Combined multi-channel intraluminal impedance measurement and pHmetry in the detection of gastroesophageal reflux disease in children with cystic fibrosis

Abstract Objective To assess the prevalence of GERD exclusively by means of multichannel intraluminal impedanciometry associated with pH monitoring (MIIpH) and compare it with respiratory symptoms in children with CF. To compare MIIpH with pHmetry alone to perform GERD diagnosis. Methods An analytical cross-sectional study was conducted with children diagnosed with CF who underwent MIIpH. Clinical and laboratory markers, including respiratory and digestive symptoms, were used for comparative analyses. High-resolution chest computed tomography was performed on patients with symptoms of chronic lung disease. Severity was classified according to the Bhalla score. Results A total of 29 children < 10 yo (18 girls) were evaluated; 19 of whom with physiological GER and 10 with GERD. Of the children with GERD, seven had predominantly acid GER, two acid+non-acid GER, and one non-acid GER. Three patients had GERD diagnosed only by MIIpH. Bhalla scores ranged from seven to 17.75 with no significant relationship with GERD. The number of pulmonary exacerbations was associated with a decrease in esophageal clearance regardless of the position in pHmetry and MIIpH. Conclusions The prevalence of GERD was 34% in children with CF. There was no association between respiratory disease severity and GER types. MIIpH detected 30% more patients with GERD than pHmetry.

Application of self-directed learning-oriented multi-channel teaching in clinical digestive system integration course / 中华医学教育探索杂志

Objective:To apply self-directed learning-oriented multi-channel teaching to clinical digestive system integration course and explore its teaching effect.Methods:Seventy undergraduates of Batch 2015 majoring in clinical medicine in a medical college of Shandong Province were selected as subjects. In the clinical digestive system integration course, we designed and implemented multi-channel teaching methods including problem-based learning (PBL), integrated teaching of theory and practice, standardized patient teaching, group focus teaching and moral education. The scores of students' practice examination under the two teaching methods were compared, and the self-assessment of students' autonomous learning ability before and after the intervention was compared. SPSS 20.0 was used for t test. Results:The average total score of practical assessment in the intervention group was (86.10±6.01), which was higher than that (81.84±7.08) of the Batch 2014 students ( P<0.05). The total score of students' self-assessment of autonomous learning ability was (145.41±9.42) before the intervention. By comparison, the total score was (152.94±10.18) after the intervention. Except for the dimension of "self-innovation", the scores of self-directed learning ability in general and other dimensions were significantly different before and after the intervention ( P<0.05). Conclusion:Self-directed learning-oriented multi-channel teaching is a suitable teaching method for the integration curriculum of clinical digestive system.

Study of 3D-printed multi-channel applicator in patients treated with brachytherapy after cervical cancer surgery / 中华放射肿瘤学杂志

Objective:To compare the dosimetric difference between 3D-printed multi-channel applicator and conventional vaginal single-channel applicator for brachytherapy, aiming to provide guidance for patients receiving brachytherapy after cervical cancer surgery.Methods:From January 2019 to November 2020, 25 cervical cancer patients complicated with VAIN Ⅲ receiving 192Ir high-dose-rate brachytherapy after cervical cancer surgery were selected. Each patient was located by CT scanning with 3D-printed multi-channel applicator and conventional vaginal single-channel applicator, and corresponding plan and evaluation were carried out. The dose volume histogram (DVH) was obtained by inverse dose optimization algorithm. The dosimetric differences of high-risk clinical target volume (HRCTV), bladder and rectum during brachytherapy were compared with those of source applicators. The optimal treatment plan was selected. Results:D 90%, D 100%, V 100% and V 150% of the plans designed by 3D-printed individual multi-channel applicator had no significant differences compared with those designed by conventional single-channel applicator (all P>0.05). The bladder and rectal D 2cm 3 designed by 3D-printed multi-channel applicator were significantly lower than those using conventional single-channel applicator, and the differences were statistically significant (both P<0.05). Conclusion:The multi-channel individual applicator target made by 3D-printing technology has good conformal property, properly protects the bladder and rectum and possesses treatment advantages over conventional single-channel applicator.

