upper limb functional assessment using haptic interface

A new method for the assessment of the upper limb (UL) functional state, using a haptic interface is presented. A haptic interface is used as a measuring device, capable of providing objective, repeatable and quantitative data of the UL motion. A patient is presented with a virtual environment, both graphically via a computer screen and haptically via the Phantom Premium 1.5 haptic interface. The setup allows the patient to explore and feel the virtual environment with three of his/her senses; sight, hearing, and most important, touch. Specially designed virtual environments are used to assess the patient’s UL movement capabilities. The tests range from tracking tasks – to assess the accuracy of movement – tracking tasks with added disturbances in a form of random forces – to assess the patient’s control abilities, a labyrinth test – to assess both speed and accuracy, to the last test for measuring the maximal force capacity of the UL.

A new method for the assessment of the upper limb (UL) functional state, using a haptic interface is presented. A haptic interface is used as a measuring device, capable of providing objective, repeatable and quantitative data of the UL motion. A patient is presented with a virtual environment, both graphically via a computer screen and haptically via the Phantom Premium 1.5 haptic interface. The setup allows the patient to explore and feel the virtual environment with three of his/her senses; sight, hearing, and most important, touch. Specially designed virtual environments are used to assess the patient’s UL movement capabilities. The tests range from tracking tasks–to assess the accuracy of movement-tracking tasks with added disturbances in a form of random forces-to assess the patient’s control abilities, a labyrinth test-to assess both speed and accuracy, to the last test for measuring the maximal force capacity of the UL.

A comprehensive study, using the developed measurement setup within the haptic virtual environment, was carried out. 19 healthy subjects and a total of 80 patients with various neurological and neuro-muscular disorders took part in the study. In this paper, only some typical characteristics of the upper limb movement, affected by Becker type muscular dystrophy are shown in a quantitave manner and compared to a healthy subject. The numerical results of the comprehensive study were analysed using data mining techniques, leading to the most important numerical parameters and revealed the content validity of the proposed tests.

The developed measurement methodology utilizing haptic interface provides objective, quantitative and repeatable method for the assesment of the upper limb functional state.