Estimation of the Power Spectrum of Heart Rate Variability Using Improved Welch Method to Analyze the Degree of Fatigue / 生物医学工程学杂志

Heart rate variability (HRV) is an important point to judge a person's state in modern medicine. This paper is aimed to research a person's fatigue level connected with vagal nerve based on the HRV using the improved Welch method. The process of this method is that it firstly uses a time window function on the signal to be processed, then sets the length of time according to the requirement, and finally makes frequency domain analysis. Compared with classical periodogram method, the variance and consistency of the present method have been improved. We can set time span freely using this method (at present, the time of international standard to measure HRV is 5 minutes). This paper analyses the HRV's characteristics of fatigue crowd based on the database provided by Physio-Net. We therefore draw the conclusion that the accuracy of Welch analyzing HRV combining with appropriate window function has been improved enormously, and when the person changes to fatigue, the vagal activity is diminished and sympathetic activity is raised.

Application of right-to-lateral approach in laparoscopic-assisted radical gastrectomy / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore the technical feasibility, safety, and short-term clinical efficacy of right-to-lateral approach in laparoscopic-assisted radical gastrectomy.</p><p><b>METHODS</b>Clinicopathological data of 178 gastric cancer patients undergoing laparoscopic-assisted radical gastrectomy, including 92 patients with right-to-lateral approach(R-LG group) and 86 cases with left-to-lateral approach (L-LG group), in our department from October 2010 to September 2013 were analyzed retrospectively. Short-term efficacy and complication morbidity were compared between R-LG group and L-LG group according to body mass index (BMI).</p><p><b>RESULTS</b>For those patients with BMI ≥ 24 kg/m², the R-LG group (35 cases) had shorter mean operation time, less intraoperative blood loss, shorter painkiller used time than L-LG group (31 cases)[(227 ± 17) min vs. (262 ± 23) min, (73 ± 9) ml vs. (84 ± 8) ml and (2.1 ± 0.1) d vs. (2.6 ± 0.4) d, all P<0.05]. The average time to ambulation and recovery time of peristalsis in the R-LG group were faster than those in L-LG group [(2.2 ± 0.2) d vs. (2.8 ± 0.6) d and (3.6 ± 0.3) d vs. (4.2 ± 0.5) d, all P<0.05]. The R-LG group had more dissected lymph nodes per patient (35 ± 4) than the L-LG group (30 ± 5) with significant difference (P<0.05). There were no significances in postoperative hospital stay, postoperative complication morbidity and hospitalization expenses between R-LG and L-LG group (all P>0.05). For those patients with BMI<24 kg/m², there were no significant differences in all above parameters between R-LG group (57 cases) and L-LG group (55 cases). No mortality and recurrence was observed during follow-up of 3 to 24 months.</p><p><b>CONCLUSION</b>Right-to-lateral approach in laparoscopic-assisted radical gastrectomy is a safe and feasible procedure, especially for the obesity patients, which can shorten the operation time, decrease intraoperative blood loss, lead to a faster postoperative recovery and harvest more lymph nodes as compared to L-LG procedure.</p>