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Publications

Publications by João Paulo Cunha

2017

VitalLogger: An adaptable wearable physiology and body-area ambiance data logger for mobile applications

Authors
Dias, D; Ferreira, N; Silva Cunha, JPd;

Publication
14th IEEE International Conference on Wearable and Implantable Body Sensor Networks, BSN 2017, Eindhoven, The Netherlands, May 9-12, 2017

Abstract
Current mobile revolution is leading to an increase of wearable health devices development and consequently a growth in ambulatory monitoring area. These systems can be applied in ambulatory diseases management and diagnosis, personal health monitoring or sports performance enhancement, providing physiological and body-Area ambiance data during daily normal activities. Nowadays several devices in the market have this type of technology, being one of them the VitalJacket® (VJ®), a product from Biodevices, S.A. This device is a medical certified smart t-shirt with textile embedded electronics for ambulatory monitoring of electrocardiogram (ECG), Heart Rate (HR) and Accelerometer (Acc) data that is in the market since 2008. © 2017 IEEE.

2019

Full-body motion assessment: Concurrent validation of two body tracking depth sensors versus a gold standard system during gait

Authors
Vilas Boas, MD; Pereira Choupina, HMP; Rocha, AP; Fernandes, JM; Silva Cunha, JPS;

Publication
JOURNAL OF BIOMECHANICS

Abstract
RGB-D cameras provide 3-D body joint data in a low-cost, portable and non-intrusive way, when compared with reference motion capture systems used in laboratory settings. In this contribution, we evaluate the validity of both Microsoft Kinect versions (v1 and v2) for motion analysis against a Qualisys system in a simultaneous protocol. Two different walking directions in relation to the Kinect (towards - WT, and away - WA) were explored. For each gait trial, measures related with all body parts were computed: velocity of all joints, distance between symmetrical joints, and angle at some joints. For each measure, we compared each Kinect version and Qualisys by obtaining the mean true error and mean absolute error, Pearson's correlation coefficient, and optical-to-depth ratio. Although both Kinect v1 and v2 and/or WT and WA data present similar accuracy for some measures, better results were achieved, overall, when using WT data provided by the Kinect v2, especially for velocity measures. Moreover, the velocity and distance presented better results than angle measures. Our results show that both Kinect versions can be an alternative to more expensive systems such as Qualisys, for obtaining distance and velocity measures as well as some angles metrics (namely the knee angles). This conclusion is important towards the off-lab non-intrusive assessment of motor function in different areas, including sports and healthcare.

2019

Optical Fiber-based Sensing Method for Nanoparticles Detection through Back-Scattering Signal Analysis

Authors
Paiva, JS; Ribeiro, RSR; Jorge, PAS; Rosa, CC; Sampaio, P; Cunha, JPS;

Publication
OPTICAL FIBERS AND SENSORS FOR MEDICAL DIAGNOSTICS AND TREATMENT APPLICATIONS XIX

Abstract
In view of the growing importance of nanotechnologies, the detection of nanoparticles type in several contexts has been considered a relevant topic. Several organisms, including the National Institutes of Health, have been highlighting the urge of developing nanoparticles exposure risk assessment assays, since very little is known about their physiological responses. Although the identi fi cation/characterization of synthetically produced nanoparticles is considered a priority, there are many examples of \ naturally" generated nanostructures that provide useful information about food components or human physiology. In fact, several nanoscale extracellular vesicles are present in physiological fluids with high potential as cancer biomarkers. However, scientists have struggled to fi nd a simple and rapid method to accurately detect/identify nanoparticles, since their majority have diameters between 100-150 nm -far below the di ff raction limit. Currently, there is a lack of instruments for nanoparticles detection and the few instrumentation that is commonly used is costly, bulky, complex and time consuming. Thus, considering our recent studies on particles identi fi cation through back-scattering, we examined if the time/frequency-domain features of the back-scattered signal provided from a 100 nm polystyrene nanoparticles suspension are able to detect their presence only by dipping a polymeric lensed optical fi ber in the solution. This novel technique allowed the detection of synthetic nanoparticles in distilled water versus \ blank solutions" (only distilled water) through Multivariate Statistics and Arti fi cial Intelligence (AI)-based techniques. While the state-of-the-art methods do not o ff er a ff ordable and simple approaches for nanoparticles detection, our technique can contribute for the development of a device with innovative characteristics.

