Upper Body Robotic Exoskeleton

Robotics Automation and Control
Upper Body Robotic Exoskeleton (MSC-TOPS-85)
Portable device provides upper extremity motor rehabilitation for patients with neurological impairments
Innovators at the NASA Johnson Space Center (JSC) have developed a soft, wearable, robotic upper limb exoskeleton garment designed to actively control the shoulder and elbow, both positioning the limb in specific orientations and commanding the limb through desired motions. The invention was developed to provide effective upper extremity motor rehabilitation for patients with neurological impairments (e.g., traumatic brain injury, stroke). Due to its portable, battery-compatible design, NASA's garment allows for task-specific and intensive motor practice, an important part of rehabilitation for such patients, to be performed outside clinical environments (including in the home). In addition to upper extremity motor rehabilitation, the technology may also find applications in human performance augmentation, including in future spacesuit designs.

The Technology
NASA's soft, portable, wearable robotic device is "plug and play" - it includes all necessary electronics, actuation, software, and sensors required to achieve augmented limb movement. The garment is designed such that the human-robot interface distributes load across the torso, maximizing user comfort. Donning and doffing is simple, as the device lowers over the head, straps to the torso via Velcro, and possesses adjustable custom arm cuffs. Actuators are housed in the back of the garment, which pull custom conduit-tendon-based systems attached to the limb at optimized locations, causing the joint of interest to move to the specified orientation. Force sensing is employed to enable optimal control of the limb, measuring user-applied force to maintain commanded joint orientations. Integrated electronics and software provide power distribution, safety monitoring, data transfer and data logging. NASA's garment has multiple modes of operation. In active assist mode, shoulder abduction and flexion, and elbow flexion, may be commanded either simultaneously via coordinated control or individually while holding position/orientation of the other joints. In passive assist mode, the user can freely move the limb while the system provides minimal torque to the shoulder and elbow. The upper body robotic exoskeleton is at a TRL 6 (system/subsystem prototype demonstration in a relevant environment) and it is now available for your company to license and develop into a commercial product. Please note that NASA does not manufacture products itself for commercial sale.
  • Shoulder and elbow positioning: Positions the limb as programmed (e.g., for rehabilitation exercises), capable of isolating shoulder and elbow degrees of freedom
  • Portability: Unlike ground-based wearable robotics, the garment can be used outside the clinic, enabling task-oriented therapy (performing functional tasks as opposed to simple prescribed motions)
  • Comfort: The soft design utilizes rigid components only when necessary, effectively distributes loads around the torso to eliminate pressure points, and is easy to don and doff
  • Multiple control modes: Operators can select how much resistance is applied at the joint and set the device in different modes

  • Upper-limb motor rehabilitation
  • Assistance with upper-limb activities of daily living
  • Human performance augmentation: enhancing human strength and reducing muscle fatigue for industrial and military applications
  • Spacesuit designs: providing astronauts with additional strength to accomplish safer, more efficient spacewalks
Technology Details

