Permanent circulatory support systems at the Pennsylvania StateUniversity

Permanent circulatory support systems are required for patients in whom myocardial damage is irreversible and cardiac transplantation is not possible. Two systems are described which provide long term circulatory support: the left ventricular assist system and the total artificial heart. These systems are based on the design of a pusher plate actuated blood pump, driven by a small brushless dc electric motor and rollerscrew driver. An implantable motor controller maintains suitable physiologic flow rates for both systems and controls left-right balance in the total artificial heart. Other parts of the system include an intra-thoracic compliance chamber, transcutaneous energy and data transmission system, and internal and external batteries.     

Coil‐Capacitor Circuit Design of a Transcutaneous Energy Transmission System to Deliver Stable Electric Power

A new transcutaneous energy transmission (TET) system was developed for transmitting electrical power to an implanted device, such as an artificial heart in a patient's body. This new design can maintain a stable output voltage independent of the load resistance. The system includes a compensation capacitor to reduce energy loss and increase power transfer efficiency. Experimental results show that the output voltage of the receiving coil changes very little as the load resistance varies from 14.8 Ω to 15 kΩ, which corresponds to a change in output power from 0.1 to 97 W.     

A moving-actuator type electromechanical total artificial heart. I.Linear type and mock circulation experiments

A new type of motor-driven total artificial heart system with a moving-actuator mechanism has been developed. The prototype system consists of a brushless dc motor inside of a rolling-cylinder, two arc-shaped pusher-plates and two polyurethane sacs. The moving-actuator type electromechanical pump has structural advantages of small size and light weight, as compared to other reported motor-driven pumps with fixed-actuator mechanisms. The results of the mock circulation tests are reported in this paper with a cardiac output of 9 L/min at an aortic pressure of 120 mmHg and a heart rate of 120 bpm. The fulfillment of the basic control requirements of the artificial heart was also confirmed, i.e., preload sensitive and afterload insensitive cardiac output response and balanced right and left ventricular outputs.     

氧化锆单晶光纤拉制系统电机控制系统的设计

高温单晶光纤是制作光纤高温传感头的理想材料,于是我们在LHPG法的基础上设计出了环形聚焦激光加热系统,在此主要介绍该系统中电机控制系统的设计。系统以AT89S52单片机为核心构成步进电机数控系统,选用步进电机作为驱动元件,电机输出轴经过联轴器连接滚珠丝杆可控制工作平台在直线导轨的支撑下以给定的速度和行程做平稳的直线运动,振动较小。该系统利用单片机的定时中断系统可以严格控制步进电机的转速和步数,进而可以控制工作平台直线运动的速度和行程,最终可以控制氧化锆单晶光纤的直径和拉制的长度。     

Integral motor with driver and wireless transmission of power andinformation for autonomous subspindle drive

This paper describes the novel technology of an integral motor with the associated driver and wireless transmission of power and information (WTPI), which is effectively applied to autonomous spindle drive for the sophisticated workpiece machining. The power supply to the integral motor is made by way of a separable WTPI coupling. In addition, calculation for variable voltage and variable frequency (VVVF) control is done at the primary side of the coupling, and then the frequency command is transmitted to the secondary side by an overlapped transmission of the data on the power transmission through the WTPI coupling. At the secondary side, direct power conversion from the induced high-frequency voltage to the motor terminal voltage is conducted using a bidirectionally controllable power switch. The amplitude of the terminal voltage is adjusted by changing the inverter voltage at the primary side. In this way, the VVVF drive is made through the WTPI coupling, thus providing the integral subspindle with the autonomy for sophisticated machining     

Effects of Unphysiological Factors on Cardiac Output Regulation During Artificial Heart Pumping

Several Factors affecting artificial heart output were studied employing two mathematical models of prosthetic hearts, i.e., sac and diaphragm heart models. The stroke volume sensitivity to changes in venous pressure was analyzed by numerical computations. Increased inflow valve resistance, increased pump vacuum pressure, decreased elasticity of the ventricular sac or diaphragm and decreased size of the ventricle were shown to depress artificial heart function. In total prosthetic heart replacement experiments in calves, the resistance at the junction of the right heart to the natural atrium was measured by varying the pump vacuum pressure. When the vacuum pressure exceeded ?20 mmHg, the orifice resistance to flow increased approximately 4 times. Optimizing the above factors, a prosthetic heart should be designed that provides sufficient flow with a pump vacuum pressure not greater than ?20 mmHg.     

