Detecting and imaging method of biological electrical characteristics based on magneto-acoustic coupling effect gives valuable information of tissue in early tumor diagnosis and bioelectrical current monitoring. Normal exciting and receiving method is to use single pulse. In this method the signal to noise ratio (SNR) is limited, so the imaging quality and imaging speed are low. In this study, we propose a processing method based on coded excitation to improve SNR and shorten the processing time. The processing method using 13 bit Barker coded excitation and 16 bit Golay code excitation are studied by simulation and experiments. The results show that SNR of magneto-acoustic signal is improved by 20.96 dB and 20.62 dB by using 13 bit Barker coded and 16 bit Golay coded excitation, respectively. It also indicates the processing time is short compare to single pulse mode. In the case of the SNR increasing, the overall acquiring and processing time under 13 bit Barker coded excitation and the 16 bit Golay coded excitation is shortened to 3.62% and 4.73%, respectively, compared to the single pulse excitation with waveform averaging method. In conclusion, the coded excitation will be significant for the improvement of magneto-acoustic signal SNR and imaging quality.
The global incidence of benign biliary tract diseases is high. Not only its anatomical variations are complex and the disease heterogeneity is strong, but also its preoperative assessment methods, surgical techniques and diagnostic and treatment strategies need to be improved. Consequently, patients have many perioperative complications and a poor long-term prognosis. According to the anatomical characteristics of the biliary tract and the pathophysiological characteristics of benign biliary diseases, we propose the surgical treatment concept of benign biliary tract diseases with the removal of the diseased bile duct tree drainage as the core, which is different from the traditional biliary surgery that takes “patency and obstruction” as the focus of treatment, and “alleviates symptoms” as the treatment goal. Through a series of improvements such as preoperative evaluation, surgical planning, surgical operations, and postoperative management, we have designed a series of innovative diagnosis and treatment strategies and procedures with the goal of curing biliary diseases, with a view to changing the diagnosis and treatment status of biliary surgery. We hope that can change the current the diagnosis and treatment status of biliary surgery.
Repetitive transcranial magnetic stimulation (rTMS) can influence the stimulated brain regions and other distal brain regions connecting to them. The purpose of the study is to investigate the effects of low-frequency rTMS over primary motor cortex on brain by analyzing the brain functional connectivity and coordination between brain regions. 10 healthy subjects were recruited. 1 Hz rTMS was used to stimulate primary motor cortex for 20 min. 1 min resting state electroencephalography (EEG) was collected before and after the stimulation respectively. By performing phase synchronization analysis between the EEG electrodes, the brain functional network and its properties were calculated. Signed-rank test was used for statistical analysis. The result demonstrated that the global phase synchronization in alpha frequency band was decreased significantly after low-frequency rTMS (P<0.05). The phase synchronization was down-regulated between motor cortex and ipsilateral frontal/parietal cortex, and also between contralateral parietal cortex and bilateral frontal cortex. The mean degree and global efficiency of brain functional networks in alpha frequency band were significantly decreased (P<0.05), and the mean shortest path length were significantly increased (P<0.05), which suggested the information transmission of the brain networks and its efficiency was reduced after low-frequency rTMS. This study verified the inhibition function of the low-frequency rTMS to brain activities, and demonstrated that low-frequency rTMS stimulation could affect both stimulating brain regions and distal brain regions connected to them. The findings in this study could be of guidance to clinical application of low-frequency rTMS.
Magneto-acoustic-electric tomography (MAET) boasts high resolution in ultrasound imaging and high contrast in electrical impedance imaging, making it of significant research value in the fields of early tumor diagnosis and bioelectrical monitoring. In this study, a method was proposed that combined high conductivity liquid metal and maximum length sequence (M sequence) coded excitation to improve the signal-to-noise ratio. It was shown that, under rotational scanning, the liquid metal significantly improved the signal-to-noise ratio of the inter-tissue magneto-acoustic-electric signal and enhanced the quality of the reconstructed image. The signal-to-noise ratio of the signal was increased by 5.6, 11.1, 21.7, and 45.7 times under the excitation of 7-, 15-, 31-, and 63-bit M sequence code, respectively. The total usage time of 31-bit M sequence coded excitation imaging was shortened by 75.6% compared with single-pulse excitation when the same signal-to-noise ratio was improved. In conclusion, the imaging method combining liquid metal and M-sequence coding excitation has positive significance for improving MAET image quality.