In order to improve the speech quality and auditory perceptiveness of electronic cochlear implant under strong noise background, a speech enhancement system used for electronic cochlear implant front-end was constructed. Taking digital signal processing (DSP) as the core, the system combines its multi-channel buffered serial port (McBSP) data transmission channel with extended audio interface chip TLV320AIC10, so speech signal acquisition and output with high speed are realized. Meanwhile, due to the traditional speech enhancement method which has the problems as bad adaptability, slow convergence speed and big steady-state error, versiera function and de-correlation principle were used to improve the existing adaptive filtering algorithm, which effectively enhanced the quality of voice communications. Test results verified the stability of the system and the de-noising performance of the algorithm, and it also proved that they could provide clearer speech signals for the deaf or tinnitus patients.
Objective To investigate the protective effect of autologous platelet separation on blood in surgery for Standford type A aortic dissection. Methods A total of 180 patients with Standford type A aortic dissection undergoing elective major vascular surgery in our hospital from July 2014 to March 2016 were enrolled. There were 123 males and 57 females with age ranging from 19 to 68 years and weight of 50-85 kg. The patients were randomly divided into two groups. Patients in group A (n=92, 65 males, 27 females, mean age of 45±21 years) received intraoperative autologous blood recovery; while those in group B (n=88, 58 males, 30 females, mean age of 43±24 years) received autologous platelet rich plasma (APRP) and intraoperative autologous blood recovery. The whole process of platelet separation was completed before heparinization. The relevant indicators of blood coagulation function before the induction of anesthesia (T1), before heparinization (T2), immediately postoperatively (T3) and 1 h (T4), 24 h (T5) postoperatively were measured. Cardiopulmonary bypass, aortic cross-clamping time, drainage volume at postoperative 1 h, 24 h and allogeneic blood transfusion volume were recorded. Results The whole blood volume of group B in the platelet separation in emergency was 1 305±110 ml, and collected platelet rich plasma was 275±30 ml, platelet counts (630±220)×109/L, accounting for 25%±5% of platelets of whole blood, and platelet separation time was 32±9 min. Compared with group A, platelet count at postoperative 1 h in group B was significantly higher; drainage volume at postoperative 1 h, 24 h, allogeneic red blood cells, plasma transfusion volume and allogeneic platelet infusion rate decreased significantly (P<0.05). Group B had less postoperative complications (P<0.05). Conclusion Preoperative autologous plateletpheresis combined with intraoperative autologous blood recovery can significantly improve the coagulation function of patients with vascular surgery, and reduce the amount of allogeneic blood transfusion and postoperative bleeding.