Evaluation of a New Smartphone Powered Low-cost Pulse Oximeter Device

BACKGROUND: Measurement of blood oxygen saturation is a vital part of monitoring coronavirus 2019 (COVID-19) patients. Pulse oximetry is commonly used to measure blood oxygen saturation and pulse rate for appropriate clinical intervention. But the majority of direct-to-consumer grade pulse oximeters did not pass through in-vivo testing, which results in their accuracy being questionable. Besides this, the ongoing COVID-19 pandemic exposed the limitations of the device in resource limited areas since independent monitoring is needed for COVID-19 patients. The purpose of this study was to perform an in-vivo evaluation of a newly developed smartphone powered low-cost pulse oximeter.METHODS: The new prototype of a smartphone powered pulse oximeter was evaluated against the standard pulse oximeter by taking measurements from fifteen healthy volunteers. The accuracy of measurement was evaluated by calculating the percentage error and standard deviation. A repeatability and reproducibility test were carried out using the ANOVA method.RESULTS: The average accuracy for measuring spot oxygen saturation (SPO2) and pulse rate (PR) was 99.18% with a standard deviation of 0.57 and 98.78% with a standard deviation of 0.61,respectively, when compared with the standard pulse oximeter device. The repeatability and reproducibility of SPO2 measurements were 0.28 and 0.86, respectively, which is in the acceptable range.CONCLUSION: The new prototype of smartphone powered pulse oximeter demonstrated better performance compared to the existing low-cost fingertip pulse oximeters. The device could be used for independent monitoring of COVID-19 patients at health institutions and also for home care

A Low Cost Wearable Medical Device for Vital Signs Monitoring in Low-Resource Settings

Medical devices are often expensive, so people in low-income countries cannot afford them. This paper presents the design of a low-cost wearable medical device to measure vital signs of a patient including heart rate, blood oxygen saturation level (SpO2) and respiratory rate. The wearable medical device mainly consists of a microcontroller and two biomedical sensors including airflow thermal sensor to measure respiratory rate and pulse oximeter sensor to measure SpO2 and heart rate. We can monitor the vital signs from a smartphone using a web browser through IEEE802.11 wireless connectivity to the wearable medical device. Furthermore, the wearable medical device requires simple management to operate; hence, it can be easily used. Performance evaluation results show that the designed wearable medical device works as good as a standard SpO2 device and it can measure the respiratory rate properly.  The designed wearable medical device is inexpensive and appropriate for low-resource settings. Moreover, as its components are commonly available in the market, it easy to assembly and repair locally

A Novel Real-Time Non-invasive Hemoglobin Level Detection Using Video Images from Smartphone Camera

Hemoglobin level detection is necessary for evaluating health condition in the human. In the laboratory setting, it is detected by shining light through a small volume of blood and using a colorimetric electronic particle counting algorithm. This invasive process requires time, blood specimens, laboratory equipment, and facilities. There are also many studies on non-invasive hemoglobin level detection. Existing solutions are expensive and require buying additional devices. In this paper, we present a smartphone-based non-invasive hemoglobin detection method. It uses the video images collected from the fingertip of a person. We hypothesized that there is a significant relation between the fingertip mini-video images and the hemoglobin level by laboratory gold standard. We also discussed other non-invasive methods and compared with our model. Finally, we described our findings and discussed future works

On the Capability of Smartphones to Perform as Communication Gateways in Medical Wireless Personal Area Networks

This paper evaluates and characterizes the technical performance of medical wireless personal area networks (WPANs) that are based on smartphones. For this purpose, a prototype of a health telemonitoring system is presented. The prototype incorporates a commercial Android smartphone, which acts as a relay point, or “gateway”, between a set of wireless medical sensors and a data server. Additionally, the paper investigates if the conventional capabilities of current commercial smartphones can be affected by their use as gateways or “Holters” in health monitoring applications. Specifically, the profiling has focused on the CPU and power consumption of the mobile devices. These metrics have been measured under several test conditions modifying the smartphone model, the type of sensors connected to the WPAN, the employed Bluetooth profile (SPP (serial port profile) or HDP (health device profile)), the use of other peripherals, such as a GPS receiver, the impact of the use of theWi-Fi interface or the employed method to encode and forward the data that are collected from the sensors.Ministerio de Educación y Ciencia TEC2009-13763-C02-0

