BraceIO: biosensing through hydrogel dental ligatures

Background: Measurement of bite force plays a crucial role in assessment of the masticatory system. With a growing interest in detecting occlusal irregularities, bite force sensors have garnered attention in the biomedical field. This study aimed to introduce a hydrogel bite force sensor, based on hydroxyethyl-cellulose-fructose-water (HEC-F-water), for premolar and molar teeth, and to evaluate it using optical profilometry, infrared spectroscopy (FTIR), and Instron Tension testing system, with 2.5 cm (1 inch) margins at top, bottom, right, and left. Material/Methods: We fabricated 20 HEC-F-water hydrogel samples sized with surface of 1×1 cm, with 2 different widths-1 mm and 5 mm. The samples were characterized using optical profilometry and FTIR and their electrical characteristics were determined using an impedance analyzer. Aluminum (Al) electrodes, fabricated using Cutting Plotter, were used to form a HEC-F-water-based transducer, which was used for bite force sensing. The Instron tensile testing system was employed, utilizing 3D printed models of the upper and lower jaw, to simulate biting. Forces in the range between 40 N and 540 N were exerted upon the transducer, and the output change in the electrical signal was measured. Results: The study determined the transfer function between bite force and capacitance. The fabricated sensor exhibited a sensitivity of 3.98 pF/N, an input range of 500 N, output range of 2 nF, and accuracy of 95.9%. Conclusions: This study introduces an edible bite force sensor employing an edible hydrogel as a dielectric, presenting a novel avenue in the development of edible sensorics in dentistry.

2019 41st Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2019

Wearables are being widely researched for monitoring individual's health and wellbeing. Current generation wearable devices sense an individual's physiological data such as heart rate, respiration, electrodermal activity, and EEG, but lack in sensing their biological counterparts, which drive the majority of individual's physiological signals. On the other hand, biosensors for detecting biochemical markers are currently limited to one-time use, are non-continuous and don't provide flexibility in choosing which biomarker they sense. We present "wearable lab on body", a platform for active continuous monitoring of human biomarkers from the biological fluid. Our platform contains both digital sensors such as IMU for activity recognition, as well as an automated system for continuous sampling of biomarkers from saliva by leveraging already existing paper-based biochemical sensors. The platform could aid with longitudinal studies of biomarkers and early diagnosis of diseases.

Dentistry Journal

Wearable technology to augment traditional approaches are increasingly being added to the arsenals of treatment providers. Wearable technology generally refers to electronic systems, devices, or sensors that are usually worn on or are in close proximity to the human body. Wearables may be stand-alone or integrated into materials that are worn on the body. What sets medical wearables apart from other systems is their ability to collect, store, and relay information regarding an individual’s current body status to other devices operating on compatible networks in naturalistic settings. The last decade has witnessed a steady increase in the use of wearables specific to the orofacial region. Applications range from supplementing diagnosis, tracking treatment progress, monitoring patient compliance, and better understanding the jaw’s functional and parafunctional activities. Orofacial wearable devices may be unimodal or incorporate multiple sensing modalities. The objective data collecte...

Advanced materials (Deerfield Beach, Fla.), 2018

Living organisms ubiquitously display colors that adapt to environmental changes, relying on the soft layer of cells or proteins. Adoption of soft materials into an artificial adaptive color system has promoted the development of material systems for environmental and health monitoring, anti-counterfeiting, and stealth technologies. Here, a hydrogel interferometer based on a single hydrogel thin film covalently bonded to a reflective substrate is reported as a simple and universal adaptive color platform. Similar to the cell or protein soft layer of color-changing animals, the soft hydrogel layer rapidly changes its thickness in response to external stimuli, resulting in instant color change. Such interference colors provide a visual and quantifiable means of revealing rich environmental metrics. Computational model is established and captures the key features of hydrogel stimuli-responsive swelling, which elucidates the mechanism and design principle for the broad-based platform. T...

Biosensors and Bioelectronics, 2017

The development of smartphone-based biosensors for point-of-care testing (POCT) applications allows realizing "all in one" instruments, with large potential distribution among the general population. With this respect, paper color-based detection performed by reflectance measurement is the most popular, simple, inexpensive and straightforward method. Despite the large number of scientific publications related to these biosensors, they still suffer from a poor detectability and reproducibility related to inhomogeneity of color development, which leads to low assay reproducibility. To overcome these problems, we propose a smartphone paper-based biosensor, in which all the reagents necessary to complete the analysis are co-entrapped on paper in a "wafer"-like bilayer film of polyelectrolytes (Poly (allyl amine hydrochloride/poly(sodium 4-styrene sulfonate)). Using a 3D printing low-cost technology we fabricated the smartphone-based device that consists in a cover accessory attached to the smartphone and incorporating a light diffuser over the flash to improve the image quality, a mini dark box and a disposable analytical cartridge containing all the reagents necessary for the complete analysis. The biosensor was developed exploiting coupled enzyme reactions for quantifying L-lactate in oral fluid, which is considered a biomarker of poor tissue perfusion, a key element in the management of severe sepsis, septic shock and in sports performance evaluation. The developed method is sensitive, rapid, and it allows detecting L-lactate in oral fluid in the relevant physiological range, with a limit of detection of 0.1 mmol L−1. The extreme simplicity of assay execution (no reagents need to be added) and flexibility of fabrication of the device, together with the high assay versatility (any oxidase can be coupled with HRP-based color change reaction) make our approach suitable for the realization of smartphone-based biosensors able to noninvasively detect a large variety of analytes of clinical interest.

