In order to improve the reliability of cardiac pacemaker contact-less power supply technology, this paper proposes a novel application of wireless feedback voltage stabilizing technology to adjust heart disease patients with inner power supply filter circuit output voltage and current control method, to keep the output voltage stability, and to ensure that the super capacitor and cardiac pacemaker to get a stable power supply. To implement the real-time accurate voltage control with considering the primary and secondary side inductance coupling coefficient changes, the change of the external power supply voltage and load, it is necessary to test thee real-time and accurate output voltage and current value after rectifying filtering. Therefore, based on the chaotic control theory, we adopted method of phase diagram on the basis of the quick observation after rectifying filtering, so that the method of voltage and current could improve the detection time of the circuit. The phase diagram of proposed control method can be divided into 8 segments, and we got 7 zero-extreme points. When these zero-extreme points are detected, according to extreme points of the zero instantaneous values, the corresponding average values of voltage and current were obtained. Simulation and experimental results showed that using the above method can shorten the response time to less than switch devices 1/2 switching cycles, thus validating the effectiveness and feasibility of the proposed detection algorithm.
Algorithms ; Electric Power Supplies ; Feedback ; Humans ; Nonlinear Dynamics ; Pacemaker, Artificial ; Wireless Technology

Objective To discuss the safety,efficacy and time window of thombolysis using recombinant staphylokinase(r-Sak).Methods The model of acute cerebral infarction was established with interventional embolization technique in 24 adult beagle dogs,which were randomly divided into 3 groups including control group,6 h intra-arterial group and 3 h intravenous group.Angiography was performed before thrombolysis.We administered r-Sak for thrombolysis(10 ml of saline in control group,0.2 mg/kg of r-Sak in the intra-arterial group through left internal carotid artery 6 h after embolization,and 0.2 mg/kg of r-Sak in the intravenous group through femoral vein 3 h after embolization).Follow-up angiography was repeated half,1 and 2 hours after thrombolysis.The plasma levels of PT,APTT and D-dimer were assayed at the time points of 30 min before thrombolysis,30 min,60 min and 120 min after thrombolysis.These canines were sacrificed,and their brains were taken out for pathological study at 24 hours after embolization.Results The recanaled vessels at 2 hours after thrombolysis was 11(11/13) in the intra-arterial group,8(8/11) in r-Sak intravenous group and 1(1/10) in control group,and the vessels of complete recanalization was 6(6/13),2(2/11) and 0(0/10),respectively.There were statistically significant differences among the three groups (P=0.001 and P=0.035 respectively),but there were no statistically significant differences between the intra-arterial and the intravenous groups (P=0.630 and P=0.211).The PT and APTT are significantly prolonged in the thrombolytic groups.The levels of D-dimer was not changed after thrombolysis (P＞0.05). All dogs were alive 24 h ours after embolization.The clinical presentations in the thrombolytic groups were better.Pathologically,there were no cerebral hemorrhage in all groups.Conclusion r-Sak has strong effect of thrombolysis,and its complication of intracerebral hemorrhage is rare.The intra-arterial thrombolysis 6 h after embolization using r-Sak is safe and effective.

Objective To construct an eukaryotic expression vector of human telomerase reverso transcriptase (hTERT) gene specific shRNA, and investigate the effect of pshRNA-hTERT combined with γ-irradiation on telomerase activity and DNA damage. Methods The recombinant expression plasmid pshRNA-hTERT was constructed and transfected into Hep-2 cells. The telomerase activity was examined by the PCR-hased telomeric repeat amplification protocol (TRAP). DNA single-stranded break (SSB) and the DNA double-stranded break (DSB) were detected by Comet assay. The xenograft model of human laryngeal carcinoma with the same genetic background and different radiosensitivity (Hep-2 and Hep-2R) was established in nude mice. The mixture of pshRNA-hTERT and liposome was injected to the transplanted tumor to observe the inhibition of the tumor growth. The cell apoptosis was detected by TUNEL. The hTERT protein expression was determined by streptavidin-peroxidase conjugated method (AP). Results Recombinant expression plasmid pshRNA-hTERT was successfully constructed and transfected into Hep-2 cells. The hTERT expression inhibition rate reached 60.78 %. pshRNA-hTERT not only inhibited telomerase activity of Hep-2 inehiding the increase of telomerase activity induced by γ-irradiation, but also inhibited the repair of the SSB and DSB induced by irradiation in the human laryngeal carcinoma xenograft in nude mice with the same genetic background and different radiosensitivity. The pshRNA-hTERT combined with γ-irradiation could inhibit the growth of transplanted tumor (Hep-2: EPO = 1.79; Hep-2R: EPO = 2.01) with reduced telomerase activity and hTERT protein expression. Conclusions The eukaryotic expression vector pshRNA-hTERT could enhance the radiosensitivity of Hep-2 cells in vitro and the human laryngeal carcinoma xenograft in nude mice which had the same genetic background with different radiosensitivity.