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.Feasibility study of using bridging temporary permanent pacemaker in patients with high-degree atrioventricular block after TAVR.
San Shuai CHANG ; Xin Min LIU ; Zhi Nan LU ; Jing YAO ; Cneng Qian YIN ; Wen Hui WU ; Fei YUAN ; Tai Yang LUO ; Zheng Ming JIANG ; Guang Yuan SONG
Chinese Journal of Cardiology 2023;51(6):648-655
Objective: To determine the feasibility of using temporary permanent pacemaker (TPPM) in patients with high-degree atrioventricular block (AVB) after transcatheter aortic valve replacement (TAVR) as bridging strategy to reduce avoidable permanent pacemaker implantation. Methods: This is a prospective observational study. Consecutive patients undergoing TAVR at Beijing Anzhen Hospital and the First Affiliated Hospital of Zhengzhou University from August 2021 to February 2022 were screened. Patients with high-degree AVB and TPPM were included. Patients were followed up for 4 weeks with pacemaker interrogation at every week. The endpoint was the success rate of TPPM removal and free from permanent pacemaker at 1 month after TPPM. The criteria of removing TPPM was no indication of permanent pacing and no pacing signal in 12 lead electrocardiogram (EGG) and 24 hours dynamic EGG, meanwhile the last pacemaker interrogation indicated that ventricular pacing rate was 0. Routinely follow-up ECG was extended to 6 months after removal of TPPM. Results: Ten patients met the inclusion criteria for TPPM, aged (77.0±11.1) years, wirh 7 females. There were 7 patients with third-degree AVB, 1 patient with second-degree AVB, 2 patients with first degree AVB with PR interval>240 ms and LBBB with QRS duration>150 ms. TPPM were applied on the 10 patients for (35±7) days. Among 8 patients with high-degree AVB, 3 recovered to sinus rhythm, and 3 recovered to sinus rhythm with bundle branch block. The other 2 patients with persistent third-degree AVB received permanent pacemaker implantation. For the 2 patients with first-degree AVB and LBBB, PR interval shortened to within 200 ms. TPPM was successfully removed in 8 patients (8/10) at 1 month without permanent pacemaker implantation, of which 2 patients recovered within 24 hours after TAVR and 6 patients recovered 24 hours later after TAVR. No aggravation of conduction block or permanent pacemaker indication were observed in 8 patients during follow-up at 6 months. No procedure-related adverse events occurred in all patients. Conclusion: TPPM is reliable and safe to provide certain buffer time to distinguish whether a permanent pacemaker is necessary in patients with high-degree conduction block after TAVR.
Female
;
Humans
;
Atrioventricular Block/therapy*
;
Feasibility Studies
;
Transcatheter Aortic Valve Replacement
;
Pacemaker, Artificial
;
Bundle-Branch Block
6.Characteristics of responsiveness of cochlear nerve to electrical stimulation in patients with cochlear nerve deficiency.
Xiu Hua CHAO ; Jian Fen LUO ; Rui Jie WANG ; Zhao Min FAN ; Hai Bo WANG ; Lei XU
Chinese Journal of Otorhinolaryngology Head and Neck Surgery 2023;58(7):657-665
Objectives: This study aimed to evaluate the responsiveness of cochlear nerve to electrical stimulation in patients with cochlear nerve deficiency(CND), to compare their results with those measured in implanted children with normal-sized cochlear nerves, and to investigate the characteristics of the cochlear nerve injury of children with CND. Methods: Participants were children who underwent cochlear implantation at Shandong Provincial ENT Hospital from January 2012 to January 2020, including CND group and control group. The CND group included 51 subjects (male:20; female: 31) who were diagnosed with CND and had normal cochlea. For the CND group, four children had been bilaterally implanted, the mean implantation age was (2.7±1.5) years old. The control group included 21 subjects (male:10; femal:11) who had normal-sized cochlear nerve and normal cochlea. For the control group, all children had been unilaterally implanted except one, and the mean implantation age was (3.0±1.9)years old. Three subjects in the CND group used CI422 electrode arrays, and all the other subjects used CI24RECA/CI512 electrode arrays. The electrically evoked compound action potentials (ECAP) had been tried to record for each electrode using Custom Sound EP software (v. 4.3, Cochlear Ltd.) at least six months post first activation. Furthermore, ECAP amplitude growth functions (AGF) were measured at multiple electrode locations across the electrode array. Generalized linear mixed effect models with the subject group and electrode location as the fixed effects and subjects as the random effect were used to compare results of ECAP measurements. Results: In the control group, ECAP could been recorded at all electrodes (100%), but it could only be recorded in 71% (859/1 210) electrodes in the CND group. Additionally, the percentage of electrodes with measurable ECAP decreased from electrode 1 to electrode 22 in the CND group. Compared to the control group, the ECAP thresholds significantly increased, the ECAP amplitudes and AGF slopes significantly decreased, and the ECAP latency significantly increased in the CND group (P<0.01). GLMM showed that the stimulating site had a significant effect on the ECAP threshold, maximum amplitude, and AGF slope (P<0.01), but had no significant effect on the ECAP latency (P>0.05) in the CND group. However, the stimulating site had no significant effects on the ECAP measurements in the control group. Furthermore, the functional status of cochlear nerve varied greatly among CND group. From electrode 1 to electrode 22, the ECAP thresholds gradually increased, the ECAP maximum amplitudes and AGF slopes gradually decreased in the CND group. Conclusion: Compared with patients with normal-sized cochlear nerve, not only the number of residual spinal ganglion neurons reduce,but also the function of spinal ganglion neurons damages in CND patients. The degree of cochlea nerve deterioration varies greatly among CND patients. Generally, the deterioration of cochlear nerve tends to increase from the basal to the apical site of the cochlea.
Child, Preschool
;
Female
;
Humans
;
Infant
;
Male
;
Cochlea
;
Cochlear Implantation/methods*
;
Cochlear Implants
;
Cochlear Nerve
;
Electric Stimulation
;
Evoked Potentials, Auditory/physiology*
10.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

Result Analysis
Print
Save
E-mail