Point-of-care testing of plasma free hemoglobin and hematocrit for mechanical circulatory support

Abstract

Hematological analysis is essential for patients who are supported by a mechanical circulatory support (MCS). The laboratory methods used to analyze blood components are conventional and accurate, but they require a mandatory turn-around-time for laboratory results, and because of toxic substances, can also be hazardous to analysis workers. Here, a simple and rapid point-of-care device is developed for the measurement of plasma free hemoglobin (PFHb) and hematocrit (Hct), based on colorimetry. The device consists of camera module, minimized centrifuge system, and the custom software that includes the motor control algorithm for the centrifuge system, and the image processing algorithm for measuring the color components of blood from the images. We show that our device measured PFHb with a detection limit of 0.75 mg/dL in the range of (0–100) mg/dL, and Hct with a detection limit of 2.14% in the range of (20–50)%. Our device had a high correlation with the measurement method generally used in clinical laboratories (PFHb R = 0.999, Hct R = 0.739), and the quantitative analysis resulted in precision of 1.44 mg/dL for PFHb value of 14.5 mg/dL, 1.36 mg/dL for PFHb value of 53 mg/dL, and 1.24% for Hct 30%. Also, the device can be measured without any pre-processing when compared to the clinical laboratory method, so results can be obtained within 5 min (about an 1 h for the clinical laboratory method). Therefore, we conclude that the device can be used for point-of-care measurement of PFHb and Hct for MCS.

Challenge of material haemocompatibility for microfluidic blood-contacting applications

“…When the erythrocyte membrane ruptures haemoglobin is released into the surrounding plasma and can be detected. The level is reported as the percentage of free haemoglobin to the total haemoglobin concentration ( Shin et al, 2021 ). Clinically, haemolysis is a concern due the loss of erythrocytes which can result in anaemia.…”

Perspective Chapter: Delivering LVAD Care to the Local Community

“…Additionally, laboratory tests are followed closely to ensure proper function of the LVAD. Regular INR checks, lactate dehydrogenase (LDH), and plasma free hemoglobin or hematocrit are measured regularly to monitor for adequate anticoagulation, as well as to monitor for hemolysis [44]. In addition, echocardiography is used to monitor ventricular function.…”

Current and Emerging Microfluidic-Based Integrated Solutions for Free Hemoglobin and Hemolysis Detection and Measurement

“…Furthermore, the sample was excited by a wide range of wavelengths (white light), and other absorption species in plasma such as bilirubin can interfere with the true value of brightness. Shin et al also used a similar approach, measuring the CIELAB parameters using a custom-made point-of-care device to calculate hematocrit (Hct) and fHgb . The device was equipped with a camera module, a miniaturized centrifuge for plasma separation, and a colorimetric analysis unit for analyzing the sample’s hue.…”

“…Shin et al also used a similar approach, measuring the CIELAB parameters using a custom-made point-of-care device to calculate hematocrit (Hct) and fHgb. 70 The device was equipped with a camera module, a miniaturized centrifuge for plasma separation, and a colorimetric analysis unit for analyzing the sample's hue. As a result, the sensitivity was improved to 0.75 mg/dL with a detection range between 0 and 100 mg/dL.…”