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closed-loop controller for Chest Compression During Cardiopulmonary Resuscitation: A Computer Simulation Study

JOURNAL OF MEDICAL AND BIOLOGICAL ENGINEERING 2012年第5期32卷 313-322页

作者： Zhang, Guang Zheng, Jie-Wen Wu, Jian Wu, Tai-Hu Natl Biol Protect Engn Ctr Inst Med Equipment Tianjin 300161 Peoples R China Tianjin Univ Commerce Dept Informat Engn Tianjin 300134 Peoples R China

To provide an effective and personalised chest compression (CC) method for automatic mechanical compression devices, CC parameters must be improved according to the chest compression physiological feedback parameters (CCPFPs). The CCPFPs include the partial pressure of end-tidal CO2 and the mean arterial relaxation pressure. This study proposes a closed-loop controller for adjusting CCPFPs based on a fuzzy proportional integral derivative (PID) control algorithm. The performance of the fuzzy PID controller is evaluated and compared to that of a traditional PID controller in simulation studies based on a human circulation model. The simulation results demonstrate that the proposed fuzzy PID controller outperforms the traditional PID controller in CCPFPs regulation and maintenance. The fuzzy PID controller produces smoother CCPFPs regulation curves, shorter regulation time, fewer oscillations, smaller overshoot, and a significantly smaller peak depth than those of the traditional PID controller. The proposed closed-loop controller is thus potentially useful for practical cardiopulmonary resuscitation with its personalised and high-quality innovative automated control method for CC.

关键词： closed-loop controller Chest compressions (CC) Fuzzy proportional integral derivative (PID) controller Partial pressure of end-tidal CO2 (PETCO2) Mean arterial relaxation pressure (MARP)

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Feasibility of closed-loop controller for righting seated posture after spinal cord injury

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JOURNAL OF REHABILITATION RESEARCH AND DEVELOPMENT 2014年第5期51卷 747-760页

作者： Murphy, Julie O. Audu, Musa L. Lombardo, Lisa M. Foglyano, Kevin M. Triolo, Ronald J. Case Western Reserve Univ Dept Biomed Engn Cleveland OH 44106 USA Louis Stokes Cleveland Dept Vet Affairs Med Ctr Cleveland OH USA Case Western Reserve Univ Dept Orthopaed Cleveland OH 44106 USA

Spinal cord injury (SCI) can compromise the ability to maintain an erect seated posture. This study examined the feasibility of a sensor-based threshold controller to automatically modulate stimulation to paralyzed hip and trunk extensor muscles to restore upright sitting from forward leaning postures. Forward trunk tilt was estimated from the anterior- posterior component of gravitational acceleration sensed by a sternum-mounted wireless accelerometer. Stimulation increased if trunk tilt exceeded a specified flexion threshold and ceased once upright sitting was resumed. The controller was verified experimentally in five volunteers with SCI and successfully returned all subjects to upright postures from forward leaning positions. Upper-limb effort exerted while returning to erect posture was significantly reduced (to 7.4% +/- 3.7% of body mass) pooled across all volunteers while using the controller compared with using continuous and no stimulation (p < 0.03). controller response times were consistent among subjects when applied while sitting with (0.30 +/- 0.05 s) or without (0.34 +/- 0.11 s) a backrest. The controller enabled volunteers to lean farther forward (59.7 degrees +/- 16.4 degrees) in wheelchairs without upper-limb effort than with no stimulation. Clinical utility of the system for facilitating reach or preventing falls remains to be determined in future studies.

关键词： closed-loop controller feedback control functional electrical stimulation functional neuromuscular stimulation neuroprosthesis SCI seated posture spinal cord injury trunk stability wireless accelerometer

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A mechanical chest compressor closed-loop controller with an effective trade-off between blood flow improvement and ribs fracture reduction

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MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING 2015年第6期53卷 487-497页

作者： Zhang, Guang Wu, Taihu Song, Zhenxing Wang, Haitao Lu, Hengzhi Wang, Yalin Wang, Dan Chen, Feng Natl Biol Protect Engn Inst Med Equipment Tianjin Peoples R China