Can improved paediatric pneumonia diagnostic aids support frontline health workers in low resource settings? : large scale evaluation of four respiratory rate timers and five pulse oximeters in Cambodia, Ethiopia, South Sudan and Uganda

Background: Pneumonia is the leading cause of infectious death in children under-five in sub-Saharan Africa and Southeast Asia. Currently, the diagnostic criterion for pneumonia is based on increased respiratory rate (RR) in children with cough and/or difficulty breathing. Low oxygen saturation, usually measured using pulse oximeters, is an indication of severe pneumonia. Health workers report finding it difficult to accurately count the number of breaths and current RR counting aids are often difficult to use or unavailable. Improved RR counting aids and lower-cost pulse oximeters are now available but their suitability in these settings and for these populations are untested. Objective: The studies sought to identify and evaluate the most accurate, acceptable and user-friendly respiratory rate counting devices and pulse oximeters for diagnosis of pneumonia symptoms and severity in children by frontline health workers in low-resource settings. Methods: Three sub-studies (I-III) were conducted among health workers, children under five and their caregivers, and national stakeholders. Sub-study I uses an explanatory qualitative approach with pile sorting and focus group discussions with frontline health workers and national stakeholders to explore their perspectives regarding the potential usability and scalability of seven pneumonia diagnostic aids. In sub-study II (a & b) four RR counters and five pulse oximeters were evaluated for performance by a cross-sectional sample of frontline health workers in hospital settings against reference standards in Cambodia, Ethiopia, South Sudan and Uganda. In sub-study III the same nine devices were evaluated using mixed methods for usability and acceptability in routine practice, over three months, in the four countries. Findings: Frontline health workers and national stakeholders’ universally valued device simplicity, affordability and sustainability. They prioritised different device characteristics according to their specific focus of work, with health workers focusing more on device acceptability and national stakeholders’ being less accepting of new technologies (Sub-study I). In sub-study IIa most CHWs managed to achieve a RR count with the four devices. The agreement with the reference standard was low for all; the mean difference of RR measurements or breaths per minute (bpm) from the reference standard for the four devices ranged from 0.5 bpm (95% CI -2.2 to 1.2) for the respirometer to 5.5 bpm (95% CI 3.2 to 7.8) for Rrate. Performance was consistently lower for young infants (0 to <2 months) than for older children (2 to ≤59 months). Agreement of RR classification into fast and normal breathing was moderate across all four devices, with Cohen’s Kappa statistics ranging from 0.41 (SE 0.04) to 0.49 (SE 0.05). In Sub-study IIb, although all five pulse oximeters tested in the field had performed well on a simulator (±2% SpO2 from the simulator), their performance was more varied when used on real children by frontline health workers. The handheld pulse oximeters had greater overall agreement with the reference standard, ranging from -0.6% SpO2 (95% CI -0.9, 0.4) to -3.0% SpO2 (95% CI -3.4, -2.6) than the finger-tip pulse oximeters, which ranged from -3.9% SpO2 (95% CI -4.4, -3.4) to -7.9% SpO2 (95% CI -8.6,-7.2). This was particularly pronounced in the younger children, where handheld devices had -0.7 SpO2 (95% CI -1.4, -0.1) to -5.9 SpO2 (95% CI -6.9, -4.9) agreement, compared to fingertip devices, which had -8.0 SpO2 (95% CI -9.4, -6.6) to -13.3 SpO2 (95% CI -15.1, -11.5) agreement. First level health facility workers had better agreement in classification of hypoxaemia with the reference standard (=0.32; SE 0.05 to =0.86; SE 0.07) for all five devices, when compared to CHWs (=0.15; SE 0.02 to =0.59; SE 0.03). In Sub-study III health workers reported being better supported by assisted RR counters, which provided more support than their standard practice ARI timer in counting and classifying RR in sick children under 5 in these settings. Conclusions: Frontline health workers were able to use the nine test devices to measure RR and oxygen saturation in children under 5, but with variable performance, and found it more difficult to get a successful measurement in younger children. Frontline health workers were better supported by assisted RR counters, such as Rrate and respirometer, compared to their standard practice diagnostic aid, MK2 ARI timer. Handheld pulse oximeters with multiple probes performed better than fingertip pulse oximeters, especially in younger children. The views of different stakeholder groups should be considered when looking to take these types of pneumonia diagnostic aids to scale. A consensus view on a robust research method and reference standard to evaluate future pneumonia diagnostic aids needs to be reached. While laboratory testing of new diagnostic aids can be valuable it should not replace field testing with frontline health workers in routine practice. Automated, easy to use, robust and affordable pneumonia diagnostics aids need to be developed and launched at scale to better support frontline health workers to address the high pneumonia burden in resource poor settings

