Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1988-2-29
pubmed:abstractText
Ultrasonic Doppler-shifted signals from blood can be displayed in various forms using either analogue or digital processing techniques. One of the most commonly extracted parameters from the Doppler spectrum is the mean frequency envelope. This waveform can be used for the interpretation of physiological changes within man and can also be used for the estimation of volume flow rate within a vessel. This paper describes a practical implementation of an analogue, instantaneous mean frequency estimator and its use in the measurement of blood flow volume. The circuit is linear to within two per cent and operates over a frequency range of 200 Hz to 10 kHz. It can extract a velocity-time envelope from a Doppler signal within noise and performs well in a clinical environment. It is relatively inexpensive compared with digital signal processing techniques and requires minimal setting up. Simple connection to a Doppler velocimeter using phase quadrature demodulation will produce a directional output.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0143-0815
pubmed:author
pubmed:issnType
Print
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
309-15
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
An analogue mean frequency estimator for the quantitative measurement of blood flow by Doppler ultrasound.
pubmed:affiliation
Department of Medical Physics, Bristol Royal Infirmary, England.
pubmed:publicationType
Journal Article, Comparative Study