OptoBeat: An ultra-low-cost optical system for measuring skin tone calibrated SpO2 with a smartphone. (Preprint)

2021 ◽  
Author(s):  
Alexander T Adams ◽  
Ilan Mandel ◽  
Yixuan Gao ◽  
Bryan Heckman ◽  
Rajalakshmi Nandakumar ◽  
...  
Keyword(s):  
Optical System ◽  
Pulse Oximeter ◽  
Ex Vivo ◽  
Low Cost ◽  
Ground Truth ◽  
Skin Tone ◽  
Sensing System ◽  
Validation Experiment ◽  
Wide Range

BACKGROUND Many commodity pulse oximeters are insufficiently calibrated for patients of darker skin. We demonstrate a quantitative measurement of this disparity in SpO2 measurement with a controlled experimental set up using synthetic skin. To mitigate this, we present OptoBeat, an ultra-low-cost smartphone based optical sensing system that captures SpO2 and heart rate while calibrating for differences in skin tone. Our sensing system can be constructed from commodity plastics, fiber-optic cable and three clips that can be 3D printed for approximately $1, or cheaply manufactured at scale. In our experiments, we demonstrate the efficacy of the OptoBeat system, which can measure SpO2 levels within 1% accuracy of the ground truth (an FDA approved pulse oximeter) in SpO2 levels as low as 75%. OBJECTIVE The objective of this work is to test the following hypothesis and implement an ultra-low-cost smartphone adaptor to measure SpO2. • H1: Skin tone has a significant effect on pulse oximeter measurements. • H2: Pulse oximeter error based on skin tone can be corrected if skin tone is known. • H3: SpO2 can be measured with a smartphone camera using the screen as a light source. METHODS We used three tones of synthetic skin (Syndaver), with the same optical and chemical properties as human skin, to conduct all ex-vivo experiments. A skin tone scale was printed out and placed in the images captured by a mobile phone to calibrate and serve as a ground truth. To achieve a wide range of SpO2 measurements, we used sheep blood (Hardy Diagnostics) that was reoxygenated in a pressure chamber and pulsed through synthetic arteries with a peristaltic pump system. Custom optical clips coupled with fiberoptic cables focus the light from a smartphone screen through the analyte into the phone’s camera. SpO2 measurements are captured by pulsing the screen red and blue. RESULTS Skin tones were accurately classified as being type 2, 3, and 5 on the Fitzpatrick scale using the Euclidian distance of the captured RGB values. Traditional pulse oximeter measurements showed significant differences between skin tones in both AC and DC measurements. The standard deviations in the ratio of IR/red were 0.4184% for type 5, 0.2484% for type 3, and 0.2536% for type 2. Results show a significant difference between the three skin tones as shown in the results of an ANOVA test: 5997 Degrees of Freedom, F score of 3.1170e+05, and p < 0.001. Using our system, SpO2 measurements between 98-75% blood oxygen saturation were reliably captured in an ex-vivo experiment and are accurate to within 1% of ground the truth. In the human subject’s validation experiment, SpO2 measurements were accurate to within 0.5% of ground truth and pulse rate measurements were accurate within 2% of the ground truth. CONCLUSIONS Skin tone has a significant effect on SpO2 measurements using standard commodity hardware. This can be corrected by normalizing for variations in skin tone using an RGB image and reference scale. Leveraging existing smartphone hardware, we classify skin tone, measure SpO2, and normalize the measurements. To do this, we designed OptoBeat, an ultra-low-cost optical system

scholarly journals Image-based surface reconstruction in geomorphometry – merits, limits and developments of a promising tool for geoscientists

2015 ◽  
Vol 3 (4) ◽  
pp. 1445-1508 ◽  
Author(s):  
A. Eltner ◽  
A. Kaiser ◽  
C. Castillo ◽  
G. Rock ◽  
F. Neugirg ◽  
...  
Keyword(s):  
Structure From Motion ◽  
High Performance ◽  
Scientific Practice ◽  
Low Cost ◽  
Image Data ◽  
Ground Truth ◽  
Scale Invariant ◽  
High Quality ◽  
Promising Tool ◽  
Wide Range