Chest compression (CC) is a significant emergency medical procedure for maintaining circulation during cardiac arrest. Although CC produces the necessary blood flow for patients with heart arrest, improperly deep CC will contribute significantly to the risk of chest injury. In this paper, an optimal CC closed-loop controller for a mechanical chest compressor (OCC-MCC) was developed to provide an effective trade-off between the benefit of improved blood perfusion and the risk of ribs fracture. The trade-off performance of the OCC-MCC during real automatic mechanical CCs was evaluated by comparing the OCC-MCC and the traditional mechanical CC method (TMCM) with a human circulation hardware model based on hardware simulations. A benefit factor (BF), risk factor (RF) and benefit versus risk index (BRI) were introduced in this paper for the comprehensive evaluation of risk and benefit. The OCC-MCC was developed using the LabVIEW control platform and the mechanical chest compressor (MCC) controller. PID control is also employed by MCC for effective compression depth regulation. In addition, the physiological parameters model for MCC was built based on a digital signal processor for hardware simulations. A comparison between the OCC-MCC and TMCM was then performed based on the simulation test platform which is composed of the MCC, LabVIEW control platform, physiological parameters model for MCC and the manikin. Compared with the TMCM, the OCC-MCC obtained a better trade-off and a higher BRI in seven out of a total of nine cases. With a higher mean value of cardiac output (1.35 L/min) and partial pressure of end-tidal CO2 (15.7 mmHg), the OCC-MCC obtained a larger blood flow and higher BF than TMCM (5.19 vs. 3.41) in six out of a total of nine cases. Although it is relatively difficult to maintain a stable CC depth when the chest is stiff, the OCC-MCC is still superior to the TMCM for performing safe and effective CC during CPR. The OCC-MCC is superior to the TMCM in perfor

关键词： Chest compression (CC) Trade-off closed-loop controller Partial pressure of end-tidal CO2 (PETCO2) Cardiopulmonary resuscitation (CPR) Chest stiffness

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Improving temporal stability of stable cavitation activity of circulating microbubbles using a closed-loop controller based on pulse-length regulation

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ULTRASONICS SONOCHEMISTRY 2022年 82卷 105882-105882页

作者： Tan, Chunjie Yan, Bo Han, Tao Yu, Alfred C. H. Qin, Peng Shanghai Jiao Tong Univ Sch Sensing Sci & Engn Shanghai 200240 Peoples R China Univ Waterloo Schlegel Res Inst Aging Waterloo ON N2L 3G1 Canada Shanghai Jiao Tong Univ Inst Med Robot Shanghai 200240 Peoples R China

Stable cavitation (SC) has shown great potential for novel therapeutic applications. The spatiotemporal distri-bution of the SC activity of microbubbles circulating in a target region is not only correlated with the uniformity of treatment, but also with some undesirable effects. Therefore, it is important to achieve controllable and desirable SC activity in target regions for improved therapeutic efficiency and biosafety. This study proposes a closed-loop feedback controller based on pulse length (PL) regulation to improve the temporal stability of SC activity. Microbubbles circulating in a physiological flowing phantom were exposed to a 1 MHz focused trans-ducer. The SC signals produced were initially received by another 7.5 MHz plane transducer, followed by high-speed signal acquisition and real-time processing. Based on the real-time-measured SC intensity excited by the current acoustic pulse, the proposed closed-loop feedback controller used three proportional coefficients to regulate the peak negative pressure (PNP) and PL of the next acoustic pulse during the acceleration and stable stages, respectively. The results show that the rise time and the temporal stability of the SC intensity of the microbubbles circulating in these two stages were improved significantly by the optimized proportional co-efficients used in the proposed controller. Importantly, when compared with the traditional closed-loop feedback controller based on PNP regulation, the proposed closed-loop feedback controller based on PL regulation reduced the probability of a transition between stable and inertial cavitation, thus avoiding the risk of disadvantageous bioeffects in practical applications. These results demonstrate the effectiveness of the proposed PL-based closed-loop feedback controller and provide a feasible strategy for realization of controllable cavitation activity in applications.

关键词： Ultrasound Circulating microbubbles Stable cavitation closed-loop controller Pulse length

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Analysis and design of a closed loop controller for single-phase high-frequency link inverter based on pole-assignment

Analysis and design of a closed loop controller for single-p...

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International Conference on Electrical Machines and Systems

作者： Yan Xiangwu Gu Xiaobin Zhang Bo Zhang Lixia N China Elect Power Univ Dept Elect Engn Baoding Peoples R China

ISBN: (纸本)9788986510089

This paper presents a closed dual-loop controller based on pole-assignment for single-phase high-frequency (HF) link inverter. It is not difficult for the controller to design the controlled parameters using the method. The controller consists of the inner current loop and the outer voltage loop. To improve overall performance of the system, it is adopted that the control method combined the instantaneous inductance current control with the forward compensation control of the disturbing loads. The controller has the function to limit load current, compared with the instantaneous voltage single-loop controller. Simulation results are presented for the closed loop system under linear and nonlinear loads. It is shown that the control method provides good dynamic response with low harmonic distortion and nice static characteristics, even under full-bridge rectifier loads.

