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Chalumuri YR, Arabidarrehdor G, Tivay A, Sampson CM, Khan M, Kinsky M, Kramer GC, Hahn JO, Scully CG, Bighamian R. A Lumped-Parameter Model of the Cardiovascular System Response for Evaluating Automated Fluid Resuscitation Systems. IEEE ACCESS : PRACTICAL INNOVATIONS, OPEN SOLUTIONS 2024; 12:62511-62525. [PMID: 38872754 PMCID: PMC11170980 DOI: 10.1109/access.2024.3395008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2024]
Abstract
Physiological closed-loop controlled (PCLC) medical devices, such as those designed for blood pressure regulation, can be tested for safety and efficacy in real-world clinical settings. However, relying solely on limited animal and clinical studies may not capture the diverse range of physiological conditions. Credible mathematical models can complement these studies by allowing the testing of the device against simulated patient scenarios. This research involves the development and validation of a low-order lumped-parameter mathematical model of the cardiovascular system's response to fluid perturbation. The model takes rates of hemorrhage and fluid infusion as inputs and provides hematocrit and blood volume, heart rate, stroke volume, cardiac output and mean arterial blood pressure as outputs. The model was calibrated using data from 27 sheep subjects, and its predictive capability was evaluated through a leave-one-out cross-validation procedure, followed by independent validation using 12 swine subjects. Our findings showed small model calibration error against the training dataset, with the normalized root-mean-square error (NRMSE) less than 10% across all variables. The mathematical model and virtual patient cohort generation tool demonstrated a high level of predictive capability and successfully generated a sufficient number of subjects that closely resembled the test dataset. The average NRMSE for the best virtual subject, across two distinct samples of virtual subjects, was below 12.7% and 11.9% for the leave-one-out cross-validation and independent validation dataset. These findings suggest that the model and virtual cohort generator are suitable for simulating patient populations under fluid perturbation, indicating their potential value in PCLC medical device evaluation.
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Affiliation(s)
- Yekanth Ram Chalumuri
- Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA
| | - Ghazal Arabidarrehdor
- Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA
| | - Ali Tivay
- Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA
| | - Catherine M Sampson
- Department of Anesthesiology, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Muzna Khan
- Department of Anesthesiology, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Michael Kinsky
- Department of Anesthesiology, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - George C Kramer
- Department of Anesthesiology, The University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Jin-Oh Hahn
- Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA
| | - Christopher G Scully
- Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Ramin Bighamian
- Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD 20993, USA
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2
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Vazhnichaya E, Lytvyn S, Kurapov Y, Semaka O, Lutsenko R, Chunikhin A. The influence of pure (ligandless) magnetite nanoparticles functionalization on blood gases and electrolytes in acute blood loss. NANOMEDICINE: NANOTECHNOLOGY, BIOLOGY AND MEDICINE 2023; 50:102675. [PMID: 37028737 DOI: 10.1016/j.nano.2023.102675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 03/14/2023] [Accepted: 03/28/2023] [Indexed: 04/08/2023]
Abstract
Objective was to compare the effect of functionalization of magnetite (Fe3O4) nanoparticles (NPs) with sodium chloride (NaCl), or its combination with ethylmethylhydroxypyrydine succinate (EMHPS) and polyvinylpyrrolidone (PVP) on blood gases and electrolytes in acute blood loss. Ligandless magnetite NPs were synthesized by the electron beam technology and functionalized by mentioned agents. Size of NPs in colloidal solutions Fe3O4@NaCl, Fe3O4@NaCl@EMHPS, Fe3O4@NaCl@PVP, Fe3O4@NaCl@EMHPS@PVP (nanosystems 1-4) was determined by dynamic light scattering. In vivo experiments were performed on 27 Wistar rats. Acute blood loss was modeled by removal 25 % circulating blood. Nanosystems 1-4 were administered to animals intaperitoneally after the blood loss with followed determination of blood gases, pH and electrolytes. In blood loss, nanosystems Fe3O4@NaCl and Fe3O4@NaCl@PVP were able to improve the state of blood gases, pH, and the ratio of sodium/potassium in the blood. So, magnetite NPs with a certain surface modification can promote oxygen transport under hypoxic conditions.
