I. INTRODUCTIONA. NeuroplasticityB. Rehabilitation methodsC. Robot-aided therapyII. MethodsA. Grip and Twist OverviewB. Safety FeaturesC. ProgrammingIII. ConclusionAbstract— A device for acute phase post-strokerehabilitation was designed to aid patients in recoveringsupination/pronation of the wrist and flexion/extension of thehand. The loss of these two motions are common adverse aftereffects of stroke. The device consists of a wrist rotator and ahand grasper, both of which are driven by DC Brush Servomotors with encoders. These motors are controlled by amicroprocessor that allows for active and passive movement.Resistance levels can be adjusted based on the level offunctionality of each patient. The system is interfaced with acomputerized video game that prompts the patient to performa specific motion: either rotation of the wrist or grasping-ungrasping of the hand. If the patient is unable to completethe motion in a short period of time, the device assists them.The microprocessor continually monitors the degree to whichthe patient is capable of performing each motion, whichfacilitates progress tracking of each patient. I. INTRODUCTIONEARLY 700,000 people are affected by stroke each year,commonly leading to impairments of speech andmotor control, depending on the location in the brain that isdamaged. A common result of stroke is hemiplegia, which isthe paralysis, or impairment of motor functioning on oneside of the patient’s body. Stroke leaves approximately470,000 with this chronic disability making it the leadingcause of adult disability in the United States. Improvementsof rehabilitation methods and therapy continue to be anactive and ongoing area of research.NResearch has shown that combining various methods ofrehabilitation leads to a more efficient and completesuccessful recovery of motor functioning. Robot – aidedtherapy is a technology that is at the forefront of thisgrowing field of stroke rehabilitation. Robot – aidedtherapy techniques incorporate many methods that havebeen shown clinically to improve motor functioningincluding repetitive motion, visual stimulation, andprogression tracking. Many robot – aided devices havebeen developed, including the MIT-Manus devices. Thesedevices focus on arm, hand or leg motions exclusively byfocusing on linear motion, such as planar extension of theelbow. Neuroplasticty provides the theoretical groundworkfor Robot-aided stroke rehabilitation and is described below.A. NeuroplasticityAccording to classical belief of brain functionality, braindamage was deemed permanent and it was consideredManuscript received April 7, 2008. This work was supported in part byMichelle Johnson, PhD of the Medical College of Wisconsin at Milwaukeewho sponsored this project and the Medical College of Wisconsin atMilwaukee for funding the project. C. Brown is a senior in BME at the University of Wisconsin – Madison,USA (e-mail: cbrown2@ wisc.edu). N. Kleinhans is a senior in BME at the University of Wisconsin – Madison,USA (e-mail: [email protected]).L. Linstroth is a senior in BME at the University of Wisconsin – Madison,USA (e-mail: [email protected]).S. C. Lesher-Perez is a senior in BME at the University of Wisconsin –Madison, USA (e-mail: [email protected]).impossible to regain lost function. However, with advancesin neurological research a new model of neuroplasticity isbecoming more and more accepted. Neuropasticity is the“ability of neural systems to reorganize based on sensoryand motor experience1.” Improved imaging techniques aredemonstrating that new neural pathways can be constructedafter damage has occurred. Cao et al provides neural imagesthat shows new neural pathways being formed in the brainafter damage has occurred. Figure 1 shows brain activationin both hemispheres of the brain after damage had occurred.B. Rehabilitation methods Rehabilitation treatments that are clinically shown toincrease functional ability of impaired limbs in patientsutilize the theory of neuroplasticity to explain their success.Fischer, Barbas and Kahn et. al. 2005 provide furtherevidence for neuroplasticity by demonstrating that massedpractice, task-oriented re-education, visual imagery, andguided-force training leads to an elevated success rate ofrehabilitation.Massed practice refers to the repetitive use of the impairedlimb by performing specific functional tasks. Studiessuggest that highly repetitive movements are one of themost effective approaches to arm and hand functionrestoration (Prange, et al., 2006). Task-oriented re-education gives the patient a specific goal to accomplish byperforming motions with their impaired limb, which helpsengage the patient, alleviate boredom and instill a sense ofaccomplishment. Visual cues are also often used to make theperformed task seem more realistic and to provide visualstimulus to again alleviate boredom and monotony. Guided-force training involves applying force to assist the patient inperforming the desired motion or applying a resistive forceGrip and Twist: Hand Rehabilitation Device for Patients during theAcute Phase after StrokeCarly Brown, Nathan Kleinhans, Lee Linstroth, Sasha Cai Lesher - PerezFigure 1: MRI scan The MRI scan shows activated parts in both hemispheres of the brain in a patient who had a stroke. The right side of the brain activates to compensate for loss of functioning on left side of brain when moving the impaired limb. Source: Cao, et al., 1994to strengthen muscles while the patient performs a desiredmotion. Robot-aided therapy devices utilize some or all ofthe aforementioned methods, thereby providing effectiveand engaging rehabilitation. C. Robot-aided therapyRobot-aided therapy devices aim to provide a means toassist patients in performing specific motions whileemploying a task orientated environment and providingtherapists with continual feedback on patient progress.These devices allow patients to train under passive, active,resistive and bimanual modes.
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