An integrated centrifugal microfluidic strategy for point-of-care complete blood counting

Centrifugal microfluidics holds the potential to revolutionize point-of-care (POC) testing by simplifying laboratory tests through automating fluid and cell manipulation within microfluidic channels. This technology can facilitate blood testing, the most frequent clinical test, at the POC. However, an integrated centrifugal microfluidic device for complete blood counting (CBC) has not yet been fully realized. To address this, we propose an integrated portable system comprising a centrifuge and a hybrid microfluidic disc specifically designed for CBC analysis at the POC. The disc enables the implementation of various spin profiles in different stages of CBC to facilitate in-situ cell separation, solution metering and mixing, and differential cell counting. Furthermore, our system is coupled with a custom script that automates the process and ensures precise quantification of cells using light and fluorescent images captured from the detection chamber of the disc. We demonstrate a close correlation between the proposed method and the hematology analyzer, considered the gold standard, for quantifying hematocrit (R2 = 0.99), white blood cell count (R2 = 0.98), white blood cell differential count (granulocyte/agranulocyte; R2 = 0.89), red blood cell count (R2 = 0.97), and mean corpuscular volume (R2 = 0.94). The integration of our portable system offers significant advantages, enabling more accessible and affordable CBC testing at the POC. Considering the simplicity, affordability (∼$250 capital cost and <$2 operational cost per test), as well as low power consumption (>100 tests using a typical 24 V/10 Ah battery), this system has the potential to enhance healthcare delivery, particularly in resource-limited settings and remote areas where access to traditional laboratory facilities is limited.

Real-time monitoring and actuation of a hybrid siphon valve for hematocrit-independent plasma separation from whole blood

Centrifugal microfluidics have emerged as a pivotal area of research spanning multiple domains, including medicine and chemistry. Among passive valving strategies, siphon valves have gained prominence due to their inherent simplicity and self-reliance, eliminating the need for external equipment. However, achieving optimal valve performance mandates supplementary elements like surface adjustments or pneumatic pressure. These introduce intricacies such as time-dependent behavior and augmented spatial demands. This research introduces inventive design and manufacturing methodologies to amplify siphon valve functionality. Our proposed innovation situates the siphon microchannel on the external surface of the primary chamber, linked via an inlet. The crux of novelty lies in the adaptable material selection for the microchannel's upper or lower surfaces, allowing the integration of hydrophilic materials such as glass or super hydrophilic coverslips, ensuring a leakage-free operation. Our approach offers a streamlined concept and manufacturing process, ensures consistent time-independent functionality, and accommodates the integration of multiple siphon valves within a solitary chamber, tailored for specific applications. Experimental evaluations validate a robust alignment between acquired data and analytical outcomes based on a modified equation. A customized disc is engineered, featuring four siphon valves meticulously calibrated for hematocrit (HCT) levels spanning from 20% to 50% at 10% intervals. Harnessing these valves yields a substantial surge in plasma separation efficiency, scaling up to 75%. Notably, this performance eclipses traditional single-valve reliant microfluidic methodologies, achieving a purity level exceeding 99% in plasma separation. These findings underscore the auspicious practical applicability of our proposed technique in plasma separation, fostering heightened platelet concentration, and expediting blood sample analysis.

Conceptual Design of a Device for Online Calibration of Spirometer Based on Neural Network

Daily calibration of spirometry devices plays an important role in promoting the accuracy of pulmonary diagnostic results. It is needed to have more precise and adequate instruments for calibrating spirometry during the clinical use. In this work, a device was designed and developed based on a calibrated-volume syringe and an electrical circuit was also built to measure the air flux. Some colored tapes with specific size and order covered the syringe piston. When the piston moved in front of the color sensor, the input air flow was calculated according to the width of the strips and transferred to the computer. A Radial Basis Function (RBF) neural network estimator used new data to modify the previous estimation function for increasing the accuracy and the reliability. The simulation showed that the root mean square of the error improved from 13.7±0.37% to 4.2±0.22%, i.e. the calibration curve has improved about 70%.