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Affiliation(s)
- Elena Vazhnichaya
- Department of Pharmacology, Clinical Pharmacology and Pharmacy, Poltava State Medical University, 23 Shevchenko Street, 36011 Poltava, Ukraine
| | - Stanislav Lytvyn
- Laboratory of Electron Beam Nanotechnology of Inorganic Materials for Medicine, E. O. Paton Electric Welding Institute of the National Academy of Sciences of Ukraine, 11 Kazymyr Malevych Street, 03150 Kyiv, Ukraine.
| | - Yurii Kurapov
- Laboratory of Electron Beam Nanotechnology of Inorganic Materials for Medicine, E. O. Paton Electric Welding Institute of the National Academy of Sciences of Ukraine, 11 Kazymyr Malevych Street, 03150 Kyiv, Ukraine
| | - Oleksandr Semaka
- Department of Pharmacology, Clinical Pharmacology and Pharmacy, Poltava State Medical University, 23 Shevchenko Street, 36011 Poltava, Ukraine
| | - Ruslan Lutsenko
- Department of Pharmacology, Clinical Pharmacology and Pharmacy, Poltava State Medical University, 23 Shevchenko Street, 36011 Poltava, Ukraine
| | - Alexander Chunikhin
- Department of Smooth Muscle, O.V. Palladin Institute of Biochemistry of the National Academy of Sciences of Ukraine, 9 Leontovich Street, 01054 Kyiv, Ukraine
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Polz M, Bergmoser K, Horn M, Schörghuber M, Lozanović J, Rienmüller T, Baumgartner C. A system theory based digital model for predicting the cumulative fluid balance course in intensive care patients. Front Physiol 2023; 14:1101966. [PMID: 37123264 PMCID: PMC10133509 DOI: 10.3389/fphys.2023.1101966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 04/04/2023] [Indexed: 05/02/2023] Open
Abstract
Background: Surgical interventions can cause severe fluid imbalances in patients undergoing cardiac surgery, affecting length of hospital stay and survival. Therefore, appropriate management of daily fluid goals is a key element of postoperative intensive care in these patients. Because fluid balance is influenced by a complex interplay of patient-, surgery- and intensive care unit (ICU)-specific factors, fluid prediction is difficult and often inaccurate. Methods: A novel system theory based digital model for cumulative fluid balance (CFB) prediction is presented using recorded patient fluid data as the sole parameter source by applying the concept of a transfer function. Using a retrospective dataset of n = 618 cardiac intensive care patients, patient-individual models were created and evaluated. RMSE analyses and error calculations were performed for reasonable combinations of model estimation periods and clinically relevant prediction horizons for CFB. Results: Our models have shown that a clinically relevant time horizon for CFB prediction with the combination of 48 h estimation time and 8-16 h prediction time achieves high accuracy. With an 8-h prediction time, nearly 50% of CFB predictions are within ±0.5 L, and 77% are still within the clinically acceptable range of ±1.0 L. Conclusion: Our study has provided a promising proof of principle and may form the basis for further efforts in the development of computational models for fluid prediction that do not require large datasets for training and validation, as is the case with machine learning or AI-based models. The adaptive transfer function approach allows estimation of CFB course on a dynamically changing patient fluid balance system by simulating the response to the current fluid management regime, providing a useful digital tool for clinicians in daily intensive care.