A comparative study of microwire electrode array with built-in and external reference electrodes / 中国应用生理学杂志

Objective: To compare the difference between the built-in and external reference electrode of microwire electrode array in the process of recording rat brain neuron firings, optimizing the production and embedding of the microwire electrode array, and providing a more affordable and excellent media tool for multi-channel electrophysiological real-time recording system. Methods: A 16 channel microwire electrode array was made by using nickel chromium alloy wires, circuit board, electrode pin and ground wires (silver wires). The reference electrode of the microwire electrode array was built-in (the reference electrode and electrode array were arranged in parallel) or external (the reference electrode and ground wire were welded at both ends of one side of the electrode), and the difference between the two electrodes was observed and compared in recording neuronal discharges in ACC brain area of rats. Experimental rats were divided into built-in group and external group, n=8-9. The test indicators included signal-to-noise ratio (n=8), discharge amplitude (n=380) and discharge frequency (n=54). Results: The microwire electrode array with both built-in and external reference electrodes successfully recorded the electrical signals of neurons in the ACC brain region of rats. Compared with the external group, the electrical signals of neurons in built-in group had the advantages of a higher signal-to-noise ratio (P＜0.05), a smaller amplitude of background signals and less noise interference, and a larger discharge amplitude(P＜0.05); there was no significant difference in spike discharge frequency recorded by these two types of electrodes (P＞0.05). Conclusion: When recording the electrical activity of neurons in the ACC brain region of rats, the microwire electrode array with built-in reference electrode recorded electrical signals with higher signal-to-noise ratio and larger discharge amplitude, providing a more reliable tool for multi-channel electrophysiology technology.

Outcomes of intermediate-risk to high-risk stage I endometrial cancer: 10-year clinical experiences of using in-house multi-channel applicators in a single center / 中华医学杂志(英文版)

Background@#There are only very few reports on clinical outcomes using multi-channel applicators (MCA) for patients with endometrial cancer (EC) in China. We aimed to evaluate the clinical experience of treating intermediate-risk (IR) to high-risk (HR) stage I EC using in-house made multi-channel applicators (IH-MCA) in a single institution.@*Methods@#Three hundred and ninety patients with stage I IR to HR EC were treated with hysterectomy and adjuvant radiotherapy from 2003 to 2015. All patients received post-operative vaginal cuff brachytherapy (VBT) alone or as a boost after external beam radiotherapy (EBRT). The prescriptions were 500 cGy per fraction for a total of 5 to 6 fractions with brachytherapy alone or 400 to 600 cGy per fraction for 2 to 3 fractions if it was combined with EBRT. Two types of applicators including a traditional rigid IH-MCA and a recent model custom-made with 3 dimension printing technology were used for treatment. The Kaplan-Meier method was used to calculate survival rate.@*Results@#Follow-up rate was 92.8% and the median follow-up time was 48 months (range 4–172 months). The 5-year overall survival (OS), progression-free survival, local recurrence, and distant metastasis rates for all patients were 96.3%, 92.1%, 2.9%, and 4.8% respectively. Two patients had isolated relapse in vagina outside the irradiated volume. The univariate and multivariate analysis showed that age and grade were the prognostic factors correlated with OS (hazard ratio: 0.368, 95% confidence interval [CI]: 0.131–1.035, P = 0.048; hazard ratio: 0.576, 95% CI: 0.347–0.958, P = 0.026,).@*Conclusions@#For patients with IR to HR stage I EC, adjuvant VBT alone or in combination with EBRT using IH-MCA led to excellent survival and recurrence rates. Age and grade were the prognostic factors correlated with OS.

