Hand Measurement System Based on Haptic and Vision Devices towards Post-Stroke Patients

Abstract

Diagnostics of a hand requires measurements of kinematics and joint limits. The standard tools for this purpose are manual devices such as goniometers which allow measuring only one joint simultaneously, making the diagnostics time-consuming. The paper presents a system for automatic measurement and computer presentation of essential parameters of a hand. Constructed software uses an integrated vision system, a haptic device for measurement, and has a web-based user interface. The system provides a simplified way to obtain hand parameters, such as hand size, wrist, and finger range of motions, using the homogeneous-matrix-based notation. The haptic device allows for active measurement of the wrist’s range of motion and additional force measurement. A study was conducted to determine the accuracy and repeatability of measurements compared to the gold standard. The system functionality was confirmed on five healthy participants, with results showing comparable results to manual measurements regarding fingers’ lengths. The study showed that the finger’s basic kinematic structure could be measured by a vision system with a mean difference to caliper measurement of 4.5 mm and repeatability with the Standard Deviations up to 0.7 mm. Joint angle limits measurement achieved poorer results with a mean difference to goniometer of 23.6º. Force measurements taken by the haptic device showed the repeatability with a Standard Deviation of 0.7 N. The presented system allows for a unified measurement and a collection of important parameters of a human hand with therapist interface visualization and control with potential use for post-stroke patients’ precise rehabilitation.

Development and Operation of an Experimental System to Measure the Moments Generated in the Finger Joints

“…These results differ from those that only offer measurements of global forces in the fingers [11,13,16]. The resulting global force depends on the length of the phalanges, but additional information can be obtained on the geometry of the fingers using [19]. The global measurements of pinch or grip allow us to obtain a global effort in the tendons but do not give the values in each joint; only the global efforts at the fingertips are obtained.…”

“…The objective is to develop a device capable of measuring the maximum bending moment of the PI joint in different angular configurations. The system must be able to adapt to different finger sizes, even though these may vary significantly [19]. In this objective, the device must be able to give three quantities: the maximum force, the centre of the PI joint and, finally, the point of application of the force.…”

Objectivizing Measures of Post-Stroke Hand Rehabilitation through Multi-Disciplinary Scales

“…Kinetic properties pertaining to forces that act on the hand and contribute to the movement can be assessed using force sensors, dynamometers (grip test devices and hand dynamometers), and myographic devices (electromyography and mechanomyography). Dynamic properties encompassing both aspects and the hand function during activities can be measured using instrumented gloves (CyberGlove), robotic devices, and 3D scanner-based integrated vision systems, such as Microsoft Kinect or Leap Motion [21]. Electromyography (EMG) is a reliable tool that clinicians utilize to confirm improvements in treatment or rehabilitation when assessing muscle tone.…”

“…A manual goniometer is used less and less frequently in studies. Testing of joint range of motion with a goniometer is more often noted in technical studies, where detailed movement analysis and comparison of goniometry, rather than mere recovery and return of upper limb function, is important [18,21]. The manual goniometer continues to find favor among experienced clinicians [178].…”

“…The need to obtain accurate results led to the development of many tools used in the diagnosis of stroke patients, including hand dynamometers, haptic sensors, position tracking systems, leap motion, and the use of artificial intelligence. Hand measurement is essential in the diagnostic process in the context of enabling individualization of therapy [19][20][21][22].…”