Gripper - Grip Force Measurement Device

(Used in cojunction with GripAlyzeR - a MovAlyzeR suite item)

Bimanual grip-force coordination can be quantified using a device measuring the grip forces in left and right hands and the simultaneous pulling force to separate the upper and lower force transducers. The task compares to holding a marker pen in one hand and pulling the cap off with the other hand. The grip and pulling forces show a highly proportional increase while increasing the pulling force. The first prototype is by Alberts et al., 1998. (Click Here for the abstract).

Gripper Hardware Setup

The gripper hardware (consisting of an upper grip unit, lower grip unit and a load unit) can be used as an input device by connecting it through a device interface and National Instruments DAQPad data acquisition device.

The gripper device is to be used in conjunction with NeuroScript's GripAlyzeR. The software communicates with the gripper device through the NI DAQPad and the device interface to acquire force sensor data. GripAlyzeR can be used to conduct and record trials in an experiment, analyze, quantify and plot the results.

Gripper Trial Execution

A typical gripper task consists of pulling the upper and lower grip units apart (a magnet holds them together). While pulling the units apart, apply pressure on the upper and lower grip sensors using the left and right hand thumbs, as shown in the above diagrams.

The gripper consists of two units with each possessing a force sensor for the thumb. The upper and lower units are held together with a magnet of a programmable force.

For more information on the gripper device and testing and installation, refer to the GripAlyzeR online help.