Validation and clinical application of a first order step response equation for nitrogen clearance during FRC measurement.
Objective: To derive a difference equation based on mass conservation and on alveolar tidal volumes for the calculation of Functional Residual Capacity. Derive an equation for the FRC from the difference equation. Furthermore, to derive and validate a step response equation as a solution of the diff...
| Publicado en: | Journal of Clinical Monitoring & Computing Vol. 22; no. 1; pp. 1 - 10 |
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| Autores principales: | , , , , , |
| Formato: | research Journal Article |
| Publicado: |
Springer Nature
Jan2008
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=105747577&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 105747577 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 13871307 OHC jtl: Journal of Clinical Monitoring & Computing issn: 13871307 maglogo: N pubinfo: dt: Jan2008 vid: 22 iid: 1 pid: 237 pub: Springer Nature place: New York, New York artinfo: ui: 105747577 105747577 NLM18004668 2009821577 10.1007/s10877-007-9101-0 NLM18004668 105747577 ppf: 1 ppct: 9 formats: fmt: @attributes: type: P tig: atl: Validation and clinical application of a first order step response equation for nitrogen clearance during FRC measurement. aug: au: Choncholas G Sondergaard S Heinonen E Choncholas, Gary Sondergaard, Soren Heinonen, Erkki affil: Department of Research & Development, GE Healthcare, Madison, WI, USA sug: subj: Functional Residual Capacity Physiology Models, Biological Nitrogen Metabolism Signal Processing, Computer Assisted Adult Aged Breath Tests Female Male Middle Age Monitoring, Physiologic Methods Pulmonary Alveoli Metabolism Regression Tidal Volume Physiology Respiration, Artificial Human Adult: 19-44 years Aged: 65+ years Middle Aged: 45-64 years Female Male ab: Objective: To derive a difference equation based on mass conservation and on alveolar tidal volumes for the calculation of Functional Residual Capacity. Derive an equation for the FRC from the difference equation. Furthermore, to derive and validate a step response equation as a solution of the difference equation within the framework of digital signal processing where the FRC is known a priori.Methods: A difference equation for the calculation of Functional Residual Capacity is derived and solved as step response of a first order system. The step response equation calculates endtidal fractions of nitrogen during multiple breath nitrogen clearance. The step response equation contains the eigenvalue defined as the ratio of FRC to the sum of FRC and alveolar tidal ventilation. Agreement of calculated nitrogen fractions with measured fractions is demonstrated with data from a metabolic lung model, measurements from patients in positive pressure ventilation and volunteers breathing spontaneously. Examples of eigenvalue are given and compared between diseased and healthy lungs and between ventilatory settings.Results: Comparison of calculated and measured fractions of endtidal nitrogen demonstrates a high degree of agreement in terms of regression and bias and limits of agreement (precision) in Bland & Altman analysis. Examples illustrate the use of the eigenvalue as a possible discriminator between disease states.Conclusion: The first order step response equation reliably calculates endtidal fractions of nitrogen during washout based on a Functional Residual Capacity. The eigenvalue may be a clinically valuable index alone or in conjunction with other indices in the analysis of respiratory states and may aid in the setting of the ventilator. pubtype: Academic Journal doctype: research Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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