Holographic sensors in contact lenses for minimally-invasive glucose measurements

Domschke, Angelika; Kabilan, Satyamoorthy; Anand, R. S.; Caines, M.; Fetter, Damien; Griffith, Paul; James, K.; Karangu, N.; Smith, Dawn A.; Vargas, Mike; Zeng, Jimmy; Hussain, Abid; Yang, Xiaoping; Blyth, Jeff; Mueller, Alexander; Herbrechtsmeier, Peter; Lowe, Christopher R.

doi:10.1109/icsens.2004.1426425

Cited by 15 publications

(12 citation statements)

References 9 publications

(22 reference statements)

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“…Contact lenses for CGM were developed based on optical transducers (holograms, light diffusive microstructures, 1D gratings) that were capable of monitoring the volumetric response of the glucose-sensitive hydrogel which was based on PBA derivatives immobilized in a polyacrylamide hydrogel matrix. [37,38,42,43] However, these contact lenses could not function in the physiological glucose concentration range of tears. The developed contact lens in the present work functions in the low glucose concentration range of tears and the role of the optical transducer (Fresnel structure) may extend to control myopia, and assist presbyopes by providing clear near viewing, which make the developed contact lens favorable for patients who suffer from both diabetes and refractive errors.…”

Section: Resultsmentioning

confidence: 99%

Wearable Bifocal Contact Lens for Continual Glucose Monitoring Integrated with Smartphone Readers

Elsherif

Alam

Salih

et al. 2021

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day. The CGM systems have revolutionized the way diabetes is managed, especially in type 1 diabetes. The first "professional" CGM system was approved by U.S Food and Drug Administration (FDA) in 1999. [2] The first non-invasive CGM, which allowed patients and providers to measure glucose concentration, was the "Glucowatch Biographer", which was approved by the FDA in 2001; however, this device has been withdrawn from the market due to low clinical efficacy and irreproducibility of measurements. [3] An advanced real-time CGM system (Guardian) was introduced by Medtronic in 2004. [4] In 2006, Dexcom released its first real-time CGM which is called the Short-Term Sensor (STS). [5] Free-Style Navigator by Abbott was released in 2008. [6] Dexcom introduced the G4 Platinum, G5, and G6 in 2012, 2015, and 2018, respectively, which allowed the glucose readings to be transmitted to the user's smartphone. [7] In 2016, Abbott released FreeStyle Libre Pro CGM which does not require frequent calibration and can be worn for 14 days. [8] In 2017, FreeStyle Libre, which could be worn for 10 days, with real-time user access was introduced. [9] However, the advances in CGM systems remained limited due to: i) they haven't been approved by the FDA for insulin dosing, and for use in hospitals and intensive care units, ii) high costs, iii) necessity for calibrations (at least twice a day) as a result of signal drift, and iv) regular replacement of the electrochemical sensor. [10] Commercial CGM systems detect glucose concentration in the interstitial fluid, which requires the insertion of the electrochemical probe through the skin. On the contrary, tears are easy and minimally-invasively accessed, and could be used as a blood proxy for diagnosing cancer, Alzheimer's disease, Parkinson's disease, cystic fibrosis, systemic sclerosis, aniridia, glaucoma, and dry eye. [11][12][13][14][15][16][17][18][19][20] In this context, contact lenses-integrated sensors that sample and measure tears offer a minimally-invasive diagnostic platform to detect numerous biomarkers. [21,22] The advances in electronics and microfabrication allowed for the miniaturization of the biosensors to fit in contact lenses without blocking the eye vision.The contact lenses have been integrated with electrochemical, light diffraction, and fluorescent glucose sensors. The electrochemical sensors are enzyme-based and they have been successfully attached to contact lenses comprising polyethylene terephthalate (PET), and polydimethylsiloxane (PDMS). [23][24][25][26][27] Commercial implantable continuous glucose monitoring devices are invasive and discomfort. Here, a minimally-invasive glucose detection system is developed to provide quantitative glucose measurements continually based on bifocal contact lenses. A glucose-sensitive phenylboronic acid derivative is immobilized in a hydrogel matrix and the surface of the hydrogel is imprinted with a Fresnel lens. The glucose-responsive hydrogel is attached to a commercial soft contact lens to be transformed into a bifocal conta...

