高渗环境对假体周围感染生物膜形成影响的实验研究

目的探讨高渗环境对关节置换术后假体周围感染中表皮葡萄球菌生长和生物膜形成影响。方法用新西兰大白兔建立假体表皮葡萄球菌感染的动物模型,分为实验组和对照组各15只。实验组注入细菌的同时注入40g/L的氯化钠溶液0.1mL,对照组注入生理盐水0.1mL。分别于注入细菌后2、4、6、8和16d对假体感染动物行关节液细菌计数、假体周围组织学观察和假体扫描电镜观察。结果注入细菌后2-4d实验组和对照组关节液细菌计数差异无显著性（P〉0.05）,注入细菌后6、8和16d两组细菌计数差异有统计学意义（t=2.16-3.17,P〈0.05）。注入细菌后4d实验组动物假体周围组织均有中性粒细胞浸润;对照组注入细菌后4d开始出现炎细胞浸润,注入细菌后6d所有动物假体周围组织中均有炎细胞浸润。两组注入细菌后4d均观察到假体表面有少量细菌黏附;注入细菌后6、8和16d实验组假体表面黏附的细菌较对照组增多。结论关节置换术后假体周围高渗环境能够促进表皮葡萄球菌的生长以及生物膜的形成。     

前列腺素E1降低心脏瓣膜置换术患者心肌细胞NF-κB活性及血浆TNF-α水平

目的：评价前列腺素E1（PGE1）对心脏瓣膜置换术患者心肌细胞核转录因子κB（NF‐κB）活性和血浆肿瘤坏死因子α（T N F‐α）水平的影响。方法择期行体外循环下心脏瓣膜置换术的患者40例,年龄32～67岁,体质量指数17～28 kg／m2,美国麻醉师协会（ASA）分级Ⅱ或Ⅲ级,纽约心脏病协会（NYHA）分级Ⅱ或Ⅲ级。采用随机数字表法,将患者分为2组（n＝20）：对照组（C组）和PGE1组（P组）。麻醉诱导后P组静脉输注PGE120 ng · kg －1· min－1,至手术结束,C组给予等容量生理盐水。于体外循环前（T0,基础值）、体外循环开始后30 min（T1）、体外循环结束时（T2）、体外循环结束后12 h（T3）、体外循环结束后24 h（T4）抽取动脉血,检测血浆TNF‐α水平;于T0和T2时取右心耳组织,观察组织病理学变化,并用蛋白免疫印迹法（Western blot）检测NF‐κB活性。结果与C组比较,P组T1～T4时血浆 TNF‐α水平下降（P＜0．05）,T2时心肌病理学损伤明显减轻,心肌细胞NF‐κB活性下降（P＜0．05）。结论 PGE1可减轻心脏瓣膜置换术患者心肌损伤,其机制与抑制心肌细胞NF‐κB活性,减少血浆TNF‐α水平有关。     

Bentall手术治疗升主动脉瘤14例报告

目的总结连续14例周升主动脉瘤伴主动脉瓣关闭不全行升主动脉及主动脉瓣复合带瓣人工血管置换、双侧冠状动脉开口移植手术(Bentall手术)无死亡的治疗体会。方法14例升主动脉瘤伴主动脉瓣关闭不全病例中13例行冠状动脉原位移植,对其中3例采用股动脉插管结合深低温停循环技术;另1例由于冠状动脉开口位置较低行Cabrol手术。结果14例病人均无手术死亡,术后平均引流720ml,平均住院28.5d,随访未发现远期并发症,心功能均恢复至Ⅰ~Ⅱ级。结论Bentall手术是治疗升主动脉瘤伴主动脉瓣关闭不全的有效方法。     

Evaluation of a Neural Network-Based Control Strategy for a Cost-Effective Externally-Powered Prosthesis

ABSTRACT

This paper presents a control strategy that compensates for the nonlinearity in the inexpensive sensors and hardware of a cost effective prosthetic hand. The control strategy uses neural network-based force control and sensory feedback to detect disturbance induced by slippage. The neural network approach is chosen over other nonlinear models because it is easy to implement and it offered the additional advantage of having its parameters easily adjusted over the life span of the device. The proposed strategy was evaluated on a functional multi-digit underactuated prosthetic hand. The initial and incremental forces exerted from each finger were adjusted to balance the amount of disturbance and the deformation of the objects. Experiments were conducted to test the performance of the protocol in situations encountered in activities of daily living. The displacement of each object under three grasping configurations was measured as a performance criterion while the object's mass was changed. The results showed that with the adjusted parameters for each grasping configuration, the control strategy was able to detect the dynamic changes in mass of the object and was also able to successfully adjust the grasping force before the object drops from the hand.     

