Investigation of Five Algorithms for Selection of the Optimal Region of Interest in Smartphone Photoplethysmography

Journal of Sensors ◽

10.1155/2016/6830152 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Rong-Chao Peng ◽

Wen-Rong Yan ◽

Ning-Ling Zhang ◽

Wan-Hua Lin ◽

Xiao-Lin Zhou ◽

...

Keyword(s):

Template Matching ◽

Low Cost ◽

Region Of Interest ◽

Physiological Parameters ◽

Home Healthcare ◽

Spectral Energy ◽

Optimal Region ◽

Subject Experiment ◽

Parameters Measurement

Smartphone photoplethysmography is a newly developed technique that can detect several physiological parameters from the photoplethysmographic signal obtained by the built-in camera of a smartphone. It is simple, low-cost, and easy-to-use, with a great potential to be used in remote medicine and home healthcare service. However, the determination of the optimal region of interest (ROI), which is an important issue for extracting photoplethysmographic signals from the camera video, has not been well studied. We herein proposed five algorithms for ROI selection: variance (VAR), spectral energy ratio (SER), template matching (TM), temporal difference (TD), and gradient (GRAD). Their performances were evaluated by a 50-subject experiment comparing the heart rates measured from the electrocardiogram and those from the smartphone using the five algorithms. The results revealed that the TM and the TD algorithms outperformed the other three as they had less standard error of estimate (<1.5 bpm) and smaller limits of agreement (<3 bpm). The TD algorithm was slightly better than the TM algorithm and more suitable for smartphone applications. These results may be helpful to improve the accuracy of the physiological parameters measurement and to make the smartphone photoplethysmography technique more practical.

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ANÁLISE DOS POLUENTES ATMOSFÉRICOS NO2 E O3 VIA AMOSTRADORES PASSIVOS DE BAIXO CUSTO

e-xacta ◽

10.18674/exacta.v10i1.1960 ◽

2017 ◽

Vol 10 (1) ◽

pp. 29

Author(s):

Danielle Cristine Miranda ◽

Gabriel Campos Ferreira ◽

Larissa Domingues Barbosa ◽

Nara Luíza Andrade Pereira ◽

Tatiany Ciríaco Ribeiro ◽

...

Keyword(s):

Factor Analysis ◽

Data Analysis ◽

Low Cost ◽

Passive Samplers ◽

Optimal Region ◽

Paper Filter ◽

Petri Dishes ◽

Absorber Solution ◽

The University

O uso de equipamentos que monitorem a concentração de poluentes pode contribuir para prevenção de possíveis danos à saúde humana. Esse trabalho consiste no desenvolvimento de amostradores passivos de baixo custo para a determinação dos poluentes NO2 e O3 no campus Alto Paraopeba, através da análise fatorial e superfície de resposta. Os amostradores foram construídos em placas de Petri com filtros de papel contendo diferentes soluções absorvedoras para cada tipo de gás monitorado. Os amostradores de NO2 foram expostos no refeitório da Universidade e os amostradores de O3 foram expostos na sala de máquinas fotocopiadoras. Nos amostradores foram usadas diferentes quantidades de solução absorvedora e, também, diferentes tempos de exposição. Os resultados mostraram que a melhor condição para o NO2 foi obtida com 4,6 mL de solução absorvedora e no tempo de 68 horas de exposição. Nessas condições, a concentração de NO2 no Restaurante Universitário foi de 10,5 µg/m3. Para o ozônio, as concentrações variaram entre 4,2 µg/m3 e 40 µg/m3, e a melhor condição (3 mL de solução absorvedora e tempo de 77 horas) está localizada no ponto sela e não na região ótima do gráfico. Isso ocorre devido ao fato do ozônio se decompor rapidamente a oxigênio. Os amostradores passivos apresentaram resultados satisfatórios e recomenda-se seu uso como uma alternativa de baixo custo para o monitoramento de NO2 e O3 no Restaurante Universitário e sala de Fotocopiadoras. ABSTRACTThe use of equipment that monitors the concentration of pollutants can contribute to the prevention of possible damages to human health. This work is to develop inexpensive passive samplers for the determination of NO2 and O3 pollution in the campus Alto Paraopeba beyond the optimization of analytical methods by software that provides a complete environment for data analysis; by factor analysis and response surface generated by it. The samplers were constructed on Petri dishes with paper filter containing different absorbing solutions according to each monitored gas. The samplers were exposed to NO2 at university restaurant and others samplers were exposed to O3 at the photocopier room of the campus. In samplers were used different amounts of absorber solution and also different exposure times. The results showed that the best condition for NO2 was obtained with 4.6 mL of absorbing solution in time of 68 hours exposure. Under these conditions, the concentration of NO2 in the university restaurant was 10.5 µg/m3. For ozone, the concentrations ranged from 4.2 µg/m3 and 40 µg/m3, and the best condition (3 mL absorbing solution and time of 77 hours) is located at saddle point and not at the optimal region of the graph. This is because ozone has rapidly decomposes to oxygen. Passive samplers presented satisfactory results and it is recommended to use them as a low cost alternative for the monitoring of NO2 and O3 in the University Restaurant and Photocopiers room.