关键词： closed-loop controller Control Methods controllers pole assignment compensator control Inventors nonlinear load closed loop systems Current rings Harmonic distortion Dynamic response

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A tutorial on the synthesis and validation of a closed-loop wind farm controller using a steady-state surrogate model

A tutorial on the synthesis and validation of a closed-loop ...

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American Control Conference

作者： Bart M Doekemeijer Jan-Willem Van Wingerden Paul A Fleming Faculty of Materials Mechanical and Maritime Engineering (3mE) Delft Center for Systems and Control (DCSC) Delft University of Technology The Netherlands National Renewable Energy Laboratory (NREL) Golden Colorado United States of America

ISBN: (纸本)9781538679012;9781538679265

In wind farms, wake interaction leads to losses in power capture and accelerated structural degradation when compared to freestanding turbines. One method to reduce wake losses is by misaligning the rotor with the incoming flow using its yaw actuator, thereby laterally deflecting the wake away from downstream turbines. However, this demands an accurate and computationally tractable model of the wind farm dynamics. This problem calls for a closed-loop solution. This tutorial paper fills the scientific gap by demonstrating the full closed-loop controller synthesis cycle using a steady-state surrogate model. Furthermore, a novel, computationally efficient and modular communication interface is presented that enables researchers to straight-forwardly test their control algorithms in large-eddy simulations. High-fidelity simulations of a 9-turbine farm show a power production increase of up to 11% using the proposed closed-loop controller compared to traditional, greedy wind farm operation.

关键词： Wind farms wake current interference Interfacing and Communications closed-loop controller incoming flow closed loop synthesis Computer algorithms turbines wake loss Wake Island

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An Exploration on the Use of IMUs for Real-Time Detection of Gait Events, Towards closed-loop Gait Rehabilitation Based on Functional Electrical Stimulation 47th

An Exploration on the Use of IMUs for Real-Time Detection of...

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47th Mexican Conference on Biomedical Engineering

作者： Gonzalez-Gutierrez, E. Mercado-Gutierrez, J. A. Yanez-Suarez, O. Univ Autonoma Metropolitana Iztapalapa Mexico City DF Mexico Inst Nacl Rehabil Luis Guillermo Ibarra Ibarra Mexico City DF Mexico

ISBN: (纸本)9783031821226;9783031821233

Functional Electrical Stimulation (FES) systems for gait rehabilitation after stroke commonly rely on open-loop control strategies based on foot switches, with their main stimulation target being the tibialis anterior muscle, innervated by the peroneal nerve. The desired effect in such systems is assistance of the ankle dorsiflexion (foot lift) during the swing phase of gait. However, foot switches in FES systems present shortcomings regarding ergonomics, durability and personalization. As an alternative to foot switches, inertial measurement units (IMUs) have been used to detect gait events as part of FES control strategies. However, in many stroke patients not only ankle dorsiflexion, but also plantar flexion is impaired. Few works have reported the use of IMUs to detect gait events for assistance of both key ankle movements. The main aim of this project was to study the use of IMUs for the detection, in real time, of two relevant gait events: heel strike and toe off. A secondary aim was to explore the feasibility of using the proposed detection method as a part of a closed loop system that controls two FES channels (eventually targeted to tibialis anterior and gastrocnemius muscles). This proposal is based on previous offline movement analysis studies that have shown the usefulness of IMUs to define pathological and non-pathological gait patterns. A comparison was made between the data collected from two IMUs placed at two different points on the lower limb and the data obtained was used to develop an algorithm to detect two gait events: Initial (IC) and End Contact (EC). A Python-based script was developed and executed on a single board computer (Raspberry Pi 4), to simultaneously read sensor information, run the detection algorithm, and deliver, in real-time, control commands to two electrical stimulation channels, as dictated by a Finite State Machine (FSM) controller. A healthy volunteer was instrumented with the system and asked to walk, while the acquisitio

关键词： gait event detection IMU closed-loop controller real time controller functional electrical stimulation

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Adaptive regulation of blood glucose levels: A triadic methodology incorporating super twisting and deep policy gradient

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BIOMEDICAL SIGNAL PROCESSING AND CONTROL 2025年 103卷

作者： Mohammadzadeh, Ardashir Alattas, Khalid A. Sakarya Univ Fac Engn Dept Elect & Elect Engn Sakarya Turkiye Univ Jeddah Coll Comp Sci & Engn Dept Comp Sci & Artificial Intelligence Jeddah Saudi Arabia