A New Detection Chamber Design on Centrifugal Microfluidic Platform to Measure Hemoglobin of Whole Blood

Undoubtedly, microfluidics has been a focal point of interdisciplinary science during the last two decades, resulting in many developments in this area. Centrifugal microfluidic platforms have good potential for use in point-of-care devices because they take advantage of some intrinsic forces, most notably centrifugal force, which obviates the need to any external driving forces. Herein, we introduce a newly designed detection chamber for use on microfluidic discs that can be employed as an absorbance readout step in cases where the final solution has a very low viscosity and surface tension. In such situations, our chamber easily eliminates the air bubbles from the final solution without any interruption. One microfluidic disc for measuring the hemoglobin concentration was designed and constructed to verify the correct functioning of this detection chamber. This disc measured the hemoglobin concentration of the blood samples via the HiCN method. Then, the hemoglobin concentration of 11 blood samples was quantified and compared with the clinic's data using the hemoglobin measurement disc, which included four hemoglobin measurement sets, and each set contained two inlets for the blood sample and the reagent, one two-part mixing chamber, and one bubble-free detection chamber. The measured values of the disc had good linearity and conformity compared with the clinic's data, and there were no air bubbles in the detection step. In this study, the standard deviation and the turnaround time were ± 0.51 g/dL and 68 s, respectively.

Prospective comparative study assessing role of ultrasound versus thermography in breast cancer detection

BACKGROUND

The limitations of mammography as a screening and diagnostic tool, especially for younger women with dense breasts, makes it necessary to use an adjunctive modality to cover its shortcomings. Ultrasound and thermography both have potential role in this era.

OBJECTIVES

We will compare the accuracy of thermography with ultrasound in breast cancer diagnosis in a clinical setting.

PATIENTS AND METHODS

This study consisted of 78 women who underwent ultrasound and thermography on the same day, since evaluations were performed for both breasts in all patients separately, each breast was considered a distinct case. Biopsy was performed in 14 suspicious cases with an outcome of 7 malignant results. All women were followed for one year.

RESULTS

The average age of 78 patients was 41.0 ± 10.4 years. Sensitivity, specificity, PPV, NPV, and overall accuracy for ultrasound in diagnosing malignant breast lesions were 100%, 95.3%, 50.0%, 100%, 95.5% and for thermography 85.7%, 78.5%, 15.8%, 99.1%, and 78.8% respectively.

CONCLUSION

We believe that thermography is a non-invasive, safe, and accepted method by patients; however, despite technical advances in it, its diagnostic abilities are still less than those of sonography, so we suggest that it be used as an adjunct in breast cancer diagnosis in selective situations.

The Effect of Moment of Inertia on the Liquids in Centrifugal Microfluidics

The flow of liquids in centrifugal microfluidics is unidirectional and dominated by centrifugal and Coriolis forces (i.e., effective only at T-junctions). Developing mechanisms and discovering efficient techniques to propel liquids in any direction other than the direction of the centrifugal force has been the subject of a large number of studies. The capillary force attained by specific surface treatments, pneumatic energy, active and passive flow reciprocation and Euler force have been previously introduced in order to manipulate the liquid flow and push it against the centrifugal force. Here, as a new method, the moment of inertia of the liquid inside a chamber in a centrifugal microfluidic platform is employed to manipulate the flow and propel the liquid passively towards the disc center. Furthermore, the effect of the moment of inertia on the liquid in a rectangular chamber is evaluated, both in theory and experiments, and the optimum geometry is defined. As an application of the introduced method, the moment of inertia of the liquid is used in order to mix two different dyed deionized (DI) waters; the mixing efficiency is evaluated and compared to similar mixing techniques. The results show the potential of the presented method for pumping liquids radially inward with relatively high flow rates (up to 23 mm³/s) and also efficient mixing in centrifugal microfluidic platforms.

Fuzzy logic controller for hemodialysis machine based on human body model

Fuzzy controllers are being used in various control schemes. The aim of this study is to adjust the hemodialysis machine parameters by utilizing a fuzzy logic controller (FLC) so that patient's hemodynamic condition remains stable during hemodialysis treatment. For this purpose, a comprehensive mathematical model of the arterial pressure response during hemodialysis, including hemodynamic, osmotic, and regulatory phenomena has been used. The multi-input multi-output (MIMO) fuzzy logic controller receives three parameters from the model (heart rate, arterial blood pressure, and relative blood volume) as input. According to the changes in the controller input values and its rule base, the outputs change so that the patient's hemodynamic condition remains stable. The results of the simulations illustrate that applying the controller can improve the stability of a patient's hemodynamic condition during hemodialysis treatment and it also decreases the treatment time. Furthermore, by using fuzzy logic, there is no need to have prior knowledge about the system under control and the FLC is compatible with different patients.