{"id":225,"date":"2016-06-02T10:18:11","date_gmt":"2016-06-02T10:18:11","guid":{"rendered":"http:\/\/wordix.inesctec.pt\/wp-brain\/?page_id=225"},"modified":"2017-01-04T14:37:49","modified_gmt":"2017-01-04T14:37:49","slug":"towards-a-pervasive-system-for-real-time-blood-pressure-monitoring-estimation-models-and-events-detector","status":"publish","type":"page","link":"https:\/\/brain.inesctec.pt\/?page_id=225","title":{"rendered":"Towards a pervasive system for real-time blood pressure monitoring: Estimation models and events detector"},"content":{"rendered":"<div itemprop=\"articleBody\">\n<h3 style=\"font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; color: #333333;\"><span style=\"color: #2d82a4;\">Thesis type:&nbsp;<\/span><\/h3>\n<p>MSc<\/p>\n<h3 style=\"font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; color: #333333;\"><span style=\"color: #2d82a4;\">Author:<\/span><\/h3>\n<p>Pedro Pinto da Silva<\/p>\n<h3 style=\"font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; color: #333333;\"><span style=\"color: #2d82a4;\">Supervisor:<\/span><\/h3>\n<p>Jo\u00e3o Paulo Trigueiros da Silva Cunha<\/p>\n<h3 style=\"font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; color: #333333;\"><span style=\"color: #2d82a4;\">Title:<\/span><\/h3>\n<p>Towards a pervasive system for real-time blood pressure monitoring: Estimation models and events detector<\/p>\n<p>(<a href=\"https:\/\/repositorio-aberto.up.pt\/bitstream\/10216\/72686\/1\/000157937.pdf\">available here<\/a>)<\/p>\n<h3 style=\"font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; color: #333333;\"><span style=\"color: #2d82a4;\">Abstract:<\/span><\/h3>\n<p style=\"text-align: justify;\">It is widely spread and accepted that regulation and monitoring of arterial blood pressure contributes actively to the prevention of cardiovascular events and diseases.<\/p>\n<p style=\"text-align: justify;\">Although developments have been made in non-invasive ambulatory blood pressure measurement,&nbsp;ambulatory blood pressure monitors or devices based on Finapres technology carry significant&nbsp;costs or performance drawbacks that do not make them eligible for a widespread use of the&nbsp;technology.<\/p>\n<p style=\"text-align: justify;\">Recently, pulse transit time (PTT) based techniques have been suggested as a promising tool to deliver non-invasive and continuous monitoring of BP on a personalized wearable level. In&nbsp;this work the question of how PTT-based models performs as an estimator of SBP is addressed&nbsp;using several approaches. Off-line least squares fitting and recursive least squares are applied to&nbsp;determine parameter correlation and evolution in time. Low correlation coefficients are found and&nbsp;no systematic components are observed. On-line exponentially-weighted regression is applied by&nbsp;performing an initial calibration and then re-calibrating the system every T minutes. Standard&nbsp;deviation of the error and minimum squared error were observed to increase considerably with&nbsp;T, suggesting that initially determined parameters become increasingly obsolete after 30 to 60&nbsp;minutes of activity.<\/p>\n<p style=\"text-align: justify;\">However, the question whether a PTT-based model is an indicator of SBP variability strong&nbsp;enough to detect events of SBP remained. By imposing medical requirements, namely a threshold&nbsp;for significant SBP changes of 20 mmHg, SBP events are characterized and a set of techniques&nbsp;for SBP event detection are developed. Upon generating the ground truth, the thresholds that&nbsp;maximize the tradeoffs between the number of true and false positive detections are analysed&nbsp;by generating ROC performance curves for three different methods of estimating SBP. Specific&nbsp;points in the ROC curve of a exponentially-weighted regression with period of re-calibration of&nbsp;20 minutes suggested that the method could be incorporated with current technology for ambulatory&nbsp;BP measurement using a threshold of tr = 12.5 and providing reasonable performance (82%&nbsp;sensibility and 79% specificity).<\/p>\n<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Thesis type:&nbsp; MSc Author: Pedro Pinto da Silva Supervisor: Jo\u00e3o Paulo Trigueiros da Silva Cunha Title: Towards a pervasive system for real-time blood pressure monitoring: Estimation models and events detector (available here) Abstract: It is widely spread and accepted that regulation and monitoring of arterial blood pressure contributes actively to the prevention of cardiovascular events [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-225","page","type-page","status-publish","czr-hentry"],"_links":{"self":[{"href":"https:\/\/brain.inesctec.pt\/index.php?rest_route=\/wp\/v2\/pages\/225","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/brain.inesctec.pt\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/brain.inesctec.pt\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/brain.inesctec.pt\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/brain.inesctec.pt\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=225"}],"version-history":[{"count":5,"href":"https:\/\/brain.inesctec.pt\/index.php?rest_route=\/wp\/v2\/pages\/225\/revisions"}],"predecessor-version":[{"id":804,"href":"https:\/\/brain.inesctec.pt\/index.php?rest_route=\/wp\/v2\/pages\/225\/revisions\/804"}],"wp:attachment":[{"href":"https:\/\/brain.inesctec.pt\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=225"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}