Portable Multi Channel EEG Signal Acquisition System / 中国医疗器械杂志

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.

Research Progress on Enzyme-free Blood Glucose Sensor / 中国医疗器械杂志

Blood glucose monitoring is of great significance to diabetic patients, and the development of rapid, accurate and real-time glucose detection technology has become a research hotspot nowadays. This study introduces the concept and classification of the enzyme-free glucose sensor, expounds enzymefree glucose sensor electrode characterization methods and the application progress of different materials in enzyme-free blood glucose sensors. Meanwhile, some problems of enzyme-free glucose sensor existing in the current research and its future application prospects also will be discussed.

Design and Application of Home Wireless Electrocardiograph Machine Based on Internet / 中国医疗器械杂志

This study introduces the design and application of home wireless electrocardiograph(ECG) machine based on Internet. The world's first three-lead dry electrode mobile electrocardiograph machine has been developed, on the basis of the successful development of dry electrodes. Moreover, it is not only chips filtering, but also wireless, as a result it is applied to ECG monitoring and diagnosis of patients. Compared with traditional electrocardiograph machine, the machine is very convenient and comes into the home, ECG Machines is connected to mobile phones by Bluetooth, wireless upload, therefore we recommend to achieve remote monitoring and early warning and reduce sudden death, to achieve Internet medical by using Internet technology, people can be self-test. It is playing an increasingly important role and it is an inevitable machine to improve the success rate of diagnosis, monitoring and first aid.

Development of Non-invasive Endoscope System with Magnetic Anchored Ablation Electrode for Early Cancer of Digestive Tract / 中国医疗器械杂志

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.

Construction and performance analysis of a microbial electrochemical sensor for monitoring heavy metals in water environment / 生物工程学报

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.

Voltammetric Determination of Ascorbic Acid in Pharmaceutical Formulations Using Modified Iodine-Coated Platinum Electrode / Determinación voltamétrica del ácido ascórbico en formulaciones farmacéuticas utilizando un electrodo de platino modificado recubierto de yodo

Background: Despite the high reactivity of the platinum electrode, the iodine-coated platinum electrode shows obvious inertness toward adsorption and surface processes. For that, iodine-coated platinum electrodes accommodate themselves to interesting voltammetric applications. Objectives: This study reports using the modified iodine-coated polycrystalline platinum electrode as a voltammetric sensor for ascorbic acid determination in pharmaceutical formulations. Methods: The developed voltammetric method based on recording cyclic voltammograms of ascorbic acid at iodine-coated electrode The optimized experimental parameters for the determination of ascorbic acid were using 0.1 M KCl as a supporting electrolyte with a scan rate of 50mV/s. Results: The anodic peak related to ascorbic acid oxidation was centered at nearly 0.28V. An excellent and extended linear dependence of the oxidative peak current on the concentration of ascorbic acid was observed in the range 2.84x10-3 - 5.68 mM. The limit of detection (LOD) and limit of quantitation (LOQ) were 1.0 µM and 3.01 µM, respectively, attesting to the method's sensitivity. The investigation for the effect of potential interference from multivitamin tablet ingredients (vitamins B1, B6, B12, folic acid, citric acid, sucrose, glucose, and zinc) indicated specific selectivity toward ascorbic acid and the absence of any electrochemical response toward these components. Recovery results in the range 98.93±2.78 - 99.98±5.20 for spiked standard ascorbic acid in pharmaceutical formulations further confirmed the potential applicability of the developed method for the determination of ascorbic acid in real samples. Conclusions: The developed method was successfully applied to the analysis of ascorbic acid (vitamin C), and the obtained results were in good agreement with the labeled values; besides, the statistical tests indicated no significant difference at p=0.05 with a 95% confidence level

