A Control-Oriented Model of Blood Volume Response to Hemorrhage and Fluid Resuscitation

2015 ◽  
Author(s):  
Ramin Bighamian ◽  
Andrew T. Reisner ◽  
Jin-Oh Hahn
Keyword(s):  
Blood Volume ◽  
Fluid Resuscitation ◽  
Closed Loop ◽  
The Body ◽  
Loop Control ◽  
Proposed Model ◽  
Volume Response ◽  
Proportional Integral Controller ◽  
Fluid Transfer ◽  
Using Data

This paper presents a control-oriented model of blood volume response to hemorrhage and fluid resuscitation that can be potentially utilized in closed-loop control of fluid resuscitation. A unique characteristic of the proposed model is that it is built to ensure structural parsimony while retaining physiological transparency. To accomplish this characteristic, blood volume regulation in the body to external perturbations of hemorrhage and fluid resuscitation was modeled as a low-order control system in which the fluid transfer between blood and interstitial fluid is governed by a proportional-integral controller. This in essence resulted in a minimal model with four parameters to be adapted to each individual. The validity of the proposed model was tested using data available in the literature. The results indicated that the proposed model was able to reproduce the blood volume response to hemorrhage and fluid resuscitation with high fidelity: on the average, the prediction error was only 1.53 ± 11.5 %, thus strongly supporting our claim that it can be used as viable basis for the design of closed-loop fluid resuscitation controllers.

Closed-Loop Control of Fluid Resuscitation via Blood Volume Estimation

2014 ◽  
Author(s):  
Ramin Bighamian ◽  
Andrew T. Reisner ◽  
Jin-Oh Hahn
Keyword(s):  
Control System ◽  
Blood Volume ◽  
Fluid Resuscitation ◽  
Closed Loop ◽  
Closed Loop Control ◽  
Loop Control ◽  
Model Based ◽  
Closed Loop Control System ◽  
Volume Response ◽  
Loop Control System

This paper presents a model-based approach to the closed-loop control of fluid resuscitation against hypovolemia. In this approach, the control system consists of a model-based blood volume estimator and a feedback controller. The model-based blood volume estimator derives relative changes in the blood volume response to the augmented fluid by analyzing an arterial blood pressure waveform and the electrocardiogram. Then, the feedback controller determines the amount of fluid to be augmented by comparing targeted versus estimated relative changes in the blood volume. In this way, unlike many previous methods for fluid resuscitation based on indirect surrogate(s) of blood volume, fluid resuscitation can be directly guided by the blood volume response. This paper reports initial design of the closed-loop control system and its simulation-based evaluation in a wide range of hypovolemic and physiologic scenarios. The results suggest that the proposed closed-loop control system is very effective in resuscitation against hypovolemia: in 97 out of 100 simulated hypovolemia, the final blood volume achieved by the control system was within 10% of its optimal value.

scholarly journals Closed-Loop Fluid Resuscitation Control Via Blood Volume Estimation

2016 ◽  
Vol 138 (11) ◽  
Author(s):  
Ramin Bighamian ◽  
Chang-Sei Kim ◽  
Andrew T. Reisner ◽  
Jin-Oh Hahn
Keyword(s):  
Blood Volume ◽  
Fluid Resuscitation ◽  
Closed Loop ◽  
Volume Estimation ◽  
Closed Loop Control ◽  
Loop Control ◽  
Model Based ◽  
Arterial Blood ◽  
Wide Range ◽  
Electrocardiogram Ecg

This paper presents a closed-loop control of fluid resuscitation to overcome hypovolemia based on model-based estimation of relative changes in blood volume (BV). In this approach, the control system consists of a model-based relative BV (RBV) estimator and a feedback controller. The former predicts relative changes in the BV response to augmented fluid by analyzing an arterial blood pressure (BP) waveform and the electrocardiogram (ECG). Then, the latter determines the amount of fluid to be augmented by comparing target versus predicted relative changes in BV. In this way, unlike many previous methods for fluid resuscitation based on controlled variable(s) nonlinearly correlated with the changes in BV, fluid resuscitation can be guided by a controlled variable linearly correlated with the changes in BV. This paper reports initial design of the closed-loop fluid resuscitation system and its in silico evaluation in a wide range of hypovolemic scenarios. The results suggest that closed-loop fluid resuscitation guided by a controlled variable linearly correlated with the changes in BV can be effective in overcoming hypovolemia: across 100 randomly produced hypovolemia cases, it resulted in the BV regulation error of 7.98 ± 171.6 ml, amounting to 0.18 ± 3.04% of the underlying BV. When guided by pulse pressure (PP), a classical controlled variable nonlinearly correlated with the changes in BV; the same closed-loop fluid resuscitation system resulted in persistent under-resuscitation with the BV regulation error of −779.1 ± 147.4 ml, amounting to −13.9 ± 2.65% of the underlying BV.

