. The University of Pittsburgh team behind the study didn't stop there, though. By improving the technology in the arm and working more closely with test subject Jan Scheuermann, researchers have since enabled her to replace the simple pincer grip of before with four new hand shapes – fingers spread, pinch, scoop, and thumb up – that allow for more complicated object manipulation.

Back in February 2012, Schuermann had two electrode grids – with 96 contact points each – surgically implanted into her left motor cortex, which controls right arm and hand movements. Hooked up to a brain-computer-interface, she was able to reach in and out, left and right, and up and down with the arm within a week of the surgery. In a few months she learned to flex the wrist back and forth, move it from side to side, and rotate it. She could also grip objects using a crab-like pincer hand shape.

For this second study, the researchers sought to increase the hand's functional utility while also maintaining a relatively low-complexity control space because more possible maneuvers means considerably more calibration. The 10-dimensional (10D) control (three dimensions of translation, three of orientation, four of hand shape) that they settled on had not been tested elsewhere, and they were unsure whether the brain would exhibit a preference for just one dimension or simultaneously handle all 10.

To calibrate the arm, Scheuermann watched animations of the movements and new hand shapes and imagined herself doing them while the team recorded the resultant signals in her brain. After identifying the brain activity patterns that correspond to each movement, these signals were then translated into instructions for the robotic arm.

As in the previous study, Scheuermann's performance improved over time, though the researchers were surprised that her overall ability to control the arm was better with the higher complexity of the 10D version than in the prior 7D experiments. Scheuermann still struggled to perform more difficult object manipulation, however, and she tended to favor the strategies she developed in the 7D trials – as though attempting to negate the extra dimensions of hand control. The researchers believe this behavior was a direct result of the previous experience, which suggests it might not occur in subjects who jump straight from nothing to 10D control.

The researchers also note with curiosity that Schuermann found objects easier to grasp if they had been displayed during the preceding calibration.

Schuermann underwent surgery in October to have the electrode arrays removed. She speaks of the experience fondly, saying "this study has enriched my life, given me new friends and coworkers, helped me contribute to research, and taken my breath away."

For other victims of paralysis, the research provides a new hope. "Our results indicate that highly coordinated, natural movement can be restored to people whose arms and hands are paralyzed," said co-author Andrew Schwartz.

A paper describing the research was published in the Journal of Neural Engineering.

Source: University of Pittsburgh School of Medicine

残疾病人成功使用意念控制机械手臂

12月18日，2014Quadriplegic成功地使用心灵控制的机械手arm

四肢瘫痪一月休门给心灵控制机械臂一个大拇指在她的试用期（图片结束：神经工程的

IOP出版）

图片廊（3图像）

2012年，一个四肢瘫痪女子设法移动机械臂，只用她的想法，以熟练的水平，让她吃用上述臂一块巧克力。美国匹兹堡大学的研究小组研究的背后并没有就此停止，但。通过改进技术，在手臂和考试科目一月休门更密切合作，研究人员已经使她有四个新的手形替换之前简单的夹击抓地力 - 手指张开，捏，舀，并竖起大拇指 - 这允许。更复杂的对象操作

早在2012年2月，Schuermann有两个电极板栅 - 96接触点的每个 - 手术植入她的左运动皮质，控制右胳膊和手部动作。迷上了脑机接口，她能够达到进出，左，右，以及上下一周??内手术的手臂。在短短的几个月，她学会了弯曲手腕来回穿梭，从一边移动到另一边，并旋转。她也可以使用一个螃蟹状钳手形握物体。

对于此第二项研究中，研究人员试图增加手的功能性的效用，同时也保持相对低的复杂度控制的空间，因为更可能操纵装置相当多的校准。的10维（10D）控制（三个维度平移，3个姿态的，四手形的），它们在没有被别处测试解决，他们不确定大脑是否会显示出对于仅有一个维度或同时偏爱处理所有10

要校准手臂，休门观看了动作和新的手形状的动画和想象自己在做他们，而球队记录在她的大脑产生的信号。确定对应于每个运动的大脑活动模式后，这些信号，然后转换成指令的机器人手臂。

正如在以前的研究中，休门的性能改善随着时间的推移，虽然研究人员感到惊讶的是她的整体能力控制臂是与更高的10D版本复杂优于在现有7D实验。伊尔曼仍然挣扎但是执行更加困难对象操作，和她倾向于赞成她开发的7D试验的策略 - 就像试图否定手动控制的额外维度。研究人员认为，这种行为是以前的经验，这表明它可能不会发生在谁跳直接从一无所有到10D对照组的直接结果。

研究人员还注意到好奇心Schuermann找到的对象更容易把握，如果他们已经前面的校准过程中显示出来。

Schuermann接受手术十月有去除电极阵列。她讲的经验深情地说：“这项研究丰富了我的生命，给了我新的朋友和同事，让我贡献的研究，并采取了我的呼吸。”

瘫痪的其他受害者，该研究提供了新的希望。 “我们的研究结果表明，高度协调，自然的运动可以恢复到人，他们的胳膊和手都瘫痪了，说：”合着者安德鲁·施瓦茨

一份文件，说明这项研究发表在神经工程学杂志

资料来源：医学匹兹堡大学法学院