1.Simulation Results and Analysis of Electric Field Distribution in Myocardial Tissue under Circular Electrode Electric Pulse Ablation.
Wencai WANG ; Qunshan WANG ; Binfeng MO ; Jinhai NIU
Chinese Journal of Medical Instrumentation 2023;47(3):242-246
As a new energy source for atrial fibrillation ablation, electric pulse ablation has higher tissue selectivity and biosafety, so it has a great application prospect. At present, there is very limited research on multi-electrode simulated ablation of histological electrical pulse. In this study, a circular multi-electrode ablation model of pulmonary vein will be built on COMSOL5.5 platform for simulation research. The results show that when the voltage amplitude reaches about 900 V, it can make some positions achieve transmural ablation, and the depth of continuous ablation area formed can reach 3 mm when the voltage amplitude reaches 1 200 V. When the distance between catheter electrode and myocardial tissue is increased to 2 mm, a voltage of at least 2 000 V is required to make the depth of continuous ablation area reach 3 mm. Through the simulation of electric pulse ablation with ring electrode, the research results of this project can provide reference for the voltage selection in the clinical application of electric pulse ablation.
Humans
;
Heart Rate
;
Atrial Fibrillation/surgery*
;
Electrodes
;
Catheter Ablation
;
Electricity
2.Roadmap of Medical Device for Implanted Brain-computer Interface.
Tao SU ; Chunshan DENG ; Xiaojian LI
Chinese Journal of Medical Instrumentation 2023;47(3):304-308
Implanted brain-computer interface (iBCI) is a system that establishes a direct communication channel between human brain and computer or an external devices by implanted neural electrode. Because of the good functional extensibility, iBCI devices as a platform technology have the potential to bring benefit to people with nervous system disease and progress rapidly from fundamental neuroscience discoveries to translational applications and market access. In this report, the industrialization process of implanted neural regulation medical devices is reviewed, and the translational pathway of iBCI in clinical application is proposed. However, the Food and Drug Administration (FDA) regulations and guidances for iBCI were expounded as a breakthrough medical device. Furthermore, several iBCI products in the process of applying for medical device registration certificate were briefly introduced and compared recently. Due to the complexity of iBCI in clinical application, the translational applications and industrialization of iBCI as a medical device need the closely cooperation between regulatory departments, companies, universities, institutes and hospitals in the future.
Humans
;
Brain-Computer Interfaces
;
Brain/physiology*
;
Electrodes, Implanted
3.Chinese emergency expert consensus on bedside temporary cardiac pacing (2023).
EMERGENCY MEDICINE BRANCH OF CHINESE MEDICAL ASSOCIATION ; BEDSIDE TEMPORARY CARDIAC PACING CONSENSUS EMERGENCY EXPERT GROUP
Chinese Critical Care Medicine 2023;35(7):678-683
Temporary cardiac pacing is an essential technique in the diagnosis and treatment of arrhythmias. Due to its urgency, complexity, and uncertainty, it is necessary to develop an evidence-based emergency operation norms. Currently, there is no specific consensus guidelines at home or abroad. The Emergency Branch of Chinese Medical Association organized relevant experts to draft the Chinese emergency expert consensus on bedside temporary cardiac pacing (2023) to guide the operation and application of bedside cardiac pacing. The formulation of the consensus adopts the consensus meeting method and the evidentiary basis and recommendation grading of the Oxford Center for Evidence-based Medicine in the United States. A total of 13 recommendations were extracted from the discussion on the methods of bedside temporary cardiac pacing, the puncture site of transvenous temporary cardiac pacing, the selection of leads, the placement and placement of leads, pacemaker parameter settings, indications, complications and postoperative management. The recommended consensus includes the choice between transcutaneous and transvenous pacing, preferred venous access for temporary transvenous pacing, the target and best guidance method for implantation of bedside pacing electrodes, recommended default pacemaker settings, recommended indications for sinoatrial node dysfunction, atrioventricular block, acute myocardial infarction, cardiac arrest, ventricular and supraventricular arrhythmias. They also recommended ultrasound guidance and a shortened temporary pacing support time to reduce complications of temporary transvenous cardiac pacing, recommended bedrest, and anticoagulation after temporary transvenous pacing. Bedside temporary cardiac pacing is generally safe and effective. Accurate assessment, correct selection of the pacing mode, and timely performance of bedside temporary cardiac pacing can further improve the survival rate and prognosis of related emergency patients.
