Upper Body Robotic Exoskeleton

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.

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.

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.

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 astronaut’s 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 SSRG’s 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.

ARC ANGEL is an active robotic system like ARGOS; however, its electric motor is not mounted overhead to a runway and bridge system, but instead is mounted to the test subject’s backpack-like PLSS where the motor(s) supplies real-time actuation torque off-loading to the upper arms via cabling. If a test subject picks-up a hammer, the system will react immediately to offload the weight of the hammer relative to the programmed environment. The ARC ANGEL system is comprised of an electric motor(s), soft goods, electronics hardware, firmware, and software. To provide a smoothly operating arm offloading analog and optimize system performance, engineers at JSC coded software that leverages kinematic algorithms and closed-loop architecture for motor control, along with custom computer language scripts to ingest sensor data. This allows ARC ANGEL’s subsystems to be seamlessly integrated and accurately simulate one to zero G environments. During operation, compact tension sensors and inertial measurement units detect arm weight and motion and provide a closed-loop control system that feeds data to a single-board computer and requisite firmware for processing. A custom graphical user interface was also developed in-house to provide controls for inputting desired arm offload values. Additionally, ARC ANGEL features its own power supply that provides power to its subcomponents without external cables. This allows the ability to function independently from ARGOS and further lends itself to potential terrestrial applications. This work directly correlates to active exosuit development that is being implemented for rehabilitation and/or assistive medical devices. ARC ANGEL is essentially providing a desired assistance (offload) while maintaining a subject’s full range of motion. The system hardware and software can be modified to custom-fit an individual without a spacesuit and toward limb-assisted movement – not just arm offloading. ARC ANGEL may already meet a higher physical demand and robustness given that it is engineered to perform in challenging environments with greater loads. ARC ANGEL is at a technology readiness level (TRL) 5 (component and/or breadboard validation in laboratory environment) and is now available for patent licensing. Please note that NASA does not manufacture products itself for commercial sale.