Mechatronics and control of a long-range nanometer positioning servomechanism

Since the manufacturing accuracy of semiconductor and biochemical products is increased to nanometer level gradually, the development of long-range positioning servomechanism has become a hot research topic. The piezoelectric actuator is widely chosen to design precise positioning system for achieving the sub-micro or nano-position. However, their motion range is only 100 μm. Here, a long-range nanometer positioning servo system with AC servo motor and ball screw mechanism is built for the precision manufacturing purpose. It needs a special design control algorithm to obtain quick transient response and precise steady state accuracy. A new model-free fuzzy controller is designed to control this low-cost motion stage for achieving nanometer step response positioning. It has a novel gain auto-tuning strategy in response to the transient or steady state responses requirement. The experimental results show that this approach can reach more than 30 cm stroke and the step response error is less than 60 nm.     

基于SPCE061A的智能血液参数分析系统

智能化的医疗设备可以减少人为错误,保证测量的精度准确率。采用SPCE061A单片机为核心设计了智能血液参数分析系统,智能控制整个液路,包括被测样本的走向和压力泵。通过以EPM7128为核心的逻辑判断系统,检测电磁阀,其工作状态用LED灯指示,使用通用异步串口和其他部分进行通信,根据系统的实时状态和功能实现语音提示。     

Determining optimal tuning capacitor values of TET system for achieving maximum power transfer

Optimal tuning capacitor values corresponding to the maximum power transfer of a voltage-fed series-tuned transcutaneous energy transfer (TET) system are derived. The theoretical analysis is verified by experimental results. The maximum power transfer capacity can be three times greater compared to the traditional method, which tunes the capacitor at the nominal resonant frequency without considering the mutual inductance effect. These results are useful to enable an existing series-tuned TET system to meet short-term high-power demands where efficiency is not a key factor.     

轴承预紧力对滚珠丝杠系统动态特性影响分析

为了解轴承预紧力对滚珠丝杠系统动态特性的影响,以某卧式磨床滚珠丝杠为研究对象,建立了丝杠的三维模型,并以弹性支承约束模拟角接触球轴承对丝杠的支承。在此基础上,利用ANSYS对磨床滚珠丝杠系统进行模态分析。通过修改不同预紧力下轴承的支撑刚度,得到了在不同预紧力下的系统各阶固有频率。分析结果表明,在不同的轴承预紧力下,滚珠丝杠系统的结构刚度会发生变化,使系统的固有频率改变,且随着预紧力增大而增大。磨削状态稳定时,磨削预应力对滚珠丝杠系统的影响较小。     

微型轴流式血泵外磁驱动电路设计

微型轴流式血泵是目前人工心脏结构研究的热点，外磁驱动是一种新型的血泵驱动方式。文中介绍了血泵外磁驱动电路的设计方案。通过该方案能够产生双向励磁电流，可直接驱动电机以实现血泵的外磁驱动。     

Multifunctional Artificial Artery from Direct 3D Printing with Built‐In Ferroelectricity and Tissue‐Matching Modulus for Real‐Time Sensing and Occlusion Monitoring

Treating vascular grafts failure requires complex surgery procedures and is associated with high risks. A real‐time monitoring vascular system enables quick and reliable identification of complications and initiates safer treatments early. Here, an electric fieldassisted 3D printing technology is developed to fabricate in situ‐poled ferroelectric artificial arteries that offer battery‐free real‐time blood pressure sensing and occlusion monitoring capability. The functional artery architecture is made possible by the development of a ferroelectric biocomposite which can be quickly polarized during printing and reshaped into devised objects. The synergistic effect from the potassium sodium niobite particles and the polyvinylidene fluoride polymer matrix yields a superb piezoelectric performance (bulk‐scale d₃₃ > 12 pC N^?1). The sinusoidal architecture brings the mechanical modulus close to the level of blood vessels. The desired piezoelectric and mechanical properties of the artificial artery provide an excellent sensitivity to pressure change (0.306 mV mmHg^?1, R² > 0.99) within the range of human blood pressure (11.25–225.00 mmHg). The high pressure sensitivity and the ability to detect subtle vessel motion pattern change enable early detection of partial occlusion (e.g., thrombosis), allowing for preventing grafts failure. This work demonstrates a promising strategy of incorporating multifunctionality to artificial biological systems for smart healthcare systems.     

