Point-of-care testing (POCT), which is diagnostic testing performed on site, has the potential to improve healthcare and healthcare delivery. The motivation for POCT is to bring medical testing conveniently and immediately to the patient. Samples can be obtained and tested, and results are analyzed immediately at or near the location of the patient, thus enabling more rapid medical diagnostics and treatment. Early POCT research included the work of Clark and Lyons in the 1960s, which resulted in the “enzyme electrode”for glucose measurement using the enzyme glucose oxidase (GOD). This work was the first demonstration of a biosensor, as well as the first glucose monitor. More comprehensive portable POCT technology was developed in the early 1990s, with a portable simultaneous multiple analyte whole-blood analyzer for optical monitoring of chemical reactions at nine wavelengths. However, the most significant advance in POCT technology has been the emergence of modern consumer handheld devices, such as the smartphone, which enables POCT devices to be portable, and handheld instruments, such as lab-on-a-chip (LOC), leading to the proliferation of POCT, especially in resource-poor settings.

Chapter Contents:

• 1.1 Introduction
• 1.1.1 Medical applications for POCT
• 1.1.2 Portable technologies for POCT
• 1.1.3 Optical detection and analysis
• 1.1.4 Examples for the broader use of optical detection in medicine
• 1.1.4.1 Ophthalmology
• 1.1.4.2 Endoscopy
• 1.1.4.3 Flow cytometry
• 1.1.4.4 Wide-field imaging
• 1.1.5 Smartphone and webcam-based POCT
• 1.2 Portable CMOS and CCD imaging-based detection technologies
• 1.2.1 POCT bioassay for foodborne toxins
• 1.2.2 Webcam-based fluorescence plate reader for POCT of foodborne toxins
• 1.2.2.1 LED illumination module
• 1.2.2.2 Assay plate
• 1.2.3 Fluorescence detection of Stx2 activity
• 1.2.4 Application of the webcam-based fluorescence plate reader to other food bone toxins
• 1.3 Computational enhancement of the sensitivity of webcam-based detectors
• 1.3.1 Image stacking-based computational signal enhancement
• 1.4 Capillary arrays as waveguides for enhancing the sensitivity of optical detectors
• 1.4.1 Webcam detector with capillary array
• 1.4.2 Fluorescein detection using capillary array
• 1.5 Smartphone-based fluorescence detection system using capillary array
• 1.5.1 Smartphone-based capillary array fluorescence detector
• 1.5.2 Orthographic optical configuration
• 1.6 Summary of factors contributing to the sensitivity of low-cost optical detectors
• 1.7 Conclusions
• Acknowledgment
• References

Inspec keywords: patient diagnosis; biomedical equipment; chemical sensors; blood; health care; optical sensors; biosensors; sugar; portable instruments; enzymes

Other keywords: portable optical detectors; glucose monitor; medical testing; portable simultaneous multiple analyte whole-blood analyzer; optical monitoring; glucose measurement; consumer handheld devices; biosensor; medical treatment; enzyme electrode; healthcare delivery; medical diagnostics; point-of-care diagnostics; point-of-care testing; chemical reactions; enzyme glucose oxidase

Subjects: Optical instruments and techniques; Optical and laser radiation (biomedical imaging/measurement); Biosensors; Chemical sensors; Optical and laser radiation (medical uses); Chemical sensors; Biosensors; Patient diagnostic methods and instrumentation