{"id":202,"date":"2015-12-22T11:10:42","date_gmt":"2015-12-22T16:10:42","guid":{"rendered":"https:\/\/support.mindwaretech.com\/?post_type=ht_kb&#038;p=202"},"modified":"2018-05-16T16:38:59","modified_gmt":"2018-05-16T20:38:59","slug":"kb0004","status":"publish","type":"ht_kb","link":"https:\/\/support.mindwaretech.com\/knowledge-base\/kb0004\/","title":{"rendered":"KB0004: Calculate Pulse Transit Time Using the IMP Analysis Application"},"content":{"rendered":"<p><strong><em>Select analysis version to modify content below:<\/em> <\/strong><select class='consel_dropdown consel_name_app'>\n<option value='app_three_two'>3.2<\/option>\n<option value='app_three_one'>3.1<\/option>\n<\/select><\/p>\n<p>Pulse Transit Time (PTT) is a measure of pulse propagation time from the heart to another part of the body. To measure this, you need an ECG signal and a\u00a0Plethysmograph (PPG), typically from the finger.<\/p>\n<p>PTT is then calculated by subtracting the R peak time from the plethysmograph peak time on a cycle-by-cycle basis. The Impedance Cardiography analysis application is a great place to calculate this, as we perform a very similar procedure\u00a0to determine Pre-Ejection Period (PEP), albeit using ECG and dZ\/dt.<\/p>\n<p><!--more--><\/p>\n<p>To calculate PTT in the Impedance Cardiography analysis applicion:<\/p>\n<p>Open the desired file, and on the\u00a0Map Channels screen map the ECG channel and the PPG channel as dZ\/dt. This is so the program uses the PPG signal as if it were a dZ\/dt waveform.<\/p>\n<p><em>(Note &#8211; the IMP application requires that a Z0 channel be mapped. If you do not have Z0 recorded, you can map any other channel in the file as Z0 to satisfy that requirement since we aren&#8217;t actually analyzing impedance).<\/em><\/p>\n<span class=\"consel_content consel_name_app consel_sel_app_three_one\">\n<p><a href=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-1.png\" rel=\"attachment wp-att-209\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-209 size-full\" src=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-1.png\" alt=\"PTT Part 1\" width=\"1027\" height=\"735\" srcset=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-1.png 1027w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-1-300x215.png 300w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-1-768x550.png 768w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-1-1024x733.png 1024w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-1-50x36.png 50w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-1-920x658.png 920w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-1-600x429.png 600w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-1-320x229.png 320w\" sizes=\"auto, (max-width: 1027px) 100vw, 1027px\" \/><\/a><\/p>\n<\/span>\n<span class=\"consel_content consel_name_app consel_sel_app_three_two\">\n<p><a href=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/1-3.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-4722\" src=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/1-3.png\" alt=\"\" width=\"542\" height=\"278\" srcset=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/1-3.png 542w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/1-3-300x154.png 300w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/1-3-50x26.png 50w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/1-3-320x164.png 320w\" sizes=\"auto, (max-width: 542px) 100vw, 542px\" \/><\/a><\/p>\n<\/span>\n<p>Press OK, and proceed to the\u00a0<strong>Impedance Calibration Settings<\/strong> tab. Pre-Ejection Period is calculated by taking the time difference between the Q point on the ECG waveform and the B point on the dZ\/dt waveform. If we make some adjustments to the calculation algorithms for these 2 points, we can use them to get PTT.<\/p>\n<ul>\n<li>Change the\u00a0<strong>Q Point Calculation Method<\/strong> to &#8220;R Minus Constannt&#8221; with a constant of &#8220;0&#8221;. This will place the Q point at the same time as the R peak.<\/li>\n<li>Change the\u00a0<strong>B Point Calculation Method<\/strong> to &#8220;dZ\/dt Peak Minus Constant&#8221; with a constant of &#8220;0&#8221;. This will place the B point at the same time as the peak of the PPG signal.<\/li>\n<li>Ensure that the\u00a0<strong>dZ\/dt<\/strong> source is set to &#8220;Measured&#8221;<\/li>\n<\/ul>\n<span class=\"consel_content consel_name_app consel_sel_app_three_one\">\n<p><a href=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-2.png\" rel=\"attachment wp-att-211\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-211 size-full\" src=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-2.png\" alt=\"PTT Part 2\" width=\"996\" height=\"547\" srcset=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-2.png 996w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-2-300x165.png 300w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-2-768x422.png 768w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-2-50x27.png 50w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-2-920x505.png 920w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-2-600x330.png 600w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-2-320x176.png 320w\" sizes=\"auto, (max-width: 996px) 100vw, 996px\" \/><\/a><\/p>\n<\/span>\n<span class=\"consel_content consel_name_app consel_sel_app_three_two\">\n<p><a href=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/2-1.