Dynamic image analysis of transparent particles released during the simulated use test of cardiovascular devices

AbstractFor product approval of coated cardiovascular devices, the assessment of particle release is essential. Particularly challenging are delivery systems equipped with hydrophilic coatings releasing highly transparent particles. The aim of this study was to compare two different methods of particle counting, namely the light obscuration method and the dynamic image analysis (DIA), with respect to optical transparent particles. The particles were collected during the simulated use of cardiovascular catheters and analysed in suspension with a dynamic imaging device (FlowCam, Fluid Imaging Technologies). Particles were detected by a greyscale threshold and imaged to analyse their shape and transparency. The statistical influence of the threshold on particle counts and size distribution was determined and compared to light obscuration particle counting (Model 9703 with sensor HRLD 400CE, HIAC ROYCO). The light obscuration method provided lower particle counts in suspensions containing a high amount of transparent particles. The lower the detection threshold, the higher the particle counts were. In conclusion, it is important to adapt the threshold value for samples that are expected to contain a high amount of transparent particles. DIA may be suggested as a valuable additional method for particulate analysis.

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Optimization of online particle counting with a 3D-printed bubble trap

Current Directions in Biomedical Engineering ◽

10.1515/cdbme-2020-3108 ◽

2020 ◽

Vol 6 (3) ◽

pp. 418-421

Author(s):

Anja Kurzhals ◽

Christoph Brandt-Wunderlich ◽

Finja Borowski ◽

Klaus-Peter Schmitz ◽

Niels Grabow ◽

...

Keyword(s):

Air Bubbles ◽

Cardiovascular Devices ◽

Particle Counter ◽

Light Obscuration ◽

Particle Counting ◽

Custom Made ◽

Bubble Trap ◽

3D Printed ◽

Particle Counts ◽

Flow Circuit

AbstractParticulate evaluation is needed for the approval of cardiovascular devices. Air bubbles lead to higher particle counts when light obscuration method (LOM) is used. The aim of the study was to test a custom made bubble trap that removes air bubbles (2 - 100 μm) from a flow circuit prior to online particle counting. Artificially generated air bubbles were counted with an online particle counter with and without the bubble trap. Air bubbles were reduced by about 71 % to 91 % by using the bubble trap.

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Systematic morphological characterization of sub-visible particles generated from cardiovascular devices using dynamic image analysis

Current Directions in Biomedical Engineering ◽

10.1515/cdbme-2021-2157 ◽

2021 ◽

Vol 7 (2) ◽

pp. 617-620

Author(s):

Anja Kurzhals ◽

Christoph Brandt-Wunderlich ◽

Klaus-Peter Schmitz ◽

Niels Grabow ◽

Wolfram Schmidt

Keyword(s):

Image Analysis ◽

Aspect Ratio ◽

Test Procedure ◽

Morphological Characterization ◽

International Standards ◽

Cardiovascular Devices ◽

Dynamic Image ◽

Dynamic Image Analysis ◽

Particle Shapes

Abstract The assessment of particulate matter generated during a simulated use is requested by international standards for approval of cardiovascular devices. The particle suspension was generated during a simulated use test procedure of a commercially available coronary stent delivery system and analyzed by Dynamic image analysis (DIA) using FlowCAM 8000. Four parameters were analyzed: the diameter, the aspect ratio value, the circularity and the intensity. The results revealed that 53% of the particles were larger than 25 μm. The particle shapes were inhomogeneous with a wide ranging aspect ratio of 0.03 to 0.95. Around 83% had an intensity value of more than 140 grey scales and appeared translucent.

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