Antecedentes: A pesar de su alta reactividad, el electrodo de platino recubierto de yodo muestra una inercia evidente hacia la adsorción y los procesos superficiales. Por ello, los electrodos de platino recubiertos de yodo se adaptan a interesantes aplicaciones voltamétricas. Objetivos: Este estudio informa sobre el uso del electrodo de platino policristalino recubierto de yodo modificado como sensor voltamétrico para la determinación del ácido ascórbico en formulaciones farmacéuticas. Métodos: El método voltamétrico desarrollado se basa en el registro de voltamperogramas cíclicos del ácido ascórbico en el electrodo recubierto de yodo Los parámetros experimentales optimizados para la determinación del ácido ascórbico fueron utilizando KCl 0,1 M como electrolito de soporte con una velocidad de barrido de 50mV/s. Resultados: El pico anódico relacionado con la oxidación del ácido ascórbico se centró en casi 0,28V. Se observó una excelente y extendida dependencia lineal de la corriente del pico oxidativo con respecto a la concentración de ácido ascórbico en el rango 2,84x10-3 - 5,68 mM. El límite de detección (LOD) y el límite de cuantificación (LOQ) fueron 1,0 µM y 3,01 µM, respectivamente, lo que demuestra la sensibilidad del método. La investigación del efecto de la interferencia potencial de los ingredientes de las tabletas multivitamínicas (vitaminas B1, B6, B12, ácido fólico, ácido cítrico, sacarosa, glucosa y zinc) indicó una selectividad específica hacia el ácido ascórbico y la ausencia de cualquier respuesta electroquímica hacia estos componentes. Los resultados de recuperación en el rango de 98,93±2,78 - 99,98±5,20 para el ácido ascórbico estándar adicionado en formulaciones farmacéuticas confirmaron además la potencial aplicabilidad del método desarrollado para la determinación del ácido ascórbico en muestras reales. Conclusiones: El método desarrollado se aplicó con éxito al análisis de ácido ascórbico (vitamina C), y los resultados obtenidos coincidieron con los valores etiquetados; además, las pruebas estadísticas no indicaron diferencias significativas a p=0,05 con un nivel de confianza del 95%

Design of Portable EEG and Blood Oxygen Synchronous Acquisition System / 中国医疗器械杂志

In order to obtain comprehensive brain activity information conveniently in real time, this study designs a portable EEG and blood oxygen synchronous acquisition system for real-time monitoring of brain functional activities. The EEG electrodes filter and amplify the detected EEG signals, and send them to the microprocessor via Bluetooth to analyze the EEG data; the photoelectric probe converts the optical signals into electrical signals, which are amplified and separated, filtered, and AD converted, calculates the brain's oxygenation and blood-red protein (ΔHbO

Effect of electrode temperature on measurements of transcutaneous carbon dioxide partial pressure and oxygen partial pressure in very low birth weight infants / 中国当代儿科杂志

OBJECTIVES@#To evaluate the accuracy and safety of measurements of transcutaneous carbon dioxide partial pressure (TcPCO@*METHODS@#A total of 45 very low birth weight infants were enrolled. TcPCO@*RESULTS@#There was no significant difference in TcPCO@*CONCLUSIONS@#Lower electrode temperatures (38-41℃) can accurately measure blood carbon dioxide partial pressure in very low birth weight infants, and thus can be used to replace the electrode temperature of 42°C. Transcutaneous measurements at the lower electrode temperatures may be helpful for understanding the changing trend of blood oxygen partial pressure.

Effects of parameters selection with transcranial direct current stimulation based on real head model / 生物医学工程学杂志

Transcranial direct current stimulation (tDCS) is a brain stimulation intervention technique, which has the problem of different criteria for the selection of stimulation parameters. In this study, a four-layer real head model was constructed. Based on this model, the changes of the electric field distribution in the brain with the current intensity, electrode shape, electrode area and electrode spacing were analyzed by using finite element simulation technology, and then the optimal scheme of electrical stimulation parameters was discussed. The results showed that the effective stimulation region decreased and the focusing ability increased with the increase of current intensity. The normal current density of the quadrilateral electrode was obviously larger than that of the circular electrode, which indicated that the quadrilateral electrode was more conducive to current stimulation of neurons. Moreover, the effective stimulation region of the quadrilateral electrode was more concentrated and the focusing ability was stronger. The focusing ability decreased with the increase of electrode area. Specifically, the focusing tended to increase first and then decrease with the increase of electrode spacing and the optimal electrode spacing was 64.0-67.2 mm. These results could provide some basis for the selection of electrical stimulation parameters.

Microneedles in diagnosis and treatment: a review / 生物工程学报

Microneedles have been developed rapidly in the field of transdermal administration in the past few decades. In recent years, the development of microelectronics technology has expanded the applications of microneedles by combining with microelectronic systems, especially in biological diagnosis and treatment. Different types of microneedles have been designed to extract blood and tissue fluids for detection, or as electrodes to directly detect blood sugar, melanoma and pH in real-time in vivo, both show good prospects for real-time detection applications. In this paper, we review the design of materials and structure of microelectronic-based microneedles, and discuss their advances in biological diagnosis.