Humans
;
Cardiac Pacing, Artificial/methods*
;
Pacemaker, Artificial
;
Arrhythmias, Cardiac/therapy*
;
Myocardial Infarction/therapy*
;
Electrodes
4.Cochlear electrode array misplacement into the superior semicircular canal: a case report and literature review.
Chen SUN ; Zhenghua HUANG ; Yingxue MA ; Ye GU ; Qi LI
Journal of Clinical Otorhinolaryngology Head and Neck Surgery 2023;37(4):310-312
Electrode array misplacement is a rare complication of cochlear implant. This article reports an 11-year-old boy who was mistakenly implanted the cochlear electrode array into the superior semicircular canal during the initial cochlear implant. After the diagnosis was confirmed, he underwent a second cochlear implant and the electrode array were successfully implanted into the cochlea. This article conducted a systematic review of the literature on electrode array misplacement, and the causes of electrode array misplacement were analyzed from different implantation position.
Male
;
Humans
;
Child
;
Electrodes, Implanted
;
Reoperation
;
Cochlea
;
Cochlear Implantation
;
Cochlear Implants/adverse effects*
;
Semicircular Canals/surgery*
5.Advances in electrochemically active biofilm of Shewanella oneidensis MR-1.
Chinese Journal of Biotechnology 2023;39(3):881-897
Facing the increasingly severe energy shortage and environmental pollution, electrocatalytic processes using electroactive microorganisms provide a new alternative for achieving environmental-friendly production. Because of its unique respiratory mode and electron transfer ability, Shewanella oneidensis MR-1 has been widely used in the fields of microbial fuel cell, bioelectrosynthesis of value-added chemicals, metal waste treatment and environmental remediation system. The electrochemically active biofilm of S. oneidensis MR-1 is an excellent carrier for transferring the electrons of the electroactive microorganisms. The formation of electrochemically active biofilm is a dynamic and complex process, which is affected by many factors, such as electrode materials, culture conditions, strains and their metabolism. The electrochemically active biofilm plays a very important role in enhancing bacterial environmental stress resistance, improving nutrient uptake and electron transfer efficiency. This paper reviewed the formation process, influencing factors and applications of S. oneidensis MR-1 biofilm in bio-energy, bioremediation and biosensing, with the aim to facilitate and expand its further application.
Bioelectric Energy Sources/microbiology*
;
Biofilms
;
Electrodes
;
Electron Transport
;
Shewanella/metabolism*
6.Research on the effect of multi-modal transcranial direct current stimulation on stroke based on electroencephalogram.
Hongli YU ; Shaoqian ZHANG ; Chunfang WANG ; Lei GUO ; Guizhi XU
Journal of Biomedical Engineering 2022;39(5):966-973
As an emerging non-invasive brain stimulation technique, transcranial direct current stimulation (tDCS) has received increasing attention in the field of stroke disease rehabilitation. However, its efficacy needs to be further studied. The tDCS has three stimulation modes: bipolar-stimulation mode, anode-stimulation mode and cathode-stimulation mode. Nineteen stroke patients were included in this research (10 with left-hemisphere lesion and 9 with right). Resting electroencephalogram (EEG) signals were collected from subjects before and after bipolar-stimulation, anodal-stimulation, cathodal-stimulation, and pseudo-stimulation, with pseudo-stimulation serving as the control group. The changes of multi-scale intrinsic fuzzy entropy (MIFE) of EEG signals before and after stimulation were compared. The results revealed that MIFE was significantly greater in the frontal and central regions after bipolar-stimulation ( P< 0.05), in the left central region after anodal-stimulation ( P< 0.05), and in the frontal and right central regions after cathodal-stimulation ( P< 0.05) in patients with left-hemisphere lesions. MIFE was significantly greater in the frontal, central and parieto-occipital joint regions after bipolar-stimulation ( P< 0.05), in the left frontal and right central regions after anodal- stimulation ( P< 0.05), and in the central and right occipital regions after cathodal-stimulation ( P< 0.05) in patients with right-hemisphere lesions. However, the difference before and after pseudo-stimulation was not statistically significant ( P> 0.05). The results of this paper showed that the bipolar stimulation pattern affected the largest range of brain areas, and it might provide a reference for the clinical study of rehabilitation after stroke.