Photovoltaic-powered piston-type water pump controlled by a linear motor

This paper presents a unique technique to control a photovoltaic (PV)-powered piston-type water pump. the method uses a linear motor mounted directly onto the piston rod of the pump. This linear motor method replaces the traditional piston-type water pump, which employs a DC motor with a bulky gear mechanism to convert the rotational motion of the motor to linear motion for the piston. The electric circuit used to control the linear motor employs a four-quadrant chopper, which uses four fast MOSFETs and a simple logic circuit for the switching. The experimental results show that the PV-powered linear motor system can be used as an alternative to the PV-powered DC motor gear system.     

INVT变频器在恒压供水系统中的应用

本文设计了一个由Siemens S7—300PLC与英威腾（INVT）变频器组成的恒压供水系统。它由一台变频水泵、一台工频水泵、一台备用水泵组成,以PLC作为主控制器,实现系统的启动运行、制动控制、供水模式选择、水泵电机监控、电机故障报警以及故障电机切换等功能。该系统通过实时检测供水管网压力信号,根据压力值决定启动电机...     

高压变频器在热电厂锅炉恒压供水上的应用

本文阐述了高压变频器在热电厂锅炉给水中的应用。利用变频调速系统自带的PID功能结合压力变送器实现闭环控制,为恒压供水提供一种可行的方案。文中所示的数据表明锅炉给水泵的高压电机的变频节能改造是可行的。     

Estimation of the Non-Measurable State Variables of a Transcutaneous Energy Transmission System for Artificial Human Implants Using Extended Kalman Filters

Due to the separation of the two sides of the coupling network, the acquisition of data on the operating state variables of a transcutaneous energy transmission system (TETS) inside the human body is difficult. A non-measurable state estimation approach is used in this work to facilitate the estimation of non-measurable variables on the secondary side of the TETS, including the current of the secondary coil and the output voltage of the secondary side. The estimation algorithm is based on a discrete dynamic mathematical model of the TETS. Following this model, using the extended Kalman filter (EKF) algorithm, the complexity of the TETS for artificial human implants can be reduced, while the reliability is simultaneously enhanced. Additionally, as an adaptive filter, the EKF can also successfully filter out processing noise during energy transmission. All of the results are verified by simulation using MATLAB.     

A contactless electrical energy transmission system

Most mains-operated equipment in use today is connected to the supply via plugs and sockets. These are generally acceptable in benign environments, but can be unsafe or have limited life in the presence of moisture. In explosive atmospheres and in undersea applications, special connectors must be used. This paper describes a technique, the contactless energy transfer system (CETS), by which electrical energy may be transmitted, without electrical connection or physical contact, through nonmagnetic media of low conductivity. The CETS, which has been used to transfer up to 5 kW across a 10 mm gap, employs high-frequency magnetic coupling and enables plug-in power connections to be made in wet or hazardous environmental conditions without the risk of electric shock, short circuiting, or sparking. Energy may be transmitted without the necessity for accurately manufactured “plug-and-socket” mechanisms and may be transmitted from source to load, even when there is relative motion. Load-source voltage matching may be made inherent to the system     

基于AT89S52数字血压计的设计与实现

以AT89S52单片机为主要控制核心,利用血压传感器把用户的血压信号转变为微弱的电信号,微弱的电信号经过放大后输入A/D转换芯片MAX197中,由MAX197把电压信号转换为数字量,再经过单片机处理后在LED上显示,随时可以观看到血压值,同时将数据传送到病人的电子档案之中,让医生从整体上了解病人的血压情况做出诊断。文中设计有效解决了传统血压计需要人工读取和记录数据的缺点。     

直线型超声电机电参量的测试研究

超声电机电参量的测量是指其启动和制动过程中电流及电压的测量,使用一般的传统仪器很难满足这一测量要求.该文利用LabVIEW软件平台,使用高速数据采集卡、霍尔电压和电流传感器等建立了一个直线超声电机电参量测试系统,可同时测量超声电机在启动、工作和制动过程中电压和电流的瞬时值及有效值等.最后通过对所研制的超声电机的实验测试,表明了该系统的可行性和有效性.     

An energy transmission system for an artificial heart using leakageinductance compensation of transcutaneous transformer

A power supply system using a transcutaneous transformer to power an artificial heart through intact skin has been designed and built. In order to realize both high-voltage gain and minimum circulating current, compensation of leakage inductances on both sides of a transcutaneous transformer is proposed. A frequency region which realizes the robustness against coupling coefficient and load variation is identified. In this region, the power converter has inherent advantages such as zero-voltage switching (ZVS) or zero-current switching (ZCS) of the switches, high-voltage gain, minimum circulating current and high efficiency