Studies on the robot-assisted single port laparoscopic surgery of gynecological malignant tumors / 解放军医学杂志

Objective To explore the technique of single port laparoscopy assisted by the third generation SI class Da Vinci robot in treatment of gynecological malignant tumors. Methods The clinical data were retrospectively analyzed of 8 patients with robot-assisted single port laparoscopy of gynecological malignant tumor from June to August 2018 in Changzheng Hospital. Of the 8 patients [aged 34–51 (43±6) years and BMI of 20.1–26.3 (23.2±3.1) kg/m2], 4 were early endometrial cancer and another 4 were early cervical cancer. With the help of porous instruments of ordinary robot system and Lagiport single-site multi-channel platform, the third generation SI class Da Vinci robotic surgical system was used to complete the robot assisted transumbilical single port laparoscopic surgery. Four patients with early endometrial cancer received total hysterectomy + double-adnexy resection + sentinel lymph node biopsy, and another 4 with early cervical cancer received radical resection of cervical carcinoma. Results Robot assisted single port laparoscopic surgery was successfully performed in all 8 patients with no additional auxiliary puncture port or laparotomy. The operation time was (208±68) min, and the intraoperative blood loss was (155±71) ml. No injury of ureter, bladder, rectum and obturator nerve and blood transfusion occurred during operation. No postoperative complications occurred such as blood transfusion, persistent fever, wound exudation, pelvic and abdominal infection and deep venous thrombosis. Four patients with endometrial cancer were discharged 4 days after operation, and another 4 with cervical cancer were discharged 7 days after operation. All patients were satisfied with the wound after operation. Conclusion The third generation SI-class Da Vinci robot can complete gynecological malignant tumor surgery with the help of ordinary robot instruments and Lagiport single-site multi-channel platform, which is one of the effective surgical methods for gynecological malignant tumor.

Application of the bionic multi-channel nerve conduit in the rabbit sciatic nerve defect by reducing mismatch of regenerated nerve fibers / 中华显微外科杂志

To investigate the role of the bionic multi-channel nerve conduit by reducing mis-match of regenerated nerve fibers in the rabbit sciatic nerve defect. Methods The experiment was conducted from July, 2017 to February, 2019. A total of 55 New Zealand white rabbits were randomly divided into two groups (First group, n=30 and Second group, n=25).There were 5 subgroups (n=6) in the first group, which were autograft and cus-tom-anatomic nerve conduits (CANC) with different channel (1-CANC, 2-CANC, 3-CANC, 4-CANC) that implanted to repair the rabbit sciatic nerve defect (10 mm). The electrophysiological, triceps muscle wet weight recovery rate, histological study and ankle index analysis were used to evaluate the treatment of each group at 12 and 24 weeks postoperatively. There were 5 subgroups (n=5) in the second group. The simultaneous retrograde tracing method was applied to compare with the number of mismatched nerve fibers at 24 weeks postoperatively. All data were recorded and analyzed by One-way ANOVA method, the Turkey’s method was used to compare the differences between each subgroup. The difference was considered to be statistically significant if P＜0.05. Results The autograft group showed the best recovery in the electrophysiology, histology study and ankle index at 12 and 24 weeks postoperatively (P＜0.05).Histology results showed that the same number of myelinated nerve fibers in all CANC group (P＞0.05), but di-ameters of nerve fiber and myelin thickness were higher in 2-CANC and 3-CANC [(10.67±0.56) μm,(10.65±0.53) μm, respectively] compared with 1-CANC and 4-CANC groups [(8.43±0.63) μm, (9.03±0.55) μm, respectively].The differ-ences were similar in electrophysiological, wet weight recovery rate of triceps muscle, histological study and ankle index analysis.Simultaneous retrograde tracing showed that the autograft group had highest total number of labeled profiles, but no significant difference of the total number of labeled profile was showed among the CANC groups. However, the 1-CANC group[(7.1±2.4) %] showed highest percentage of the FB-NY-neurons than other CANC groups[(2.7±1.9)% in 2-CANC, (2.5±2.3) % in 3-CANC, and (2.2±1.2)% in 4-CANC](P＜0.05). Conclusion The autograft group showed the best results among all groups.Compared with the 1-CANC group, the 2-CANC and 3-CANC group obtained more mature regenerated nerve fibers and with a fewer mismatch rate.Moreover, that did not affect the number of regenerated fibers.

