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<front>
<journal-meta>
<journal-id journal-id-type="doi">10.1002/(ISSN)2051-817X</journal-id>
<journal-id journal-id-type="publisher-id">PHY2</journal-id>
<journal-id journal-id-type="hwp">physreports</journal-id>
<journal-title-group>
<journal-title xml:lang="en">Physiological Reports</journal-title>
<abbrev-journal-title abbrev-type="publisher" xml:lang="en">Physiol Rep</abbrev-journal-title>
</journal-title-group>
<issn publication-format="ppub">2051-817X</issn>
<issn publication-format="epub">2051-817X</issn>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.14814/phy2.15040</article-id>
<article-id pub-id-type="publisher-id">PHY215040</article-id>
<article-categories>
<subj-group subj-group-type="overline" xml:lang="en">
<subject>ORIGINAL ARTICLE</subject>
</subj-group>
<subj-group subj-group-type="heading" xml:lang="en">
<subject>ORIGINAL ARTICLES</subject>
</subj-group>
</article-categories>
<title-group>
<article-title xml:lang="en">Transfer‐function‐free technique for the noninvasive determination of the human arterial pressure waveform</article-title>
<alt-title alt-title-type="left-running-head">GIUDICI et al.</alt-title>
</title-group>
<contrib-group>
<contrib id="phy215040-cr-0001" contrib-type="author">
<name>
<surname>Giudici</surname>
<given-names>Alessandro</given-names>
</name>
<contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-8288-3980</contrib-id>
<xref ref-type="aff" rid="phy215040-aff-0001">
<sup>1</sup>
</xref>
</contrib>
<contrib id="phy215040-cr-0002" contrib-type="author">
<name>
<surname>Palombo</surname>
<given-names>Carlo</given-names>
</name>
<xref ref-type="aff" rid="phy215040-aff-0002">
<sup>2</sup>
</xref>
</contrib>
<contrib id="phy215040-cr-0003" contrib-type="author">
<name>
<surname>Morizzo</surname>
<given-names>Carmela</given-names>
</name>
<xref ref-type="aff" rid="phy215040-aff-0002">
<sup>2</sup>
</xref>
</contrib>
<contrib id="phy215040-cr-0004" contrib-type="author">
<name>
<surname>Kozakova</surname>
<given-names>Michaela</given-names>
</name>
<xref ref-type="aff" rid="phy215040-aff-0003">
<sup>3</sup>
</xref>
</contrib>
<contrib id="phy215040-cr-0005" contrib-type="author">
<name>
<surname>Cruickshank</surname>
<given-names>J. Kennedy</given-names>
</name>
<xref ref-type="aff" rid="phy215040-aff-0004">
<sup>4</sup>
</xref>
</contrib>
<contrib id="phy215040-cr-0006" contrib-type="author">
<name>
<surname>Wilkinson</surname>
<given-names>Ian B.</given-names>
</name>
<xref ref-type="aff" rid="phy215040-aff-0005">
<sup>5</sup>
</xref>
</contrib>
<contrib id="phy215040-cr-0007" contrib-type="author" corresp="yes">
<name>
<surname>Khir</surname>
<given-names>Ashraf W.</given-names>
</name>
<contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-0845-2891</contrib-id>
<email>ashraf.khir@brunel.ac.uk</email>
<xref ref-type="corresp" rid="correspondenceTo">*</xref>
<xref ref-type="aff" rid="phy215040-aff-0001">
<sup>1</sup>
</xref>
</contrib>
</contrib-group>
<aff id="phy215040-aff-0001">
<label>
<sup>1</sup>
</label>
<named-content content-type="organisation-division">Department of Mechanical and Aerospace Engineering</named-content>
 <institution>Brunel University London</institution>
 <city>Uxbridge</city>
 <country country="GB">UK</country>
</aff>
<aff id="phy215040-aff-0002">
<label>
<sup>2</sup>
</label>
<named-content content-type="organisation-division">Department of Surgical</named-content>
 <named-content content-type="organisation-division">Medical, Molecular Pathology and Critical Area Medicine</named-content>
 <institution>University of Pisa</institution>
 <city>Pisa</city>
 <named-content content-type="country-part">Tuscany</named-content>
 <country country="IT">Italy</country>
</aff>
<aff id="phy215040-aff-0003">
<label>
<sup>3</sup>
</label>
<named-content content-type="organisation-division">Department of Clinical and Experimental Medicine</named-content>
 <institution>University of Pisa</institution>
 <city>Pisa</city>
 <named-content content-type="country-part">Tuscany</named-content>
 <country country="IT">Italy</country>
</aff>
<aff id="phy215040-aff-0004">
<label>
<sup>4</sup>
</label>
<named-content content-type="organisation-division">School of Life‐Course/Nutritional Sciences</named-content>
 <institution>King’s College</institution>
<institution>St. Thomas’ &amp; Guy’s Hospitals, London</institution>
 <named-content content-type="country-part">Middlesex</named-content>
 <country country="GB">UK</country>
</aff>
<aff id="phy215040-aff-0005">
<label>
<sup>5</sup>
</label>
<named-content content-type="organisation-division">Division of Experimental Medicine and Immunotherapeutics</named-content>
 <institution>University of Cambridge</institution>
 <city>Cambridge</city>
 <named-content content-type="country-part">Cambridgeshire</named-content>
 <country country="GB">UK</country>
</aff>
<author-notes>
<corresp id="correspondenceTo"><label>*</label>


