In this paper, we present a novel microfluidic system with pulsatile cell storing, cell-delivering and cell culturing functions on a single PDMS platform. For this purpose, we have integrated two reservoirs, a pulsatile pumping system containing two soft check valves, which were fabricated by in situ photopolymerization, six switch valves, and three cell culture chambers all developed through a simple and rapid fabrication process. The sample volume delivered per stroke was 120 nl and the transported volume was linearly related to the pumping frequency. We have investigated the effect of the pulsatile pneumatic micropumping on the cells during transport. For this purpose, we pumped two types of cell suspensions, one containing human breast adenocarcinoma cells (MCF-7) and the other mesenchymal stem cells (hMSCs) derived from bone marrow. The effect of pulsatile pumping on both cell types was examined by short and long-term culture experiments. Our results showed that the characteristics of both cells were maintained; they were not damaged by the pumping system. Evaluations were carried out by morphological inspection, viability assay and immunophenotyping analysis. The delivered MCF-7 cells and hMSCs spread and proliferated onto the gelatin coated cell culture chamber. This total micro cell culture system can be applied to cell-based high throughput screening and for co-culture of different cells with different volume.
Tumor volume and standard uptake value (SUV) calculated from positron emission tomography/computed tomography (PET/CT) images differ from their real values. Besides errors introduced by scintillation materials, photomultiplier tubes, and image reconstruction algorithms, measurements are affected by patients' prostheses, body movements, and body shape. To address these problems, we calculated tumor volume and SUV using the standard phantom (PET Phantom-NEMA IEC/2001) and obtained calibration constants. We found that while tumor volume increases with increasing SUV and tumor diameter, it also increases with increasing SUV and decreasing tumor diameter. Conversely, tumor volume decreases with decreasing SUV and tumor diameter and with decreasing SUV and increasing diameter. These results suggest that a correction factor should be applied to SUV and tumor volume obtained from PET/CT images.
Photoplethysmography (PPG) offers the clinically meaningful parameters, such as, heart rate, and respiratory rate. In this study, we presented three respiratory signal detection algorithms using photoplethysmography raw data generated from commercial PPG sensor: (1)Min-Max (2)Peak-to-Peak (3)Pulse Shape. As reference signal, nasal sensor signal was acquired simultaneously and compared and analyzed. We used two types of moving average filtering technique to process three PPG parameters. In laboratory experiment, 6 subjects' PPG signals were measured when they respire ten and fifteen, and arbitrary times per minute. From the results, following conclusions were drawn. Min-Max and Peak-to-Peak algorithms perform better than Pulse shape algorithm. They can be used to detect respiratory rate. But, Pulse Shape algorithm was accurate for subject 4 only. More experimental data is necessary to improve the accuracy and reliability.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.