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Marker-Less 3d Object Recognition and 6d Pose Estimation for Homogeneous Textureless Objects: An RGB-D Approach

Sensors ◽

10.3390/s20185098 ◽

2020 ◽

Vol 20 (18) ◽

pp. 5098

Author(s):

Nasim Hajari ◽

Gabriel Lugo Bustillo ◽

Harsh Sharma ◽

Irene Cheng

Keyword(s):

Object Recognition ◽

Pose Estimation ◽

Template Matching ◽

Low Cost ◽

Region Of Interest ◽

Depth Information ◽

Natural Scenes ◽

Proposed Model ◽

Industrial Assembly ◽

Rgb Images

The task of recognising an object and estimating its 6d pose in a scene has received considerable attention in recent years. The accessibility and low-cost of consumer RGB-D cameras, make object recognition and pose estimation feasible even for small industrial businesses. An example is the industrial assembly line, where a robotic arm should pick a small, textureless and mostly homogeneous object and place it in a designated location. Despite all the recent advancements of object recognition and pose estimation techniques in natural scenes, the problem remains challenging for industrial parts. In this paper, we present a framework to simultaneously recognise the object’s class and estimate its 6d pose from RGB-D data. The proposed model adapts a global approach, where an object and the Region of Interest (ROI) are first recognised from RGB images. The object’s pose is then estimated from the corresponding depth information. We train various classifiers based on extracted Histogram of Oriented Gradient (HOG) features to detect and recognize the objects. We then perform template matching on the point cloud based on surface normal and Fast Point Feature Histograms (FPFH) to estimate the pose of the object. Experimental results show that our system is quite efficient, accurate and robust to illumination and background changes, even for the challenging objects of Tless dataset.

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A technique for protecting delicate specimens during processing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100156894 ◽

1989 ◽

Vol 47 ◽

pp. 982-983

Author(s):

R.J. Mount ◽

R.V. Harrison

Keyword(s):

Basilar Membrane ◽

Low Cost ◽

Organ Of Corti ◽

Region Of Interest ◽

Sensory Epithelium ◽

Physical Damage ◽

Air Drying ◽

Specimen Handling ◽

Two Component

The sensory end organ of the ear, the organ of Corti, rests on a thin basilar membrane which lies between the bone of the central modiolus and the bony wall of the cochlea. In vivo, the organ of Corti is protected by the bony wall which totally surrounds it. In order to examine the sensory epithelium by scanning electron microscopy it is necessary to dissect away the protective bone and expose the region of interest (Fig. 1). This leaves the fragile organ of Corti susceptible to physical damage during subsequent handling. In our laboratory cochlear specimens, after dissection, are routinely prepared by the O-T- O-T-O technique, critical point dried and then lightly sputter coated with gold. This processing involves considerable specimen handling including several hours on a rotator during which the organ of Corti is at risk of being physically damaged. The following procedure uses low cost, readily available materials to hold the specimen during processing ,preventing physical damage while allowing an unhindered exchange of fluids.Following fixation, the cochlea is dehydrated to 70% ethanol then dissected under ethanol to prevent air drying. The holder is prepared by punching a hole in the flexible snap cap of a Wheaton vial with a paper hole punch. A small amount of two component epoxy putty is well mixed then pushed through the hole in the cap. The putty on the inner cap is formed into a “cup” to hold the specimen (Fig. 2), the putty on the outside is smoothed into a “button” to give good attachment even when the cap is flexed during handling (Fig. 3). The cap is submerged in the 70% ethanol, the bone at the base of the cochlea is seated into the cup and the sides of the cup squeezed with forceps to grip it (Fig.4). Several types of epoxy putty have been tried, most are either soluble in ethanol to some degree or do not set in ethanol. The only putty we find successful is “DUROtm MASTERMENDtm Epoxy Extra Strength Ribbon” (Loctite Corp., Cleveland, Ohio), this is a blue and yellow ribbon which is kneaded to form a green putty, it is available at many hardware stores.

