Background: Multiple laboratory tests are used in the diagnosis and management of patients with diabetes mellitus The quality of the scientific evidence supporting the use of these assays varies substantially

Approach: An expert committee drafted evidence-based recommendations for the use of laboratory analysis in patients with diabetes An external panel of experts reviewed a draft of the guidelines, which were modified in response to the reviewers’ suggestions A revised draft was posted on the Internet and was presented at the AACC Annual Meeting in July, 2000 The recommendations were modified again in response to oral and written comments The guidelines were reviewed by the Professional Practice Committee of the American Diabetes Association

Content: Measurement of plasma glucose remains the sole diagnostic criterion for diabetes Monitoring of glycemic control is performed by the patients, who measure their own plasma or blood glucose with meters, and by laboratory analysis of glycated hemoglobin The potential roles of noninvasive glucose monitoring, genetic testing, autoantibodies, microalbumin, proinsulin, C-peptide, and other analytes are addressed

Summary: The guidelines provide specific recommendations based on published data or derived from expert consensus Several analytes are of minimal clinical value at the present time, and measurement of them is not recommended

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Guidelines and Recommendations for Laboratory Analysis in the Diagnosis and Management of Diabetes Mellitus

The present invention relates generally to systems and methods for measuring an analyte in a host. More particularly, the present invention relates to systems and methods for transcutaneous measurement of glucose in a host.

Transcutaneous analyte sensor

Blood glucose monitoring has been established as a valuable tool in the management of diabetes. Since maintaining normal blood glucose levels is recommended, a series of suitable glucose biosensors have been developed. During the last 50 years, glucose biosensor technology including point-of-care devices, continuous glucose monitoring systems and noninvasive glucose monitoring systems has been significantly improved. However, there continues to be several challenges related to the achievement of accurate and reliable glucose monitoring. Further technical improvements in glucose biosensors, standardization of the analytical goals for their performance, and continuously assessing and training lay users are required. This article reviews the brief history, basic principles, analytical performance, and the present status of glucose biosensors in the clinical practice.

Glucose biosensors: an overview of use in clinical practice

BACKGROUND Multiple laboratory tests are used to diagnose and manage patients with diabetes mellitus. The quality of the scientific evidence supporting the use of these tests varies substantially. APPROACH An expert committee compiled evidence-based recommendations for the use of laboratory testing for patients with diabetes. A new system was developed to grade the overall quality of the evidence and the strength of the recommendations. Draft guidelines were posted on the Internet and presented at the 2007 Arnold O. Beckman Conference. The document was modified in response to oral and written comments, and a revised draft was posted in 2010 and again modified in response to written comments. The National Academy of Clinical Biochemistry and the Evidence-Based Laboratory Medicine Committee of the American Association for Clinical Chemistry jointly reviewed the guidelines, which were accepted after revisions by the Professional Practice Committee and subsequently approved by the Executive Committee of the American Diabetes Association. CONTENT In addition to long-standing criteria based on measurement of plasma glucose, diabetes can be diagnosed by demonstrating increased blood hemoglobin A 1c (HbA 1c ) concentrations. Monitoring of glycemic control is performed by self-monitoring of plasma or blood glucose with meters and by laboratory analysis of HbA 1c . The potential roles of noninvasive glucose monitoring, genetic testing, and measurement of autoantibodies, urine albumin, insulin, proinsulin, C-peptide, and other analytes are addressed. SUMMARY The guidelines provide specific recommendations that are based on published data or derived from expert consensus. Several analytes have minimal clinical value at present, and their measurement is not recommended.

