Microwave thermal ablation technology is widely used in the treatment of liver tumors because of its minimal invasiveness and small side effects. The precise control of the thermal dose largely determines the therapeutic effect of microwave thermal ablation. However, the current magnetron-based microwave thermal ablation device has the disadvantages of poor power output stability and high operating voltage. In view of the above problems, this paper selected the microwave solid-state source as the core device of microwave output, and designed a dual-frequency microwave thermal ablation system based on 2 450 MHz and 433 MHz. The system used the power detection circuit to perform PID feedback control on the actual output power of the system. The experimental results show that the maximum output power of the system is less than 1 W. The PID algorithm further enhances the accuracy and stability of the system output power while improving the system security. The dual-frequency microwave thermal ablation system designed in this paper can provide a safe and reliable experimental platform for subsequent research.
Catheter Ablation ; instrumentation ; Humans ; Liver Neoplasms ; therapy ; Microwaves ; Radiofrequency Ablation

OBJECTIVE: In this study,computational modelling was used to study whether different conduction pathways have impact on the AF initiation and maintenance based on a human atrial model. METHODS: MRI images from one patient who has atrial fibrillation were used to reconstruct the human atrial anatomical model.The number of MRI images was 112.In order to study the effect of different conduction pathways to AF,4 different atrial models were generated in this study,which were biatrial conduction via only LFO;biatrial conduction via only CS;biatrial conduction via both LFO and CS;model without biatrial conduction. RESULTS: In the case of biatrial conduction simulation via only LFO,the same re-entries were induced as in the LFO and CS case.But for the two cases of only CS conduction and both LFO and CS cannot conduct electricity,one stimulus site induced unsustained re-entry which only lasted for 2 cycles,and then terminated.The other two sites induced the same re-entries as in the previously described two cases,which were biatrial conduction simulation via both LFO and CS and only LFO. CONCLUSIONS Our simulation showed that these conduction pathways played a minor role in the re-entry initiation and maintenance,the possible explanation is that all the re-entries induced in our simulation is local drivers and maintained by fibrosis.
Atrial Fibrillation ; Catheter Ablation ; instrumentation ; Heart Atria ; Heart Rate ; Humans

To explore the safety and efficacy for radiofrequency ablation of paroxysmal supraventricular tachycardia (PSVT) guided by Carto Univu three-dimensional mapping system.
 Methods: A total of 99 patients with PSVT underwent radiofrequency catheter ablation (RFCA) were assigned to a Carto Univu group (51 patients) and a two-dimensional X-ray group (48 patients) according to the mapping method. The operation time, X-ray exposure time, X-ray exposure dose, dose area product (DAP), operation success rate and complication rate were compared between the two groups.
 Results: The Carto Univu group and the two-dimensional X-ray group were not significant difference in the operation time, the X-ray exposure time of placing catheter, the X-ray DAP of placing catheter, the number of discharge, the discharge power, and the total discharge time (P>0.05). The mapping and ablation time, total exposure time, mapping and ablation DAP and total DAP in the Carto Univu group were significantly lower than those in the two-dimensional X-ray group (P<0.01). In the right accessory pathway cases, the mapping and ablation DAP and the total DAP in the Carto Univu group decreased compared with X-ray group (P<0.05), but it decreased more profound (P<0.01) in the left accessory pathway cases and the dual atrioventricular nodal pathways cases. Seven cases in the Carto Univu group achieved "zero X-ray", including 5 cases of the dual atrioventricular nodal pathways and 2 cases of the left accessory pathway. The immediate success rate for the two groups was 100%. After 3-12 months of follow-up, there was no recurrence in the Carto Univu group but 3 suspected recurrences in the two-dimensional X-ray group. In addition, no complications occurred in the two groups. 
 Conclusion: Carto Univu electroanatomic mapping system can guide PSVT safely and effectively during radiofrequency ablation and reduce radiation exposure to both doctors and patients. It is especially suitable for dual atrioventricular nodal pathways, which may even achieve "zero X-ray". Perhaps Carto Univu will be the first choice for RFCA of dual atrioventricular nodal pathways.
Catheter Ablation ; instrumentation ; methods ; Humans ; Imaging, Three-Dimensional ; instrumentation ; methods ; Operative Time ; Radiation Exposure ; prevention & control ; statistics & numerical data ; Radiography ; statistics & numerical data ; Recurrence ; Tachycardia, Supraventricular ; diagnostic imaging ; surgery ; Treatment Outcome

