ABSTRACT
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
Subject(s)
Female , Humans , Male , Electric Stimulation , Electrodes , Electromyography , Feedback , NeurofeedbackABSTRACT
Objective To evaluate the therapeutic effectiveness of echo-guided percutaneous radiofrequency ablation(RFA) by using a LeVeen needle electrode combination in the treatment of large liver tumor,and to discuss the relationship between the amount as well as the distribution pattern of the electrodes and the therapeutic effectiveness.Methods During the period of Feb.2006-Dec.2008,echo-guided RFA was performed in 113 patients with large and unresectable liver tumor,with a total of 118 lesions.According to the size of the tumor,the patients were divided into four groups.The tumor’s diameter of Group A(n = 64) was 4.0-5.0 cm,Group B(n = 28) was 5.1-6.0 cm,Group C(n = 11) was 6.1-7.0 cm and Group D(n = 10) was 7.1-9.3 cm.Based on the tumor’s diameter,the amount of the electrodes to be used and the sites to be ablated were determined.After the procedure,the follow-up checks with MRI or CT scanning were carried out to observe the necrotic extent and the local recurrence.Results Two months after the treatment,the complete necrosis rate of the tumor in Group A,B,C and D was 88.4%,78.6%,63.6% and 40.0%,respectively,with an overall necrosis rate of 79.7% in total 118 lesions.During a follow-up period of 3-36 months,the local recurrence rate in Group A,B,C and D was 5.5%,10.0%,28.6% and 50.0%,respectively.Severe complications,including intrahepatic infection(n = 2),puncture passage bleeding(n = 1),symptomatic pleural effusion(n = 4) and biloma(n = 2),occurred in 9 cases.No death related to RFA treatment occurred.Conclusion Echo-guided percutaneous radiofrequency ablation by means of multi-sites superimposition method with a LeVeen needle electrode combination is an safe and effective therapy for the hepatic tumors with the diameter over 4 cm.