针对传统变焦腹腔镜调焦结构所需空间大、调焦精度难以保证等问题，提出了一种以液体透镜为核心元件参与变焦的腹腔镜光学系统，利用液体透镜代替机械变焦结构，实现了变焦功能。推导了液体透镜电压与焦距的关系方程，结合COMSOL软件设计并仿真了满足所需焦距范围的双液体透镜。用ZEMAX软件设计优化了腹腔镜液体透镜变焦光学系统，通过控制电压即可实现焦距5~15 mm范围内同一像面高清晰成像。在焦距15 mm时，全视场点列图均方根（RMS）半径为6.694 μm，在焦距5 mm时，全视场点列图RMS半径为4.596 μm，均小于7.4 μm的像元尺寸。系统调制传递函数（MTF）在68 lp/mm处均大于0.5，4个组态（焦距分别为5、7.2、10.4、15 mm）畸变分别为7.047%、1.961%、0.732%、0.295%，满足腹腔镜对光学系统畸变的要求。

提出了一种基于融合i-vector特征的长短时记忆(LSTM)循环神经网络模型,用于腹腔镜扶持器语音控制,在小训练样本下实现对特定医生语音中的短时、孤立词指令的识别。该模型以LSTM循环神经网络作为基础模型,以梅尔频率倒谱系数(MFCC)作为输入特征参数,将i-vector特征作为LSTM循环神经网络的深层输入信息,与神经网络中LSTM层后的深层特征信息进行拼接,达到参数融合的目的,实现对特定主刀医生语音指令的准确识别以及对非主刀医生语音指令的拒识别,为腹腔镜操作提供安全智能的语音识别方案。使用自建语音库进行实验,分别验证所提算法对训练库内语音的识别性能以及对训练库外语音的拒识别性能。实验结果表明:与动态时间规整算法(DTW)和混合高斯模型-隐马尔可夫模型(GMM-HMM)相比,所提模型在对训练库内特定人语音指令识别正确率高达99.6%的同时保持着错误接受率为0%,对训练库外语音的平均错误接受率为2.5%,满足腹腔镜扶持器控制的准确性和安全性要求。

This study aimed to investigate the influence of laparoscopic total mesorectal excision combined with sphincter-preserving surgery on the postoperative defecation function, urinary function and sexual function in low or ultralow rectal cancer. A retrospective study was undertaken on 107 patients (65 laparoscopic resection and 42 laparoctomic resection) with rectal cancer undergoing laparoscopic or open laparoscopic total mesorectal excision combined with sphincter-preserving surgery from April 2009 to April 2013. The quality of life outcomes of all patients, including defection, urinary and sexual function, were assessed at 6, 12 and 24 months after operation. Gastrointestinal quality of life index (GQOLI) was used to evaluate the fecal incontinence and bowel dysfunction. Urinary and sexual functions were studied by means of questionnaires on the basis of the international prostatic symptom score (IPSS) and international index of erectile function (IIEF), respectively. In laparoscopic surgery group, there were two cases of anastomotic leakage, three cases of anastomotic stricture, seven cases of local recurrence, ten cases of hepatic metastasis and five cases of lung metastasis. The satisfaction rates of patients about their defecation function reached 60.3% (35/58, 84.5% (49/58) and 91.3% (53/58) at 6, 12, and 24 months follow-up, respectively. The assessment after one year showed that the overall incidence of urinary dysfunction was 10.7% (7/65); Among male patients, 18.4% (7/36) suffered from erectile dysfunction and 27.8% (10/36) suffered from ejaculatory dysfunction; 65.5% (19/29) female patients investigated were satisfied with their postoperative sexual life. In open surgery group, there were two cases of anastomotic leakage, two cases of anastomotic stricture, nine cases of local recurrence, ten cases of hepatic metastasis and seven cases of lung metastasis. The satisfaction rates of patients about their defecation function were 56.4% (22/39), 82.1% (32/39) and 94.8% (37/39) at 6, 12, and 24 months follow-up, respectively. The assessment after one year showed that the overall incidence of urinary dysfunction was 11.9% (5/42); 25% (4/16) male patients suffered from erectile dysfunction and 31.3% (5/16) suffered from ejaculatory dysfunction; 69.2% (19/26) female patients investigated were satisfied of their postoperative sexual life. There was no statistic difference in the two groups. Laparoscopic total mesorectal excision combined with sphincter-preserving surgery in low or ultralow rectal carcinoma is safe and practicable. It can be helpful for enhancing the probability of anus reservation, and obtains satisfactory defecation, sexual and urinary functions.