Humans
;
Transcranial Direct Current Stimulation/methods*
;
Electroencephalography
;
Stroke Rehabilitation
;
Stroke/therapy*
;
Electrodes
8.Portable Multi Channel EEG Signal Acquisition System.
Hangyu LE ; Zifu ZHU ; Sinian YUAN ; Zichen LIU ; Gaozang LIN ; Jilun YE ; Xu ZHANG
Chinese Journal of Medical Instrumentation 2022;46(4):404-407
This study introduces a portable multi-channel EEG signal acquisition system. The system is mainly composed of EEG electrode connector, signal conditioning circuit, EEG acquisition part, main control MCU and power supply part. The low-power EEG acquisition front-end ADS1299 and STM32 are used to form the signal acquisition and data communication part. The collected EEG signal can be transmitted to the PC for real-time display. After relevant tests, the system has small volume, low power consumption, high signal-to-noise ratio, and meets the requirements of portable wearable medical devices.
Electric Power Supplies
;
Electrodes
;
Electroencephalography
;
Signal Processing, Computer-Assisted
;
Signal-To-Noise Ratio
9.Construction and performance analysis of a microbial electrochemical sensor for monitoring heavy metals in water environment.
Xiaoxiao LIU ; Fei YE ; Chuanchao WEI ; Mingjie ZHAO ; Yongtian LI
Chinese Journal of Biotechnology 2022;38(5):1903-1914
A microbial fuel cell (MFC)-based microbial electrochemical sensor was developed for real-time on-line monitoring of heavy metals in water environment. The microbial electrochemical sensor was constructed with staggered flow distribution method to optimize the parameters such as external resistance value and external circulation rate. The inhibition of concentration of simulated heavy metal wastewater on voltage under optimal parameters was analyzed. The results showed that the best performance of MFC electrochemical sensor was achieved when the external resistance value was 130 Ω and the external circulation rate was 1.0 mL/min. In this case, the microbial electrochemical sensors were responsive to 1-10 mg/L Cu2+, 0.25-1.25 mg/L Cd2+, 0.25-1.25 mg/L Cr6+ and 0.25-1.00 mg/L Hg2+ within 60 minutes. The maximum rejection rates of the output voltage were 92.95%, 73.11%, 82.76% and 75.80%, respectively, and the linear correlation coefficients were all greater than 0.95. In addition, the microbial electrochemical sensor showed a good biological reproducibility. The good performance for detecting heavy metals by the newly developed microbial electrochemical sensor may facilitate the real-time on-line monitoring of heavy metals in water environment.
Bioelectric Energy Sources
;
Electrodes
;
Metals, Heavy/analysis*
;
Reproducibility of Results
;
Waste Water
;
Water
10.Development of Non-invasive Endoscope System with Magnetic Anchored Ablation Electrode for Early Cancer of Digestive Tract.
Cheng ZHANG ; Xichen YUAN ; Peng SHANG
Chinese Journal of Medical Instrumentation 2022;46(1):1-4
This study introduces a non-invasive gastrointestinal early cancer magnetic anchor ablation electrode endoscopy system, including a magnetic anchor module and ablation electrode module. The magnetic anchoring module is composed of an external guide magnet and an internal magnet, made of permanent magnet material NdFeB; the ablation electrode module is based on the modification of the front end lens hood of the existing endoscope (CMD-90D LED electronic upper gastrointestinal endoscope). The new endoscope system not only includes all the functions of the original endoscope, but also introduces magnetic anchoring to enable the ablation electrode to be accurately positioned and controllable in the process of treating tumors, avoiding the phenomenon of gastric perforation; the introduction of steep pulse electric field ablation electrodes realizes the purpose of non-invasive treatment. Its clinical application will become a new method to treat early cancer of the digestive tract.
Electrodes
;
Endoscopes
;
Gastrointestinal Tract
;
Humans
;
Magnetic Phenomena
;
Neoplasms

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