The insufficiency of insulin secretion by the pancreas leads to elevated blood glucose levels (BGL) in individuals diagnosed with diabetes. Addressing this challenge, the artificial pancreas (AP) has emerged as a viable solution for the autonomous regulation of BGL through the continuous infusion of insulin. The proposed methodology employs a triadic approach to develop an intelligent closed-loop pancreatic system. First, a nonlinear controller, specifically the supertwisting sliding mode control (SSMC), is applied for the regulation of blood glucose. To enhance the quality and efficacy of the controller, a deep reinforcement learning (DRL) algorithm is then integrated to facilitate online updates of the SSMC coefficients. Finally, a sine-cosine algorithm (SCA) is formulated to optimize the hyperparameters of the DRL approach, addressing the challenges associated with the calibration of reinforcement learning algorithms. The developed system has been evaluated on six diabetic patients, involving various tests with differing BGL references, meal consumption, and the management of uncertainties. A comparative analysis with conventional methodologies further substantiates the superiority of the proposed SSMC-based DRL-SCA system, demonstrating an overall average superiority of approximately 61.13% in tracking performance compared to traditional control methods across various cases.

关键词： Pancreas system Diabetes patients closed-loop controller Supertwisting sliding mode control (SSMC) Deep reinforcement learning algorithm (DRL) Sine-Cosine algorithm (SCA)

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Selection criteria of closed-loop controllers for DC-DC voltage regulators based on nominal and tolerance design: Monte Carlo & interval arithmetic based optimization

Selection criteria of closed-loop controllers for DC-DC volt...

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IEEE International Symposium on Industrial Electronics

作者： Di Lorenzo, M Femia, N Lamberti, P Mainardi, V Spagnuolo, G Dipartimento Ingn Elettr I-90128 Palermo Italy

ISBN: (纸本)0780373693

A novel method to select optimal feedback Compenstation networks for dc-dc switching converters is presented in this, paper. This method provides a support to robust design, allowing the optimal soloution choice among different projects that fulfil given constraints. The considered case of study concerns the optimization of the feedback control circuit of a voltage-mode regulated dc-dc converter. Given control loop performance constraints and the circuit Parameters Commericial values and tolerances, six different approaches are adopted to select a set of optimal feasible design solutions. Indeed, they, have been found by means of a numerical method based on Monte-Carlo technique. Interval Arithmetic is used to make computations with tolerances. The results presented in this paper highlight that, given a set of design constraints, the best projects are identified by means of a comparative evaluation of the robustness of the different possible design solution with respect to parameters tolerance.

关键词： DC-DC power convertors Monte Carlo bas DC-DC voltage regulators selection criteria closed-loop controllers compensation switching convertors feedback voltage regulators Monte Carlo methods closed loop systems voltage control optimisation Voltage regulators switching converters DC-DC power convertors closed loop systems closed-loop controller Voltage regulation Monte Carlo technique compensated design constraints Feedback Interval arithmetic

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Simple and fast computation photovoltaic emulator using shift controller

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IET RENEWABLE POWER GENERATION 2020年第11期14卷 2017-2026页

作者： Ayop, Razman Wei Tan, Chee Lawan Bukar, Abba Univ Teknol Malaysia Sch Elect Engn Utm Johor Bahru 81310 Malaysia Univ Maiduguri Fac Elect Engn PMB 1069 Borno Nigeria

Photovoltaic (PV) emulator (PVE) is a non-linear power supply that produces a similar output to that of the PV module. It requires a closed-loop controller such as the proportional-integral (PI) and fuzzy logic controllers to operate properly. The PI controller has a low-computational burden and is not robust since the transient response varies under different load conditions. Although the fuzzy logic controller is robust, it requires high-computation capability. This study proposed an alternative approach called the shift controller for the PVE to easily compute and maintain a fast transient response under various load conditions. The performance of the proposed shift controller for the PVE is compared with the performance of the PVEs using the PI and fuzzy logic controllers, respectively. The controllers are simulated using MATLAB/Simulink and implemented using dSPACE ds1104 for experimental validation. The results show that the proposed shift controller computes up to 18 times faster than the fuzzy logic controller. The proposed controller also responds faster to load change than the PI controller.

关键词： PI control photovoltaic power systems transient response fuzzy control closed loop systems computer simulation control engineering computing power engineering computing computational complexity fast computation photovoltaic emulator PVE nonlinear power supply PV module closed-loop controller fuzzy logic controllers PI controller low-computational burden transient response varies high-computation capability fast transient response shift controller MATLAB-Simulink dSPACE ds1104

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