Paper-based sensors have great potential for use in a variety of areas, from environmental monitoring to clinical and pointof-care testings. Here, a microfluidic paper-based analytical device (µPAD) was integrated with a smartphone app capable of offline (without internet access) image processing and analysis for rapid colorimetric detection of glucose. A self-inking stamp was used to form hydrophobic channels on a piece of paper-towel due to its superior water absorption efficiency. As demonstrated, the developed sensor was employed for colorimetric detection of glucose in artificial saliva in the linear scope of 0-1 mM with a calculated detection limit of 29.65 µM. In addition, experimental results show that quantitative analysis of glucose with the proposed smartphone platform could be completed in less than one minute. The app developed for the smartphone platform is capable of extracting the color changing area with an embedded image processing tool which could address the prob...

Analytical Sciences, 2021

In this study, a microfluidic paper-based analytical device (μPAD) was integrated with a smartphone app capable of offline (without internet access) image processing and analysis for the rapid colorimetric detection of glucose. A selfinking stamp was used to form hydrophobic channels on a piece of paper-towel due to its superior water absorption efficiency. As demonstrated, the developed sensor was employed for the colorimetric detection of glucose in artificial saliva in the linear scope of 0-1 mM with a calculated detection limit of 29.65 μM. The experimental results show that the quantitative analysis of glucose with the proposed smartphone platform could be completed in less than one minute. The app developed for the smartphone platform is capable of extracting the color-changing area with an embedded image processing tool which could address the problem of color uniformity in the detection zones of μPAD. The integrated platform has great potential to be used for non-invasive measurements of glucose in body fluids, like tears, sweat and saliva.

Polymers

To treat and manage chronic diseases, it is necessary to continuously monitor relevant biomarkers and modify treatment as the disease state changes. Compared to other bodily fluids, interstitial skin fluid (ISF) is a good choice for identifying biomarkers because it has a molecular composition most similar to blood plasma. Herein, a microneedle array (MNA) is presented to extract ISF painlessly and bloodlessly. The MNA is made of crosslinked poly(ethylene glycol) diacrylate (PEGDA), and an optimal balance of mechanical properties and absorption capability is suggested. Besides, the effect of needles’ cross-section shape on skin penetration is studied. The MNA is integrated with a multiplexed sensor that provides a color change in a biomarker concentration-dependent manner based on the relevant reactions for colorimetric detection of pH and glucose biomarkers. The developed device enables diagnosis by visual inspection or quantitative red, green, and blue (RGB) analysis. The outcomes...

Advanced Materials, 2018

Wearables as medical technologies are becoming an integral part of personal analytics, measuring physical status, recording physiological parameters, or informing schedule for medication. These continuously evolving technology platforms do not only promise to help people pursue a healthier life style, but also provide continuous medical data for actively tracking metabolic status, diagnosis, and treatment. Advances in the miniaturization of flexible electronics, electrochemical biosensors, microfluidics, and artificial intelligence algorithms have led to wearable devices that can generate real‐time medical data within the Internet of things. These flexible devices can be configured to make conformal contact with epidermal, ocular, intracochlear, and dental interfaces to collect biochemical or electrophysiological signals. This article discusses consumer trends in wearable electronics, commercial and emerging devices, and fabrication methods. It also reviews real‐time monitoring of v...

International journal of odontostomatology, 2014

The objective of this study was to evaluate the possible changes in color of aesthetic elastic ligatures soaked in different solutions. Five different brands of aesthetic elastic ligatures were evaluated in the present study. Measurement of the discs´ color was performed using a reflectance spectrophotometer (UV-visible spectrophotometer, UV-2450, Shimadzu®, Kyoto, Japan). Subsequently, the discs were immersed in artificial saliva (AS) or three different solutions: red wine (RW) (Miolo Terranova® 2010, Casa Nova, Brazil), coffee (CF) (Café Três Corações®, RioGrande do Norte, Brazil) or Coca-Cola® (CC) (Coca-Cola®, Belo Horizonte, Brazil). It was determined that the tested solutions were able to cause color changes in the aesthetic elastic ligatures. The coffee solution caused the greatest color change in all of the brands of ligatures evaluated, followed by the red wine solution. In conclusion, OSE and GAC brands of aesthetic elastic ligatures displayed the best performance.