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Affiliation(s)
- Mathias Polz
- Institute of Health Care Engineering with European Testing Center of Medical Devices, Graz University of Technology, Graz, STM, Austria
| | - Katharina Bergmoser
- Institute of Health Care Engineering with European Testing Center of Medical Devices, Graz University of Technology, Graz, STM, Austria
- CBmed Center for Biomarker Research in Medicine, Graz, STM, Austria
| | - Martin Horn
- Institute of Automation and Control, Graz University of Technology, Graz, STM, Austria
| | - Michael Schörghuber
- Department of Anesthesiology and Intensive Care Medicine, Medical University of Graz, Graz, STM, Austria
| | - Jasmina Lozanović
- Institute of Health Care Engineering with European Testing Center of Medical Devices, Graz University of Technology, Graz, STM, Austria
| | - Theresa Rienmüller
- Institute of Health Care Engineering with European Testing Center of Medical Devices, Graz University of Technology, Graz, STM, Austria
| | - Christian Baumgartner
- Institute of Health Care Engineering with European Testing Center of Medical Devices, Graz University of Technology, Graz, STM, Austria
- *Correspondence: Christian Baumgartner,
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Kanal V, Pathmanathan P, Hahn JO, Kramer G, Scully C, Bighamian R. Development and validation of a mathematical model of heart rate response to fluid perturbation. Sci Rep 2022; 12:21463. [PMID: 36509856 PMCID: PMC9744837 DOI: 10.1038/s41598-022-25891-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 12/06/2022] [Indexed: 12/15/2022] Open
Abstract
Physiological closed-loop controlled (PCLC) medical devices monitor and automatically adjust the patient's condition by using physiological variables as feedback, ideally with minimal human intervention to achieve the target levels set by a clinician. PCLC devices present a challenge when it comes to evaluating their performance, where conducting large clinical trials can be expensive. Virtual physiological patients simulated by validated mathematical models can be utilized to obtain pre-clinical evidence of safety and assess the performance of the PCLC medical device during normal and worst-case conditions that are unlikely to happen in a limited clinical trial. A physiological variable that plays a major role during fluid resuscitation is heart rate (HR). For in silico assessment of PCLC medical devices regarding fluid perturbation, there is currently no mathematical model of HR validated in terms of its predictive capability performance. This paper develops and validates a mathematical model of HR response using data collected from sheep subjects undergoing hemorrhage and fluid infusion. The model proved to be accurate in estimating the HR response to fluid perturbation, where averaged between 21 calibration datasets, the fitting performance showed a normalized root mean square error (NRMSE) of [Formula: see text]. The model was also evaluated in terms of model predictive capability performance via a leave-one-out procedure (21 subjects) and an independent validation dataset (6 subjects). Two different virtual cohort generation tools were used in each validation analysis. The generated envelope of virtual subjects robustly met the defined acceptance criteria, in which [Formula: see text] of the testing datasets presented simulated HR patterns that were within a deviation of 50% from the observed data. In addition, out of 16000 and 18522 simulated subjects for the leave-one-out and independent datasets, the model was able to generate at least one virtual subject that was close to the real subject within an error margin of [Formula: see text] and [Formula: see text] NRMSE, respectively. In conclusion, the model can generate valid virtual HR physiological responses to fluid perturbation and be incorporated into future non-clinical simulated testing setups for assessing PCLC devices intended for fluid resuscitation.
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Affiliation(s)
- Varun Kanal
- grid.417587.80000 0001 2243 3366Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD USA
| | - Pras Pathmanathan
- grid.417587.80000 0001 2243 3366Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD USA
| | - Jin-Oh Hahn
- grid.164295.d0000 0001 0941 7177Department of Mechanical Engineering, University of Maryland, College Park, MD USA
| | - George Kramer
- grid.176731.50000 0001 1547 9964Department of Anesthesiology, The University of Texas Medical Branch, Galveston, TX USA
| | - Christopher Scully
- grid.417587.80000 0001 2243 3366Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD USA
| | - Ramin Bighamian
- grid.417587.80000 0001 2243 3366Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD USA
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5
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Snider EJ, Berard D, Vega SJ, Hernandez Torres SI, Avital G, Boice EN. An Automated Hardware-in-Loop Testbed for Evaluating Hemorrhagic Shock Resuscitation Controllers. Bioengineering (Basel) 2022; 9:bioengineering9080373. [PMID: 36004898 PMCID: PMC9405047 DOI: 10.3390/bioengineering9080373] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/03/2022] [Accepted: 08/03/2022] [Indexed: 12/04/2022] Open
Abstract
Hemorrhage remains a leading cause of death, with early goal-directed fluid resuscitation being a pillar of mortality prevention. While closed-loop resuscitation can potentially benefit this effort, development of these systems is resource-intensive, making it a challenge to compare infusion controllers and respective hardware within a range of physiologically relevant hemorrhage scenarios. Here, we present a hardware-in-loop automated testbed for resuscitation controllers (HATRC) that provides a simple yet robust methodology to evaluate controllers. HATRC is a flow-loop benchtop system comprised of multiple PhysioVessels which mimic pressure-volume responsiveness for different resuscitation infusates. Subject variability and infusate switching were integrated for more complex testing. Further, HATRC can modulate fluidic resistance to mimic arterial resistance changes after vasopressor administration. Finally, all outflow rates are computer-controlled, with rules to dictate hemorrhage, clotting, and urine rates. Using HATRC, we evaluated a decision-table controller at two sampling rates with different hemorrhage scenarios. HATRC allows quantification of twelve performance metrics for each controller configuration and scenario, producing heterogeneous results and highlighting the need for controller evaluation with multiple hemorrhage scenarios. In conclusion, HATRC can be used to evaluate closed-loop controllers through user-defined hemorrhage scenarios while rating their performance. Extensive controller troubleshooting using HATRC can accelerate product development and subsequent translation.
