Background The pendulum test is a standard clinical test for quantifying the severity of spasticity. In the test, an electrogoniometer is typically used to measure the knee angular motion. The device is costly and difficult to set up such that the pendulum test is normally time consuming. Objective The goal of this study is to determine whether a Nintendo Wii remote can replace the electrogroniometer for reliable assessment of the angular motion of the knee in the pendulum test. Methods The pendulum test was performed in three control participants and 13 hemiplegic stroke patients using both a Wii remote and an electrogoniometer. The correlation coefficient and the Bland–Altman difference plot were used to compare the results obtained from the two devices. The Wilcoxon signed-rank test was used to compare the difference between hemiplegia-affected and nonaffected sides in the hemiplegic stroke patients. Results There was a fair to strong correlation between measurements from the Wii remote and the electrogoniometer (0.513 < R2 < 0.800). Small but consistent differences between the Wii remote and electrogoniometer were identified from the Bland–Altman difference plot. Within the hemiplegic stroke patients, both devices successfully distinguished the hemiplegia-affected (spastic) side from the nonaffected (nonspastic) side (both with p < .0001*). In addition, the intraclass correlation coefficient, standard error of measurement, and minimum detectable differences were highly consistent for both devices. Conclusion Our findings suggest that the Wii remote may serve as a convenient and cost-efficient tool for the assessment of spasticity.

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nformation security has become a major issue in recent years, as new ways of information exchange arise due to the rapid development of computing, communication and internet technologies. We propose the image communication systems to secure the information by using a steganographic system and empirical mode decomposition method. The concealed message between the sender and receiver is important in the steganographic system. The encrypted message is further decomposed by using the empirical mode decomposition. The information is transmitted via the public channel and secure channel. At the receiver side the weak message can be retrieved back effectively. The retrieved message carries the same characteristics as the original message. Simulation results have confirmed that this combination model is highly robust against various signal processing operations and geometric attacks. The system increases the security of information data given a variety of constraints and conditions. Our methods have been proven effective for application in various fields which require secure communication, such as mobile telephone, internet and others. By means of this method, researchers can better understand the characteristics of the secure communication.

Image presents the basic physical features of an object. Geometry, on the other hand, provides us a powerful way to quantify the information reflected by images or their shapes. Traditional geometry however finds limitation in describing the differences between highly irregular objects，which requires us to find new approaches to measure an object and quantify its difference from another. In this paper, we define some scalars in two dimensions to meet this demand. These approaches, grounded on circularity, convexity and cavity, describe the geometry of shapes in statistic sense, and they can also be applied to qualify the differences of shapes.