旋转式组织工程生物反应器检测控制及驱动系统

目的 生物反应器是组织工程的重要载体,旋转式生物反应器是目前研究的热点.本文探讨了可提供优良环境条件的可控生物反应器系统的设计与实践.方法 系统采用PWM可调驱动直流电机等;同时可对温度等物理量进行检测,并反馈控制调节反应器;测控系统与PC连接,可实现远程视频监测控等,使整个组织生物反应器系统初步实现了分步式、自动化.结果 经实验系统培养所得到的细胞相对于一般培养细胞其生物学特性有相当的改善.结论自动化旋转式生物反应器驱动控制的实践具有较大的应用推广价值.     

高原手术方舱微环境温度控制系统设计

高原环境昼夜温差大，空气稀薄，手术方舱要抵抗较大温度冲击，工作环境恶劣，对微环境温度控制系统的抗干扰能力提出了更高的要求。传统微环境温度控制多采用仪表显示、开关控制，抗干扰能力差、故障率高。以可编程控制器（ PLC）为控制核心，采用触摸屏为人机界面，设计一套高原舱室微环境温度控制系统，实现温度实时监测与控制，有效控制方舱升温与降温设施，抵御高原温度冲击，合理调节暖风机空燃比，适应高原环境。该文论述了高原手术方舱微环境控制系统硬件、软件和算法设计。     

空间乙烯过滤器地面试验样机研制

目的 研制成空间乙烯过滤器地面试验样机,采用微生物技术控制受控生态生保系统中高等植物产生的微量乙烯(C2H4),以保障植物的正常生长发育.方法 通过详细的技术方案论证、图纸设计与加工、部件安装与调试以及样机试运行,最后进行验证实验来检验其技术性能.结果 样机反应器中基质的温度、含水量、pH值以及气体的流量、温湿度等参数均能实行有效控制,反应器中的微生物经过一段时间驯化后,对乙烯气体的最高降解率可达到9.04 mg/(m3·h).结论 样机实际性能基本达到了设计要求,运行稳定,可用于控制受控生态生保系统中乙烯气体的浓度.     

一种仿生型心肌组织工程生物反应器的设计

目的 研制一种仿生型心肌组织工程生物反应器.方法 根据心肌细胞培养的要求,设计了温度、pH值、CO2浓度、溶解氧含量参数检测和控制电路及细胞拉伸加栽装置及电场刺激装置.结果 实验结果表明,该生物反应器能够准确检测各项参数,并给细胞合适的拉伸频率和幅度及电场刺激.结论 研制的生物反应器能够在一定程度上模拟人体心肌工作环境.     

空间生物反应器研究进展与策略

空间生物反应器是人类利用空间资源进行空间生物学与空间生物技术研究的重要硬件设备,其应用为空间生命科学研究提供了必要的生物材料,如细胞、组织和微生物等。本文针对空间生物反应器对空间生物学和空间生物技术的重要作用,综述了空间生物反应器的研制发展历程和现状,并对灌流式中的旋转壁式生物反应器、细胞培养单元反应器、单环路细胞培养反应器、微型连续培养反应器和非灌流式中的多层逆流细胞培养反应器、新型膜生物反应器等空间生物反应器的主体结构和工作原理做了介绍。最后,对空间生物反应器的发展趋势进行了分析和展望。     

空间站SabatierCO2还原系统的比较分析

Sabatier CO2还原系统是实现空间站O2闭路再生的重要一环,本文通过对Sabatier的反应机理、动力学及热力学特性的分析,认为Sabatier反应是自限制温度及反应产物的反应,高效、性能优良反应器的设计在于控制反应器温度梯度;同时通过剖析不同系统流程所产生的性能差异,提出了空间站Sabati-er系统设计的优...     

微生物处理废物实验装置的研制

目的 建成微生物处理废物实验装置，拟将植物不可食生物量转化为植物营养液供植物生长发育，方法 提出技术指标和性能要求，进行方案论证、图纸设计、加工、调试和初步微生物废物转化试验。结果 该装置生物反应器中的温度、搅拌速度和供气流量可以实现自动控制，ｐＨ值和溶解氧浓度可以实现自动测量和手动控制，达到了预设的技术指标要求。１５ｄ的初步微生物处理废物试验表明，该装置运行平稳，参数测控精确，生菜不可食生物量的     