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Affiliation(s)
- Eric. J. Snider
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
- Correspondence: ; Tel.: +1-210-539-8721
| | - David Berard
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
| | - Saul J. Vega
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
| | | | - Guy Avital
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
- Trauma and Combat Medicine Branch, Surgeon General’s Headquarters, Israel Defense Forces, Ramat-Gan 52620, Israel
- Division of Anesthesia, Intensive Care and Pain Management, Tel-Aviv Sourasky Medical Center, Tel-Aviv 64239, Israel
| | - Emily N. Boice
- U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA
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6
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Closed-Loop Controlled Fluid Administration Systems: A Comprehensive Scoping Review. J Pers Med 2022; 12:jpm12071168. [PMID: 35887665 PMCID: PMC9315597 DOI: 10.3390/jpm12071168] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/14/2022] [Accepted: 07/15/2022] [Indexed: 02/07/2023] Open
Abstract
Physiological Closed-Loop Controlled systems continue to take a growing part in clinical practice, offering possibilities of providing more accurate, goal-directed care while reducing clinicians’ cognitive and task load. These systems also provide a standardized approach for the clinical management of the patient, leading to a reduction in care variability across multiple dimensions. For fluid management and administration, the advantages of closed-loop technology are clear, especially in conditions that require precise care to improve outcomes, such as peri-operative care, trauma, and acute burn care. Controller design varies from simplistic to complex designs, based on detailed physiological models and adaptive properties that account for inter-patient and intra-patient variability; their maturity level ranges from theoretical models tested in silico to commercially available, FDA-approved products. This comprehensive scoping review was conducted in order to assess the current technological landscape of this field, describe the systems currently available or under development, and suggest further advancements that may unfold in the coming years. Ten distinct systems were identified and discussed.
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7
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Snider EJ, Vega SJ, Ross E, Berard D, Hernandez-Torres SI, Salinas J, Boice EN. Supervisory Algorithm for Autonomous Hemodynamic Management Systems. SENSORS (BASEL, SWITZERLAND) 2022; 22:529. [PMID: 35062489 PMCID: PMC8780453 DOI: 10.3390/s22020529] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/07/2022] [Accepted: 01/09/2022] [Indexed: 02/04/2023]
Abstract
Future military conflicts will require new solutions to manage combat casualties. The use of automated medical systems can potentially address this need by streamlining and augmenting the delivery of medical care in both emergency and combat trauma environments. However, in many situations, these systems may need to operate in conjunction with other autonomous and semi-autonomous devices. Management of complex patients may require multiple automated systems operating simultaneously and potentially competing with each other. Supervisory controllers capable of harmonizing multiple closed-loop systems are thus essential before multiple automated medical systems can be deployed in managing complex medical situations. The objective for this study was to develop a Supervisory Algorithm for Casualty Management (SACM) that manages decisions and interplay between two automated systems designed for management of hemorrhage control and resuscitation: an automatic extremity tourniquet system and an adaptive resuscitation controller. SACM monitors the required physiological inputs for both systems and synchronizes each respective system as needed. We present a series of trauma experiments carried out in a physiologically relevant benchtop circulatory system in which SACM must recognize extremity or internal hemorrhage, activate the corresponding algorithm to apply a tourniquet, and then resuscitate back to the target pressure setpoint. SACM continues monitoring after the initial stabilization so that additional medical changes can be quickly identified and addressed, essential to extending automation algorithms past initial trauma resuscitation into extended monitoring. Overall, SACM is an important step in transitioning automated medical systems into emergency and combat trauma situations. Future work will address further interplay between these systems and integrate additional medical systems.
