A Multi-Axis Biodynamic Measuring Handle for a Human Hand-Arm System

Abstract

The biodynamic response method is increasingly being used to study the human hand-arm system and vibration-induced injuries that affect the hand. Most measurements are made in the dominant forearm direction of excitation, but recently research has turned to multi-axis measurements as well as excitation. This study looks at a new instrument handle that measures the biodynamic responses at the palm and the fingers in multiple directions and, at the same time, removes the need to stop the test and change the orientation of the handle. In addition to the biodynamic response, the sensors inside the handle are able to measure the static push and grip forces simultaneously and therefore remove the need for an additional force plate or force sensor at the handle base, which is typically used to measure the push force. The apparent mass of the handle was measured in order to determine the usable frequency range of the system. Additionally, the apparent mass distribution along the hand was investigated and it was found that the apparent mass distribution along the hand varies with frequency.

A Sequential Approach to the Biodynamic Modeling of a Human Finger

“…The experimental data used in the models was derived in the form of the apparent mass using a purpose-built measuring device. The device was developed based on our previous research [9,10] as well as the current state of the art from other researchers [11,27,28]. The parameters for each of the models were obtained by data fitting and the search was conducted sequentially: the distal phalanx parameters were derived first, followed by the middle and proximal phalanx parameters.…”

“…A comparison was made between the standard and biodynamic methods in [7] and the biodynamic method was found to be practical since it removes the need for the standard handheld palm adapter. The biodynamic-response method originally measured the dynamic responses of the palm only [5,8], but it was recently upgraded to finger-response measurements [9][10][11] as well. The biodynamic-response method is based on the biodynamic parameters, for example, apparent mass, mechanical impedance, and apparent stiffness, which are derived from measurements made on a device subjected to vibration.…”