scholarly journals Neural Bases of Postural Control

Physiology ◽  
2006 ◽  
Vol 21 (3) ◽  
pp. 216-225 ◽  
Author(s):  
Tatiana G. Deliagina ◽  
Grigori N. Orlovsky ◽  
Pavel V. Zelenin ◽  
Irina N. Beloozerova
Keyword(s):  
Postural Control ◽  
Closed Loop ◽  
Functional Organization ◽  
The Body ◽  
Closed Loop Control ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
The Central Nervous System ◽  
Different Parts

The body posture during standing and walking is maintained due to the activity of a closed-loop control system. In the review, we consider different aspects of postural control: its functional organization, the distribution of postural functions in different parts of the central nervous system, and the activity of neuronal networks controlling posture.

The Development and Application of Portable Infusion Devices

1986 ◽  
Vol 15 (4) ◽  
pp. 191-195 ◽  
Author(s):  
M L Derlien
Keyword(s):  
Closed Loop ◽  
Iron Chelation ◽  
Extended Period ◽  
The Body ◽  
Controlled Delivery ◽  
Loop Control ◽  
Heparin Administration ◽  
Post Operative Pain ◽  
Infusion Devices ◽  
Drug Solution

Portable infusion devices are designed for the controlled delivery of a drug solution into the body over an extended period of time. Two categories of pumps are described. Non-electric pumps, which include balloon-powered, vapour-pressure, and spring-powered pumps; and electric pumps, which include peristaltic, piston-and-valve, and syringe pumps. The drug may be delivered to a variety of sites (e.g., subcutaneous or intramuscular) through various channels. Current clinical applications include iron chelation, analgesics in terminal cancer, post-operative pain, Heparin administration, insulin for diabetes, cancer chemotherapy, and various hormone administrations. Infusion can be continuous or pulsatile depending on the application. It is predicted that there will be more widespread adoption of current techniques and that smaller and more intelligent pumps, which may include closed loop control, will be developed.

scholarly journals Real-time Closed-loop Control in a Rodent Model of Medically Induced Coma Using Burst Suppression

2013 ◽  
Vol 119 (4) ◽  
pp. 848-860 ◽  
Author(s):  
ShiNung Ching ◽  
Max Y. Liberman ◽  
Jessica J. Chemali ◽  
M. Brandon Westover ◽  
Jonathan D. Kenny ◽  
...  
Keyword(s):  
Real Time ◽  
Delivery System ◽  
Closed Loop ◽  
Brain Injuries ◽  
Estimation Procedure ◽  
Burst Suppression ◽  
Real Time Control ◽  
Loop Control ◽  
Time Control ◽  
Proportional Integral Controller

Abstract Background: A medically induced coma is an anesthetic state of profound brain inactivation created to treat status epilepticus and to provide cerebral protection after traumatic brain injuries. The authors hypothesized that a closed-loop anesthetic delivery system could automatically and precisely control the electroencephalogram state of burst suppression and efficiently maintain a medically induced coma. Methods: In six rats, the authors implemented a closed-loop anesthetic delivery system for propofol consisting of: a computer-controlled pump infusion, a two-compartment pharmacokinetics model defining propofol’s electroencephalogram effects, the burst-suppression probability algorithm to compute in real time from the electroencephalogram the brain’s burst-suppression state, an online parameter-estimation procedure and a proportional-integral controller. In the control experiment each rat was randomly assigned to one of the six burst-suppression probability target trajectories constructed by permuting the burst-suppression probability levels of 0.4, 0.65, and 0.9 with linear transitions between levels. Results: In each animal the controller maintained approximately 60 min of tight, real-time control of burst suppression by tracking each burst-suppression probability target level for 15 min and two between-level transitions for 5–10 min. The posterior probability that the closed-loop anesthetic delivery system was reliable across all levels was 0.94 (95% CI, 0.77–1.00; n = 18) and that the system was accurate across all levels was 1.00 (95% CI, 0.84–1.00; n = 18). Conclusion: The findings of this study establish the feasibility of using a closed-loop anesthetic delivery systems to achieve in real time reliable and accurate control of burst suppression in rodents and suggest a paradigm to precisely control medically induced coma in patients.