<bold>Correspondence</bold>
<break/>
Ashraf W. Khir, Brunel Institute for Bioengineering, Brunel University, Kingston Lane, Uxbridge, Middlesex UB8 3PH, UK.<break/>
Email: <email>ashraf.khir@brunel.ac.uk</email><break/>

</corresp>
</author-notes>
<pub-date date-type="pub" publication-format="electronic"><day>22</day>
<month>09</month>
<year>2021</year>
</pub-date><pub-date date-type="pub" publication-format="print"><month>09</month>
<year>2021</year>
</pub-date><volume>9</volume>
<issue seq="80">18</issue>
<issue-id pub-id-type="doi">10.1002/phy2.v9.18</issue-id>
<elocation-id>e15040</elocation-id>
<history>

<date date-type="received">
<day>02</day>
<month>06</month>
<year>2021</year>
</date>

<date date-type="accepted">
<day>18</day>
<month>06</month>
<year>2021</year>
</date>

</history>
<permissions>
<copyright-statement content-type="issue-copyright">© 2021 Published by the Physiological Society and the American Physiological Society</copyright-statement>
<copyright-statement content-type="article-copyright">© 2021 The Authors. <italic>Physiological Reports</italic> published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society</copyright-statement>
<copyright-year>2021</copyright-year>
<copyright-holder>© 2021 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society</copyright-holder>
<license>
<ali:license_ref>http://creativecommons.org/licenses/by/4.0/</ali:license_ref>
<license-p>This is an open access article under the terms of the <ext-link ext-link-type="uri" xlink:href="http://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution</ext-link> License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.</license-p>
</license>
</permissions>
<abstract xml:lang="en" abstract-type="main" id="phy215040-abs-0001">
<title>Abstract</title>
<p xml:lang="en">The estimation of central aortic blood pressure is a cardinal measurement, carrying effective physiological, and prognostic data beyond routine peripheral blood pressure. Transfer function‐based devices effectively estimate aortic systolic and diastolic blood pressure from peripheral pressure waveforms, but the reconstructed pressure waveform seems to preserve features of the peripheral waveform. We sought to develop a new method for converting the local diameter distension waveform into a pressure waveform, through an exponential function whose parameters depend on the local wave speed. The proposed method was then tested at the common carotid artery. Diameter and blood velocity waveforms were acquired via ultrasound at the right common carotid artery while simultaneously recording pressure at the left common carotid artery via tonometer in 203 people (122 men, 50 ± 18 years). The wave speed was noninvasively estimated via the ln<italic>DU</italic>‐loop method and then used to define the exponential function to convert the diameter into pressure. Noninvasive systolic and mean pressures estimated by the new technique were 3.8 ± 21.8 (<italic>p</italic> = 0.015) and 2.3 ± 9.6 mmHg (<italic>p</italic> = 0.011) higher than those obtained using tonometery. However, differences were much reduced and not significant in people &gt;35 years (0.6 ± 18.7 and 0.8 ± 8.3 mmHg, respectively). This proof of concept study demonstrated that local wave speed, estimated from noninvasive local measurement of diameter and flow velocity, can be used to determine an exponential function that describes the relationship between local pressure and diameter. This pressure‐diameter function can then be used for the noninvasive estimation of local arterial pressure.</p>
</abstract>
<kwd-group xml:lang="en">
<kwd id="phy215040-kwd-0001">carotid artery</kwd>
<kwd id="phy215040-kwd-0002">hypertension</kwd>
<kwd id="phy215040-kwd-0003">local wave speed</kwd>
<kwd id="phy215040-kwd-0004">noninvasive estimation of pressure</kwd>
<kwd id="phy215040-kwd-0005">pressure</kwd>
</kwd-group>
<funding-group>
<award-group id="funding-0001">
<funding-source>

<institution-wrap>
<institution>Innovative Medicines Initiative</institution>
</institution-wrap>

</funding-source>
</award-group>
</funding-group>
<funding-group>
<award-group id="funding-0002">
<funding-source>

<institution-wrap>
<institution>Addenbrooke's Hospital</institution>
</institution-wrap>

</funding-source>
<award-id>10696100</award-id>
</award-group>
</funding-group>
<counts>
<fig-count count="5"/>
<table-count count="1"/>
<page-count count="12"/>
<word-count count="7754"/>
</counts>
</article-meta>
</front>
</article>