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Affiliation(s)
- Eric J. Snider
- Engineering, Technology, and Automation Group, U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA; (E.J.S.); (S.J.V.); (D.B.); (S.I.H.-T.); (J.S.)
| | - Saul J. Vega
- Engineering, Technology, and Automation Group, U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA; (E.J.S.); (S.J.V.); (D.B.); (S.I.H.-T.); (J.S.)
| | - Evan Ross
- Blood and Shock Resuscitation Group, United States Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA;
| | - David Berard
- Engineering, Technology, and Automation Group, U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA; (E.J.S.); (S.J.V.); (D.B.); (S.I.H.-T.); (J.S.)
| | - Sofia I. Hernandez-Torres
- Engineering, Technology, and Automation Group, U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA; (E.J.S.); (S.J.V.); (D.B.); (S.I.H.-T.); (J.S.)
| | - Jose Salinas
- Engineering, Technology, and Automation Group, U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA; (E.J.S.); (S.J.V.); (D.B.); (S.I.H.-T.); (J.S.)
| | - Emily N. Boice
- Engineering, Technology, and Automation Group, U.S. Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, TX 78234, USA; (E.J.S.); (S.J.V.); (D.B.); (S.I.H.-T.); (J.S.)
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8
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Muir WW, Hughes D, Silverstein DC. Editorial: Fluid Therapy in Animals: Physiologic Principles and Contemporary Fluid Resuscitation Considerations. Front Vet Sci 2021; 8:744080. [PMID: 34746284 PMCID: PMC8563835 DOI: 10.3389/fvets.2021.744080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 09/21/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- William W Muir
- College of Veterinary Medicine, Lincoln Memorial University, Harrogate, TN, United States
| | - Dez Hughes
- Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Melbourne, VIC, Australia
| | - Deborah C Silverstein
- Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States
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9
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Tivay A, Kramer GC, Hahn JO. Collective Variational Inference for Personalized and Generative Physiological Modeling: A Case Study on Hemorrhage Resuscitation. IEEE Trans Biomed Eng 2021; 69:666-677. [PMID: 34375275 DOI: 10.1109/tbme.2021.3103141] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Individual physiological experiments typically provide useful but incomplete information about a studied physiological process. As a result, inferring the unknown parameters of a physiological model from experimental data is often challenging. The objective of this paper is to propose and illustrate the efficacy of a collective variational inference (C-VI) method, intended to reconcile low-information and heterogeneous data from a collection of experiments to produce robust personalized and generative physiological models. METHODS To derive the C-VI method, we utilize a probabilistic graphical model to impose structure on the available physiological data, and algorithmically characterize the graphical model using variational Bayesian inference techniques. To illustrate the efficacy of the C-VI method, we apply it to a case study on the mathematical modeling of hemorrhage resuscitation. RESULTS In the context of hemorrhage resuscitation modeling, the C-VI method could reconcile heterogeneous combinations of hematocrit, cardiac output, and blood pressure data across multiple experiments to obtain (i) robust personalized models along with associated measures of uncertainty and signal quality, and (ii) a generative model capable of reproducing the physiological behavior of the population. CONCLUSION The C-VI method facilitates the personalized and generative modeling of physiological processes in the presence of low-information and heterogeneous data. SIGNIFICANCE The resulting models provide a solid basis for the development and testing of interpretable physiological monitoring, decision-support, and closed-loop control algorithms.