微生物处理空间模拟废水工艺初探

目的 开展模拟空间废水处理试验研究,探讨空间废水处理膜生物反应器处理模拟空间废水的较适环境条件,为今后设计空间膜生物反应器提供技术支持.方法 利用前期研制的空间废水处理膜生物反应器和驯化后微生物,进行了模拟空间废水处理试验,检测了处理液进口和出口的化学耗氧量(COD)、生物耗氧量(BOD)、总有机碳和总氮的去除效率.结果 空间废水处理膜生物反应器发挥最佳工作效能需要的环境条件分别为:pH6.5 ～7.5,温度24.0 ～ 26.0℃,水力滞留时间20 h,碳氮比0.81；在该条件下模拟空间废水的化学耗氧量和生物好氧量下降率均接近90％.结论 研制的膜生物反应器可以有效地进行空间模拟废水的处理,适合的工艺条件能明显提高其废水处理效率.     

组织工程生物反应器及其仿生力学环境探讨

组织工程生物反应器是在体外造就一个与体内相似的环境，加速培养细胞、组织乃至器官的系统，可广泛应用于如器官缺损患者替代、构建、保持或增强其组织功能，以及生物制药等领域。生物反应器作为组织工謦中重要的功能型载体，已成为当前研究的热点。目前，生物反应器主要是从空间三维培养、生物力．学、传质、培养环境（pH、PO2等）和物理因素（电场、磁场、超声）等方面开展研究。本文着重从力学环境的角度探讨了各种组织工程生物反应器，并在此基础上介绍了我们从仿生角度所分析、综合、设计的旋转壁式生物反应器，以及优化细胞生长力学环境的思路。     

微重力旋转细胞培养的研究及应用进展

1990 年, Kleis 等人首先研制了一种生物反应器, 随后美国国家航空与宇宙航行局( national aeronautics and space administration, NASA) 对此进行改进研制了圆柱形旋转壁式生物反应器( rotating wall vesselbioreactor, RWVB)并应用到组织培养领域.RWVB 是由2个同心圆柱体构成的旋转装置,将细胞与培养液置入内、外圆柱体之间, 整个装置绕纵轴旋转,根据细胞的种类、性质、数量、培养物的大小调节容器的旋转速度, 使培养物长时间保持悬浮状态.     

Automatic spatial and temporal temperature control for MR-guided focused ultrasound using fast 3D MR thermometry and multispiral trajectory of the focal point.

Of the different modalities to induce local hyperthermia, focused ultrasound is the only noninvasive technology available at the moment. In addition to the 3D localization of the target region, it has been shown that MRI can provide real-time thermometry and allows online, automatic control of temperature evolution of the focal point. Treatment of a large tissue volume (as compared to the focal spot size, i.e., the ultrasound wavelength) can be achieved rapidly by moving the focal point along an inside-out spiral trajectory. It has been shown previously that under linear conditions of energy deposition versus temperature, the spatial profile of the temperature within a large area can be controlled. In this study, a proportional, integral, and derivative (PID) spatial-and-temporal controller is described for the control of the temperature evolution within the target region under more variable conditions. The aim was to reach a predefined temperature profile after a few successive trajectories. Heat conduction in tissue is exploited to obtain a uniform temperature increase in a volume using discrete sonications without any waiting time. Input data sets consisted of 3D temperature maps provided online by a MR scanner. For each new trajectory, the controller recalculates the number of sonications per surface unit (spatial density of points describing the trajectory) and the applied power. Its performance was tested ex vivo and in vivo. Diameters of the target region ranged from 9 mm to 19 mm. Targeted temperature increase ranged from +8 degrees C to +18 degrees C. Spatiotemporal temperature control showed good stability and fast convergence, for both circular and elliptic ROIs.     

Three‐dimensional spatial and temporal temperature control with MR thermometry‐guided focused ultrasound (MRgHIFU)

High‐intensity focused ultrasound (HIFU) is an efficient noninvasive technique for local heating. Using MRI thermal maps, a proportional, integral, and derivative (PID) automatic temperature control was previously applied at the focal point, or at several points within a plane perpendicular to the beam axis using a multispiral focal point trajectory. This study presents a flexible and rapid method to extend the spatial PID temperature control to three dimensions during each MR dynamic. The temperature in the complete volume is regulated by taking into account the overlap effect of nearby sonication points, which tends to enlarge the heated area along the beam axis. Volumetric temperature control in vitro in gel and in vivo in rabbit leg muscle was shown to provide temperature control with a precision close to that of the temperature MRI measurements. The proposed temperature control ensures heating throughout the volume of interest of up to 1 ml composed of 287 voxels with 95% of the energy deposited within its boundaries and reducing the typical average temperature overshoot to 1°C. Magn Reson Med, 2009. © 2008 Wiley‐Liss, Inc.     

