Abstract:
:The availability of a simple-to-use, automatic measurement system for noninvasive flow estimation is imperative, given the clinical demand for an acceptable noninvasive procedure rather than the standard invasive procedure of thermodilution. A method for calculating cardiac output from noninvasively derived pressure pulses has been developed, and the results of a preliminary evaluation study on post-cardiac surgery patients for whom invasive flow measures were readily available for comparison are provided in this report. The proposed method relies on fast Fourier transform (FFT) analysis of pulses measured externally at the carotid and femoral pressure points. A transfer function of the aorta is computed from digitally filtered pulse measurements, and a tapered model of the aorta is parametrically adapted using a simplex optimization algorithm so that its transfer function matches that derived experimentally. An aortic input impedance term is obtained from the optimized model and utilized along with the carotid pulse (analogous to input voltage) to compute aortic flow. In addition to its automation, attractive features of this method include the requirement for relatively few pulses for analysis as well as considerable resistance to noise artifact. For 59 data records collected from 54 post-cardiac surgery patients, the average flow measurements computed over several pulses compare well with the standard, invasive method of thermodilution. Preliminary results also indicate a strong potential for tracking changes in cardiac output over time, and invite further use of the method in monitoring hemodynamically unstable patients.
journal_name
Biol Cybernjournal_title
Biological cyberneticsauthors
Redling JD,Akay Mdoi
10.1007/s004220050372subject
Has Abstractpub_date
1997-08-01 00:00:00pages
111-22issue
2eissn
0340-1200issn
1432-0770journal_volume
77pub_type
杂志文章abstract::Fast as possible (time optimal) single joint movements throughout the body are characterized by the triphasic (3 pulse) pattern of activation in the agonist and antagonist muscles. Simulation studies using a sixth order, non-linear model were undertaken to determine the relationship between time optimal movement and t...
journal_title:Biological cybernetics
pub_type: 杂志文章
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journal_title:Biological cybernetics
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journal_title:Biological cybernetics
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journal_title:Biological cybernetics
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journal_title:Biological cybernetics
pub_type: 杂志文章
doi:10.1007/BF00355749
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journal_title:Biological cybernetics
pub_type: 杂志文章
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journal_title:Biological cybernetics
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journal_title:Biological cybernetics
pub_type: 杂志文章
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pub_type: 杂志文章
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journal_title:Biological cybernetics
pub_type: 杂志文章
doi:10.1007/BF00453373
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pub_type: 杂志文章
doi:10.1007/s004220170005
更新日期:2001-01-01 00:00:00
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journal_title:Biological cybernetics
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