Sensory afferent touch temporarily reduces spasticity in the lumbrical muscles
Introduction
Merging visual and interactive devices, this project recreates the experience of a sensory trick ("geste antagoniste") – a physical touch to the afflicted dystonic region that temporarily relieves painful muscle contractions and abnormal posture in individuals with focal (musician’s) dystonia. Focal dystonia is a neurological condition caused by reduced inhibition at different levels of the sensorimotor system. Unlike normal muscle movement, where agonist and antagonist muscles contract and relax in conjunction with each other, dystonic patients undergo a loss of selectivity in muscle contraction, leading to painful muscle stiffness. While the disease’s pathophysiology is generally unclear, symptoms tend to arise during task-specific actions and damage is frequently irreversible, consequently resulting in the debilitating loss of one’s musical career. While a conceptual and mechanistic understanding of the disease is important in medical study and treatment, the visceral experience undergone by the patient impacts many sectors of their life and questions their changed existence. In this phenomenon, the disease represents the patient’s art, as a musician’s inability to perform results in a silencing of self. Without this art, who do they become?
I decided to focus on the phenomenon of a sensory trick because it provides an interactive approach to learning about a complicated neurological disease. I am interested in learning how visualization of medical phenomenon can be translated to wider audiences. My project involves capacitive touch sensors at the tip of the fingers and fiber optic lights representing motor nerve firing on antagonist muscles. When a physical touch is sensed, discharging a capacitor on the circuit board, neuron firing rate decreases allowing antagonist muscles to relax and music to play.
Tools
Sculpture - Multimedia
• bone - poplar wood
• neurons - fiber optics
• ligaments, tendons - latex bands (cut from glove fingers)
• muscle - wire mesh and cable wire
Functional Platform - Raspberry Pi (Python)
• circuitry features capacitive touch sensors that control and modulate LED light pulse (connected to fiber optics) and volume of a classical music track
Sculptural model of a hand afflicted with musician’s dystonia (side view).
Zoomed in view of carpal bones, hand bones, ligaments and lumbrical muscle. The jump wire serves as the capacitive touch feature representing sensory receptors on the hand.
Neural firing from ulnar nerve onto the flexor digitorum profundus muscle, a muscle that controls flexion in the fingers.
Observational Studies
Illustrative studies on the anatomy of the hand and arm. Drawings are referenced from observation of real human bones, courtesy of the Anatomy Lab at Washington University School of Medicine, and Frank Netter medical illustrations
Muscular attachment sites of the right ulna, radius, humerus, carpus, and finger bones
Illustration of the muscular arrangement of the anterior (left side) and posterior (right side) right forearm overlaid onto skeletal illustrations. Skeletal illustrations were self-drawn but referenced from Frank Netter medical illustrations.
Superificial muscles of the anterior (left side) and posterior (right side) right forearm
(TURN SOUND ON)
When the capacitive touch sensor detects a physical interaction, LED fiber optic flashing slows down and music begins to play. This process simulates how haptic communication to an extremity afflicted with musician's dystonia can cause temporary reduction in muscle spasticity and regained ability to play a musical instrument.
A special thanks to:
Dr. Jane Phillips-Conroy, Ron Leax, Dr. Ram Dixit, Dr. Joel Perlmutter, Nicholas Siow, and Aimee Morris for access to resources, assistance with implementing technical components, and mentoring/guidance.
