16th Meeting of the Society of Neurosonology and Cerebral Hemodynamics, 21-24 May, Munich, 2011
R. Hoogenboezem and R.W.M. Keunen
Introduction
Micro-emboli of both solid or gaseous origin can occur during cardiac surgery. It is important to differentiate both, because solid emboli are generally associated with an increased stroke risk, whilst gaseous emboli are not (unless the embolic load is extremely high). Intensity and duration of MES are not reliable indices for discrimination. Therefore, the zero-crossing dynamics of solid and gaseous MES were examined to look whether this parameter could make a reliable distinction between gaseous and solid MES.
Methods
From a recording of a cardiovascular procedure 300 MES which were clearly associated with the entrapment of air into the circulation were selected and labeled by a human expert. Another 300 MES were selected and labeled from a recording of the postoperative phase of carotidendarterectomy. These events were associated with the presence of solid emboli. To make the problem more practical another 300 HITS which were clearly no MES were selected from both files. MES and artefacts were detected by the 2 MHz transcranial Doppler (EMS-9U/DelicaSystem/Shenzen Delicate Electronics Co. Ltd./China). and classified by the Embolus Detection System (see Fig.1) (EDS, SMT Medical, Wuerburg, Germany). The EDS allows to verify of every event the velocity display, the audio file and calculates for every event: intensity, duration and a socalled zerocrossing index (ZCI) For details of ZCI see reference Keunen.
介紹
心臟手術(shù)期間可能發(fā)生固體或氣體來源的微栓塞。 區(qū)分兩者很重要，因?yàn)楣腆w栓子通常會增加中風(fēng)風(fēng)險(xiǎn)，而氣態(tài)栓子則不會（除非栓子負(fù)荷極高）。 MES的強(qiáng)度和持續(xù)時(shí)間不是區(qū)分的可靠指標(biāo)。 因此，檢查了固態(tài)和氣態(tài)MES的過零動力學(xué)特性，看該參數(shù)是否可以可靠地區(qū)分氣態(tài)和固態(tài)MES。
方法
從心血管程序的記錄中，選擇了300個(gè)與空氣進(jìn)入循環(huán)系統(tǒng)明顯相關(guān)的MES，并由專家進(jìn)行了標(biāo)記。 選擇了另外300個(gè)MES，并從記錄了一個(gè)全齒狀結(jié)腸切除術(shù)術(shù)后階段的記錄中進(jìn)行了標(biāo)記。 這些事件與固體栓子的存在有關(guān)。 為了使問題更實(shí)際，另外兩個(gè)文件中均未選擇MES的300個(gè)HITS。 通過2 MHz經(jīng)顱多普勒儀（EMS-9U / DelicaSystem /深圳市德力凱醫(yī)療設(shè)備股份有限公司/中國）檢測到MES和偽像。 并由栓子檢測系統(tǒng)分類（見圖1）（EDS，SMT Medical，德國維爾堡）。 EDS可以驗(yàn)證每個(gè)事件的速度顯示，音頻文件并計(jì)算每個(gè)事件：強(qiáng)度，持續(xù)時(shí)間和所謂的零交叉指數(shù)（ZCI）。有關(guān)ZCI的詳細(xì)信息，請參見參考Keunen。（譯文來自GOOGLE)
