No abstract

Switched reluctance motor (SRM) has some advantages such as low cost, high torque density, etc., but SRM has essentially high torque ripple due to its salient structure. To apply SRM to the industrial field, we have to minimize torque ripple, which is the weak point of SRM. This article introduces optimal design process of SRM using a numerical method such as two-dimensional (2D) finite element method. The electrical and geometrical design parameters have been adopted as 2D design variables. From this work, we can obtain the optimal design, which minimizes the torque ripple. We also can obtain the optimal design, which maximizes the average torque. Finally, this article presents performance comparison of two optimal designs, the minimized torque ripple, and the maximized average torque.

Blood sample collection and rapid separation—critical preanalytical steps in clinical chemistry—can be challenging in decentralized collection settings. To address this gap, the Torq™ zero delay centrifuge system includes a lightweight, hand-portable centrifuge (ZDrive™) and a disc-shaped blood collection device (ZDisc™) enabling immediate sample centrifugation at the point of collection. Here, we report results from clinical validation studies comparing performance of the Torq System with a conventional plasma separation tube (PST). Blood specimens from 134 subjects were collected and processed across three independent sites to compare ZDisc and PST performance in the assessment of 14 analytes (K, Na, Cl, Ca, BUN, creatinine, AST, ALT, ALP, total bilirubin, albumin, total protein, cholesterol, and triglycerides). A 31-subject precision study was performed to evaluate reproducibility of plasma test results from ZDiscs, and plasma quality was assessed by measuring hemolysis and blood cells from 10 subject specimens. The ZDisc successfully collected and processed samples from 134 subjects. ZDisc results agreed with reference PSTs for all 14 analytes with mean % biases well below clinically significant levels. Results were reproducible across different operators and ZDisc production lots, and plasma blood cell counts and hemolysis levels fell well below clinical acceptance thresholds. ZDiscs produce plasma samples equivalent to reference PSTs. Results support the suitability of the Torq System for remotely collecting and processing blood samples in decentralized settings.

Quantifying circulating tumor DNA (ctDNA) markers for liquid biopsy testing often requires shipping blood samples to centralized laboratories. Mechanical damage to blood cells can occur during transport, especially if samples endure extensive vibration and temperature excursions. Such mechanical damage may result in Red Blood Cell (RBC) disruption known as in vitro hemolysis, as well as White Blood Cell (WBC) lysis leading to the release of nuclear DNA and several types of nucleases into the plasma. Nuclear DNA and nuclease contamination are the primary interfering factors impeding ctDNA recovery. Several commercial products are developed to address this issue by chemically stabilizing the cells in the tube during transport (e.g., the Streck cell-free DNA BCT™). Nevertheless, such products do not entirely resolve the problem, and cell lysis during shipping remains a complication. The Torq™ zero delay centrifuge system offers a novel solution by immediately centrifuging and separating plasma from the cell component at the point of collection, after the blood draw and prior to shipping, preventing ctDNA dilution from whole blood interferents. Here we compare hemolysis levels in blood samples collected and prepared by the Torq system and Streck BCTs following simulated shipping conditions including time, vibration, and temperature excursions. Blood samples from healthy individuals were collected into Torq ZDiscs™ and Streck BCTs. The plasma was immediately separated within the ZDiscs using the Torq ZDrive™ and transferred to microtubes. The specimens in Streck BCTs remained as whole blood, as per the manufacturer's instructions. Both sample types went through shipping simulation for 24 and 72 hours following ISTA 3A standards while experiencing temperature conditions of 4°C, 24°C, and 40°C. The blood within Streck BCTs was separated into plasma and cell components after reaching the designated time point, and all samples were inspected for hemolysis by quantifying hemoglobin content. Samples collected and processed with the Torq zero delay centrifuge system showed minimal hemolysis throughout the simulation and at all temperature conditions, whereas samples in the Streck BCTs exhibited significantly higher hemolysis, especially after 72 hours (p-value: 0.0001). Streck samples stored at 4°C and 40°C were notably susceptible to high hemolysis contamination. Compared to the Torq system, the Streck BCTs yielded significantly increased sample hemolysis following simulated shipping times and temperature excursions (both low and high), thereby increasing the likelihood of genomic contamination. The ZDiscs provide enhanced shipping resiliency and decreased nuclear DNA background, thus increasing the chance for rare mutation detection in liquid biopsy applications. Citation Format: Ali Rahimian, Kyungjin Hong, Clara Neal, Gabriella Iacovetti, Greg Sommer, Ulrich Schaff. TorqTM system improves liquid biopsy sample shipping stability [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3103.

No abstract