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10
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Bighamian R, Hahn JO, Kramer G, Scully C. Accuracy assessment methods for physiological model selection toward evaluation of closed-loop controlled medical devices. PLoS One 2021; 16:e0251001. [PMID: 33930095 PMCID: PMC8087034 DOI: 10.1371/journal.pone.0251001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 04/18/2021] [Indexed: 12/03/2022] Open
Abstract
Physiological closed-loop controlled (PCLC) medical devices are complex systems integrating one or more medical devices with a patient’s physiology through closed-loop control algorithms; introducing many failure modes and parameters that impact performance. These control algorithms should be tested through safety and efficacy trials to compare their performance to the standard of care and determine whether there is sufficient evidence of safety for their use in real care setting. With this aim, credible mathematical models have been constructed and used throughout the development and evaluation phases of a PCLC medical device to support the engineering design and improve safety aspects. Uncertainties about the fidelity of these models and ambiguities about the choice of measures for modeling performance need to be addressed before a reliable PCLC evaluation can be achieved. This research develops tools for evaluating the accuracy of physiological models and establishes fundamental measures for predictive capability assessment across different physiological models. As a case study, we built a refined physiological model of blood volume (BV) response by expanding an original model we developed in our prior work. Using experimental data collected from 16 sheep undergoing hemorrhage and fluid resuscitation, first, we compared the calibration performance of the two candidate physiological models, i.e., original and refined, using root-mean-squared error (RMSE), Akiake information criterion (AIC), and a new multi-dimensional approach utilizing normalized features extracted from the fitting error. Compared to the original model, the refined model demonstrated a significant improvement in calibration performance in terms of RMSE (9%, P = 0.03) and multi-dimensional measure (48%, P = 0.02), while a comparable AIC between the two models verified that the enhanced calibration performance in the refined model is not due to data over-fitting. Second, we compared the physiological predictive capability of the two models under three different scenarios: prediction of subject-specific steady-state BV response, subject-specific transient BV response to hemorrhage perturbation, and leave-one-out inter-subject BV response. Results indicated enhanced accuracy and predictive capability for the refined physiological model with significantly larger proportion of measurements that were within the prediction envelope in the transient and leave-one-out prediction scenarios (P < 0.02). All together, this study helps to identify and merge new methods for credibility assessment and physiological model selection, leading to a more efficient process for PCLC medical device evaluation.
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Affiliation(s)
- Ramin Bighamian
- Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD, United States of America
- * E-mail:
| | - Jin-Oh Hahn
- Department of Mechanical Engineering, University of Maryland, College Park, MD, United States of America
| | - George Kramer
- Department of Anesthesiology, The University of Texas Medical Branch, Galveston, TX, United States of America
| | - Christopher Scully
- Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD, United States of America
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11
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Tivay A, Jin X, Lo AKY, Scully CG, Hahn JO. Practical Use of Regularization in Individualizing a Mathematical Model of Cardiovascular Hemodynamics Using Scarce Data. Front Physiol 2020; 11:452. [PMID: 32528303 PMCID: PMC7264422 DOI: 10.3389/fphys.2020.00452] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 04/09/2020] [Indexed: 12/16/2022] Open
Abstract
Individualizing physiological models to a patient can enable patient-specific monitoring and treatment in critical care environments. However, this task often presents a unique "practical identifiability" challenge due to the conflict between model complexity and data scarcity. Regularization provides an established framework to cope with this conflict by compensating for data scarcity with prior knowledge. However, regularization has not been widely pursued in individualizing physiological models to facilitate patient-specific critical care. Thus, the goal of this work is to garner potentially generalizable insight into the practical use of regularization in individualizing a complex physiological model using scarce data by investigating its effect in a clinically significant critical care case study of blood volume kinetics and cardiovascular hemodynamics in hemorrhage and circulatory resuscitation. We construct a population-average model as prior knowledge and individualize the physiological model via regularization to illustrate that regularization can be effective in individualizing a physiological model to learn salient individual-specific characteristics (resulting in the goodness of fit to individual-specific data) while restricting unnecessary deviations from the population-average model (achieving practical identifiability). We also illustrate that regularization yields parsimonious individualization of only sensitive parameters as well as adequate physiological plausibility and relevance in predicting internal physiological states.
