1244 Part F Field and Service Robotics operation,sending of alarms and discussions with able to measure.analyze.and communicate physiologi- rehabilitation professionals at medical centers. cal signals to an external computer wirelessly.Systems such as the LifeShirt (VivoMetrics,Inc.)[53.148]have The host computer software may also have higher-order been and are being developed for front-line soldiers features,for example,timers for repetitive actuation of and rescue operation personnel whose health may be- lights and monitoring for anomalous sensor readings come imperiled when out of touch with and unable to (e.g.,call security when the smoke detector activates, communicate verbally with their base command.For alert inhabitants with an in-home alarm when stove- rehabilitative purposes,for example the Intel Proactive top power is on and no pot is on the stove).More Health Initiative [53.149]is an example of a system advanced features that involve multi-input and multi- that use on-person position and motion sensing to detect output control and adaptive,predictive,context-aware potentially dangerous or undesirable situations. operation [53.147]are areas of active research,and The most significant obstacles to the widespread especially important to the rehabilitation community. adoption of these technologies in the short term are cost, false-positive alarms,inconvenience,and encumbrance. 53.5.4 Wearable Monitoring Devices Advances in microelectronics,nanotechnologies,soft- ware algorithms,and networking capabilities will drive One component of an automated rehabilitation envi- the research and consumer acceptance of this technology ronment is the subsystem that a person wears to be sector. Part 53.6 Safety,Ethics,Access,and Economics Rehabilitation robots interact closely with humans,often reducing the risk of forcing a limb into an undesirable sharing the same workspace and sometimes physi-configuration,or of a high-impact collision.A manual cally attaching to humans,as is the case of robotic override switch can be incorporated so that the user can movement-training devices and prosthetic limbs.Fur- shutdown the system.Finally,the user can be instructed thermore,the devices are by necessity powerful enough on how to safely operate the device and avoid dangerous to manipulate the environment or the user's own situations.Safety ultimately depends,however,on care- limbs,which means that they are also often powerful ful and rigorous failure mode analysis and remediation enough to injure the user or another person nearby by the system designers. by colliding with them or moving their limbs inap- From a systems perspective,when all else fails ac- propriately.Safety is clearly of paramount importance.tively to protect the user,it must be the design itself See Chap.56 for an in-depth discussion of safety and that makes the robot inherently unable to injure its user. robotics. Part of the solution is in reducing the weight,round- A common strategy for ensuring safety is to incor- ing the surface characteristics and making appropriate porate multiple,redundant safety features.A device can materials choices.The goal of inherent safety,however, be designed to be mechanically incapable of moving is often at odds with high performance and adequate itself or the user's limbs in such a way as to cause in-payload for real-life tasks.Recently,several approaches jury.Limits can be placed on the range,strength,and to designing personal robots-in other words the class speed of actuators so that they can accomplish the de- to which assistive rehabilitation robots belong-have sired task but no more.Breakaway attachments can be sought to address both goals by dividing the two tasks of used to attach to users'limbs.Covers can protect the compensating for gravity(arm plus payload)and mov- user from pinch points in the device.Redundant sensors ing the payload around in space [53.150].The solution can be included,so that if one sensor malfunctions an-is to provide two actuators per joint on the joints that other sensor can identify the malfunction and help shut support the arm segments and payload against gravity: down the machine safely.Watchdog timers can moni-one slow,gear-reduced motor and energy-storing device tor the health of the control computer.Software checks such as a large spring or compressed air volume,and can limit forces,motions,speeds,and user adjustments one small,back-drivable motor that provides the power to control parameters,as well as check for sensor health needed to move objects around quickly and precisely. and other dangerous situations.Control strategies can be Most robot manipulators have approximately a 1:10(or designed so that the device is mechanically compliant. worse)payload-to-weight ratio.A system with a dual,1244 Part F Field and Service Robotics operation, sending of alarms and discussions with rehabilitation professionals at medical centers. The host computer software may also have higher-order features, for example, timers for repetitive actuation of lights and monitoring for anomalous sensor readings (e.g., call security when the smoke detector activates, alert inhabitants with an in-home alarm when stove￾top power is on and no pot is on the stove). More advanced features that involve multi-input and multi￾output control and adaptive, predictive, context-aware operation [53.147] are areas of active research, and especially important to the rehabilitation community. 53.5.4 Wearable Monitoring Devices One component of an automated rehabilitation envi￾ronment is the subsystem that a person wears to be able to measure, analyze, and communicate physiologi￾cal signals to an external computer wirelessly. Systems such as the LifeShirt (VivoMetrics, Inc.) [53.148] have been and are being developed for front-line soldiers and rescue operation personnel whose health may be￾come imperiled when out of touch with and unable to communicate verbally with their base command. For rehabilitative purposes, for example the Intel Proactive Health Initiative [53.149] is an example of a system that use on-person position and motion sensing to detect potentially dangerous or undesirable situations. The most significant obstacles to the widespread adoption of these technologies in the short term are cost, false-positive alarms, inconvenience, and encumbrance. Advances in microelectronics, nanotechnologies, soft￾ware algorithms, and networking capabilities will drive the research and consumer acceptance of this technology sector. 53.6 Safety, Ethics, Access, and Economics Rehabilitation robots interact closely with humans, often sharing the same workspace and sometimes physi￾cally attaching to humans, as is the case of robotic movement-training devices and prosthetic limbs. Fur￾thermore, the devices are by necessity powerful enough to manipulate the environment or the user’s own limbs, which means that they are also often powerful enough to injure the user or another person nearby by colliding with them or moving their limbs inap￾propriately. Safety is clearly of paramount importance. See Chap. 56 for an in-depth discussion of safety and robotics. A common strategy for ensuring safety is to incor￾porate multiple, redundant safety features. A device can be designed to be mechanically incapable of moving itself or the user’s limbs in such a way as to cause in￾jury. Limits can be placed on the range, strength, and speed of actuators so that they can accomplish the de￾sired task but no more. Breakaway attachments can be used to attach to users’ limbs. Covers can protect the user from pinch points in the device. Redundant sensors can be included, so that if one sensor malfunctions an￾other sensor can identify the malfunction and help shut down the machine safely. Watchdog timers can moni￾tor the health of the control computer. Software checks can limit forces, motions, speeds, and user adjustments to control parameters, as well as check for sensor health and other dangerous situations. Control strategies can be designed so that the device is mechanically compliant, reducing the risk of forcing a limb into an undesirable configuration, or of a high-impact collision. A manual override switch can be incorporated so that the user can shutdown the system. Finally, the user can be instructed on how to safely operate the device and avoid dangerous situations. Safety ultimately depends, however, on care￾ful and rigorous failure mode analysis and remediation by the system designers. From a systems perspective, when all else fails ac￾tively to protect the user, it must be the design itself that makes the robot inherently unable to injure its user. Part of the solution is in reducing the weight, round￾ing the surface characteristics and making appropriate materials choices. The goal of inherent safety, however, is often at odds with high performance and adequate payload for real-life tasks. Recently, several approaches to designing personal robots – in other words the class to which assistive rehabilitation robots belong – have sought to address both goals by dividing the two tasks of compensating for gravity (arm plus payload) and mov￾ing the payload around in space [53.150]. The solution is to provide two actuators per joint on the joints that support the arm segments and payload against gravity: one slow, gear-reduced motor and energy-storing device such as a large spring or compressed air volume, and one small, back-drivable motor that provides the power needed to move objects around quickly and precisely. Most robot manipulators have approximately a 1:10 (or worse) payload-to-weight ratio. A system with a dual, Part F 53.6