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Investigations on skeletal growth zones via bone scans as base of determination of optimal time for surgery in mandibular asymmetry

Nuklearmedizin ◽

10.1055/s-0038-1632257 ◽

2000 ◽

Vol 39 (05) ◽

pp. 121-126 ◽

Cited By ~ 1

Author(s):

R. Werz ◽

P. Reuland

Keyword(s):

Bone Growth ◽

Region Of Interest ◽

Tracer Uptake ◽

Optimal Time ◽

Mandibular Bone ◽

The Third ◽

Mandibular Asymmetry ◽

Bone Scans ◽

Epiphyseal Plates

Summary Aim of the study was to find out wether there is a common stop of growth of mandibular bone, so that no individual determination of the optimal time for surgery in patients with asymmetric mandibular bone growth is needed. As there are no epiphyseal plates in the mandibular bone, stop of growth cannot be determined on X-ray films. Methods: Bone scans of 731 patients [687 patients (324 male, 363 female) under 39 y for exact determination of end of growth and 44 (21 male, 23 female) patients over 40 y for evaluation of nongrowth dependant differences in tracer uptake] were reviewed for the study. All the patients were examined 3 hours after injection of 99mTc-DPD. Tracer uptake was measured by region of interest technique in different points of the mandibular bone and in several epiphyseal plates of extremities. Results: Tracer uptake in different epiphyseal plates of the extremities shows strong variation with age and good correlation with reported data of bone growth and closure of the epiphyseal plates. The relative maximum of bone activity is smaller in mandibular bone than in epiphyseal plates, which show well defined peaks, ending at 15-18 years in females and at 18-21 years in males. In contrast, mandibular bone shows no well defined end of growing but a gradually reduction of bone activity which remains higher than bone activity in epiphyseal plates over several years. Conclusion: No well defined end of growth of mandibular bone exists. The optimal age for surgery of asymmetric mandibular bone growth is not before the middle of the third decade of life, bone scans performed earlier for determination of bone growth can be omitted. Bone scans performed at the middle of the third decade of life help to optimize the time of surgical intervention.

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Microextraction and Chromatographic Analysis of Budesonide Epimers in Exhaled Breath Condensate

Current Analytical Chemistry ◽

10.2174/1573411015666191203104522 ◽

2020 ◽

Vol 16 (8) ◽

pp. 1032-1040

Author(s):

Laleh Samini ◽

Maryam Khoubnasabjafari ◽

Mohamad M. Alimorad ◽

Vahid Jouyban-Gharamaleki ◽

Hak-Kim Chan ◽

...

Keyword(s):

Biological Fluids ◽

Exhaled Breath Condensate ◽

Low Cost ◽

Exhaled Breath ◽

Chromatography Method ◽

Extraction Solvent ◽

Drug Concentrations ◽

Dispersive Liquid Liquid Microextraction ◽

Breath Condensate

Background: Analysis of drug concentrations in biological fluids is required in clinical sciences for various purposes. Among other biological samples, exhaled breath condensate (EBC) is a potential sample for follow up of drug concentrations. Methods: A dispersive liquid-liquid microextraction (DLLME) procedure followed by a validated liquid chromatography method was employed for the determination of budesonide (BDS) in EBC samples collected using a homemade setup. EBC is a non-invasive biological sample with possible applications for monitoring drug concentrations. The proposed analytical method is validated according to the FDA guidelines using EBC-spiked samples. Its applicability is tested on EBC samples collected from healthy volunteers receiving a single puff of BDS. Results: The best DLLME conditions involved the use of methanol (1 mL) as a disperser solvent, chloroform (200 μL) as an extraction solvent, and centrifugation rate of 3500 rpm for 5 minutes. The method was validated over a concentration range of 21-210 μg·L-1 in EBC. Inter- and intra-day precisions were less than 10% where the acceptable levels are less than 20%. The validated method was successfully applied for the determination of BDS in EBC samples. Conclusion: The findings of this study indicate that the developed method can be used for the extraction and quantification of BDS in EBC samples using a low cost method.