Oximetry use in obstructive sleep apnea

Producción CientíficaIntroduction. Overnight oximetry has been proposed as an accessible, simple, and reliable technique for obstructive sleep apnea syndrome (OSAS) diagnosis. From visual inspection to advanced signal processing, several studies have demonstrated the usefulness of oximetry as a screening tool. However, there is still controversy regarding the general application of oximetry as a single screening methodology for OSAS. Areas covered. Currently, high-resolution portable devices combined with pattern recognition-based applications are able to achieve high performance in the detection this disease. In this review, recent studies involving automated analysis of oximetry by means of advanced signal processing and machine learning algorithms are analyzed. Advantages and limitations are highlighted and novel research lines aimed at improving the screening ability of oximetry are proposed. Expert commentary. Oximetry is a cost-effective tool for OSAS screening in patients showing high pretest probability for the disease. Nevertheless, exhaustive analyses are still needed to further assess unattended oximetry monitoring as a single diagnostic test for sleep apnea, particularly in the pediatric population and in especial groups with significant comorbidities. In the following years, communication technologies and big data analysis will overcome current limitations of simplified sleep testing approaches, changing the detection and management of OSAS.This research has been partially supported by the projects DPI2017-84280-R and RTC-2015-3446-1 from Ministerio de Economía, Industria y Competitividad and European Regional Development Fund (FEDER), the project 66/2016 of the Sociedad Española de Neumología y Cirugía Torácica (SEPAR), and the project VA037U16 from the Consejería de Educación de la Junta de Castilla y León and FEDER. D. Álvarez was in receipt of a Juan de la Cierva grant IJCI-2014-22664 from the Ministerio de Economía y Competitividad

Knock! Knock! Who Is There? Investigating Data Leakage from a Medical Internet of Things Hijacking Attack

The amalgamation of Medical Internet of Things (MIoT) devices into everyday life is influencing the landscape of modern medicine. The implementation of these devices potentially alleviates the pressures and physical demands of healthcare systems through the remote monitoring of patients. However, there are concerns that the emergence of MIoT ecosystems is introducing an assortment of security and privacy challenges. While previous research has shown that multiple vulnerabilities exist within MIoT devices, minimal research investigates potential data leakage from MIoT devices through hijacking attacks. The research contribution of this paper is twofold. First, it provides a proof of concept that certain MIoT devices and their accompanying smartphone applications are vulnerable to hijacking attacks. Second, it highlights the effectiveness of using digital forensics tools as a lens to identify patient and medical device information on a hijacker’s smartphone

Multivariable measurement system based on a Blood Pressure measuring device

This Master's thesis describes the development of a multivariable acquisition system based in a sphygmomanometer format. The resulting device can acquire and plot an electrocardiogram with different configurations of electrodes. Moreover, the system is able to acquire the temperature of a person, its heart rate and their oxygen saturation. This information will be shown through a screen and the data will be shared to other devices via Bluetooth. The scope of the project includes the component selection of the system, hardware integration, development of the firmware in Python and the validation of all the functionalities

Devices and Data Workflow in COPD Wearable Remote Patient Monitoring: A Systematic Review