Implantable Neural Probes for Brain-Machine Interfaces – Current Developments and Future Prospects

A Brain-Machine interface (BMI) allows for direct communication between the brain and machines. Neural probes for recording neural signals are among the essential components of a BMI system. In this report, we review research regarding implantable neural probes and their applications to BMIs. We first discuss conventional neural probes such as the tetrode, Utah array, Michigan probe, and electroencephalography (ECoG), following which we cover advancements in next-generation neural probes. These next-generation probes are associated with improvements in electrical properties, mechanical durability, biocompatibility, and offer a high degree of freedom in practical settings. Specifically, we focus on three key topics: (1) novel implantable neural probes that decrease the level of invasiveness without sacrificing performance, (2) multi-modal neural probes that measure both electrical and optical signals, (3) and neural probes developed using advanced materials. Because safety and precision are critical for practical applications of BMI systems, future studies should aim to enhance these properties when developing next-generation neural probes.

The study of the theta oscillation characteristic in working memory in patients with mild cognitive impairment / 天津医药

Objective To study the feature of theta oscillation during working memory (WM) dysfunction in patients with mild cognitive impairment (MCI). Methods Fifteen MCI patients (MCI group) and 15 healthy subjects for checkup (control group) in Tianjin Medical University General Hospital from January to November 2016 were recruited. The differences of behavioral results in visual WM tasks were compared between the two groups. Thirty four-channel electroencephalogram (EEG) signals were recorded simultaneously. Short-Time Fourier transform was used to calculate spatial and time-frequency distribution of power and spectral coherence of multi-channel EEGs. Results Compared with control group, MCI group showed significantly longer reaction time and lower accuracy in WM tasks (P<0.01). The analysis of EEGs revealed that the power of Fz channel was the biggest at frontal midline in both groups. And the power density of theta oscillation was lower at frontal electrode sites in MCI group than that of control group ( P<0.01), and theta coherence was significantly decreased in frontal region and between frontal-posterior regions ( P<0.05). Conclusion The absence of theta oscillaton in frontal region may be one of the important reasons of working memory dysfunction for MCI.

The study of the theta oscillation characteristic for working memory in frontal lobe epilepsy / 天津医药

Objective To investigate the characteristic of theta oscillation in patients with frontal lobe epilepsy (FLE) by the analysis of multi-channel electroencephalographs (EEGs) during rest state and working memory(WM) maintenance. Methods The 19 FLE patients and 17 healthy subjects underwent EEG recording with 34-channel EEG machine during visual working memory task performance. The differences of behavioral results were analyzed between FLE group and controls. Short-time Fourier transform was used to calculate the power spectral density of different frequency bands in 34 channels. The theta power values during the retention period of working memory and rest state were compared between two groups. Results Compared with controls, reaction time of FLE increased significantly (P<0.01) and accuracy decreased (P<0.05). The power spectral density of theta band for FLE increased both in Fz and frontal region during rest state (P<0.01). Compared with controls, the power spectral density of theta oscillation decreased significantly in the frontal region for FLE during WM maintenance. Conclusion Our results suggest that working memory in patients with FLE was impaired. The absence of theta oscillation during the WM delayde period may provide a possible neural mechanism for the working memory dysfunction in FLE.

A fractionated X-ray total body irradiation technique with patients lying on side and in vivo dosimetry analysis / 中华放射医学与防护杂志

Objective To investigate an X-ray total body irradiation (TBI) technique using anterior-posterior opposed fields with patients at the side-lying position,and to analyze the real-time in vivo dosimetry results.Methods The accelerator with 10 MV X-rays of Varian Trilogy was used for the TBI with the extended source to skin distance of 390 cm.The percent depth dose,off axis factors and absolute dose output were measured.The dose accuracy and homogeneity was monitored real-time using multichannel diode dosimeter for 10 patients.The monitored sites included forehead,mandible,suprasternal fossae,xiphoid,umbilicus,pelvis,middle of thigh,knee,middle of leg and ankle.The patients were irradiated at the side-lying position,with the prescription dose of 1 200 cGy/6 f during 3 days,the middle line dose rate of 5.0 cGy/min.Solid water was used for the compensation of the dose homogeneity.Results The off axis dose homogeneity was less than ± 5.0％ for the TBI geometry.The absolute dose output was 0.072 1 cGy/MU at the maximum dose point.The total body irradiation was finished smoothly for the 10 patients lying on side.The deviation of monitored total dose from the total prescription dose was within -4.9％ to 6.7％ for the 10 monitored sites.The monitored dose homogeneity was less than 5.0％.Conclusions The fractionated anterior-posterior opposed parallel TBI can be finished smoothly with patients side-lying.Accurate and homogenous dose distribution can be obtained using real-time dose monitoring and compensation with solid water.