Investigation of the effect of tonus on the change in postural control strategy using musculoskeletal simulation

BackgroundHumans use different postural control strategies depending on perturbations. The shift from an ankle strategy to a hip strategy occurs at different perturbation magnitudes for different individuals. Although such differences relate to the differences in body parameters such as muscle strength, the parameter changes that affect the strategy shift are unclear. The relationship between tonus and strategy is especially unclear, but humans control tonus, which contributes to body stability. The objective of this study was to investigate the influence of tonus on postural control strategy.Research questionIs there a trend toward the use of a hip strategy with a decrease in the magnitude of tonus?MethodsPredictive simulations were performed for changing parameters of muscle weakness and increased sensory noise, which are considered the causes of different strategies and decreased tonus. A musculoskeletal model with 70 muscles and 15 degrees of freedom of joints was controlled using a neural controller model, and the support surface was translated backward to introduce perturbations. The parameters of the musculoskeletal and neural controller models were changed for 48 conditions of different muscle strengths, sensory noise, and tonus. The control parameters were optimized for each condition. Simulations were performed with the optimized control parameters to calculate an evaluation index to show the difference in postural control strategies (peak hip angle), and the relationship between the index and parameters was analyzed using analysis of variance and multiple regression.ResultsThe main effects of muscle weakness and decreased tonus and their interaction were confirmed. The results recognized a positive response to the research question.SignificanceThe study emphasizes the importance of considering tonus while investigating the postural control strategy. Furthermore, it was suggested that when the magnitude of tonus was larger than a threshold, only the ankle strategy was used, regardless of muscle strength.     

适用于显微镜下细胞连续观察的温度控制系统

目的研制一种适合显微镜下使用的温度控制系统,以保证显微镜下对细胞进行长时间连续观测时的温度要求。方法系统用透光性良好的氧化铟锡导电膜（ITO）作为加热元件,利用ITO导电薄膜自身温阻效应测量系统温度,辅以C8051F340单片机为控制系统核心,以改进的PID控温算法及脉宽调制技术（PWM）为依托,构成温度控制系统的核心。结果与结论设计的温度控制系统无需额外温度传感器,结构简单I,TO膜表面温度分布均匀（1℃内）,控温精度达±0.2℃;系统能够维持显微镜下BHK-21细胞保持良好的生存状态,可在显微镜下进行连续48 h观察,为细胞生物学动态行为特征研究提供一种技术手段。     

Automatic control of thermal neutrality for space suit applications using a liquid cooling garment

BACKGROUND: Thermal control in the EVA spacesuit requires attention from the astronaut which is not always desirable or feasible. Improvements in thermal control involve implementation of an automatic thermal control system operating independently of the knowledge of the working astronaut. METHODS: A control system was designed, developed, and tested to automatically maintain a subject's thermal neutrality while wearing a liquid cooling garment (LCG). Measurement of CO2 production as an indication of metabolic rate was used as a signal to initiate the control response. Mean body temperature, computed as a function of ear canal temperature and mean skin temperature, provided feedback to account for the thermal state of subjects as they were being cooled by the LCG. The control algorithm was tested on nine subjects, six males and three females, who performed a varying 90-min metabolic profile using an arm cranking ergometer. A total of 27 tests, three for each subject, were conducted in a thermal chamber at three different environmental temperatures: 10 degrees C, 18.3 degrees C and 26.7 degrees C. RESULTS AND CONCLUSIONS: Evaluation of subjective comfort rating and quantitative energy storage indicates good performance of the controller in maintaining thermal neutrality for the subject over a wide range of environmental and transient metabolic states. Measurements of metabolic rate effectively initiated controller response, and feedback of mean body temperature to the controller proved very capable of accounting for various steady-state environmental conditions and inter-subject variability.     

Real-time control of focused ultrasound heating based on rapid MR thermometry

RATIONALE AND OBJECTIVES: Real-time control of the heating procedure is essential for hyperthermia applications of focused ultrasound (FUS). The objective of this study is to demonstrate the feasibility of MRI-controlled FUS. METHODS: An automatic control system was developed using a dedicated interface between the MR system control computer and the FUS wave generator. Two algorithms were used to regulate FUS power to maintain the focal point temperature at a desired level. RESULTS: Automatic control of FUS power level was demonstrated ex vivo at three target temperature levels (increase of 5 degrees C, 10 degrees C, and 30 degrees C above room temperature) during 30-minute hyperthermic periods. Preliminary in vivo results on rat leg muscle confirm that necrosis estimate, calculated on-line during FUS sonication, allows prediction of tissue damage. CONCLUSIONS. The feasibility of fully automatic FUS control based on MRI thermometry has been demonstrated.     