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Optical spectroscopy, imaging, and therapy tissue phantoms must have the scattering and absorption properties that are characteristic of human tissues, and over the past few decades, many useful models have been created. In this work, an overview of their composition and properties is outlined, by separating matrix, scattering, and absorbing materials, and discussing the benefits and weaknesses in each category. Matrix materials typically are water, gelatin, agar, polyester or epoxy and polyurethane resin, room-temperature vulcanizing (RTV) silicone, or polyvinyl alcohol gels. The water and hydrogel materials provide a soft medium that is biologically and biochemically compatible with addition of organic molecules, and are optimal for scientific laboratory studies. Polyester, polyurethane, and silicone phantoms are essentially permanent matrix compositions that are suitable for routine calibration and testing of established systems. The most common three choices for scatters have been: (1.) lipid based emulsions, (2.) titanium or aluminum oxide powders, and (3.) polymer microspheres. The choice of absorbers varies widely from hemoglobin and cells for biological simulation, to molecular dyes and ink as less biological but more stable absorbers. This review is an attempt to indicate which sets of phantoms are optimal for specific applications, and provide links to studies that characterize main phantom material properties and recipes.

https://www.spiedigitallibrary.org/journals/journal-of-biomedical-optics/volume-11/issue-4/041102/Review-of-tissue-simulating-phantoms-for-optical-spectroscopy-imaging-and/10.1117/1.2335429.pdf

Review of tissue simulating phantoms for optical spectroscopy, imaging and dosimetry

We report here on in vitro and in vivo experiments that are intended to explore the feasibility of photoacoustic spectroscopy as a tool for the noninvasive measurement of blood glucose. The in vivo results from oral glucose tests on eight subjects showed good correlation with clinical measurements but indicated that physiological factors and person-to-person variability are important. In vitro measurements showed that the sensitivity of the glucose measurement is unaffected by the presence of common blood analytes but that there can be substantial shifts in baseline values. The results indicate the need for spectroscopic data to develop algorithms for the detection of glucose in the presence of other analytes.

/pdf/advances-in-photoacoustic-noninvasive-glucose-testing-4g5wgnpjet.pdf

Advances in Photoacoustic Noninvasive Glucose Testing

A system for measuring a biological parameter, such as blood glucose, the system comprising the steps of directing laser pulses from a light guide into a body part consisting of soft tissue, such as the tip of a finger to produce a photoacoustic interaction The resulting acoustic signal is detected by a transducer and analyzed to provide the desired parameter

System for measuring a biological parameter by means of photoacoustic interaction

A preliminary study of using a gelatin-based in vivo tissue model to investigate some of the near infrared photoacoustic characteristics that may influence the sensitivity of non-invasive photoacoustic detection of blood glucose in human tissue is described. It is shown that the optical absorption change due to glucose in the near infrared region is small and that the pulsed photoacoustic technique may offer a better detection sensitivity than other conventional optical transmission measurement systems being developed for blood glucose monitoring.

https://iopscience.iop.org/article/10.1088/0031-9155/38/12/014/pdf

Glucose determination by a pulsed photoacoustic technique: an experimental study using a gelatin-based tissue phantom

The first digital all-optical circuits based on intrinsic bistable devices have now been realized. Experimental results with two systems, InSb etalons and nonlinear interference filters containing ZnSe, are presented and discussed. These results indicate that a digital optical processor incorporating devices of this type would appear to be feasible.

Nonlinear optical circuit elements as logic gates for optical computers: the first digital optical circuits.

Studies of the angular dependence of cw degenerate four-wave mixing in n-type InSb have yielded a value for the diffusion length, l(D), of 60 +/- 2 microm. From this, the dependence of l(D) on photoexcited carrier concentration is calculated. A simple model has been developed to estimate the corresponding parallel-processing capabilities of semi-conductor-based, all-optical, parallel-processing digital computing systems.

Hugh A. MacKenzie

Papers

Advances in Photoacoustic Noninvasive Glucose Testing

System for measuring a biological parameter by means of photoacoustic interaction

Glucose determination by a pulsed photoacoustic technique: an experimental study using a gelatin-based tissue phantom

Nonlinear optical circuit elements as logic gates for optical computers: the first digital optical circuits.

Carrier diffusion measurements in InSb by the angular dependence of degenerate four-wave mixing.