Progress in enhancing electron transfer rate between exoelectrogenic microorganisms and electrode interface / 生物工程学报

Exoelectrogenic microorganisms are the research basis of microbial electrochemical technologies such as microbial fuel cells, electrolytic cells and electrosynthesis. However, their applications are restricted in organic degradation, power generation, seawater desalination, bioremediation, and biosensors due to the weak ability of biofilm formation and the low extracellular electron transfer (EET) efficiency between exoelectrogenic microorganisms and electrode. Therefore, engineering optimization of interaction between exoelectrogenic microorganisms and electrode interface recently has been the research focus. In this article, we review the updated progress in strategies for enhancing microbe-electrode interactions based on microbial engineering modifications, with a focus on the applicability and limitations of these strategies. In addition, we also address research prospects of enhancing the interaction between electroactive cells and electrodes.

Construction of conjugated polymer-exoelectrogen hybrid bioelectrodes and applications in microbial fuel cells / 生物工程学报

Microbial fuel cell (MFC) is a bioelectrochemical device, that enables simultaneous wastewater treatment and energy generation. However, a few issues such as low output power, high ohmic internal resistance, and long start-up time greatly limit MFCs' applications. MFC anode is the carrier of microbial attachment, and plays a key role in the generation and transmission of electrons. High-quality bioelectrodes have developed into an effective way to improve MFC performance. Conjugated polymers have advantages of low cost, high conductivity, chemical stability and good biocompatibility. The use of conjugated polymers to modify bioelectrodes can achieve a large specific surface area and shorten the charge transfer path, thereby achieving efficient biological electrochemical performance. In addition, bacteria can be coated with nano-scale conjugated polymer and effectively transfer the electrons generated by cells to electrodes. This article reviews the recently reported applications of conjugated polymers in microbial fuel cells, focusing on the MFC anode materials modified by conjugated polymers. This review also systematically analyzes the advantages and limitations of conjugated polymers, and how these composite hybrid bioelectrodes solve practical issues such as low energy output, high inner resistance, and long starting time.

Incidencia, tasa de éxito, complicaciones y factores predictores de empleo de la vía femoral en procedimientos percutáneos de extracción de electrodos / Incidence, success rate, complications and predictive factors of the use of the femoral route for the removal of the electrodes after percutaneous procedures

Resumen Introducción: en los procedimientos de extracción de electrodos, la vía femoral se usa cuando la vía superior ha fracasado. Objetivo: describir la incidencia, el éxito, las complicaciones y los predictores de uso de la vía femoral. Métodos: se realizó un análisis de la incidencia del uso de la vía femoral y los factores predictores en pacientes a quienes se les realizó extracción de electrodos entre noviembre de 2011 y noviembre de 2017. Resultados: se incluyeron 85 pacientes, con edad media de 62,36 ± 11,15 años. El 38,9% de los dispositivos eran marcapasos. Se extrajeron 135 electrodos, 59,3% de fijación pasiva. La mediana de tiempo desde el implante fue de 102 (60-174) meses. Se empleó la ruta femoral en el 25,9% de los procedimientos. Se obtuvo éxito clínico en el 92,9% de los pacientes. La extracción no fue exitosa en el 22,7% de los procedimientos cuando se usó la vía femoral, en comparación con el 1,6% cuando se usó la vía superior (p 0,004). La extracción no fue completa en el 36,4% de los procedimientos cuando se empleó la vía femoral en comparación con el 9,5% por vía superior (p 0,007). Los factores que predijeron el empleo de la ruta femoral fueron la presencia de electrodos de fijación pasiva [OR IC 95% 13,69 (3,06-62,5) p 0,001] y el tiempo desde el implante del electrodo [OR IC 95% por cada 10 meses 1,04 (1,00-1,09) p 0,044]. Conclusiones: se empleó la ruta femoral en el 25,9% de los procedimientos. No fue eficaz en el 22,7% de las intervenciones. Los factores que predijeron su utilización fueron la presencia de electrodos de fijación pasiva y el tiempo desde el implante del electrodo.

