Portable Interactive Pulse Tactile Recorder and Player System.

Pulse palpation is an effective method for diagnosing arterial diseases. However, most pulse measurement devices use preconfigured pressures to collect pulse signals, and most pulse tactile simulators can only display standard or predefined pulse waveforms. Here, a portable interactive human pulse measurement and reproduction system was developed that allows users to take arbitrary pulses and experience realistic simulated pulse tactile feedback in real time by using their natural pulse-taking behaviors. The system includes a pulse tactile recorder and a pulse tactile player. Pulse palpation forces and vibrations can be recorded and realistically replayed for later tactile exploration and examination. To retain subtle but vital pulse information, empirical mode decomposition was used to decompose pulse waveforms into several intrinsic mode functions. Artificial neural networks were then trained based on intrinsic mode functions to determine the relationship between the driving signals of the pulse tactile player and the resulting vibration waveforms. Experimental results indicate that the average normalized root mean square error and the average R-squared values between the reproduced and original pulses were 0.0654 and 0.958 respectively, which indicate that the system can reproduce high-fidelity pulse tactile vibrations.

Usability study of multiple vibrotactile feedback stimuli in an entire virtual keyboard input.

With advances in information technology, people spend more time on touchscreen-based virtual keyboards than physical keyboards. However, typing on touchscreens usually lacks informative tactile feedback and anchoring references to locate the right keys, and thus requires more visual attention. Most prior tactile keyboard research used single stimulus pattern, which was not enough to recognize different keys. The purpose of this study was to investigate the usability of multiple vibrotactile feedback patterns in an entire virtual QWERTY keyboard input. A set of highly discriminable vibration patterns was designed and associated with different regions of a virtual keyboard to help users to locate the right keys. However, the number of stimulus patterns might also affect the typing performance. A user study was conducted to evaluate the effectiveness of the multiple vibrotactile feedback. The results showed that an appropriate number of stimulus patterns provided higher typing speed, higher typing efficiency, and lower error rate.