空中交通管制员心理选拔指标的模糊综合评价

目的 研究空中交通管制员主要心理选拔指标的模糊综合评价,以提供一个真实、综合的心理选拔方法.方法 设计了空中交通管制员心理选拔指标结构模型,将总目标分解为系列子目标,从而形成不同的层次,以模糊数学为手段,对空中交通管制员心理选拔指标进行了模糊综合评价.结果 通过对空中交通管制员心理选拔指标的模糊计算,验证了心理选拔指标的正确性.结论 用模糊综合评判方法评价管制员心理选拔指标可以提供真实,全面的选拔方法.     

Cycle time control of an onboard oxygen generation system

The outlet oxygen concentration of an onboard oxygen generation system (OBOGS) is controlled in this study by varying the cycle time of a pressure swing adsorption process. The control of the oxygen concentration is highly desirable since both high and low concentrations of oxygen can cause physiological problems. This cycle time control method can be easily implemented using a DC motor and a simple electronic controller. The physiological requirements recommended for high-performance tactical aircraft can be met by this method with either an open-loop or closed-loop configuration. The open-loop configuration requires the measurement of crew breathing flowrate and cabin pressure. The closed-loop configuration requires an additional measurement of oxygen concentration, but it has the advantage of being more adaptive to system variability during setup and operation. The method in either configuration requires very little adjustment and setup time in order to meet the specifications.     

Near-real-time feedback control system for liver thermal ablations based on self-referenced temperature imaging

Our challenge was to design and implement a dedicated temperature imaging feedback control system to guide and assist in a thermal liver ablation procedure in a double-donut 0.5T open MR scanner. This system has near-real-time feedback capability based on a newly developed "self-referenced" temperature imaging method using "moving-slab" and complex-field-fitting techniques. Two phantom validation studies and one ex vivo experiment were performed to compare the newly developed self-referenced method with the conventional subtraction method and evaluate the ability of the feedback control system in the same MR scanner. The near-real-time feedback system was achieved by integrating the following primary functions: (1) imaging of the moving organ temperature; (2) on-line needle tip tracking; (3) automatic turn-on/off the heating devices; (4) a Windows operating system-based novel user-interfaces. In the first part of the validation studies, microwave heating was applied in an agar phantom using a fast spoiled gradient recalled echo in a steady state sequence. In the second part of the validation and ex vivo study, target visualization, treatment planning and monitoring, and temperature and thermal dose visualization with the graphical user interface of the thermal ablation software were demonstrated. Furthermore, MR imaging with the "self-referenced" temperature imaging method has the ability to localize the hot spot in the heated region and measure temperature elevation during the experiment. In conclusion, we have demonstrated an interactively controllable feedback control system that offers a new method for the guidance of liver thermal ablation procedures, as well as improving the ability to assist ablation procedures in an open MR scanner.     

Revisit image control for pediatric chest radiography

Purpose The aim of this study was to analyze the fraction defectiveness and efficacy of the patient immobilization device (PID) for pediatric chest radiography. Materials and methods We examined 840 plain chest radiographs in six hospitals, including four children's hospitals and two general hospitals. The mean age of the patients was 1.9 years (range 0–5 years). Two board-qualified pediatric radiologists rated (into three grades, by consensus) the degree of inspiration, rotation, lordosis, scoliosis, and cutoff or coning as well as the quality of the chest radiographs. Results The incidence of “poor” and “very poor” quality examinations was 2/140 and 3/140 in each of two children's hospitals using PID. The corresponding figures were 9/139 and 17/140 in the two children's hospitals that did not use PID. The general hospital using PID had 14/140 “poor” and “very poor” examinations. The general hospital that did not use PID had 28/140 “poor” and “very poor” examinations. Thus, statistically better quality chest radiography was obtained with the use of PID (P < 0.001). Likewise, rotation, lordosis, and scoliosis were less frequently diagnosed as present when PID was used (P < 0.001, 0.001, 0.05). Cutoff or coning had no relation to the use of PID (P = 0.13). No significant difference was found between the degree of inspiration and the use of PID (P = 0.56). Conclusion Fraction defectiveness in the general hospital that did not use PID was as much as 14 times higher than that of the children's hospitals that used PID. The patient immobilization device is recommended for hospitals with technologists not specifically trained for pediatric examination.