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Affiliation(s)
- Ali Tivay
- Department of Mechanical Engineering, University of Maryland, College Park, College Park, MD, United States
| | - Xin Jin
- Department of Mechanical Engineering, University of Maryland, College Park, College Park, MD, United States
| | - Alex Kai-Yuan Lo
- Department of Mechanical Engineering, University of Maryland, College Park, College Park, MD, United States
| | - Christopher G Scully
- Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD, United States
| | - Jin-Oh Hahn
- Department of Mechanical Engineering, University of Maryland, College Park, College Park, MD, United States
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12
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Zaouter C, Joosten A, Rinehart J, Struys MMRF, Hemmerling TM. Autonomous Systems in Anesthesia. Anesth Analg 2020; 130:1120-1132. [DOI: 10.1213/ane.0000000000004646] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Population Kinetics of 0.9% Saline Distribution in Hemorrhaged Awake and Isoflurane-anesthetized Volunteers. Anesthesiology 2020; 131:501-511. [PMID: 31246604 DOI: 10.1097/aln.0000000000002816] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Population-based, pharmacokinetic modeling can be used to describe variability in fluid distribution and dilution between individuals and across populations. The authors hypothesized that dilution produced by crystalloid infusion after hemorrhage would be larger in anesthetized than in awake subjects and that population kinetic modeling would identify differences in covariates. METHODS Twelve healthy volunteers, seven females and five males, mean age 28 ± 4.3 yr, underwent a randomized crossover study. Each subject participated in two separate sessions, separated by four weeks, in which they were assigned to an awake or an anesthetized arm. After a baseline period, hemorrhage (7 ml/kg during 20 min) was induced, immediately followed by a 25 ml/kg infusion during 20 min of 0.9% saline. Hemoglobin concentrations, sampled every 5 min for 60 min then every 10 min for an additional 120 min, were used for population kinetic modeling. Covariates, including body weight, sex, and study arm (awake or anesthetized), were tested in the model building. The change in dilution was studied by analyzing area under the curve and maximum plasma dilution. RESULTS Anesthetized subjects had larger plasma dilution than awake subjects. The analysis showed that females increased area under the curve and maximum plasma dilution by 17% (with 95% CI, 1.08 to 1.38 and 1.07 to 1.39) compared with men, and study arm (anesthetized increased area under the curve by 99% [0.88 to 2.45] and maximum plasma dilution by 35% [0.71 to 1.63]) impacted the plasma dilution whereas a 10-kg increase of body weight resulted in a small change (less than1% [0.93 to 1.20]) in area under the curve and maximum plasma dilution. Mean arterial pressure was lower in subjects while anesthetized (P < 0.001). CONCLUSIONS In awake and anesthetized subjects subjected to controlled hemorrhage, plasma dilution increased with anesthesia, female sex, and lower body weight. Neither study arm nor body weight impact on area under the curve or maximum plasma dilution were statistically significant and therefore no effect can be established.
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Closed-loop hemodynamic management. Best Pract Res Clin Anaesthesiol 2019; 33:199-209. [PMID: 31582099 DOI: 10.1016/j.bpa.2019.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 04/23/2019] [Indexed: 12/11/2022]
Abstract
As the operating room and intensive care settings become increasingly complex, the required vigilance practitioners must dedicate to a wide array of clinical systems has increased concordantly. The resulting shortage of available attention to these various clinical tasks creates a vacuum for the introduction of systems that can administer well-established goal-directed therapies without significant provider feedback. Recently, there has been an explosion of academic exploration into creating such automated systems, with a strong specific focus on hemodynamic control. Within this field, the largest focus has been on goal-directed fluid therapy as systems automating vasopressor administration have only recently become viable options. Our goal in this review article is to summarize the validity of the relevant goal-directed hemodynamic systems and explore the expanding role of automation within these systems.