Robotics Automation and Control
MSC-26191-1 MSC-26191-2
"On the Efficacy of Isolating Shoulder and Elbow Movements with a Soft, Portable, and Wearable Robotic Device," Kadivar Z., Beck C.E., Rovekamp R.N., O'Malley M.K., Joyce C.A. (2017)
Similar Results
Originally developed by NASA and GM, the Robo-Glove technology was a spinoff of the Robonaut 2 (R2), the first humanoid robot in space. This wearable device allows the user to tightly grip tools and other items for longer periods of time without experiencing muscle discomfort or strain. An astronaut working in a pressurized suit outside the space station or an assembly operator in a factory might need to use 15 to 20 lbs of force to hold a tool during an operation. Use of the Robo-Glove, however, would potentially reduce the applied force to only 5 to 10 lbs. The Robo-Glove is a self-contained unit, essentially a robot on your hand, with actuators embedded into the glove that provide grasping support to human fingers. The pressure sensors, similar to the sensors that give R2 its sense of touch, are incorporated into the fingertips of the glove to detect when the user is grasping an object. When the user grasps the object, the synthetic tendons automatically retract, pulling the fingers into a gripping position and holding them there until the sensor is released by releasing the object. The current prototype weighs around two pounds, including control electronics and a small display for programming and diagnostics. A lithium-ion battery, such as one for power tools, is used to power the system and is worn separately on the belt.
Bio-Magnetic Device To Enhance Mammalian Tissue Repair
Most magnetic therapy research and resulting devices have centered around pulsed unidirectional bioelectric systems. The technology available here for licensing utilizes a square-wave time-varying electrical current, which generates an electromagnetic field, via a wound coil incorporated into a sleeve and encircles the affected appendage. An external and commercially available time-varying compact electrical generator connects to the wound coil within the sleeve and is powered by a 9-volt battery. Prior industry attempts to use electromagnetic therapy on mammalian tissue have historically applied higher than necessary levels of electromagnetism, typically at 50 gauss or more. Researchers found that by inducing a Fourier-curve, time-varying electromagnetic wave at levels within 0.05 0.5 gauss for a pre-determined time-period, was optimum to achieve successful mammalian tissue regeneration. It is theorized that magnetic fields can alter the flow of positively charged calcium ions that interact with the muscles around small blood vessels causing them to relax. This effect in turn, causes constricted blood vessels to dilate, and dilated blood vessels to constrict. Depending upon the type of injury, enhanced tissue repair may occur through the suppression of inflammation, or the increase in blood flow.
Image of the SpaceSuit Roboglove Prototype
Space Suit RoboGlove (SSRG)
NASA is currently developing the next generation space suit for future missions, including the optimization of space suit gloves. When non-assisted space suit gloves are coupled to a pressurized suit and operated in a vacuum, they tend to limit the range of motion of an astronaut's hand to as little as 20% of normal range. Many of NASA's future missions will be in challenging environments where an astronauts hand dexterity will be critical for the success of NASA missions. Innovators at JSC have improved the performance on the second-generation, robotically assisted SSRG, to reduce exertion and improve the hand strength and dexterity of an astronaut in situ. The SSRGs system detects user finger movements using string potentiometers and contact with objects using force-sensitive resistors (FSRs). FSRs are imbedded in the distal and medial phalanges, palmar side of the glove. To move a finger, an actuator pulls a tendon through a Bowden Cable system which transfers mechanical pulling force of an inner cable relative to a hollow outer cable, like the brakes on a bicycle, as seen in the Figure below. An improved controller commands the new, more powerful linear actuator to drive tendon operation while minding custom controller parameters inputted through a digital editor tool. The Space Suit RoboGlove is at TRL 6 (system/subsystem model or prototype demonstrated in a relevant environment) and it is now available for licensing. Please note that NASA does not manufacture products itself for commercial sale.
Split-Ring Torque Sensor, Top View
Split-Ring Torque Sensor
The SRTS enables measurement of position, velocity, and torque of a rotating system (e.g., actuator, motor, crankshaft, rotor, etc.) using two optical sensors and a single, custom-designed split-ring rather than the standard dual-ringed systems commonly used for similar applications. The split-ring is comprised of two structural arcs positioned in a concentric, coplanar relationship, wherein each arc is attached to a component capable of rotation (e.g., a lower leg and upper leg, where the SRTS acts as a knee). The two arcs contain indications or codes on their outer surfaces that are read by the optical sensors to determine the relative deflection of the structural arcs as they rotate. The SRTS configuration discussed above is limited to 180-degree applications. The addition of a third structural arc and a third optical reader, however, would enable 360-degree functionality. Tests have shown the SRTS has a high degree of tolerance to temperature differences and provides higher resolution measurements than competing technologies.
Tri-Rotor Steering Wheel Yields Programmable Vehicular Control
Since NASAs Apollo program of the late 1960s and 1970s, many previous LTV hand controllers (e.g., joysticks, T-handles) were developed and utilized albeit with shortcomings. Some of these options yielded the desired level of control but were too physically taxing to use for long periods of time in a spacesuit environment. Others simply did not offer the necessary fine motor control. Thus, there has been a long-standing need for controllers that improve upon both of these limitations. The Tri-Rotor is a novel hand controller designed to reduce operator fatigue, add control capabilities (beyond those of a joystick), and increase the fidelity of control inputs. The design consists of two slotted handles that rotate independently within opposite sides of the Tri-Rotor main-body. Each handle is programmable and can rotate 45 degrees. In this iteration, the right handle rotates counterclockwise and acts as an accelerator and brake. The left handle rotates both clockwise and counterclockwise and controls crabbing whereby the vehicles rear wheels turn in the same direction as the front wheels facilitating diagonal or possibly lateral movement. The main-body of the Tri-Rotor rotates upon a central pivot like an automotive steering wheel and can provide directional input for Ackermann-like steering. The handles on the Tri-Rotor are designed with spacesuit kinematics in mind and are operated using the pronated and supinated motions of the astronauts hands allowed by the wrist bearings between the glove and the forearm of the spacesuit. The devices central steering pivot is also operated by the hands and is leveraged by the up and down motions of the arms allowed by the constant volume joints in the spacesuits shoulders. This hand controller design staves off operator fatigue and sheds the need for separate fine-dexterity controls without sacrificing precision. The Tri-Rotor Hand Controller has a technology readiness level (TRL) 5 (component and/or breadboard validation in relevant environment) and is now available for patent licensing. Please note that NASA does not manufacture products itself for commercial sale.
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