scholarly journals Credibility Assessment of a Subject-Specific Mathematical Model of Blood Volume Kinetics for Prediction of Physiological Response to Hemorrhagic Shock and Fluid Resuscitation

2021 ◽  
Vol 12 ◽  
Author(s):  
Bahram Parvinian ◽  
Ramin Bighamian ◽  
Christopher George Scully ◽  
Jin-Oh Hahn ◽  
Pras Pathmanathan
Keyword(s):  
Mathematical Model ◽  
Blood Volume ◽  
Fluid Resuscitation ◽  
Predictive Capability ◽  
Calibration And Validation ◽  
Subject Specific ◽  
Volume Response ◽  
Validation Tests ◽  
Volume Kinetics ◽  
The Mathematical Model

Subject-specific mathematical models for prediction of physiological parameters such as blood volume, cardiac output, and blood pressure in response to hemorrhage have been developed. In silico studies using these models may provide an effective tool to generate pre-clinical safety evidence for medical devices and help reduce the size and scope of animal studies that are performed prior to initiation of human trials. To achieve such a goal, the credibility of the mathematical model must be established for the purpose of pre-clinical in silico testing. In this work, the credibility of a subject-specific mathematical model of blood volume kinetics intended to predict blood volume response to hemorrhage and fluid resuscitation during fluid therapy was evaluated. A workflow was used in which: (i) the foundational properties of the mathematical model such as structural identifiability were evaluated; (ii) practical identifiability was evaluated both pre- and post-calibration, with the pre-calibration results used to determine an optimal splitting of experimental data into calibration and validation datasets; (iii) uncertainty in model parameters and the experimental uncertainty were quantified for each subject; and (iv) the uncertainty was propagated through the blood volume kinetics model and its predictive capability was evaluated via validation tests. The mathematical model was found to be structurally identifiable. Pre-calibration identifiability analysis led to splitting the 180 min of time series data per subject into 50 and 130 min calibration and validation windows, respectively. The average root mean squared error of the mathematical model was 12.6% using the calibration window of (0 min, 50 min). Practical identifiability was established post-calibration after fixing one of the parameters to a nominal value. In the validation tests, 82 and 75% of the subject-specific mathematical models were able to correctly predict blood volume response when predictive capability was evaluated at 180 min and at the time when amount of infused fluid equals fluid loss.

CONTROL OF VORTEX SHEDDING BEHIND A CIRCULAR CYLINDER USING ELECTROMAGNETIC FORCES

2005 ◽  
Vol 19 (28n29) ◽  
pp. 1627-1630 ◽  
Author(s):  
ZHIHUA CHEN ◽  
BAOCHUN FAN ◽  
BENMOU ZHOU ◽  
NADINE AUBRY
Keyword(s):  
Circular Cylinder ◽  
Lorentz Force ◽  
Vortex Shedding ◽  
Closed Loop ◽  
Permanent Magnets ◽  
Control Method ◽  
The Body ◽  
Closed Loop Control ◽  
Electromagnetic Forces ◽  
Loop Control

Both open and closed loop control algorithms have been developed for manipulating wake flows past a solid cylinder in an electrically low-conducting fluid. The intent is to avoid vortex shedding and flow separation from the body, which is achieved through the introduction of localized electromagnetic forces (Lorentz forces) in the azimuthal direction generated by an array of permanent magnets and electrodes on the surface of the circular cylinder. The array of actuators offers the advantage of making the Lorentz force time and space dependent. More specifically, one closed loop control method has been derived from the equations of motion capable of determining at all times the intensity of the Lorentz force in order to control the flow. This is accomplished first, independently of the flow (open loop algorithm) and second, based on some partial flow information measured on the surface of the solid body (closed loop algorithm).

scholarly journals Partitioning of body fluids and cardiovascular responses to circulatory hypovolaemia in the turtle, Pseudemys scripta elegans