Abstract Introduction: The femoral route is used in electrode removal procedures when the upper route has failed. Objective: To describe the incidence, success rate, complications and predictive factors for the use of the femoral route. Methods: An analysis was performed on the incidence of use of the femoral route and the predictive factors in patients in whom electrode removal was carried out between November 2011 and November 2017. Results: The study included 85 patients with a mean age of 62.36 ± 11.5 years. Pacemakers made up 38.9% of the devices. A total of 135 electrodes, 59.3% of passive fixation, were removed. The median time since the implant was 102 (60-174) months. The femoral route was used in 25.9% of the procedures. Clinical success was achieved in 92.9% of the patients. The removal was not successful in 22.7% of the procedures when the femoral route was used, compared to 1.6% when the upper route was used (P = .004). The removal was not completed in 36.4% of the procedures when the femoral route was used, compared to 9.5% with the upper route (P = .007). The factors that predicted the use of the femoral route were the presence of passive-fixation electrodes (OR = 13.69: 95% CI; 3.06 - 62.5, P = .001), and the time since the electrodes were implanted (OR = 1.04, 95% CI; 1.00 - 1.09, P = .044, for every 10 months). Conclusions: The femoral route was employed in 25.9% of the procedures. It was not effective in 22.7% of the interventions. The factors that predicted its use were the presence of passive-fixation electrodes and the time since the electrode implant.

Reconocimiento de tres patrones básicos de movimiento de la mano utilizando electromiografía de superficie y algoritmos inteligentes / Identification of three basic hand movement patterns by surface electromyography and smart algorithms

Introducción: este artículo presenta la predicción de tres tipos de movimientos básicos de la mano mediante un algoritmo inteligente para extraer características imprescindibles para el reconocimiento de patrones de movimiento a partir del análisis de señales electromiográficas superficiales adquiridas con el dispositivo Myo. Objetivo: reconocer y predecir patrones básicos de movimiento de la articulación del brazo utilizando electromiografía de superficie para aplicarlo sobre un prototipo de prótesis. Métodos: se tomaron datos de 13 estudiantes de 22 y 23 años de la Universidad Politécnica Salesiana, cada uno de los cuales ejecutó tres tipos de agarre: cilíndrico, pinza y pinza planar. Se trabajó con una frecuencia de 10 Hz y se tomaron 5 muestras por tipo de agarre durante 60 segundos. Para el análisis estadístico de los datos se utilizó la herramienta Anova, estableciendo un valor de significancia mayor a 0,65. Resultados: En ciertos voluntarios hay una mayor reacción en el electrodo 1 debido a que su antebrazo es mayor. El tiempo de respuesta para el reconocimiento varía dependiendo del número de variables que se tenga que comparar. Cuando se analiza un solo movimiento es de 2,6 segundos, en cambio, cuando se analizan los 3 movimientos el tiempo de respuesta incrementa a 7,8 segundos por la cantidad de electrodos que se quieran analizar. Conclusiones: la respuesta del sistema propuesto empieza a ser más lenta a medida que se analizan más movimientos a la vez y por tanto, es menos efectiva. El tiempo de ejecución y respuesta de nuestro sistema, en comparación al estado del arte, es más alto, debido a que se utilizan menos métodos de caracterización de la señal. Adicionalemtne, una limitante del proyecto es la frecuencia de muestreo del dispositivo Myo (200Hz)(AU)

Introduction: the paper presents the prediction of three basic hand movement types by means of a smart algorithm to draw characteristics indispensable for identification of movement patterns based on the analysis of surface electromyographic signals obtained with the Myo device. Objective: recognize and predict basic movement patterns of the arm joint using surface electromyography with a view to applying them over a prosthesis prototype. Methods: data were taken from 13 students aged 22 and 23 years from the Salesian Polytechnic University, each of whom performed three types of grasp: cylindrical, pincer and palmar pincer. A 10 Hz frequency was used and 5 samples were taken of each grasp type during 60 seconds. Statistical analysis was performed with the tool ANOVA, establishing a significance value > 0.65. Results: in certain volunteers a greater reaction was observed in electrode 1, due to their larger forearms. Response time for identification varies with the number of variables to be compared. When only one movement is analyzed, response time is 2.6 seconds, but when the three movements are examined it rises to 7.8 seconds by the number of electrodes intended to be studied. Conclusions: the response of the system proposed starts to slow down as more movements are analyzed simultaneously, which makes it less effective. The performance and response time of our system is higher than in state-of-the-art systems, since fewer signal characterization methods are used. On the other hand, a limitation of the project is the sampling frequency of the Myo device (200 Hz)(AU)

History and Evolution of Epilepsy Surgery

The surgical treatment for epilepsy has a worldwide historical relevance for centuries. There are archaeological reports that date it back to ancient Egypt; however, the year 1886 is considered a landmark in the surgical treatment for epilepsy in theModern Age, when the first surgery for the treatment of focal epileptic events was performed successfully. Since then, innumerable related articles have been published evoluonarily. Over the last centuries, new techniques and technologies provided better understanding, diagnosis and management for this disease. Thus, historical and evolutionary knowledge becomes important to let us better understand the current position of the surgery for epilepsy treatment and control.

