FAMOUS: a Quantitative Assessment of Muscle Tone in the Wrist
This medical device is an automated robotic tone assessment device that non-invasively and properly quantifies tone of the flexor/extensor muscle groups that control the movement of an appendage such as muscles that control the wrist or ankle. Tone is a clinical term that describes muscle resistance to passive stretch. Current assessments of tone such as the Ashworth scale are qualitative and subjective in nature and therefore are unreliable. Qualitative results are based on the �touch and feel� response that a clinician feels. Thus this can vary from clinician to clinician. With this device we can quantify tone. This is done by using a robot that perturbs the wrist joint, for example with a smooth but random trajectory or movement. By measuring the torque response to this movement, we can isolate the muscle tone using a visco-elastic model. In Layman�s terms it�s like saying we can measure the stiffness of a spring by observing the amount of load required to displace the spring by a certain distance. Clinically quantification of tone is useful in evaluating patients with some sort of upper or lower motor neuron paralysis that affects skeletal muscles such as patients with cerebral palsy, traumatic brain injury, spinal cord injury, stroke, or Parkinson�s Disease patients. This is because muscle tone is determined not only by its passive properties such as size, but it is heavily influenced by nerve activation in patients with certain neurological disorders. Quantification of tone is important for a clinician to decide on the nature and degree of intervention to administer. A pre and post-evaluation can also determine the effectiveness of the intervention as well as track the progress of the patient, even small increments that are undetectable by the �touch and feel� of a clinician. The system software can easily be modified to output the muscle stiffness of the patient to the clinician in real time. The implications of this are in the operating room where a neurosurgeon makes temporary lesions in the brain while monitoring the patient�s muscle tone in real time. Once the surgeon finds the proper location in the brain that alleviates the degree of muscle tone with out much loss in function, he/she makes the lesion permanent. Other potential uses to quantify muscle tone are listed in the section below. Our device properly determines the muscle tone of a person�s flexors and extensors about an appendage non-i nvasively since we are able to perturb the appendage with arbitrary trajectories by virtue of its novel unique robotic design1. Previous researchers have employed a less complicated apparatus using cams and linkages that transform the rotational motion of a motor shaft into sinusoidal motion2,3,4,5,6. Sinusoidal oscillations alone cannot properly isolate the stiffness of the muscles from the inertia of the limb. We solve this problem using our closed loop automated feedback direct drive device that tracks any arbitrary desired trajectory. This is the first device that can perturb an appendage with any desired trajectory to properly determine the stiffness of the flexors and extensors of an appendage. Description (Set) Proposed Use (Set) Physical Medicine & Rehabilitation and Neurology: As mentioned above, quantification of tone is important for a clinician to decide on the nature and degree of intervention to administer in patients with some sort of upper or lower motor neuron paralysis such as cerebral palsy, traumatic brain injury, spinal cord injury, stroke, Parkinson?s Disease and/or spasticity. A pre and post-evaluation can also determine the effectiveness of the intervention as well as track the progress of the patient, even small increments that are undetectable by the ?touch and feel? of a clinician Neurosurgery: A neurosurgeon can make temporary lesions in the brain while monitoring the patient?s muscle tone in real time. Once the surgeon finds the proper location in the brain that alleviates the degree of muscle tone with out much loss in function, he/she makes the lesion permanent Space Travel: Muscle atrophy is a big problem in space travel when spending long periods of time in the absence of gravity. In subjects without movement disorders, when relaxed, muscle tone is purely a function of muscle size (length and girth). A loss in muscle mass would translate in lower tone or muscle stiffness which can be quantified with this device. Sports Medicine: Similar to the application in space travel, changes in muscle mass can be determined by quantifying muscle tone or stiffness. Patent (Set) 6,589,190Patents:
US 6,589,190
Inventor(s): Kanderian, Sami
Type of Offer: Licensing
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