scholarly journals In-Silico Evaluation of Anthropomorphic Measurement Variations on Electrical Cardiometry in Neonates

Children ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 936
Author(s):  
David B. Healy ◽  
Eugene M. Dempsey ◽  
John M. O’Toole ◽  
Christoph E. Schwarz
Keyword(s):  
Cardiac Output ◽  
Stroke Volume ◽  
In Silico ◽  
Continuous Monitoring ◽  
Assessment Tools ◽  
Physical Measurement ◽  
Electrical Cardiometry ◽  
Non Invasive ◽  
Weight Measurement ◽  
Proportional Change

Non-invasive cardiac output methods such as Electrical Cardiometry (EC) are relatively novel assessment tools for neonates and they enable continuous monitoring of stroke volume (SV). An in-silico comparison of differences in EC-derived SV in relation to preset length and weight was performed. EC (ICON, Osypka Medical) was simulated using the “demo” mode for various combinations of length and weight representative of term and preterm infants. One-centimetre length error resulted in a SV-change of 1.8–3.6% (preterm) or 1.6–2.0% (term) throughout the tested weight ranges. One-hundred gram error in weight measurement resulted in a SV-change of 5.0–7.1% (preterm) or 1.5–1.8% (term) throughout the tested length ranges. Algorithms to calculate EC-derived SV incorporate anthropomorphic measurements. Therefore, inaccuracy in physical measurement can impact absolute EC measurements. This should be considered in the interpretation of previous findings and the design of future clinical studies of EC-derived cardiac parameters in neonates, particularly in the preterm cohorts where a proportional change was noted to be greatest.

scholarly journals Non-Invasive Scale Measurement of Cardiac Output Compared with the Gold-Standard Direct Fick Method: A Feasibility Study

2021 ◽  
Author(s):  
Daniel Yazdi ◽  
Sarin Patel ◽  
Suriya Sridaran ◽  
Evan Wilson ◽  
Sarah Smith ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Stroke Volume ◽  
Cardiac Function ◽  
Exercise Test ◽  
Gold Standard ◽  
Cardiopulmonary Exercise Test ◽  
Cardiac Monitoring ◽  
Non Invasive ◽  
Cardiopulmonary Exercise ◽  
The Mean

AbstractBackgroundObjective markers of cardiac function are limited in the outpatient setting and may be beneficial for monitoring patients with chronic cardiac conditions.ObjectiveWe assess the accuracy of a scale, with the ability to capture ballistocardiography, electrocardiography, and impedance plethysmography signals from a patient’s feet while standing on the scale, in measuring stroke volume and cardiac output compared to the gold-standard direct Fick method.MethodsThirty-two patients with unexplained dyspnea undergoing level 3 invasive cardiopulmonary exercise test at a tertiary medical center were included in the final analysis. We obtained scale and direct Fick measurements of stroke volume and cardiac output before and immediately after invasive cardiopulmonary exercise test.ResultsStroke volume and cardiac output from a cardiac scale and the direct Fick method correlated with r = 0.81 and r = 0.85, respectively (P < 0.001 each). The mean absolute error of the scale estimated stroke volume was -1.58 mL, with a 95% limits of agreement (LOA) of -21.97 mL to 18.81 mL. The mean error for the scale estimated cardiac output was -0.31 L/min, with a 95% LOA of -2.62 L/min to 2.00 L/min. The change in stroke volume and cardiac output before and after exercise were 78.9% and 96.7% concordant, respectively between the two measuring methods.ConclusionsThis novel scale with cardiac monitoring abilities may allow for non-invasive, longitudinal measures of cardiac function. Using the widely accepted form factor of a bathroom scale, this method of monitoring can be easily integrated into a patient’s lifestyle.

scholarly journals Postoperative continuous non-invasive cardiac output monitoring on the ward: a feasibility study