Three-dimensional reconstruction of carp brain tissue and brain electrodes for biological control / 生物医学工程学杂志

In order to accurately implant the brain electrodes of carp robot for positioning and navigation, the three-dimensional model of brain structure and brain electrodes is to be proposed in the study. In this study, the tungsten electrodes were implanted into the cerebellum of a carp with the aid of brain stereotaxic instrument. The brain motor areas were found and their three-dimensional coordinate values were obtained by the aquatic electricity stimulation experiments and the underwater control experiments. The carp brain and the brain electrodes were imaged by 3.0 T magnetic resonance imaging instrument, and the three-dimensional reconstruction of carp brain and brain electrodes was carried out by the 3D-DOCTOR software and the Mimics software. The results showed that the brain motor areas and their coordinate values were accurate. The relative spatial position relationships between brain electrodes and brain tissue, brain tissue and skull surface could be observed by the three-dimensional reconstruction map of brain tissue and brain electrodes which reconstructed the three-dimensional structure of brain. The anatomical position of the three-dimensional reconstructed brain tissue in magnetic resonance image and the relationship between brain tissue and skull surface could be observed through the three-dimensional reconstruction comprehensive display map of brain tissue. The three-dimensional reconstruction model in this study can provide a navigation tool for brain electrodes implantation.

Clinical application of the needle electrode in transurethral plasmakinetic resection of bladder tumor around ureteral orifice: A report of 16 cases / 北京大学学报(医学版)

OBJECTIVE@#To explore the clinical application value of using needle electrode in transurethral plasmakinetic resection of bladder tumor around ureteral orifice.@*METHODS@#Retrospective analysis was performed on the clinical data of 16 cases who had bladder tumors around ureteral orifice and underwent transurethral resection using plasmakinetic needle electrode in Department of Urology, Peking University International Hospital from June 2015 to December 2019. There were nine cases with the tumor of one to two centimeters from the ureteral orifice. The rest of the seven cases had tumor that was within one centimeter from the ureteral orifice, including two cases whose ureteral orifice was invaded by the tumor. All the patients studied were diagnosed before surgery and contraindications were excluded. The plasmakinetic needle electrode was used to treat the tumor with en bloc resection, and all the excised tissue was sent for pathological examination. Intravesical chemotherapy and postoperative follow-ups were performed. Statistical analysis was performed on the operation time, the incidence of obturator nerve reflex, the peri-operative bleeding, the parameters of indwelling ureteral catheter or double-J stent, the incidence of postoperative hydronephrosis, the clinical stage of tumor, and the recurrence rate.@*RESULTS@#The operation was successfully completed for all the sixteen cases. The operation time was 16 to 57 minutes, with an average of (32.6±11.8) minutes. No obvious obturator nerve reflex and perioperative bleeding occurred in all the patients. Ureteral catheters were indwelled prior to the operation of tumor resection in seven cases. Four of the seven cases had the ureteral catheters remained while the rest three were replaced by double-J stent after surgery. Postoperative pathological analysis showed that all the tumors were urothelial carcinoma, including 9 cases of low grade and 7 cases of high grade. Pathological staging: 10 cases were in Ta stage, 5 cases in T1 stage, and 1 case in T2a stage. All tumor bases and lateral margins were negative. All the patients received 3-56 months, with an average of (26.0±18.1) months of follow-up. There was no case of upper urinary tract hydronephrosis or tumor recurrence.@*CONCLUSION@#The transurethral plasmakinetic resection of bladder tumor using needle electrode can realize en bloc tumor resection without obturator nerve reflex and reduce the risk of ureteral orifice injury. It is a safe and effective surgical method for treating bladder tumors around the ureteral orifice.

