Visualization of Aspirated Flow Pathlines in a Thrombectomy Catheter with Three Extra Holes: A CFD Study
Issue:
Volume 3, Issue 2-2, March 2015
Pages:
1-5
Received:
30 November 2014
Accepted:
31 December 2014
Published:
13 February 2015
Abstract: The aspiration catheter design requires the good understanding of blood flow, based on a complex analysis of its hemodynamic characteristics. Computational fluid dynamics (CFD) is an important approach in studying the blood flow. In this paper the effect of extra upper holes - designed for the aspiration catheter - on the aspirated fluid pathlines are studied and discussed.
Abstract: The aspiration catheter design requires the good understanding of blood flow, based on a complex analysis of its hemodynamic characteristics. Computational fluid dynamics (CFD) is an important approach in studying the blood flow. In this paper the effect of extra upper holes - designed for the aspiration catheter - on the aspirated fluid pathlines ...
Show More
Comparison of Left and Right Fingertip PPG Signals Using Signal Power Estimates and Poincare Indexes
Surhan Bozkurt,
Gokhan Ertas
Issue:
Volume 3, Issue 2-2, March 2015
Pages:
6-10
Received:
18 January 2015
Accepted:
5 February 2015
Published:
13 February 2015
Abstract: Photoplethysmography (PPG) is a non-invasive method to measure the relative blood volume change in blood vessels used in a wide range of medical applications. PPG signals can be recorded from different body regions such as fingertips, forehead and earlobes. In this study, information content of PPG signals of the left and the right index fingertips are processed and analyzed. PPG recordings are performed from ten healthy volunteers. Prior to recordings, all volunteers take rest for five minutes. Using a dedicated measurement system, signals are recorded from the left and the right fingertips of each volunteer simultaneously for 60 seconds with a sampling frequency of 50Hz, digitized with 10-bit resolution and stored in a personal computer. Signal average power and Poincare indexes of the signals are estimated and statistically analyzed. There are no systematic differences between the signal power estimated from the left and right fingertip signals (P>0.5). The signal power estimates for the left and the right fingertips show moderate correlations of 0.78, 0.80 and 0.68 for 0-4Hz, 0-2Hz and 2-4Hz frequency bands, respectively. When Poincare indexes SD1 and SD1/SD2 are considered, there are no systematic differences between the left and right fingertip signals (P > 0.5) however a systematic difference exists between the SD2 estimates (P=0.15). SD1 and SD1/SD2 estimates for the left and the right fingertips show high positive correlations of 1.00 and 0.99, respectively. However, a correlation of -0.30 exits for the left and the right fingertips when SD2 estimate is considered.
Abstract: Photoplethysmography (PPG) is a non-invasive method to measure the relative blood volume change in blood vessels used in a wide range of medical applications. PPG signals can be recorded from different body regions such as fingertips, forehead and earlobes. In this study, information content of PPG signals of the left and the right index fingertips...
Show More