In order to support study of new radiofrequency ablation treatments and finally realize of precise conformal ablation of targeted tissue, this paper proposed a system which is able to generate radio frequency currents at different frequencies. The designed system bases on the basic principle of Class E power amplifier and uses MSP430 microcontroller as a controller and uses a touch screen as human-machine interface to design a frequency-selectable radiofrequency ablation treatment system,. The RF signals at frequencies of 230 kHz, 460 kHz, 920 kHz, and 2 000 kHz were tested to verify the feasibility of the system, and by using a tissue phantom, tested the heating ability of the RF signals at frequencies of 460 kHz, 920 kHz, and 2 000 kHz. The results show the device could well heat the tissue at the three frequencies. The study has also found that both the highest temperature and the ablation area decreases with RF frequency, when using the constant power control mode.
Catheter Ablation ; instrumentation ; Hot Temperature ; Humans ; Hyperthermia, Induced ; Phantoms, Imaging ; Radio Waves

OBJECTIVETo compare the effectiveness of high-frequency jet ventilation via Wei jet nasal airway and controlled ventilation with improved laryngeal mask airway during bronchial thermoplasty.

METHODSTwenty-eight patients undergoing bronchial thermoplasty were equally divided into two groups: group A (high-frequency jet ventilation through Wei jet nasal airway) and group B (controlled ventilation with improved laryngeal mask airway). Pulse oxygenation,heart rate,and mean arterial blood pressure were recorded after entering the operating room (T0), 1 minute after administration/induction (T1), bronchoscope inserting (T2), 15 minutes (T3)/30 minutes (T4)/45 minutes (T5) after ventilation,at the end of the operation (T6), and at the recovery of patients' consciousness (T7). The pH,arterial oxygen partial pressure,and arterial carbon dioxide partial pressure were recorded at T0, T4, and T6. The endoscope indwelling duration,operative time,patients' awakening time,adverse events during anesthesia,satisfactions of patients and operators, anesthesic effectiveness were also recorded.

RESULTSThe arterial carbon dioxide partial pressur in group A at T4 and T6 were significantly higher than in group B (P<0.05). The pH in group A at T4 and T6 was significantly lower than in group B (P<0.05). The endoscope indwelling duration and the operative time in group B were significantly shorter than in group A (P<0.05) while the recovery of consciousness in group B was significantly longer than in group A (P<0.05). The satisfaction for operators and the efficacy of anesthesia in group B were better than in group A (P<0.05). The number of adverse events in group B was significantly smaller than in group A (P<0.05).

CONCLUSIONThe improved laryngeal mask airway with controlled ventilation is more suitable for bronchial thermoplasty.

Blood Gas Analysis ; Bronchoscopy ; Catheter Ablation ; Heart Rate ; High-Frequency Jet Ventilation ; instrumentation ; Humans ; Laryngeal Masks

OBJECTIVETo explore the therapeutic effect of radiofrequency ablation for tongue venous malformation( VM).

METHODSFrom July 2013 to July 2014, 30 cases with tongue VM (local or diffuse) were retrospectively analyzed. 23 cases underwent radiofrequency ablation treatment. The radiofrequency electrode tip(0. 5 mm in diameter) was inserted into the lesion 1 mm below the bottom with 25 W in power and 15-30 s of pulse. The treatment was repeated when the electrode tip was removed back every 1 mm. Multi-point treatment was performed.

RESULTS15 cases with unilateral VM were completely healed after one-stage radiofrequency ablation. 8 cases with bilateral VM received two-stage radiofrequency ablation with a 3-6 months of interval. Among the 8 cases, completely healing was achieved in 5 cases, partial VM residue happened in 3 cases due to its diffuse lesion and reservation of tongue function. 23 cases were followed up for 3 month to 1.5 years. Good cosmetic and functional results was achieved in 20 cases with no relapse. Partial VM residue was left in 3 cases.

CONCLUSIONSRadiofrequency ablation can effectively treat tongue VM with minimal morbidity and good cosmetic appearance. It also avoids the disadvantages of surgery.

Catheter Ablation ; instrumentation ; methods ; Electrodes ; Humans ; Retrospective Studies ; Tongue ; blood supply ; Treatment Outcome ; Vascular Malformations ; surgery ; Veins ; abnormalities