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Development and Validation of an Eco-Friendly and Low-Cost Method for the Quantification of Cefepime Hydrochloride in Powder for Injectable Solution Using Infrared (IR) Spectroscopy

Current Analytical Chemistry ◽

10.2174/1573411014666180704122816 ◽

2020 ◽

Vol 16 (4) ◽

pp. 456-464

Author(s):

Danilo F. Rodrigues ◽

Hérida R.N. Salgado

Keyword(s):

Ir Spectroscopy ◽

Low Cost ◽

Pharmaceutical Preparations ◽

Potassium Bromide ◽

Pharmaceutical Products ◽

Injectable Formulation ◽

Ich Guidelines ◽

Lactam Ring ◽

Development And Validation

Background: A simple, eco-friendly and low-cost Infrared (IR) method was developed and validated for the analysis of Cefepime Hydrochloride (CEF) in injectable formulation. Different from some other methods, which employ organic solvents in the analyses, this technique does not use these types of solvents, removing large impacts on the environment and risks to operators. Objective: This study aimed at developing and validating a green analytical method using IR spectroscopy for the determination of CEF in pharmaceutical preparations. Methods: The method was validated according to ICH guidelines and the quantification of CEF was performed in the spectral region absorbed at 1815-1745 cm-1 (stretching of the carbonyl group of β- lactam ring). Results: The validated method showed to be linear (r = 0.9999) in the range of 0.2 to 0.6 mg/pellet of potassium bromide, as well as for the parameters of selectivity, precision, accuracy, robustness and Limits of Detection (LOD) and Quantification (LOQ), being able to quantify the CEF in pharmaceutical preparations. The CEF content obtained by the IR method was 103.86%. Conclusion: Thus, the method developed may be an alternative in the quality control of CEF sample in lyophilized powder for injectable solution, as it presented important characteristics in the determination of the pharmaceutical products, with low analysis time and a decrease in the generation of toxic wastes to the environment.

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Graphene Modified Molecular Imprinting Electrochemical Sensor for Determining the Content of Dopamine

Current Analytical Chemistry ◽

10.2174/1573411014666180730112304 ◽

2019 ◽

Vol 15 (6) ◽

pp. 628-634

Author(s):

Rong Liu ◽

Jie Li ◽

Tongsheng Zhong ◽

Liping Long

Keyword(s):

Electrochemical Sensor ◽

Molecular Imprinting ◽

Neurological Disorders ◽

Room Temperature ◽

Low Cost ◽

Differential Pulse ◽

Current Response ◽

Specific Selectivity ◽

Pulse Voltammetry

Background: The unnatural levels of dopamine (DA) result in serious neurological disorders such as Parkinson’s disease. Electrochemical methods which have the obvious advantages of simple operation and low-cost instrumentation were widely used for determination of DA. In order to improve the measurement performance of the electrochemical sensor, molecular imprinting technique and graphene have always been employed to increase the selectivity and sensitivity. Methods: An electrochemical sensor which has specific selectivity to (DA) was proposed based on the combination of a molecular imprinting polymer (MIP) with a graphene (GR) modified gold electrode. The performance and effect of MIP film were investigated by differential pulse voltammetry (DPV) and cyclic voltammetry (CV) in the solution of 5.0 ×10-3 mol/L K3[Fe(CN)6] and K4[Fe(CN)6] with 0.2 mol/L KCl at room temperature. Results: This fabricated sensor has well repeatability and stability, and was used to determine the dopamine of urine. Under the optimized experiment conditions, the current response of the imprinted sensor was linear to the concentration of dopamine in the range of 1.0×10-7 ~ 1.0×10-5 mol/L, the linear equation was I (µA) = 7.9824+2.7210lgc (mol/L) with the detection limit of 3.3×10-8 mol/L. Conclusion: In this work, a highly efficient sensor for determination of DA was prepared with good sensitivity by GR and great selectivity of high special recognization ability by molecular imprinting membrane. This proposed sensor was used to determine the dopamine in human urine successfully.