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-4723\" src=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/2-1.png\" alt=\"\" width=\"1015\" height=\"676\" srcset=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/2-1.png 1015w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/2-1-300x200.png 300w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/2-1-768x511.png 768w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/2-1-50x33.png 50w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/2-1-920x613.png 920w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/2-1-600x400.png 600w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/2-1-320x213.png 320w\" sizes=\"auto, (max-width: 1015px) 100vw, 1015px\" \/><\/a><\/p>\n<\/span>\n<p>Now proceed to the analysis screen. You will see that the Q point lines up with the R peak, and the B point lines up with the dZ\/dt peak. Since the PEP calculation is the difference between these 2 points, PEP = PTT.<\/p>\n<span class=\"consel_content consel_name_app consel_sel_app_three_one\">\n<p><a href=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-3.png\" rel=\"attachment wp-att-214\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-214 size-full\" src=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-3.png\" alt=\"PTT Part 3\" width=\"1021\" height=\"745\" srcset=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-3.png 1021w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-3-300x219.png 300w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-3-768x560.png 768w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-3-50x36.png 50w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-3-920x671.png 920w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-3-600x438.png 600w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2015\/12\/PTT-Part-3-320x233.png 320w\" sizes=\"auto, (max-width: 1021px) 100vw, 1021px\" \/><\/a><\/p>\n<\/span>\n<span class=\"consel_content consel_name_app consel_sel_app_three_two\">\n<p><a href=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/3-1.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-4724\" src=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/3-1.png\" alt=\"\" width=\"1045\" height=\"757\" srcset=\"https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/3-1.png 1045w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/3-1-300x217.png 300w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/3-1-768x556.png 768w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/3-1-1024x742.png 1024w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/3-1-50x36.png 50w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/3-1-920x666.png 920w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/3-1-600x435.png 600w, https:\/\/support.mindwaretech.com\/wp-content\/uploads\/2018\/05\/3-1-320x232.png 320w\" sizes=\"auto, (max-width: 1045px) 100vw, 1045px\" \/><\/a><\/p>\n<\/span>\n","protected":false},"excerpt":{"rendered":"<p>Select analysis version to modify content below: Pulse Transit Time (PTT) is a measure of pulse propagation time from the heart to another part of the body. To measure this, you need an ECG signal and a\u00a0Plethysmograph (PPG), typically from the finger. PTT is then calculated by subtracting the R [&hellip;]<\/p>\n","protected":false},"author":2,"comment_status":"open","ping_status":"closed","template":"","format":"standard","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"footnotes":""},"ht-kb-category":[40],"ht-kb-tag":[13,44,30,42,43],"class_list":["post-202","ht_kb","type-ht_kb","status-publish","format-standard","hentry","ht_kb_category-imp","ht_kb_tag-analysis","ht_kb_tag-ecg","ht_kb_tag-imp","ht_kb_tag-ptt","ht_kb_tag-pulse-transit-time"],"_links":{"self":[{"href":"https:\/\/support.mindwaretech.com\/wp-json\/wp\/v2\/ht-kb\/202","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/support.mindwaretech.com\/wp-json\/wp\/v2\/ht-kb"}],"about":[{"href":"https:\/\/support.mindwaretech.com\/wp-json\/wp\/v2\/types\/ht_kb"}],"author":[{"embeddable":true,"href":"https:\/\/support.mindwaretech.com\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/support.mindwaretech.com\/wp-json\/wp\/v2\/comments?post=202"}],"version-history":[{"count":12,"href":"https:\/\/support.mindwaretech.com\/wp-json\/wp\/v2\/ht-kb\/202\/revisions"}],"predecessor-version":[{"id":4725,"href":"https:\/\/support.mindwaretech.com\/wp-json\/wp\/v2\/ht-kb\/202\/revisions\/4725"}],"wp:attachment":[{"href":"https:\/\/support.mindwaretech.com\/wp-json\/wp\/v2\/media?parent=202"}],"wp:term":[{"taxonomy":"ht_kb_category","embeddable":true,"href":"https:\/\/support.mindwaretech.com\/wp-json\/wp\/v2\/ht-kb-category?post=202"},{"taxonomy":"ht_kb_tag","embeddable":true,"href":"https:\/\/support.mindwaretech.com\/wp-json\/wp\/v2\/ht-kb-tag?post=202"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}