A new cool-tip radiofrequency (RF) ablation therapeutic instrument based on impedance control algorithm is introduced in this paper. The equipment is composed of hardware system and software system. The RF power output and real time data acquisition are completed by the hardware system, while the software is used mainly to finish the control of the ablation range, the core of which is impedance control algorithm, and it also used to complete the display of the real time data in the course of the experiment. The impedance algorithm has solved the problem of impedance increased rapidly during the RF ablation, which has also expanded the scope of ablation. The pig liver experiments showed that the impedance control algorithm had strong adaptability. It also obtained a result of ablation range up to 3.5-4.5 cm single needle. It has the high clinical practical value of one-time inactivation of 3-5 cm tumor.
Algorithms ; Animals ; Catheter Ablation ; Electric Impedance ; Humans ; Liver ; Needles ; Software ; Swine

Objective: To evaluate the safety and efifcacy of percutaneous ventricular partitioning (PVP) in ischemic heart failure (IHF) patients with apical aneurysm. Methods: A total of 19 IHF patients with apical aneurysm at the age of (68.1 ± 8.2) years were enrolled. The patients received PVP operation with adequate clinical and medical imaging examinations; the safety of operation was evaluated and post-operative clinical events with cardiac function were followed-up. Results: There were 18/19 (95%) patients with successful PVP and 1 had to stop the operation due to unsatisfactory landing of ventricular partitioning device. 2 patients suffered from vessel access related complication and received femoral artery stent implantation. With (252 ± 170) days follow-up study, no post-operative device failure, cardiac death, thromboembolism and HF re-hospitalization occurred. At 3 months after operation, the patients had improved NYHA classiifcation (2.72 ± 0.67) vs (1.67 ± 0.59) and 6 min walk test (462 ± 96) m vs (484 ± 87) m, bothP<0.01. Echocardiography indicated that post-operative left ventricle end-diastolic volume index (LVEDVI) decreased form (137.4 ± 19.1) ml/m2 to (125.6 ± 18.5) ml/m2,P=0.0056 and LVESVI decreased from (89.7 ± 22.3) ml/m2 to (78.8 ± 20.7) ml/m2,P=0.0019; while LVEF increased from (34.8 ± 8.13) % to (41.3 ± 6.2) %, P=0.031. Conclusion: Our preliminary experience showed that with adequate evaluation, PVP was safe and effective in IHF patients with apical aneurysm; short-term follow-up study implied the improved hemodynamic and cardiac function.