Abstract. Photogrammetry and geosciences are closely linked since the late 19th century. Today, a wide range of commercial and open-source software enable non-experts users to obtain high-quality 3-D datasets of the environment, which was formerly reserved to remote sensing experts, geodesists or owners of cost-intensive metric airborne imaging systems. Complex tridimensional geomorphological features can be easily reconstructed from images captured with consumer grade cameras. Furthermore, rapid developments in UAV technology allow for high quality aerial surveying and orthophotography generation at a relatively low-cost. The increasing computing capacities during the last decade, together with the development of high-performance digital sensors and the important software innovations developed by other fields of research (e.g. computer vision and visual perception) has extended the rigorous processing of stereoscopic image data to a 3-D point cloud generation from a series of non-calibrated images. Structure from motion methods offer algorithms, e.g. robust feature detectors like the scale-invariant feature transform for 2-D imagery, which allow for efficient and automatic orientation of large image sets without further data acquisition information. Nevertheless, the importance of carrying out correct fieldwork strategies, using proper camera settings, ground control points and ground truth for understanding the different sources of errors still need to be adapted in the common scientific practice. This review manuscript intends not only to summarize the present state of published research on structure-from-motion photogrammetry applications in geomorphometry, but also to give an overview of terms and fields of application, to quantify already achieved accuracies and used scales using different strategies, to evaluate possible stagnations of current developments and to identify key future challenges. It is our belief that the identification of common errors, "bad practices" and some other valuable information in already published articles, scientific reports and book chapters may help in guiding the future use of SfM photogrammetry in geosciences.

Metformin: Up to Date

2020 ◽  
Vol 20 (2) ◽  
pp. 172-181 ◽  
Author(s):  
Silvia Sciannimanico ◽  
Franco Grimaldi ◽  
Fabio Vescini ◽  
Giovanni De Pergola ◽  
Massimo Iacoviello ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Current Literature ◽  
Weight Control ◽  
Low Cost ◽  
Hepatic Glucose Production ◽  
Metabolic Effects ◽  
Hypoglycemic Agents ◽  
Positive Effects ◽  
Mesh Terms

Background: Metformin is an oral hypoglycemic agent extensively used as first-line therapy for type 2 diabetes. It improves hyperglycemia by suppressing hepatic glucose production and increasing glucose uptake in muscles. Metformin improves insulin sensitivity and shows a beneficial effect on weight control. Besides its metabolic positive effects, Metformin has direct effects on inflammation and can have immunomodulatory and antineoplastic properties. Aim: The aim of this narrative review was to summarize the up-to-date evidence from the current literature about the metabolic and non-metabolic effects of Metformin. Methods: We reviewed the current literature dealing with different effects and properties of Metformin and current recommendations about the use of this drug. We identified keywords and MeSH terms in Pubmed and the terms Metformin and type 2 diabetes, type 1 diabetes, pregnancy, heart failure, PCOS, etc, were searched, selecting only significant original articles and review in English, in particular of the last five years. Conclusion: Even if many new effective hypoglycemic agents have been launched in the market in the last few years, Metformin would always keep a place in the treatment of type 2 diabetes and its comorbidities because of its multiple positive effects and low cost.

scholarly journals Information and information resources in COVID-19: Awareness, control, and prevention

2021 ◽  
pp. 096100062110165
Author(s):  
Mohammadhiwa Abdekhoda ◽  
Fatemeh Ranjbaran ◽  
Asghar Sattari
Keyword(s):  
Low Cost ◽  
Information Resources ◽  
Age And Gender ◽  
Use Of Resources ◽  
Strategic Approach ◽  
Wide Range ◽  
Data Collection Instrument ◽  
Control And Prevention ◽  
And Gender ◽  
And Control

This study was conducted with the aim of evaluating the role of information and information resources in the awareness, control, and prevention of COVID-19. This study was a descriptive-analytical survey in which 450 participants were selected for the study. The data collection instrument was a researcher-made questionnaire. Descriptive and inferential statistics were used to analyze the data through SPSS. The findings show that a wide range of mass media has become well known as information resources for COVID-19. Other findings indicate a significant statistical difference in the rate of using information resources during COVID-19 based on age and gender; however, this difference is not significant regarding the reliability of information resources with regard to age and gender. Health information has an undisputable role in the prevention and control of pandemic diseases such as COVID-19. Providing accurate, reliable, and evidence-based information in a timely manner for the use of resources and information channels related to COVID-19 can be a fast and low-cost strategic approach in confronting this disease.

scholarly journals Advanced mycelium materials as potential self-growing biomedical scaffolds

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria Elena Antinori ◽  
Marco Contardi ◽  
Giulia Suarato ◽  
Andrea Armirotti ◽  
Rosalia Bertorelli ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Low Cost ◽  
Direct Interaction ◽  
Dermal Fibroblasts ◽  
Engineering Systems ◽  
Edible Fungi ◽  
Avant Garde ◽  
Fibrous Network ◽  
Body Tissues ◽  
Wide Range