2019

A wearable approach for intraoperative physiological stress monitoring of multiple cooperative surgeons

Authors
Pimentel, G; Rodrigues, S; Silva, PA; Vilarinho, A; Vaz, R; Silva Cunha, JPS;

Publication
INTERNATIONAL JOURNAL OF MEDICAL INFORMATICS

Abstract
It is known that excessive levels of occupational stress affect professionals' technical and non-technical skills and surgeons are no exception. However, very few studies address this problem in neurosurgeons. A system for monitoring cardiovascular strain and autonomic imbalance during intracranial aneurysm procedures is proposed in order to obtain overall cardiac measures from those procedures. Additionally, this study also allows to detect stressful events and compare their impact with the surgeon's own appraisal. Linear and nonlinear heart rate variability (HRV) features were extracted from surgeon's electrocardiogram (ECG) signal using wearable ECG monitors and mobile technology during 10 intracranial aneurysm surgeries with two surgeons. Stress appraisal and cognitive workload were assessed using self-report measures. Findings suggest that the surgeon associated to the main role during the clipping can be exposed to high levels of stress, especially if a rupture occurs (pNN20 = 0%), while the assistant surgeon tends to experience mental fatigue. Cognitive workload scores of one of the surgeons were negatively correlated with AVNN, SDNN, pNN20, pNN50, 1 V, 2 L V, SD2 and CVI measures. Cognitive workload was positively related with stress appraisal, suggesting that more mentally demanding procedures are also assessed as more stressful. Finally, pNN20 seems to better mirror behavior during stress moments than pNN50. Additionally, a sympathovagal excitation occurs in one of the professionals after changing to main role. The present methodology shows potential for the identification of harmful events. This work may be of importance for the design of effective interventions in order to reduce surgeons stress levels. Furthermore, this approach can be applied to other professions.

2019

A Novel Method for Scatterers Type Enumeration in Polydisperse Suspensions through Fiber Trapping and Unsupervised Scattering Analysis

Authors
Paiva, JS; Ribeiro, RSR; Jorge, PAS; Rosa, CC; Sampaio, P; Cunha, JPS;

Publication
IMAGING, MANIPULATION, AND ANALYSIS OF BIOMOLECULES, CELLS, AND TISSUES XVII

Abstract
Colloids and suspensions are part of our daily routines. Even the blood is considered a "naturally" occurring colloid. However, the majority of colloids are complex and composed by a diversity of nano to microparticles. The characterization of both synthetic and physiological fluids in terms of particulate types, size and surface characteristics plays a vital role in products formulation, and in the early diagnosis through the identification of abnormal scatterers in physiological fluids, respectively. Several methods have been proposed for characterizing suspensions, including imaging, electrical sensing counters, hydrodynamic or field flow fractionation. However, the Dynamic Light Scattering (DLS) has evolved as the most convenient method from these. Based also on the scattering signal, we propose a novel, simple and fast method able to determine the number of different scatterers type present in a suspension, without any previous information about its composition (in terms of particle classes). This is achieved by collecting features from a 980 nm laser back-scattered signal acquired through a polymeric lensed optical fiber tip dipped into the solution. Unlike DLS, this technique allows the trapping of particles whose diameter >= 1 mu m. For smaller particles, despite not guaranteeing their immobilization, it is also able to determine the number of different nanoparticles classes in an ensemble. The number of particle types was correctly determined for suspensions of synthetic particles and yeasts; different bacteria; and 100 nm nanoparticles types, using both Principal Component Analysis and K-means algorithms. This method could be a valuable alternative to complex and time-consuming methods for particles separation, such as field flow fractionation.

2019

VitalResponder®: Wearable wireless platform for vitals and body-area environment monitoring of first response teams

Authors
Cunha, JPS; Rodrigues, S; Dias, D; Brandão, P; Aguiar, A; Oliveira, I; Fernandes, JM; Maia, C; Tedim, AR; Barros, A; Azuaje, O; Soares, E; De La Torre, F;

Publication
Wearable Technologies and Wireless Body Sensor Networks for Healthcare

Abstract
Under the VitalResponder® (VR) line of research, mostly funded by the Carnegie Mellon University (CMU)-Portugal program, we have been developing, in partnership with colleagues from CMU, novel wearable monitoring solutions for hazardous professionals such as first responders (FR). We are exploring the synergy between innovative wearable technologies, scattered sensor network and precise localization to provide secure, reliable and effective first-response information services in emergency scenarios. This enables a thorough teams’management, namely on FR exposure to different hazardous elements, effort levels and critical situations that contribute to team members’ stress and fatigue levels. © The Institution of Engineering and Technology 2017.

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