The valve patient and pregnancy

Pregnancy causes a significant and sustained increase in cardiac output that may be poorly tolerated in cases of underlying heart disease. Valvular stenosis is often poorly tolerated and may require intervention during pregnancy, percutaneous intervention being the favored option. Conversely, regurgitant valve diseases are generally well-tolerated. Pregnancy in patients who have previously undergone prosthetic valve replacement raises specific problems linked to anticoagulant therapy. The choice is difficult between oral anticoagulation, which carries a risk of embryopathy, and heparin therapy, which is safer for the fetus but is associated with a high thromboembolic risk for the mother. The diversity of cases highlights the need for appropriate evaluation of heart disease before pregnancy and close follow-up by specialized teams.     

Looking ahead: planning for the first human intracortical visual prosthesis by using pilot data from focus groups of potential users

In planning for our research team's first human implant of a technologically advanced intracortical visual prosthesis we have conducted three focus groups with blind persons from a pool of likely participants. Guided by the principles of the Independent Living movement and Participatory Action Research (PAR), we asked the participants to share their thoughts and concerns about the procedure. The preliminary results reveal that achievement of the desired highest ethical of informed consent will require extensive pre-operative learning opportunities, such as those provided by these focus groups. Persons who are blind may be motivated to participate in research like this based on a need to know, understand, and explore ones environment, to leave a legacy, and to experience some restored perception.     

经导管主动脉瓣膜置换术在重症主动脉瓣膜病中的临床应用

目的 评估经导管主动脉瓣置换术治疗重症主动脉瓣膜疾病患者的临床应用效果.方法 回顾性分析2018年7月至2020年6月期间广州市第一人民医院心脏大血管外科进行经导管主动脉瓣置换术(TAVR)的14例患者,其中男性7例、女性7例,平均手术年龄(69.5±7.5)岁,美国胸外科医师协会STS平均评分(14.1±6.2)％,...     

主被动踝关节假肢力/位混合控制研究

为了满足小腿截肢患者的运动需求,根据踝关节在人体步态周期中的生物力学特性,结合已有的研究基础和实验条件,研制了第一代主被动混合驱动的踝关节假肢样机。通过对样机仿生运动的分析和运动模型的建立,提出了一种基于有限状态机的力/位混合伺服控制系统,采用PID和模糊PID两种控制算法对假肢运动进行Matlab仿真和角度控制实验。实验结果表明,该假肢样机可以得到类似人体运动的踝关节角度-力矩曲线,并且模糊PID算法控制输出的曲线更加符合人体特性,从而验证了样机设计的合理性和控制方案的可行性,为进一步实现样机的应用提供了依据。     

超声心动图在二尖瓣置换术后远期心功能不全病因诊断中的应用

 目的探索超声心动图在二尖瓣置换(MVR)术后远期心功能不全病因诊断中的作用。方法超声随访44例MVR患者术后3个月～13.5a,并根据手术的远期效果,分为心功能不全组(A组)和康复组(B组)。除注意人工瓣和自然瓣的病变外,还分析了这2组手术前后左房、左室内径及左室射血分数(EF)的差异。结果超声显示A组二尖瓣位单组或伴主动脉瓣位双组人工瓣异常5例,其它自然瓣明显病变11例。术后A组的左室内径明显大于B组(P＜0.05),EF值明显小于B组(P＜0.01)。超声心动图提供的信息为36.4％心功能不全代偿期和66.7％失代偿期患者诊断出了导致心功能障碍的主要原因。结论MVR手术前后超声检查对术后远期心功能不全的诊断具有实用价值。