AbstractMycelia, the vegetative part of fungi, are emerging as the avant-garde generation of natural, sustainable, and biodegradable materials for a wide range of applications. They are constituted of a self-growing and interconnected fibrous network of elongated cells, and their chemical and physical properties can be adjusted depending on the conditions of growth and the substrate they are fed upon. So far, only extracts and derivatives from mycelia have been evaluated and tested for biomedical applications. In this study, the entire fibrous structures of mycelia of the edible fungi Pleurotus ostreatus and Ganoderma lucidum are presented as self-growing bio-composites that mimic the extracellular matrix of human body tissues, ideal as tissue engineering bio-scaffolds. To this purpose, the two mycelial strains are inactivated by autoclaving after growth, and their morphology, cell wall chemical composition, and hydrodynamical and mechanical features are studied. Finally, their biocompatibility and direct interaction with primary human dermal fibroblasts are investigated. The findings demonstrate the potentiality of mycelia as all-natural and low-cost bio-scaffolds, alternative to the tissue engineering systems currently in place.

scholarly journals Rheology and Water Absorption Properties of Alginate–Soy Protein Composites

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1807
Author(s):  
Estefanía Álvarez-Castillo ◽  
José Manuel Aguilar ◽  
Carlos Bengoechea ◽  
María Luisa López-Castejón ◽  
Antonio Guerrero
Keyword(s):  
Soy Protein ◽  
Water Solubility ◽  
Divalent Cations ◽  
Low Cost ◽  
Soy Protein Isolate ◽  
Protein Isolate ◽  
Guluronic Acid ◽  
Wide Range ◽  
Anionic Polysaccharides ◽  
Porous Matrices

Composite materials based on proteins and carbohydrates normally offer improved water solubility, biodegradability, and biocompatibility, which make them attractive for a wide range of applications. Soy protein isolate (SPI) has shown superabsorbent properties that are useful in fields such as agriculture. Alginate salts (ALG) are linear anionic polysaccharides obtained at a low cost from brown algae, displaying a good enough biocompatibility to be considered for medical applications. As alginates are quite hydrophilic, the exchange of ions from guluronic acid present in its molecular structure with divalent cations, particularly Ca2+, may induce its gelation, which would inhibit its solubilization in water. Both biopolymers SPI and ALG were used to produce composites through injection moulding using glycerol (Gly) as a plasticizer. Different biopolymer/plasticizer ratios were employed, and the SPI/ALG ratio within the biopolymer fraction was also varied. Furthermore, composites were immersed in different CaCl2 solutions to inhibit the amount of soluble matter loss and to enhance the mechanical properties of the resulting porous matrices. The main goal of the present work was the development and characterization of green porous matrices with inhibited solubility thanks to the gelation of alginate.

scholarly journals Optically transparent and very thin structure against electromagnetic pulse (EMP) using metal mesh and saltwater for shielding windows

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Duy Tung Phan ◽  
Chang Won Jung
Keyword(s):  
Electromagnetic Pulse ◽  
Low Cost ◽  
High Energy ◽  
Metal Plate ◽  
Optical Transparency ◽  
Shielding Effectiveness ◽  
Concrete Wall ◽  
Metal Mesh ◽  
Wide Range ◽  
Optically Transparent

AbstractAn electromagnetic pulse (EMP) with high energy can damage electronic equipment instantly within a wide range of thousands of kilometers. Generally, a metal plate placed inside a thick concrete wall is used against an EMP, but it is not suitable for an EMP shielding window, which requires not only strong shielding effectiveness (SE) but also optical transparency (OT). In this paper, we propose a very thin and optically transparent structure with excellent SE for EMP shielding window application. The proposed structure consists of a saltwater layer held between two glass substrates and two metal mesh layers on the outside of the glass, with a total thickness of less than 1.5 cm. The SE and OT of the structure are above 80 dB and 45%, respectively, which not only meet the requirement of EMP shielding for military purposes but also retain the procedure of good observation. Moreover, the OT of the structure can be significantly improved using only one metal mesh film (MMF) layer, while the SE is still maintained high to satisfy the required SE for home applicants. With the major advantages of low cost, optical transparency, strong SE, and flexible performance, the proposed structure can be considered a good solution for transparent EMP shielding windows.

scholarly journals Experimental Setting for Applying Mechanical Stimuli to Study the Endothelial Response of Ex Vivo Vessels under Realistic Pathophysiological Environments

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 671
Author(s):  
Ana Osuna ◽  
Anna Ulldemolins ◽  
Hector Sanz-Fraile ◽  
Jorge Otero ◽  
Núria Farré ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Low Cost ◽  
Technical Information ◽  
Rabbit Aorta ◽  
Pressure Waveform ◽  
Mechanical Stimuli ◽  
Experimental Setting ◽  
Endothelial Response ◽  
Flow Through ◽  
Open Source Hardware