2020 ◽  
Author(s):  
C. E. King ◽  
A. Kermode ◽  
G. Saxena ◽  
P. Carvelli ◽  
M. Edwards ◽  
...  
Keyword(s):  
Stroke Volume ◽  
Clinical Outcomes ◽  
Feasibility Study ◽  
Continuous Monitoring ◽  
Elective Surgery ◽  
Resistance Index ◽  
Stroke Volume Index ◽  
Volume Index ◽  
Cardiac Output Monitoring ◽  
Non Invasive

Abstract Postoperative hypotension is common (occurring in one third of patients) and is associated with worse clinical outcomes. The LiDCO CNAP (continuous non-invasive arterial pressure) device measures haemodynamics but has not been widely adopted in ward environments. Improved early detection of hypotension by CNAP might guide interventions to improve clinical outcomes. We aimed to find the proportion of patients who tolerated LiDCO CNAP for 12 h postoperatively, to unmask episodes of hypotension detected by continuous monitoring and to characterise the haemodynamic profile at the time of hypotension. In this feasibility study, patients undergoing major elective surgery were continuously postoperatively monitored using CNAP. Haemodynamic data gathered from CNAP, including nSVRI (nominal systemic vascular resistance index), nSVI (nominal stroke volume index), SVV (stroke volume variation) and blood pressure, were analysed using Microsoft Excel and GraphPad Prism 8. 104 patients (age (mean ± sd): 68 ± 14, male (56%)) had CNAP sited postoperatively. 39% tolerated the CNAP device for at least 12 h. Within the 104 patients a mean of 81.2 min of hypotension detected by CNAP was not detected by usual care. The proportion of low/normal/high nSVI was 71%, 27% and 2%, nSVRI was 43%, 17% and 40%, respectively. CNAP monitoring was not tolerated for 12 h in the majority of patients. There were many episodes of hypotension unmasked through continuous monitoring. Based on the advanced haemodynamic data provided it is possible that the underlying cause of a third of postoperative hypotensive episodes is vasodilation rather than hypovolaemia. Trial registry number: NCT04010058 (ClinicalTrials.gov) Date of registration: 08/07/2019.

scholarly journals A new electric method for non-invasive continuous monitoring of stroke volume and ventricular volume-time curves

2012 ◽  
Vol 11 (1) ◽  
pp. 51 ◽  
Author(s):  
Maurits K Konings ◽  
Henk G Goovaerts ◽  
Maarten R Roosendaal ◽  
Rienk Rienks ◽  
Ferry M Koevoets ◽  
...  
Keyword(s):  
Stroke Volume ◽  
Continuous Monitoring ◽  
Ventricular Volume ◽  
Non Invasive

MATHEMATICAL MODELING OF STROKE VOLUME FROM THE PERIPHERAL BLOOD FLOW FOR NON INVASIVE PLETHYSMOGRAPHIC MEASUREMENT OF CARDIAC OUTPUT AND ITS VALIDATION

2017 ◽  
Vol 29 (06) ◽  
pp. 1750041
Author(s):  
Pranali Choudhari ◽  
M. S. Panse
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Peripheral Blood ◽  
Clinical Medicine ◽  
Patient Specific ◽  
Peripheral Blood Flow ◽  
Lung Water ◽  
Non Invasive ◽  
Multiple Variable

The ability to accurately measure Cardiac Output (CO) is important in clinical medicine as it helps in improving diagnosis of abnormalities and appropriate disease management. In spite of being an important vital parameter, it is still missing from the screens of the bedside monitors employed today. This could be due to the invasiveness of the method or the discomfort in the measurement. Invasive methods are most accurate but can be best suited for the intensive care units (ICUs) and surgeries, but for bedside measurement these methods add an unnecessary risk to the life of the patient. The existing non-invasive method employed for CO measurement is the thoracic bioimpedance method, which is risky for patients with cardiovascular diseases and inaccurate for patients with extra vascular lung water. This paper presents a novel method of CO measurement from the peripheral blood flow, which fairly overcomes the disadvantages of the existing method. The impedance pulse has been acquired across the wrist, instead of the thorax. A new stroke volume equation has been modeled by carrying out the finite element simulation of the blood flow and multiple variable regression to incorporate the patient specific factors. The stroke volume thus obtained has been validated for 57 subjects.

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