Design of a dual wavelength multi-channel laser acupuncture instrument / 国际生物医学工程杂志

Objective To design a laser acupuncture instrument with dual wavelength and multi-channel,under the guidance of traditional Chinese medicine acupuncture theory and according to low-level laser induced effect in bio-tissues and compatibility characteristics of acupuncture points.Methods Using SCM and semiconductor laser,hardware circuitry was designed to achieve the basic functions of the instrument,and the corresponding PC software was developed.Results The laser acupuncture treatment for several acupuncture points could be carried out at the same time with the same or different laser parameters (wavelength,power density,continuous/pulse),and each channel could output 635 nm and 808 nm laser,with continuous adjustable power.Conclusions The dual wavelength multi-channel laser acupuncture instrument can meet the needs of compatibility during clinical acupuncture treatment and is easy to operate.

Study of absence of theta oscillation of working memory dysfunction in temporal lobe epilepsy / 国际生物医学工程杂志

Objective Temporal lobe epilepsy (TLE),frequently accompanied by working memory dysfunction,is an important form of adult epilepsy syndrome.Study on neural mechanisms of TLE with working memory dysfunction has important scientific value and clinical significance.Theta oscillations are synchronous activity of the brain in the 4-8 Hz frequency range.It is well recognized that there is a close relationship between the theta oscillations and working memory behavior.TLE patients with working memory dysfunction were taken as the research subjects,and the theta oscillations absence in TLE with working memory behavioral disorder was carried out,which provide the reference for further research into the neural mechanisms of TLE with working memory dysfunction.Methods The 34-channel electroencephalographs (EEGs) were recorded from TLE group (18 TLE patients) and control groups (18 healthy subjects) while subjects were performing visual working memory (delayed matching-tosample) tasks.The EEGs during the 3 s delay period was analyzed as experimental data.Fourier transform was used to assess the EEGs spectrum.The channel with the strongest spectrum was selected as the feature channel.Short-time Fourier transform algosiths was employed to calculate the time-frequency representation of the feature channel for the TLE and control groups.Frequency band with the strongest spectrum was selected for control group as the feature frequency band in working memory.Then,the topographical maps of the feature frequency band spectrum were calculated for the TLE and control groups.Results Compared with the control group,the working memnory behavioral performance of the TLE group was lower:accuracy of the TLE group was significantly lower than that of the control group (P＜0.05),and reaction time of the TLE group was significantly longer than that of the control group (P＜0.001).The feature channel in working memnory was frontal midline (Fz) and the feature frequency band was theta band.The Fz spectrum of the feature frequency for TLE was lower than that for control (P＜0.05).The frontal spectrum (seven channels) of the feature frequency for TLE was lower than that of control (P＜0.01).Conclusions Theta oscillations for TLE with working memory behavioral disorder is absent,which maybe one of the possible neural mechanism of TLE with working memory dysfunction.

Spatial distributions of multi-channel electroencephalographs power in different frequency band during visual working memory / 国际生物医学工程杂志

Objective Working memory (WM) is one of important cognitive functions.The aim of this study was to investigate spatial distributions of electroencephalographs (EEGs) power during visual WM task,which may provide support for studying the principal frequency band and critical region related to WM.Methods 32-channel EEGs were recorded from 16 healthy subjects while they perform visual WM task.The data came from 240 trials and the original EEGs were preprocessed.Fourier transform was applied to calculate spatial distributions of EEGs power in the δ,θ,α,β,γfrequency bands and the percentage of each band in the total power.Results The percentages of δ,θ,α,β,γbands in the total power were (22.44±0.86)％,(31.88±0.55)％,(24.66±1.43)％,(13.54±0.64)％,(7.47±0.48)％,respectively.The power in the θ band was significantly higher than those in the other bands (paired t-test,P＜0.001).The θ power was focused in the frontal midline region.Conclusions The principal frequency band related to WM was the θ band and the critical region was the frontal region.