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Libert N, Chenegros G, Harrois A, Baudry N, Cordurie G, Benosman R, Vicaut E, Duranteau J. Performance of closed-loop resuscitation of haemorrhagic shock with fluid alone or in combination with norepinephrine: an experimental study. Ann Intensive Care 2018; 8:89. [PMID: 30225814 PMCID: PMC6141407 DOI: 10.1186/s13613-018-0436-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 09/04/2018] [Indexed: 11/28/2022] Open
Abstract
Background Closed-loop resuscitation can improve personalization of care, decrease workload and bring expert knowledge in isolated areas. We have developed a new device to control the administration of fluid or simultaneous co-administration of fluid and norepinephrine using arterial pressure. Method We evaluated the performance of our prototype in a rodent model of haemorrhagic shock. After haemorrhagic shock, rats were randomized to five experimental groups: three were resuscitated with fluid and two with co-administration of fluid and norepinephrine. Among groups resuscitated with fluid, one was resuscitated by a physician and two were resuscitated according to two different closed-loop algorithms. Among groups resuscitated with fluid and norepinephrine, one was resuscitated by a physician and the other one by the closed-loop device. The precision of arterial pressure during the resuscitation period was assessed using rising time, time passed in the target area and performance error calculations. Results Groups resuscitated with fluid had similar performances and passed as much time in the target area of 80–90 mmHg as the manual group [manual: 76.8% (67.9–78.2), closed-loop: 64.6% (45.7–72.9) and 80.9% (59.1–85.3)]. Rats resuscitated with fluid and norepinephrine using closed-loop passed similar time in target area than manual group [closed-loop: 74.4% (58.4–84.5) vs. manual: 60.1% (46.1–72.4)] but had shorter rising time to reach target area [160 s (106–187) vs. 434 s (254–1081)] than those resuscitated by a physician. Rats resuscitated with co-administration of fluid and norepinephrine required less fluid and had less hemodilution than rats resuscitated with fluid alone. Lactate decrease was similar between groups resuscitated with fluid alone and fluid with norepinephrine.
Conclusions This study assessed extensively the performances of several algorithms for closed-loop resuscitation of haemorrhagic shock with fluid alone and with co-administration of fluid and norepinephrine. The performance of the closed-loop algorithms tested was similar to physician-guided treatment with considerable saving of work for the caregiver. Arterial pressure closed-loop guided algorithms can be extended to combined administration of fluid and norepinephrine.
Electronic supplementary material The online version of this article (10.1186/s13613-018-0436-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nicolas Libert
- Laboratoire d'Etude de la Microcirculation, UMR 942, Université Paris 7, Hôpitaux Saint Louis Lariboisière, Assistance Publique-Hôpitaux de Paris, Paris, France.,Service d'Anesthésie-Réanimation, Hôpital d'instruction des armées Percy, Clamart, France
| | - Guillaume Chenegros
- Institut de la Vision, UMR-S 968, Sorbonne Université, Université Pierre et Marie Curie UPMC, Paris, France
| | - Anatole Harrois
- Laboratoire d'Etude de la Microcirculation, UMR 942, Université Paris 7, Hôpitaux Saint Louis Lariboisière, Assistance Publique-Hôpitaux de Paris, Paris, France.,Service d'Anesthésie-Réanimation Chirurgicale, UMR 942, Hôpital de Bicêtre, Université Paris-Sud, Hôpitaux Universitaires Paris-Sud, Assistance Publique-Hôpitaux de Paris, Le Kremlin Bicêtre, France
| | - Nathalie Baudry
- Laboratoire d'Etude de la Microcirculation, UMR 942, Université Paris 7, Hôpitaux Saint Louis Lariboisière, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Gilles Cordurie
- Institut de la Vision, UMR-S 968, Sorbonne Université, Université Pierre et Marie Curie UPMC, Paris, France
| | - Ryad Benosman
- Institut de la Vision, UMR-S 968, Sorbonne Université, Université Pierre et Marie Curie UPMC, Paris, France
| | - Eric Vicaut
- Laboratoire d'Etude de la Microcirculation, UMR 942, Université Paris 7, Hôpitaux Saint Louis Lariboisière, Assistance Publique-Hôpitaux de Paris, Paris, France.,Unité de recherche clinique, UMR 942, Université Paris 7, Hôpitaux Saint Louis Lariboisière, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Jacques Duranteau
- Laboratoire d'Etude de la Microcirculation, UMR 942, Université Paris 7, Hôpitaux Saint Louis Lariboisière, Assistance Publique-Hôpitaux de Paris, Paris, France. .,Service d'Anesthésie-Réanimation Chirurgicale, UMR 942, Hôpital de Bicêtre, Université Paris-Sud, Hôpitaux Universitaires Paris-Sud, Assistance Publique-Hôpitaux de Paris, Le Kremlin Bicêtre, France.
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Autonomous Resuscitation on the Horizon? Crit Care Med 2017; 45:1798-1799. [PMID: 28915183 DOI: 10.1097/ccm.0000000000002609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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