1985 ◽  
Vol 116 (1) ◽  
pp. 237-250 ◽  
Author(s):  
A. W. Smits ◽  
M. M. Kozubowski
Keyword(s):  
Blood Volume ◽  
Cardiovascular Responses ◽  
Systemic Arterial Pressure ◽  
Body Fluids ◽  
The Body ◽  
Arterial Blood ◽  
Pseudemys Scripta ◽  
Fluid Transfer ◽  
Total Body ◽  
Tracer Dilution

Investigations were conducted (1) to measure the steady state compartmentation of body fluids and (2) to assess the efficacy of blood volume and pressure maintenance during haemorrhage-induced hypovolaemia in the pond turtle, Pseudemys scripta elegans. The pre-haemorrhage blood volume, as determined by tracer dilution of 51Cr-labelled erythrocytes, averaged 6.89 +/− 0.33% of the body mass, and was part of comparatively large extracellular (40.2 +/− 0.70%) and total body fluid volumes (75.25 +/− 1.48%). Turtles exhibited progressive reductions in systemic arterial pressure throughout a cumulative haemorrhage of −48% of their original blood volume, despite dramatic increases in heart rate and comparatively large magnitudes of transcapillary fluid transfer from interstitial to intravascular spaces. Arterial blood pressure returned to pre-haemorrhage values 2h after experimental haemorrhage ceased, concomitant with the restoration of the original blood volume. Our results support arguments made in previous studies that the resistance to fluid movement between vascular and extravascular locations in reptiles is comparatively low. Furthermore, the haemodynamic responses of turtles to experimental hypovolaemia suggest that barostasis through adjustments in vascular tone is less effective than that observed in other reptiles.

A Cyber-Physical System (CPS) Based Hybrid Micro-Grid Model with Wind-Solar Complementary Power

2014 ◽  
Vol 926-930 ◽  
pp. 2325-2328
Author(s):  
Ling Xiao Hu ◽  
Jing Li Mao ◽  
Bi Ling Zhang ◽  
An Shi Zhou
Keyword(s):  
Physical System ◽  
Closed Loop ◽  
Energy Resources ◽  
Distributed Energy Resources ◽  
Cyber Physical System ◽  
Distributed Energy ◽  
Loop Control ◽  
Grid Model ◽  
Proposed Model ◽  
Micro Grid

Micro-grid, which coordinates distributed energy resources in a decentralized way, is a promising approach to allow distributed energy resources to provide full benefits while reducing the control burden on the grid. By exploiting the concept of cyber-physical system (CPS), prediction can be easily incorporated into micro-grid, which helps the micro-grid work more effectively and safely. In such a case, in this paper, based on CPS, we propose a novel micro-grid model, within the framework of which, a more explicit wind-solar complementary power system is presented. Moreover, we show how the closed-loop control is implemented in the proposed model which is of benefit to the design of micro-grid.

The Impact of Visual Feedback Type on the Mastery of Visuo-Motor Transformations

2012 ◽  
Vol 220 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Sandra Sülzenbrück
Keyword(s):  
Empirical Research ◽  
Visual Feedback ◽  
Closed Loop ◽  
Motor Planning ◽  
Visual Input ◽  
Closed Loop Control ◽  
Loop Control ◽  
Feedback Type ◽  
Effective Use ◽  
The Impact

For the effective use of modern tools, the inherent visuo-motor transformation needs to be mastered. The successful adjustment to and learning of these transformations crucially depends on practice conditions, particularly on the type of visual feedback during practice. Here, a review about empirical research exploring the influence of continuous and terminal visual feedback during practice on the mastery of visuo-motor transformations is provided. Two studies investigating the impact of the type of visual feedback on either direction-dependent visuo-motor gains or the complex visuo-motor transformation of a virtual two-sided lever are presented in more detail. The findings of these studies indicate that the continuous availability of visual feedback supports performance when closed-loop control is possible, but impairs performance when visual input is no longer available. Different approaches to explain these performance differences due to the type of visual feedback during practice are considered. For example, these differences could reflect a process of re-optimization of motor planning in a novel environment or represent effects of the specificity of practice. Furthermore, differences in the allocation of attention during movements with terminal and continuous visual feedback could account for the observed differences.

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