Causal flow distribution of multi-channel electroencephalographs during visual working memory / 国际生物医学工程杂志

Objective The ability of working memory (WM) is to temporarily hold and manipulate information for cognitive tasks.The aim of this study was to investigate the causal flow distribution of multi-channel electroencephalographs (EEGs) during Sternberg visual WM task to help understand WM mechanism from the view of neural information transform.Methods Sixteen-channel EEGs were recorded from 8 healthy subjects during Sternberg task,total EEG data for 80 trials were recorded and preprocessed.The EEG powers for each channel were calculated via Fast Fourier transform (FFT).The feature channel was extracted based on the maximum power,and the feature frequency band for WM was determined by time-frequency analysis.The directed transfer function (DTF) and the value of causal flow in EEG feature frequency band were calculated.Results The EEG power focused on θ band (4-8 Hz) and at Fz channel.The maximum value of causal flow was located at Fz,and the first 4 maximum negative values of causal flow were at C3,C4,C5,C6.Conclusions The feature frequency band for WM is the θ band.The causal source (responsible region) is at Fz (frontal region) and the causal sinks are at C3,C4,C5,C6.

Design and implementation of auto-control system for high-throughput and multi-channel DNA synthesis / 军事医学

Objective To establish an auto-control system for high-throughput and multi-channel DNA synthesis which can simultaneously and quickly synthesize up to 96 different oligonucleotides in a 96-well microtiter format.Methods The PLC and its extended modules is used as the main-control unit, which executes the DNA automatic synthesis process according to the synthesis sequences and steps set by the user,and the manual injecting reagent etc.And the configuration software and VC6.0 were used for programming the man-machine interface sofeware to set synthesis parameters, position calibration,flux calibration data etc, and communicated with PLC.Results The synthesis application of about 150 000 DNA chains has proved that the synthesis cycle time for 96 couplings was 4 min,the average coupling efficiency was 99%across the entire 96-well plate,the monomer reagent usage was reduced by 50 percent,and the synthesis configuration was more flexible.Conclusion A reliable and simple auto-control system is provided for parallel synthesis of 96-channel oligonucleotide chains,which can meet the demands of high-throughput and multi-channel DNA synthesis.

Transumbilical single-port access laparoscopic surgery of ectopic pregnancy / 대한산부인과학회지

OBJECTIVE: To evaluate the effectiveness of transumbilical single-port access laparoscopic surgery of ectopic pregnancy. METHODS: Retrospective analysis was performed on six patients who underwent transumbilical single-port access laparoscopic management of ectopic pregnancies. RESULTS: The median age of 6 cases was 33.5 years (range, 32 to 36), and the median body mass index was 20.6 kg/m2 (range, 16.5 to 28.7). The median largest diameter of G-sac was 4.8 cm (range, 3.0 to 5.4). Intracorporeal rupture and hemoperitoneum were accompanied in all cases. The median time needed for the surgery was 77.5 minutes (range, 59 to 95). The median estimated blood loss was 40 mL (range, 20 to 50). The median postoperative hospital day was 2 days (range, 1 to 3). There were no complications on postoperative course and follow-up. CONCLUSION: Transumbilical single-port access laparoscopic surgery for ectopic pregnancy was feasible and safe. This approach might be reasonable alternative to conventional laparoscopic surgery using 3 or 4 port in the management of ectopic pregnancy.

STN DBS of Advanced Parkinson's Disease Experienced in a Specialized Monitoring Unit with a Prospective Protocol

