# A Wireless Hand Grip Device for Motion and Force Analysis
## 4 Discussion, Conclusions and Future Work  
We have presented a novel wireless device that allows for the simultaneous measurement of motion and hand forces and analyzed its performance. The system has been tested against commercial force dynamometers (Takei model 5101 TKK, Constant 14192-709E) obtaining similar precision. The position and orientation have also been evaluated. Several statistical parameters are computed in order to verify the correct performance of device. According to the values measured by the three goniometers considered and the analyses performed, we can affirm that the proposed UIB system performs adequately with precision comparable to those of the two commercial systems considered. The graphs presented show similar accuracy and precision. These issues reflect the quality of the estimated parameters. The intention of this paper is to show the feasibility of the system. To improve the quality of the output data, further sensitivity analyses of different subsystems are required. A collection of serious games that validate the real interaction between a controlled user and real patients in a hospital \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**Weight** & \multicolumn{3}{c}{**UIB Device**} & \multicolumn{3}{c}{**T.K.K. 5401**} & \multicolumn{3}{c}{**Constant 14192-709E**} \\ \hline
**Kgs** & **Measure** & **Measure** & **Measure** & **Measure** & **Measure** & **Measure** & **Measure** & **Measure** & **Measure** & **Measure** & **Measure** \\
**1** & **2** & **3** & **4** & **1** & **2** & **3** & **4** & **1** & **2** & **3** & **4** \\ \hline
5 & 5.1 & 5.0 & 4.9 & 4.8 & 6.0 & 5.9 & 5.8 & 5.8 & 4.5 & 4.4 & 4.5 & 4.5 \\ \hline
10 & 10.0 & 10.1 & 10.1 & 9.9 & 10.1 & 10.0 & 10.0 & 9.9 & 9.2 & 9.2 & 9.4 & 9.2 \\ \hline
15 & 14.1 & 14.3 & 13.9 & 14.0 & 14.3 & 14.4 & 14.4 & 14.0 & 13.9 & 14.0 & 13.9 & 14.0 \\ \hline
20 & 20.4 & 19.8 & 20.2 & 20.0 & 17.9 & 19.0 & 18.5 & 18.5 & 18.5 & 18.9 & 18.8 & 18.6 \\ \hline
25 & 24.8 & 24.9 & 25.1 & 25.5 & 23.5 & 23.2 & 23.2 & 23.3 & 24.5 & 23.8 & 24.1 & 23.8 \\ \hline
30 & 31.5 & 30.8 & 31.3 & 30.8 & 28.6 & 26.5 & 26.4 & 27.3 & 28.7 & 28.7 & 28.5 & 29.0 \\ \hline
40 & 40.2 & 40.2 & 39.9 & 39.5 & 36.1 & 37.6 & 37.1 & 38.9 & 38.6 & 38.4 & 38.1 & 38.1 \\ \hline
50 & 49.8 & 53.3 & 49.5 & 50.1 & 46.5 & 44.2 & 46.2 & 46.8 & 48.4 & 49.4 & 48.3 & 48.9 \\ \hline
60 & 58.8 & 59.5 & 58.6 & 58.5 & 58.6 & 58.7 & 59.5 & 59.6 & 59.1 & 59.3 & 59.7 & 59.1 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Measurement table with calibration load and display dynamometer value. Figure 14: Measurements and linear regression. environment are being developed. A possible application in the medical rehabilitation field of the proposed prototype is the classification and quantification of various hand motor tasks (specially grasping exercises for patients with neurological diseases). In conclusion, this paper presents a new hand grip device designed for human-machine interaction developed for rehabilitation applications. The device combines 9-DoF kinematic sensing for hand and all fingers, hand position/orientation acquisition and force measurement. These aspects are integrated in an easy-to-use and low-cost system with wireless connection to the host computer. The key components are five finger contact sensors, which separately measure the contact or non-contact of fingers over the device. An inertial measurement unit facilitates hand position detection and orientation. Finally, two precise force sensors deliver, in real time, the hand force displayed by the user. In spite all of these improvements, the overall cost of the system is less than 300\(\mathrm{\char 37}\). Preliminary validation experiments have been performed to examine quantitative features of the device. The proposed system is robust and low-cost; moreover, data is transmitted using standard wireless communication. This device goes beyond pressure sensing and gesture recognition and, therefore, opens up the possibility of gathering profound insights in the field.