Background: With global increase in Chronic Obstructive Pulmonary Disease (COPD) prevalence and mortality rates, and socioeconomical burden continuing to rise, current disease management strategies appear inadequate, paving the way for technological solutions, namely remote patient monitoring (RPM), adoption considering its acute disease events management benefit. One RPM’s category stands out, wearable devices, due to its availability and apparent ease of use. Objectives: To assess the current market and interventional solutions regarding wearable devices in the remote monitoring of COPD patients through a systematic review design from a device composition, data workflow, and collected parameters description standpoint. Methods: A systematic review was conducted to identify wearable device trends in this population through the development of a comprehensive search strategy, searching beyond the mainstream databases, and aggregating diverse information found regarding the same device. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed, and quality appraisal of identified studies was performed using the Critical Appraisal Skills Programme (CASP) quality appraisal checklists. Results: The review resulted on the identification of 1590 references, of which a final 79 were included. 56 wearable devices were analysed, with the slight majority belonging to the wellness devices class. Substantial device heterogeneity was identified regarding device composition type and wearing location, and data workflow regarding 4 considered components. Clinical monitoring devices are starting to gain relevance in the market and slightly over a third, aim to assist COPD patients and healthcare professionals in exacerbation prediction. Compliance with validated recommendations is still lacking, with no devices assessing the totality of recommended vital signs. Conclusions: The identified heterogeneity, despite expected considering the relative novelty of wearable devices, alerts for the need to regulate the development and research of these technologies, specially from a structural and data collection and transmission standpoints.Introdução: Com o aumento global das taxas de prevalência e mortalidade da Doença Pulmonar Obstrutiva Crónica (DPOC) e o seu impacto socioeconómico, as atuais estratégias de gestão da doença parecem inadequadas, abrindo caminho para soluções tecnológicas, nomeadamente para a adoção da monitorização remota, tendo em conta o seu benefício na gestão de exacerbações de doenças crónicas. Dentro destaca-se uma categoria, os dispositivos wearable, pela sua disponibilidade e aparente facilidade de uso. Objetivos: Avaliar as soluções existentes, tanto no mercado, como na área de investigação, relativas a dispositivos wearable utilizados na monitorização remota de pacientes com DPOC através de uma revisão sistemática, do ponto de vista da composição do dispositivo, fluxo de dados e descrição dos parâmetros coletados. Métodos: Uma revisão sistemática foi realizada para identificar tendências destes dispositivos, através do desenvolvimento de uma estratégia de pesquisa abrangente, procurando pesquisar para além das databases convencionais e agregar diversas informações encontradas sobre o mesmo dispositivo. Para tal, foram seguidas as diretrizes PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), e a avaliação da qualidade dos estudos identificados foi realizada utilizando a ferramenta CASP (Critical Appraisal Skills Programme). Resultados: A revisão resultou na identificação de 1590 referências, das quais 79 foram incluídas. Foram analisados 56 dispositivos wearable, com a ligeira maioria a pertencer à classe de dispositivos de wellness. Foi identificada heterogeneidade substancial nos dispositivos em relação à sua composição, local de uso e ao fluxo de dados em relação a 4 componentes considerados. Os dispositivos de monitorização clínica já evidenciam alguma relevância no mercado e, pouco mais de um terço, visam auxiliar pacientes com DPOC e profissionais de saúde na previsão de exacerbações. Ainda assim, é notória a falta do cumprimento das recomendações validadas, não estando disponíveis dispositivos que avaliem a totalidade dos sinais vitais recomendados. Conclusão: A heterogeneidade identificada, apesar de esperada face à relativa novidade dos dispositivos wearable, alerta para a necessidade de regulamentação do desenvolvimento e investigação destas tecnologias, especialmente do ponto de vista estrutural e de recolha e transmissão de dados

Multi-sensor Framework for Heart Rate and Blood Oxygen Saturation Monitoring of Human Body

Cardiovascular diseases have been the cause of death for millions of people. Some of these deaths could be avoided if there was a signi cant increase of diagnosis for the detection of such diseases. This diagnosis, in turn, could be realized with the increased availability of robust and low-cost medical diagnostic devices. Integrated technology sensors available on wearable devices have been commonly used to read physiological data in users (patients). Particularly the pulse oximetry sensors, o ers a unique, non-invasive method that can be used to detect the severity of such diseases. This evaluation of the physical condition of the patient for certain diseases is possible due to non-invasive measurement through photoplethysmography, which allows the extraction of heart rate and oxygen saturation in the blood. Since some diseases diagnoses require simultaneous monitoring of blood oxygen saturation values at various sites in the body, a project has been developed to perform such reading of physiological data. This thesis presents the development of a systems platform based on the use of multiple pulse oximetry sensors connected to an application developed for a mobile device though a wireless connection. The purpose of this platform is to provide an easy-to-read experience of health data that can be analyzed to diagnose cardiovascular disease symptoms, aiding in an early diagnosis. The complete structure as well as the aspects of the analysis and implementation of the systems related to the proposed architecture are described in this dissertation