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Non-enzymatic determination of purine nucleotides using a carbon dot modified glassy carbon electrode

Analytical Methods ◽

10.1039/c9ay00718k ◽

2019 ◽

Vol 11 (30) ◽

pp. 3866-3873 ◽

Cited By ~ 1

Author(s):

R. Karthikeyan ◽

D. James Nelson ◽

S. Abraham John

Keyword(s):

Glassy Carbon ◽

Low Cost ◽

Phosphate Buffer Solution ◽

Purine Nucleotides ◽

Buffer Solution ◽

Solution Ph ◽

Carbon Dot ◽

Enzymatic Determination ◽

Sensitive Determination

Selective and sensitive determination of one of the purine nucleotides, inosine (INO) using a low cost carbon dot (CD) modified glassy carbon (GC) electrode in 0.2 M phosphate buffer solution (pH 7.2) was demonstrated in this paper.

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Using seed respiration as a tool for calculating optimal soaking times for ‘on-farm’ seed priming of barley (Hordeum vulgare)

Seed Science Research ◽

10.1017/s0960258521000039 ◽

2021 ◽

pp. 1-9

Author(s):

Javier Carrillo-Reche ◽

Adrian C. Newton ◽

Richard S. Quilliam

Keyword(s):

Morphological Changes ◽

Low Cost ◽

Germination Rate ◽

Seed Priming ◽

Embryonic Axes ◽

Seedling Vigour ◽

Soaking Time ◽

On Farm ◽

Seed Respiration

Abstract A low-cost technique named ‘on-farm’ seed priming is increasingly being recognized as an effective approach to maximize crop establishment. It consists of anaerobically soaking seeds in water before sowing resulting in rapid and uniform germination, and enhanced seedling vigour. The extent of these benefits depends on the soaking time. The current determination of optimal soaking time by germination assays and mini-plot trials is resource-intensive, as it is species/genotype-specific. This study aimed to determine the potential of the seed respiration rate (an indicator of metabolic activity) and seed morphological changes during barley priming as predictors of the priming benefits and, thus, facilitate the determination of optimal soaking times. A series of germination tests revealed that the germination rate is mostly attributable to the rapid hydration of embryo tissues, as the highest gains in the germination rate occurred before the resumption of respiration. Germination uniformity, however, was not significantly improved until seeds were primed for at least 8 h, that is, after a first respiration burst was initiated. The maximum seedling vigour was attained when the priming was stopped just before the beginning of the differentiation of embryonic axes (20 h) after which vigour began to decrease (‘over-priming’). The onset of embryonic axis elongation was preceded by a second respiration burst, which can be used as a marker for priming optimization. Thus, monitoring of seed respiration provides a rapid and inexpensive alternative to the current practice. The method could be carried out by agricultural institutions to provide recommended optimal soaking times for the common barley varieties within a specific region.

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Revisiting Electrochemical Biosensing in the 21st Century Society for Inflammatory Cytokines Involved in Autoimmune, Neurodegenerative, Cardiac, Viral and Cancer Diseases

Sensors ◽

10.3390/s21010189 ◽

2020 ◽

Vol 21 (1) ◽

pp. 189

Author(s):

Susana Campuzano ◽

Paloma Yáñez-Sedeño ◽

José Manuel Pingarrón

Keyword(s):

Point Of Care ◽

Low Cost ◽

Accurate Determination ◽

Test Time ◽

Electrochemical Biosensing ◽

Recent Developments ◽

Inflammatory Processes ◽

Human Skills ◽

Cancer Diseases

The multifaceted key roles of cytokines in immunity and inflammatory processes have led to a high clinical interest for the determination of these biomolecules to be used as a tool in the diagnosis, prognosis, monitoring and treatment of several diseases of great current relevance (autoimmune, neurodegenerative, cardiac, viral and cancer diseases, hypercholesterolemia and diabetes). Therefore, the rapid and accurate determination of cytokine biomarkers in body fluids, cells and tissues has attracted considerable attention. However, many currently available techniques used for this purpose, although sensitive and selective, require expensive equipment and advanced human skills and do not meet the demands of today’s clinic in terms of test time, simplicity and point-of-care applicability. In the course of ongoing pursuit of new analytical methodologies, electrochemical biosensing is steadily gaining ground as a strategy suitable to develop simple, low-cost methods, with the ability for multiplexed and multiomics determinations in a short time and requiring a small amount of sample. This review article puts forward electrochemical biosensing methods reported in the last five years for the determination of cytokines, summarizes recent developments and trends through a comprehensive discussion of selected strategies, and highlights the challenges to solve in this field. Considering the key role demonstrated in the last years by different materials (with nano or micrometric size and with or without magnetic properties), in the design of analytical performance-enhanced electrochemical biosensing strategies, special attention is paid to the methods exploiting these approaches.

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