1
|
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.
Collapse
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,
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
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.
Collapse
|
4
|
Parvinian B, Scully C, Wiyor H, Kumar A, Weininger S. Regulatory Considerations for Physiological Closed-Loop Controlled Medical Devices Used for Automated Critical Care: Food and Drug Administration Workshop Discussion Topics. Anesth Analg 2019; 126:1916-1925. [PMID: 28763355 DOI: 10.1213/ane.0000000000002329] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Part of the mission of the Center for Devices and Radiological Health (CDRH) at the US Food and Drug Administration is to facilitate medical device innovation. Therefore, CDRH plays an important role in helping its stakeholders such as manufacturers, health care professionals, patients, patient advocates, academia, and other government agencies navigate the regulatory landscape for medical devices. This is particularly important for innovative physiological closed-loop controlled (PCLC) devices used in critical care environments, such as intensive care units, emergency settings, and battlefield environments. CDRH's current working definition of a PCLC medical device is a medical device that incorporates physiological sensor(s) for automatic manipulation of a physiological variable through actuation of therapy that is conventionally made by a clinician. These emerging devices enable automatic therapy delivery and may have the potential to revolutionize the standard of care by ensuring adequate and timely therapy delivery with improved performance in high workload and high-stress environments. For emergency response and military applications, automatic PCLC devices may play an important role in reducing cognitive overload, minimizing human error, and enhancing medical care during surge scenarios (ie, events that exceed the capability of the normal medical infrastructure). CDRH held an open public workshop on October 13 and 14, 2015 with the aim of fostering an open discussion on design, implementation, and evaluation considerations associated with PCLC devices used in critical care environments. CDRH is currently developing regulatory recommendations and guidelines that will facilitate innovation for PCLC devices. This article highlights the contents of the white paper that was central to the workshop and focuses on the ensuing discussions regarding the engineering, clinical, and human factors considerations.
Collapse
Affiliation(s)
- Bahram Parvinian
- From the Office of Device Evaluation.,Office of Science and Engineering Laboratories
| | | | | | - Allison Kumar
- Office of the Center Director, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, Maryland
| | | |
Collapse
|
5
|
Scholten K, Meng E. A review of implantable biosensors for closed-loop glucose control and other drug delivery applications. Int J Pharm 2018; 544:319-334. [DOI: 10.1016/j.ijpharm.2018.02.022] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 01/30/2018] [Accepted: 02/15/2018] [Indexed: 12/19/2022]
|
6
|
Klingert W, Peter J, Thiel C, Thiel K, Rosenstiel W, Klingert K, Grasshoff C, Königsrainer A, Schenk M. Fully automated life support: an implementation and feasibility pilot study in healthy pigs. Intensive Care Med Exp 2018; 6:2. [PMID: 29340799 PMCID: PMC5770352 DOI: 10.1186/s40635-018-0168-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 01/09/2018] [Indexed: 01/31/2023] Open
Abstract
Background Automated systems are available in various application areas all over the world for the purpose of reducing workload and increasing safety. However, such support systems that would aid caregivers are still lacking in the medical sector. With respect to workload and safety, especially, the intensive care unit appears to be an important and challenging application field. Whereas many closed-loop subsystems for single applications already exist, no comprehensive system covering multiple therapeutic aspects and interactions is available yet. This paper describes a fully closed-loop intensive care therapy and presents a feasibility analysis performed in three healthy pigs over a period of 72 h each to demonstrate the technical and practical implementation of automated intensive care therapy. Methods The study was performed in three healthy, female German Landrace pigs under general anesthesia with endotracheal intubation. An arterial and a central venous line were implemented, and a suprapubic urinary catheter was inserted. Electrolytes, glucose levels, acid-base balance, and respiratory management were completely controlled by an automated fuzzy logic system based on individual targets. Fluid management by adaption of the respective infusion rates for the individual parameters was included. Results During the study, no manual modification of the device settings was allowed or required. Homoeostasis in all animals was kept stable during the entire observation period. All remote-controlled parameters were maintained within physiological ranges for most of the time (free arterial calcium 73%, glucose 98%, arterial base excess 89%, and etCO2 98%). Subsystem interaction was analyzed. Conclusions In the presented study, we demonstrate the feasibility of a fully closed-loop system, for which we collected high-resolution data on the interaction and response of the different subsystems. Further studies should use big data approaches to analyze and investigate the interactions between the subsystems in more detail.
Collapse
Affiliation(s)
- Wilfried Klingert
- Department of General, Visceral and Transplant Surgery, Tübingen University Hospital, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany.
| | - Jörg Peter
- Department of Computer Engineering, Tübingen University, Sand 13, 72076, Tübingen, Germany
| | - Christian Thiel
- Department of General, Visceral and Transplant Surgery, Tübingen University Hospital, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany
| | - Karolin Thiel
- Department of General, Visceral and Transplant Surgery, Tübingen University Hospital, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany
| | - Wolfgang Rosenstiel
- Department of Computer Engineering, Tübingen University, Sand 13, 72076, Tübingen, Germany
| | - Kathrin Klingert
- Department of Anesthesiology, Tübingen University Hospital, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany
| | - Christian Grasshoff
- Department of Anesthesiology, Tübingen University Hospital, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany
| | - Alfred Königsrainer
- Department of General, Visceral and Transplant Surgery, Tübingen University Hospital, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany
| | - Martin Schenk
- Department of General, Visceral and Transplant Surgery, Tübingen University Hospital, Hoppe-Seyler-Str. 3, 72076, Tübingen, Germany
| |
Collapse
|
7
|
Ramos-Luengo A, Asensio-Merino F. Hypnosis closed loop TCI systems in outpatient surgery. ACTA ACUST UNITED AC 2017; 64:323-327. [PMID: 28057334 DOI: 10.1016/j.redar.2016.10.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Revised: 10/25/2016] [Accepted: 10/26/2016] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Determine the influence of general anaesthesia with closed-loop systems in the results of outpatient varicose vein surgery. PATIENTS AND METHODS Retrospective observational study including data from 270 outpatients between 2014 and 2015. The patients were divided into 2 groups according to the type of general anaesthesia used. The CL Group included patients who received propofol in closed-loop guided by BIS and remifentanil using TCI, and the C Group received non-closed-loop anaesthesia. Age, sex, surgical time, discharge time and failure of outpatient surgery were recorded. Quantitative data were checked for normal distribution by the method of Kolmogorov-Smirnov-Lilliefors. Differences between groups were analysed by a Student-t-test or Mann-Whitney-Wilcoxon test, depending on their distribution. Categorical data were analysed by a Chi-squared test. We used Kaplan-Meier estimator and the effect size (calculated by Cohen's d) to study the discharge time. Statistical analysis was performed using R 3.2.3 binary for Mac OS X 10.9. RESULTS There were no significant differences in age, sex and surgical time and failure of outpatient surgery. Discharge time was different in both groups: 200 (100) vs. 180 (82.5) minutes, C Group and CL Group, respectively (data are median and interquartile rank); P=.005. CONCLUSION The use of closed-loop devices for the hypnotic component of anaesthesia hastens discharge time. However, for this effect to be clinically significant, some improvements still need to be made in our outpatient surgery units.
Collapse
Affiliation(s)
- A Ramos-Luengo
- Servicio de Anestesia y Reanimación, Hospital Universitario Severo Ochoa, Leganés, Madrid, España.
| | - F Asensio-Merino
- Servicio de Anestesia y Reanimación, Hospital Universitario Severo Ochoa, Leganés, Madrid, España
| |
Collapse
|