This paper describes the design, construction and testing of an experimental setting, making it possible to study the endothelium under different pathophysiological conditions. This novel experimental approach allows the application of the following stimuli to an ex vivo vessel in a physiological bath: (a) a realistic intravascular pressure waveform defined by the user; (b) shear stress in the endothelial layer since, in addition to the pressure waveform, the flow through the vessel can be independently controlled by the user; (c) conditions of hypo/hyperoxia and hypo/hypercapnia in an intravascular circulating medium. These stimuli can be applied alone or in different combinations to study possible synergistic or antagonistic effects. The setting performance is illustrated by a proof of concept in an ex vivo rabbit aorta. The experimental setting is easy to build by using very low-cost materials widely available. Online Supplement files provide all the technical information (e.g., circuits, codes, 3D printer drivers) following an open-source hardware approach for free replication.

scholarly journals Electrochemical treatment of ex vivo human abdominal skin and potential use in scar management: A pilot study

2021 ◽  
Vol 7 ◽  
pp. 205951312098853
Author(s):  
Dana M Hutchison ◽  
Amir A Hakimi ◽  
Avin Wijayaweera ◽  
Soohong Seo ◽  
Ellen M Hong ◽  
...  
Keyword(s):  
Color Change ◽  
Ex Vivo ◽  
Low Cost ◽  
Histological Evaluation ◽  
Ph Change ◽  
Level Of Evidence ◽  
Abdominal Skin ◽  
Electrochemical Therapy ◽  
Mean Width ◽  
Scar Management

Introduction: Scar treatments aim to address pathologic collagen deposition; however, they can be expensive or difficult to control. Electrochemical therapy (ECT) offers a simple alternative treatment. The purpose of this study is to examine the acid-base and histological changes in ex vivo human abdominal skin following ECT. Methods: Forty-two ex vivo human panniculus tissue sections collected from six individuals were tumesced with normal saline. ECT was performed by inserting two platinum needle electrodes connected to a DC power supply into each specimen. Voltage was varied (3–6 V) and applied for 5 minutes. Each specimen was sectioned across both electrode insertion sites and immediately stained with pH sensitive dye. The width of dye color change for each dosimetry pair was calculated. Hematoxylin and eosin staining was used to evaluate samples. Results and Discussion: ECT caused a spatially localised and dose-dependent increased area of acidic and basic pH around the anode and cathode, respectively. A significantly greater mean width of pH change was generated at the cathode compared to the anode in all treatment groups. Histological evaluation displayed broad condensation and hyalinisation of dermal collagen. Conclusion: ECT triggered dermal pH alterations and changed the underlying structural framework of the specimen. This technology may serve as a low-cost, minimally invasive local soft-tissue remodeling technique with potential application in scar management. Level of Evidence: 5 Lay Summary Electrochemical therapy is a novel treatment that causes spatially selective dermal injury in areas of interest. This study measures the effects of electrochemical therapy when applied to abdominal skin. Electrochemical therapy appears to have beneficial effects by causing a highly localised reduction in collagen content or local softening of tissue, which is consistent with other studies on scar therapies, including chemexfoliation, radiofrequency technologies, and lasers. However, electrochemical therapy can be performed at a fraction of the costs of these aforementioned modalities.

scholarly journals SpheroidPicker for automated 3D cell culture manipulation using deep learning

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Istvan Grexa ◽  
Akos Diosdi ◽  
Maria Harmati ◽  
Andras Kriston ◽  
Nikita Moshkov ◽  
...  
Keyword(s):  
Cell Culture ◽  
Precision Medicine ◽  
High Throughput Screening ◽  
Standard Sample ◽  
Ex Vivo ◽  
Low Cost ◽  
3D Cell Culture ◽  
Syringe Pump ◽  
Experimental Conditions ◽  
The Past

AbstractRecent statistics report that more than 3.7 million new cases of cancer occur in Europe yearly, and the disease accounts for approximately 20% of all deaths. High-throughput screening of cancer cell cultures has dominated the search for novel, effective anticancer therapies in the past decades. Recently, functional assays with patient-derived ex vivo 3D cell culture have gained importance for drug discovery and precision medicine. We recently evaluated the major advancements and needs for the 3D cell culture screening, and concluded that strictly standardized and robust sample preparation is the most desired development. Here we propose an artificial intelligence-guided low-cost 3D cell culture delivery system. It consists of a light microscope, a micromanipulator, a syringe pump, and a controller computer. The system performs morphology-based feature analysis on spheroids and can select uniform sized or shaped spheroids to transfer them between various sample holders. It can select the samples from standard sample holders, including Petri dishes and microwell plates, and then transfer them to a variety of holders up to 384 well plates. The device performs reliable semi- and fully automated spheroid transfer. This results in highly controlled experimental conditions and eliminates non-trivial side effects of sample variability that is a key aspect towards next-generation precision medicine.

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