# A Wireless Hand Grip Device for Motion and Force Analysis
## 1 Introduction
From the results observed in the paper, the application of the Kalman filter for fusing vision-based data with contact-based tracking data provided substantial improvements in precision and to a lesser extent improvement in accuracy. This method allows the system to mitigate the visual self-occlusion of the fingers and data completeness is obtained. On the other hand, the system is a little bit invasive and unable to measure the force done by hand and fingers. Another Data Glove approach is presented in [10]. The main idea is to obtain an accurate measurement of thumb carpometacarpal (CMC). The CMC-joint movement is still a challenge due to crosstalk between the multi-sensor outputs required to measure the degrees of freedom. In order to properly measure CMC-joint configurations, sensor locations that minimize sensor crosstalk must be identified. This work presents a novel approach in identifying optimal sensor locations. Although the proposed method improves the accuracy of the sensing system, from the pictures provided we can conclude that it is very invasive and user's preparation time can be very high. The research ideas most similar to our proposal are considered in [11]. A full evaluation of motor task performance during grasp movements requires, besides kinematic, also kinetic measures. An emerging microelectromechanical system (MEMS) for HCI purposes is proposed. The instrumentation setup consists of 3D accelerometers and gyroscopes embodied in a single chip (ST LSM30 DLC), which are distributed along the dorsal side of the hand. The system attached to the hand is robust, flexible and low-cost. The system's evaluation is done measuring kinematic and kinetic sensor data simultaneously, applying orientation filters and subsequently applying a recursive system identification algorithm. The system offers an approach for measuring pressure sensing and gesture recognition in a combined manner. This solution opens the ability to gather profound insights into interaction optimization between the human body and its environment, in particular for VR applications. Another interesting and novel haptic exoskeleton device is presented in [12]. The device can measure the user's hand motion and assist hand motion while remaining portable and lightweight. The device consists in a five-finger mechanism actuated with miniature DC motors through antagonistically routed cables at each finger, which act as both active and passive force actuators. The glove can be wirelessly linked to a computer for displaying and recording the hand status through 3D Graphical User Interface (GUI) in real-time. A positive aspect of this system is its portability (wireless) and its adaptability to a wide variety of finger sizes. The user's fatigue is low, the system is inexpensive, and over one hour of continuous operation is reached without the need for recharging. Unfortunately, this version of the glove does not include an inertial measurement unit and it is also highly invasive. The SAFE Glove needs mechanical refinement directed towards the use of smaller and stronger components to reduce bulkiness and improve comfort for the wearer. Another important aspect to note is the advancement in the area of sensors and actuators. Papers [13; 14; 15] explore the advances in tactile sensing technologies. The three abovementioned papers show different surveys about various technologies and transduction methods. The work done in [16] shows a survey of hand exoskeleton technologies for rehabilitation and assistive engineering, from basic hand biomechanics to actuator technologies. The main requirements of these hand exoskeleton devices are also identified, and the mechanical designs of existing devices are classified. The paper is oriented to the world's aging society and an increased demand for the practical application of assistance and rehabilitation technologies. The low cost of the final device proposed for human motion and force measurement is an important factor in order to achieve future commercialization.