Lower limb ischemia cured by stimulation electrode implantation assisted with microendoscopic discectomy system: A case report / 北京大学学报(医学版)

A 58-year-old male patient diagnosed with thromboangiitis obliterans (Fontaine stage IV) was recently treated with microendoscope discectomy system-assisted spinal cord stimulation electrode implantation and cured by department of vascular surgery combined with department of spinal surgery at Peking University People's Hospital. The patient suffered from cold injury to the right foot 14 years ago, which was cold, painful, numb, and then the toe was ulcerated and gangrene. Only the right foot small toe was left. The right foot skin was swollen from the toe to the proximal segment 1 year ago, accompanied by resting pain. Both pain and autologous bone marrow stem cell transplantation were ineffective. The above symptoms were aggravated three months ago, and the pain was severe. The visual analogue score was 10 points. A high amputation of the left lower extremity was performed 30 years ago due to trauma. Physical examination: the bilateral femoral artery was weak, and the right radial artery, posterior tibial artery, and dorsal artery were not touched. Buerger sign (+). Auxiliary examination: angiography of both lower extremities showed complete occlusion of the bilateral external iliac artery and its distal end. The percutaneous oxygen partial pressure was measured to be 30 mmHg on the right side of the iliac crest. The operation was performed under the local anesthesia. After X-ray positioning, the body projection of the lumbar vertebrae 1-2 lamina gap was marked. The skin had a 1.8 cm incision on the caudal side 2 cm from the mark. Then the dilators were used, and the working sleeve was tilted to the lumbar vertebrae 1-2 lamina gap. The microendoscope discectomy system was installed, the electrode was directly placed into the epidural space from the interlamina space under the microendoscope, the vascular surgeon adjusted the position of the electrode in the spinal canal under fluoroscopy, then connected the stimulator, adjusted the current until the patient had the lower limb fever, fixed electrode position, removed the microendoscope discectomy system after hemostasis under the microendoscope, used the guide needle to lead the electrode through the lumbar subcutaneous and then sutured the incision. After the operation, the electrode was connected to the temporary stimulator to stimulate for several minutes, the patient felt numbness in his lower limbs. In less than one hour, the skin temperature of the affected limb increased, and the painkiller could be stopped while sleeping. After 1 week, the skin temperature of the affected limb increased, and the percutaneous oxygen partial pressure of the foot and ankle was 36 mmHg, and the pain improved, and the score was reduced to 2 points. One month after surgery, the patient underwent permanent stimulator implantation. The pain disappeared after 3 months and half year of follow-up, and the score was reduced to 1 point. Microendoscope discectomy system-assisted spinal cord stimulation electrode implantation can complete the operation quickly, safely and effectively, and greatly reduce the number of intraoperative fluoroscopy and reduce the occurrence of complications.

Design of functional array electrode stimulation system with surface electromyography feedback / 生物医学工程学杂志

In order to solve the problems of insufficient stimulation channels and lack of stimulation effect feedback in the current electrical stimulation system, a functional array electrode electrical stimulation system with surface electromyography (sEMG) feedback was designed in this paper. Firstly, the effectiveness of the system was verified through

Feasibility of Adjustable Electrodes for Radiofrequency Ablation of Benign Thyroid Nodules

OBJECTIVE: The purpose of this study was to evaluate a novel radiofrequency ablation (RFA) application utilizing an adjustable electrode for treatment of benign thyroid nodules.MATERIALS AND METHODS: From April 2011 to December 2018, 21 patients underwent RFA treatment on 21 thyroid nodules, utilizing an 18-gauge internally cooled electrode equipped with a size adjustable active tip. The peripheral nodule portions were ablated with the moving-shot technique and a shorter active tip, and the nodule centers were ablated with the fixed technique and a longer active tip. We assessed parameters including characteristics of the treated nodules, use of variablesized active tips, volume reduction rate, therapeutic success rate, and post-procedural complications. The therapeutic success rate was defined as a > 50% volume reduction of the initial nodule volume at the 6- or 12-month follow-up.RESULTS: The treated thyroid nodules were large enough to cause symptoms (mean volume, 29.6 mL). Two types of active tips per session were used for all nodules. The mean volume reduction rate at the last follow-up was 68.3 ± 4.4% and our therapeutic success rate was 90.5%. Both symptoms and cosmetic scores decreased significantly. Minor complications in three patients were recorded during and after the procedure.CONCLUSION: This initial study demonstrated that an adjustable electrode for RFA of benign thyroid nodules effectively and safely resulted in volume reduction.