Paper-Based Microfluidic Devices: Low-Cost Platforms for Rapid Biochemical Detection.

INTRODUCTION: We developed low-cost, portable paper-based diagnostic devices for detection of human immunoglobulin M (IgM) and immunoglobulin G (IgG) in serum without any sample preparation. These devices can be used to help identify presence of diseases, used to provide rapid results (<5 minutes), readily used by untrained personnel, employed in austere environments, configured to obtain multiplexed assays, and easily disposed of. MATERIALS AND METHODS: We successfully accomplished colorimetric detection of human IgG and human IgM using a sandwich-style assay within the microfluidic paper device via vertical flow immunoassay configuration. The reaction zone in the wax printed paper layer is a small circular pattern. Gold nanoparticles conjugated with anti-human IgG and IgM antibodies have been used for colorimetric detection of IgG or IgM by naked eye. Colorimetric signal can be precisely quantified through implementation of image analysis software which can be developed as an app for a smartphone. The size of the device is 2 cm × 2 cm × 1 mm. RESULTS: Colorimetric detection of human IgG was accomplished at 100 fg/mL concentration using a gold nanoparticle-conjugated anti-human IgG antibody. The developed platform has a dynamic range of IgM and IgG concentrations between 0.1 pg/mL and 100 µg/mL. These devices provided a color readout in <5 minutes using 20 µL of serum. We also demonstrated that the devices show a significant degree of ruggedness and temperature stability as they were able to provide satisfactory results (detection of 0.1 pg/mL IgG) after 14 days of long stability and shelf-life experiment at an elevated temperature of at least 50 ˚C-the shelf life can be as long as 180 days under ambient conditions for detection of 100 µg/mL IgG. CONCLUSIONS: Because of the inherent simplicity of the device operation and their ease of use, there is no variation between samples and users of the device. This low-cost approach enables multiplexing with >1 measurement performed in parallel at the same time. We anticipate that because of the sensitivity, specificity, ease of use, and overall reliability, this approach will become a standard for diagnosis of diseases and health conditions.

Market and Patent Analyses of Wearables in Medicine.

Wearable medical devices (WMDs) will advance point-of-care diagnostics and therapeutics. This article analyses the market and patents for wearable devices. Activity monitors have the largest market share, and the intellectual property landscape is dominated by electronics corporations. However, the majority of these patents have not been realized in commercial products.

The role of baseline and post-procedural frontal plane QRS-T angles for cardiac risk assessment in patients with acute STEMI.

BACKGROUND: To our knowledge, no study so far investigated the importance of post-procedural frontal QRS-T angle f(QRS-T) in ST segment elevation myocardial infarction (STEMI). The aim of our study was to investigate the role of baseline and post-procedural f(QRS-T) angles for determining high risk STEMI patients, and the success of reperfusion. METHODS: A total of 248 patients with first acute STEMI that underwent primary percutaneous coronary intervention (pPCI) or thrombolytic therapy (TT) between 2013 and 2014 were included in this study. Baseline f(QRS-T) angle was defined as the angle which measured from the first ECG at the time of hospital admission. Post-procedural (QRS-T) angle was defined according to the treatment strategy as follows: the angle which measured from the post-PCI ECG in patients treated with pPCI; the angle which measured from the ECG taken 90 min after onset of therapy in patients treated with TT. RESULTS: The baseline (101.9° ± 48.0 vs. 72.1° ± 49.1, p = 0.014) and post-procedural f(QRS-T) angles (95.7° ± 48.1 vs. 58.1° ± 47.1, p = 0.002) were significantly higher in patients who developed in-hospital mortality than the patients who did not develop in-hospital mortality. Also, f(QRS-T) angle measured at 90 min was significantly lower in patients with successful thrombolysis group compared to failed thrombolysis group (53.2° ± 42.8 vs. 77.3° ± 52.9, p = 0.033), whereas baseline f(QRS-T) angle was similar between two groups (78.6° ± 53.4 vs. 78.9° ± 54.0, p = 0.976). Multivariate analysis showed that post-procedural f(QRS-T) angle ≥89.6° (odds ratio: 3.541, 95% confidence interval: 1.235-10.154, p = 0.019), but not baseline f(QRS-T) angle, was independent predictor of in-hospital mortality. CONCLUSION: f(QRS-T) angle may be used as a beneficial tool for determining high risk patients in acute STEMI. Unlike previous studies, we showed for the first time that that post-procedural f(QRS-T) can predict in-hospital mortality and TT failure.