Simultaneous Kinematic and Contact Force Modeling of a Human Finger Tendon System Using Bond Graphs and Robotic Validation

Abstract

This paper aims to use bond graph modeling to create the most comprehensive finger tendon model and simulation to date. Current models are limited to either free motion without external contact or fixed finger force transmission between tendons and fingertip. The forward dynamics model, presented in this work, simultaneously simulates the kinematics of tendon-finger motion and contact forces of a central finger given finger tendon inputs. The model equations derived from bond graphs are accompanied by nonlinear relationships modeling the anatomical complexities of moment arms, tendon slacking, and joint range of motion (ROM). The structure of the model is validated using a robotic testbed, Utah's Anatomically correct Robotic Testbed (UART) finger. Experimental motion of the UART finger during free motion (no external contact) and surface contact are simulated using the bond graph model. The contact forces during the surface contact experiments are also simulated. On average, the model was able to predict the steady-state pose of the finger with joint angle errors less than 6 deg across both free motion and surface contact experiments. The static contact forces were accurately predicted with an average of 11.5% force magnitude error and average direction error of 12 deg.

Investigating the effects of flexor tendon shortening on active range of motion after finger tendon repair

“…Because cadaver experimentation is subject to time and experimental constraints, computational models or robotic testbeds could conduct more extensive investigations into tendon biomechanics. Many computational and robotic hand models are limited, but recent developments from the authors (Tigue, King, & Mascaro, 2020a;Tigue, Rockwell, Foreman, & Mascaro, 2020b) demonstrate further anatomical accuracy of finger tendon modeling and robotic recreations. This article also provides experimental data for future development and validation of these tools for investigating human hand reconstructive tendon surgeries.…”

A review of the diverse applications of bond graphs in biology and physiology

“…( a ) Extensor mechanism, ( b ) corresponding mechanical representation and ( c ) the BG representation of the extensor mechanism, reproduced from Tigue et al . [42]. …”

Physically Plausible Realistic Grip-Lift Interaction Based on Hand Kinematics in VR

“…However, the speed of the entire hand or of the consequently moving virtual object may not be sufficient to reflect the force from the user's hand. In some robotics studies, the speed of each finger joint is applied biologically by the grip force of the hand connected to the forearm muscle [31,32]. Iyengar et al [31] confirmed that the moving speed of the arm affects the grip force of the fingers.…”

“…Iyengar et al [31] confirmed that the moving speed of the arm affects the grip force of the fingers. In another study by Tigue et al [32], a finger tendon model and its simulation were developed using the Bond graph modeling method. Biomechanical modeling was used, which reflected each finger's speed based on the movement of fingers by the tendon initiating from the forearm connected to the hand [32].…”

“…In another study by Tigue et al [32], a finger tendon model and its simulation were developed using the Bond graph modeling method. Biomechanical modeling was used, which reflected each finger's speed based on the movement of fingers by the tendon initiating from the forearm connected to the hand [32]. Salisbury et al [33] used a basic kinematics concept regarding the mechanical hand for a method to determine the relationship between the force applied on an object when grabbing it using fingers and the speed change of the fingers.…”