OBJECTIVE: In the evaluation of patients with Parkinson's disease (PD), most neurologists only see their patients during a limited period of their fluctuating 24-hour-a-day lives. This study aimed to assess the short-term outcome of STN stimulation for patients with advanced PD evaluated in a 24-hour monitoring unit for movement disorder (MUMD) using a prospective protocol. METHODS: Forty-two patients with advanced PD consecutively treated with bilateral STN stimulation using multi-channel microelectrode recording were included in this study. All patients were evaluated using a 24-hour MUMD with a video recording/editing system and were evaluated with a prospective protocol of the Unified Parkinson's Disease Rating Scale, Hoehn and Yahr Staging, Schwab and England Activities of Daily Living, levodopa equivalent daily dose (LEDD), Short Form-36 Health Survey, and neuropsychological tests. Magnetic resonance (MR) images of the brain were performed prior to and six months after surgery. RESULTS: All patients were evaluated at three and six months after surgery. There was a rapid and significant improvement of the motor symptoms, especially in tremor and rigidity, after STN stimulation with low morbidity. Dyskinesia was markedly decreased with much lowered LEDD values by 50% after STN stimulation. 1.5T MR images were safely taken according to the manufacturer's guidelines at six months after surgery without any adverse effects in 41 patients treated with STN stimulations. CONCLUSION: Evaluations in a 24-hour monitoring unit could reduce the dose of medication efficiently to an optimal level with patients'comfort and improve the clinical symptoms in harmony with STN stimulation.

Alterações na banda alfa do eletrencefalograma durante imagética motora visual e cinestésica / Changes in the electroencephalogram alpha band during visual and kinesthetic motor imagery

Foi investigada a contribuição em potência na vizinhança do pico da banda alfa (BPA) do EEG durante imagética motora (IM). Sinais EEG (derivações occipitais e parietais) foram adquiridos em sujeitos destros (18-40 anos), durante repouso (ESP) e IM nas modalidades cinestésica (IMC) e visual (IMV), sendo 15 atletas de voleibol e 15 não-atletas. O Revised Movement Imagery Questionnaire não indicou diferenças entre grupos ou modalidades de IM; todavia os atletas imaginaram-se melhor que os não-atletas. Para ambos os grupos, a potência em BPA resultou menor em IM do que em ESP, sendo mais reduzida em IMC. Ativação cortical similar ocorreu em ambos os hemisférios de não-atletas e mais pronunciada no hemisfério esquerdo de atletas, principalmente durante IMC. Tais resultados sugerem que IM reduz a atividade de alfa de acordo com o conhecimento real da tarefa e a modalidade de IM.

This study aims at statistically assessing the differences in alpha band power, particularly in the vicinity of the alpha peak (BPA), during motor imagery (MI). Multi-channel EEG (occipital and parietal regions) was acquired at rest condition (ESP) and MI kinesthetic (MIC) and visual (MIV) modalities from right-handed male subjects (18-40 years), 15 ‘athletes’ (experienced volleyball players) and 15 ‘non-athletes’. The Revised Movement Imagery Questionnaire indicated no differences between groups or MI modalities, but athletes imagine themselves more clearly than non-athletes during MI. The power within BPA reduces in both groups, but greater in MIC than in MIV. The cortical activation was similar in both hemispheres of non-athletes but more pronounced in left hemisphere of athletes, mainly in MIC. The findings suggest that MI reduces alpha activity according to individual knowledge of real execution of motor task and MI modalities.

A Novel Method for Multi-channel Neuronal Spike Detection and Classification / 生物化学与生物物理进展

The detection and classification of extracellular action potentials(i.e.spike) of various single neurons from extracellular recordings are crucial for extracting neuronal spike sequences and thereby for investigating the mechanisms of neural information processing in the central nervous system.In order to increase the correctness of spike detecting and sorting,a new analysis algorithm for processing multi-channel spike signals recorded from rat hippocampi with silicon microelectrode arrays is presented.Four recording contacts on the electrode array are arranged close enough to simultaneously record spikes emitted from same neurons.Firstly,the algorithm extracts all spikes in the four channel recordings by using a multi-channel threshold detection method.Secondly,the algorithm classifies the spikes based on a principle component analysis for a specifically designed type of compound spike waveforms.The compound spike waveform is formed by linking four spike waveforms of a same neuronal firing in the four recording channels one by one in series.The test results with both synthetic datasets and experimental recordings reveal that compared with corresponding traditional single-channel algorithm,the multi-channel algorithm can significantly enhance both the number of extracted spikes and the correctness of spike classifications.The algorithm can also increase the number of isolated neurons from a single experimental preparation.These results indicate that the novel method is efficient for the automatic detection and classification of neuronal spikes.