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Section: Resultsmentioning

confidence: 99%

Wearable Bifocal Contact Lens for Continual Glucose Monitoring Integrated with Smartphone Readers

Elsherif

Alam

Salih

et al. 2021

Small

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“…There has been rapid development in the use of functionalized nanostructured surfaces to allow for quantitative and accurate measurement of biological analytes with the development of sophisticated substrates such as hydrogel based ionic skins. [26] Holographic sensors for analyzing hydration, [17] monitoring respiration, [18] lactate, [27] urinalysis, [28] tear fluid analysis, [29,30] and alcohol intoxication [31] within the body has been highly investigated in recent years due to the growing drive to personalized medical care. [32] The development of these devices offers the possibility for healthcare providers to analyze the realtime concentrations of biomarkers using simple inexpensive analytical equipment.…”

Section: Requirement For Holographic Sensors In Biomedical Applicationsmentioning

confidence: 99%

Holographic Sensors in Biotechnology

Davies

Jiang

et al. 2021

Adv Funct Materials

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As populations expand worldwide, medical care will need to diversify its data collection techniques to be able to provide adequate healthcare to global populations, this can be achieved through point-of-care analysis by wearable analytical devices. Holographic sensors are reusable optical biosensors with the capability to continuously monitor variations, generating the prospect of in vivo monitoring of patient homeostasis. Holographic optical sensors have emerged as an opportunity for low cost and real-time point-of-care analysis of biomarkers to be realized. This review aims to summarize the fundamentals and fabrications of holographic sensors; a key focus will be directed to examining the biotechnology applications in a variety of analytical settings. Techniques covered include surface relief gratings, inverse opals, metal nanoparticle and nanoparticle free holographic sensors. This article provides an overview of holographic biosensing in applications such as pH, alcohol, ion, glucose, and drug detection, alongside antibiotic monitoring. Details of developments in fabrication and sensitizing techniques will be examined and how they have improved the applicability of holographic sensors to point-of-care analytics. Although holographic sensors have made significant progress in recent years, the current challenges, and requirements for advanced holographic technology to fulfil their future potential applications in biomedical devices will be discussed.

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“…The hydrogel film was photopolymerized and embedded with silver bromide along with a dye to create a polymer film. The holographic film was then incorporated into a contact lens after treatment with PVA contact lens formulation [ 95 ]. The result was a contact lens with holographic diffraction gratings that can diffract light.…”

Section: Contact-lens Biosensorsmentioning

confidence: 99%

Contact-Lens Biosensors

Tseng

Chen

Hsu

et al. 2018

Sensors

112

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Rapid diagnosis and screening of diseases have become increasingly important in predictive and preventive medicine as they improve patient treatment strategies and reduce cost as well as burden on our healthcare system. In this regard, wearable devices are emerging as effective and reliable point-of-care diagnostics that can allow users to monitor their health at home. These wrist-worn, head-mounted, smart-textile, or smart-patches devices can offer valuable information on the conditions of patients as a non-invasive form of monitoring. However, they are significantly limited in monitoring physiological signals and biomechanics, and, mostly, rely on the physical attributes. Recently, developed wearable devices utilize body fluids, such as sweat, saliva, or skin interstitial fluid, and electrochemical interactions to allow continuous physiological condition and disease monitoring for users. Among them, tear fluid has been widely utilized in the investigation of ocular diseases, diabetes, and even cancers, because of its easy accessibility, lower complexity, and minimal invasiveness. By determining the concentration change of analytes within the tear fluid, it would be possible to identify disease progression and allow patient-oriented therapies. Considering the emerging trend of tear-based biosensing technology, this review article aims to focus on an overview of the tear fluid as a detection medium for certain diseases, such as ocular disorders, diabetes, and cancer. In addition, the rise and application of minimally invasive detection and monitoring via integrated contact lens biosensors will also be addressed, in regards to their practicality and current developmental progress.

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Holographic sensors in contact lenses for minimally-invasive glucose measurements

Cited by 15 publications

References 9 publications

Wearable Bifocal Contact Lens for Continual Glucose Monitoring Integrated with Smartphone Readers

Wearable Bifocal Contact Lens for Continual Glucose Monitoring Integrated with Smartphone Readers

Holographic Sensors in Biotechnology

Contact-Lens Biosensors

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