An HMD Interactive Interface For Emotional Physiological Recognition In VR Environment

With the maturity of virtual reality technology in recent years,scientists can build immersive and interactive experiences that traditional laboratories could not create.Innovations in experimental environments have led psychologists to conduct more research on emotion recognition.Therefore,the use of wearable sensing devices on headmounted displays to collect physiological signals to study emotions has attracted significant attention from the academic community and has become a new scientific research hotspot.Although researchers are eager to carry out experiments,the industry still lacks hardware and software integration tools and platforms to support related studies.Researchers are worried about the cumbersome cables,lengthy preparations,and asynchronous data of large medical instruments.Therefore,relying on the background and technical status of emotion recognition under virtual reality,this thesis proposes three requirements of "integration","standardization",and "visualization" and develops a wearable physiological signal detection system called "HMD interface for emotional,physiological perception".The system consists of a flexible board that senses real-time physiological signals at the front of the face,a board that processes signals at the back end,a Bluetooth adapter and a graphic display terminal.The noise floor of the bioelectric acquisition channel is about 1.2 ?Vpp,and the common-mode rejection ratio is maintained above 80 d B.The battery life is up to 23 hours.After acquisition and verification,the system has a high quality of acquired signals,which is helpful for scientists to carry out various emotional experiments in virtual reality scenes.Structurally,following ergonomics and human factors engineering,the system is innovatively integrated with the head-mounted display.The signal-sensing front-end flexible board attached to the facial washer has a unique elliptical ring shape.EEG,EOG,and GSR bioelectric electrodes and temperature,pulse wave,acceleration sensors are deployed according to functional requirements and placement specifications.Through Type-C,The front-end flexible board is vertically connected to the signal processing board,fixed with a shell,and closely attached to the upper side of the plastic plane of the head-mounted display.The entire lower computer communicates with the computer through Bluetooth.The hardware design of the system focuses on the processing board part.The analogue front-end conditioning circuit of the board is built based on the ADS1299-4 chip and discrete operational amplifiers,parts of which are simulated by the Simscape application.The digital part comprises MOS tube switch control,n RF 52832 low-energy Bluetooth primary control unit and power management module.The digital and analogue part of the entire lower machine is separated by single-point magnetic beads near the AD conversion.For the software,the 52832 control program is designed to drive the chip,synchronize data and combine packets for wireless communication with the Bluetooth adapter.The adapter program receives the Bluetooth data packets from the lower computer and converts them to UART data for general-purpose computers.After that,the Python program on the computer implements a graphical user interface with data decoding,real-time filtering,offline storage and waveform display with the help of opensource libraries such as QT and pyserial.This thesis cites the JJG 1043-2008 standard to test the system's bioelectrical signal measurement performance index.At the same time,the power consumption,software function and communication quality of the system are tested.Finally,through resting experiment,electrodermal test and pulse wave signal quality test,it is verified that the system can effectively collect relevant physiological signals.