ABSTRACT
Objective To design a portable electroencephalography(EEG) acquisition system to acquire and analysis steady-state visual potentials (SSVEP). Methods The microprocessor MSP432P401 series MCU was used to control the high-performance integrated analog front end ADS1299 to realize the acquisition, amplification and analog-to-digital (AD) conversion of EEG signals. The digital EEG signal is sent to the host computer for processing by WIFI. Spontaneous EEG signals and steady-state visually evoked EEG signals from 3 healthy subjects were collected to verify system performance. Results The collected signal had a clear α-wave rhythm of closed-eye spontaneous EEG signals. The power spectrum density shows that the steady-state visually induced EEG signal frequency and harmonic frequency peak at the corresponding stimulation frequency, indicating that the system works normally and the performance is good. Conclusions The designed portable EEG acquisition system can accurately collect the spontaneous and induced EEG signals of the human body, which provides technical support for the clinical application of SSVEP technology.
ABSTRACT
Objective To design a mechanical arm assisted lumbar puncture ultrasound scanning system to realize automatic scanning imaging of the lumbar vertebrae and visualize the three-dimensional reconstruction of the acquired two-dimensional ultrasound image,so as to obtain the three-dimensional image of the scanning lumbar and provide a basis for path planning and assisted puncture.Methods The main control program of the robotic arm was programmed by C language which can control the robotic arm to scan the lumbar vertebrae of the patient by a clamped ultrasound.The acquired 2D ultrasound image was reconstructed and visualized using a VTK-based 3D reconstruction visualization program.The lumbar vertebrae model reconstruction was conducted by Enovo Medical Model in water and CIRS 034 lumbar vertebral phantom,respectively,and the experimental results were compared and analyzed.Results By using the lumbar puncture ultrasound scanning system,the obtained two-dimensional ultrasound image of the lumbar spine model was clear and the anatomy was basically complete.The results of three-dimensional reconstruction showed that the spinous processes and their gaps of the scanned lumbar model were clearly visible,and the structure was intact,indicating that the system was operating normally and could achieve the expected function.By comparing the reconstruction results of the bent-knee lateral position and prone position,it can be concluded that the body position has an important influence on the reconstruction results of the lumbar spine ultrasound image.The bent-knee lateral position should be used in the follow-up study of lumbar puncture.Conclusions A lumbar puncture ultrasound scanning system assisted by a mechanical arm was proposed.The system can effectively capture the clear ultrasound image of the model and realize the visualization of 3D reconstruction,which can provide a basis for puncture path planning and assisted puncture.
ABSTRACT
Objective To develop a light source system for the treatment of rectal cancer photodynamic therapy based on magnetic coupling resonant wireless power supply technology.Methods The proposed system consists of the implant and the external power supply device.The implant includes a light source and a resonant receiving coil.The light source is a 650 nm LED.The light source and the receiving coil were encapsulated with transparent epoxy to benefit the implantation and biocompatibility.The external power supply device was based on the magnetic coupling resonant technology,and the frequencies of the high frequency inverter and the natural frequency of the transmitting coil and the receiving coil were set at the same resonant frequency to ensure the efficient transmission of energy.Results The power density range of the light source is 3～22 mW/cm2 in the vertical distance range of 50～ 180 mm to the plane of the transmitting coil.Conclusions In the proposed light source system,the LED was separated from the power source.The size of the implant is small enough to be implanted,and the external power source can provide a real-time and stable energy supply for the implant.