BACKGROUND: The efficacy of saline-coupled bipolar sealing devices in joint arthroplasty is uncertain, and the utility in simultaneous bilateral total knee arthroplasty (TKA) has not been reported. METHODS: This study compares the use of bipolar sealing and conventional electrocautery in 71 consecutive patients. The experimental and control groups were matched for age, sex, body mass index, American Society of Anesthesiologists (ASA) classification, and preoperative hemoglobin. Variables of interest included blood loss, transfusion requirements, and operative characteristics. RESULTS: In comparison to patients treated with conventional electrocautery, those treated with the bipolar sealer were 35% less likely to require transfusion. The median number of transfusions per case was also significantly lower in the experimental group. Hemoglobin change, total blood loss, and length of stay were not significantly different between the groups. The experimental group had longer operative times. CONCLUSIONS: Bipolar sealing shows promise as a blood loss reduction tool in simultaneous bilateral TKA. The marginal savings attributed to reduced transfusion rates with use of the bipolar sealer did not exceed the additional per-case expense of using the device. The decision to use the device with the goal of less blood loss must come with the additional expense associated with its use.
Adult ; *Arthroplasty, Replacement, Knee ; Blood Loss, Surgical/*prevention & control ; Catheter Ablation/instrumentation ; Electrocoagulation/*instrumentation ; Female ; Humans ; Male

OBJECTIVE: To determine the in vivo efficiency of monopolar radiofrequency ablation (RFA) using a dual-switching (DS) system and a separable clustered (SC) electrode to create coagulation in swine liver. MATERIALS AND METHODS: Thirty-three ablation zones were created in nine pigs using a DS system and an SC electrode in the switching monopolar mode. The pigs were divided into two groups for two experiments: 1) preliminary experiments (n = 3) to identify the optimal inter-electrode distances (IEDs) for dual-switching monopolar (DSM)-RFA, and 2) main experiments (n = 6) to compare the in vivo efficiency of DSM-RFA with that of a single-switching monopolar (SSM)-RFA. RF energy was alternatively applied to one of the three electrodes (SSM-RFA) or concurrently applied to a pair of electrodes (DSM-RFA) for 12 minutes in in vivo porcine livers. The delivered RFA energy and the shapes and dimensions of the coagulation areas were compared between the two groups. RESULTS: No pig died during RFA. The ideal IEDs for creating round or oval coagulation area using the DSM-RFA were 2.0 and 2.5 cm. DSM-RFA allowed more efficient RF energy delivery than SSM-RFA at the given time (23.0 +/- 4.0 kcal vs. 16.92 +/- 2.0 kcal, respectively; p = 0.0005). DSM-RFA created a significantly larger coagulation volume than SSM-RFA (40.4 +/- 16.4 cm3 vs. 20.8 +/- 10.7 cm3; p < 0.001). Both groups showed similar circularity of the ablation zones (p = 0.29). CONCLUSION: Dual-switching monopolar-radiofrequency ablation using an SC electrode is feasible and can create larger ablation zones than SSM-RFA as it allows more RF energy delivery at a given time.
Animals ; Catheter Ablation/*instrumentation/*methods ; *Electrodes ; Feasibility Studies ; Liver/*surgery ; Male ; Sus scrofa ; Time Factors

With the enforcement of YY 0505-2012, the testing items and evaluation points of radio frequency ablation catheter in electromagnetic compatibility field should be studied and discussed. Based on the requirements of relevant standards, this paper discusses on the testing items that should be applied and the evaluation points that should be focused on by analyzing the intended use and the structure of radio frequency ablation catheter, when it intends to apply registration individually with the basic knowledge of electromagnetic compatibility field.
Catheter Ablation ; instrumentation ; Electromagnetic Fields ; Electromagnetic Phenomena ; Evaluation Studies as Topic

OBJECTIVETo compare the therapeutic effect of traditional and modified apocrine gland removal surgery with the combination of high radiofrequency knife for axillary osmidrosis.

METHODS105 cases (210 sides) were randomly divided into traditional group A (38 cases, 76 sides) and modified group B (67 cases, 134 sides). The wound healing and complications were recorded. The clinical effect was followed up for 6-12 months after operation.

RESULTSNo flap necrosis happened in both groups. The cure rate was 82.89% (63/76)) and 92.54% (124/134) in group A and B, respectively, which was significantly different (P < 0.05). The effective rate of hair removal in group A and B was 42. 1%, 59. 7% (P < 0. 05). There is no markedly difference between the two groups in postoperative hematoma( P >0.05). The recurrence rate in group A and B was 9.21% and 1.49% respectively, with a statistically difference between them (P < 0.05).

CONCLUSIONSModified apocrine gland removal surgery with the combination of high radiofrequency knife can expose the apocrine gland better and the gland, as well as hair, can be removed in the most. The residue hair and recurrency of osmidrosis are very lower.

Adolescent ; Adult ; Apocrine Glands ; surgery ; Catheter Ablation ; instrumentation ; methods ; Female ; Humans ; Hyperhidrosis ; surgery ; Male ; Middle Aged ; Treatment Outcome ; Young Adult