Daniel Simões Lopes

Prof. Dr. Daniel Simões Lopes

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Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 September 2018 in Journal of Sensors
Verified
Journal Article
Open access
PDF file
Carlo MassaroniCarlo Massaroni
Carlo Massaroni
DLDaniel Simões Lopes
Daniel Simões Lopes
Daniela Lo PrestiDaniela Lo Presti
Daniela Lo Presti
Emiliano SchenaEmiliano Schena
Emiliano Schena
SSSergio Silvestri
Sergio Silvestri
Vital signs monitoring is pivotal not only in clinical settings but also in home environments. Remote monitoring devices, systems, and services are emerging as tracking vital signs must be performed on a daily basis. Different types of sensors can be used to monitor breathing patterns and respiratory rate. However, the latter remains the least measured vital sign in several scenarios due to the intrusiveness of most adopted sensors. In this paper, we propose an inexpensive, off-the-shelf, and contactless measuring system for respiration signals taking as region of interest the pit of the neck. The system analyses video recorded by a single RGB camera and extracts the respiratory pattern from intensity variations of reflected light at the level of the collar bones and above the sternum. Breath-by-breath respiratory rate is then estimated from the processed breathing pattern. In addition, the effect of image resolution on monitoring breathing patterns and respiratory rate has been investigated. The proposed system was tested on twelve healthy volunteers (males and females) during quiet breathing at different sensor resolution (i.e., HD 720, PAL, WVGA, VGA, SVGA, and NTSC). Signals collected with the proposed system have been compared against a reference signal in both the frequency domain and time domain. By using the HD 720 resolution, frequency domain analysis showed perfect agreement between average breathing frequency values gathered by the proposed measuring system and reference instrument. An average mean absolute error (MAE) of 0.55 breaths/min was assessed in breath-by-breath monitoring in the time domain, while Bland-Altman showed a bias of −0.03 ± 1.78 breaths/min. Even in the case of lower camera resolution setting (i.e., NTSC), the system demonstrated good performances (MAE of 1.53 breaths/min, bias of −0.06 ± 2.08 breaths/min) for contactless monitoring of both breathing pattern and breath-by-breath respiratory rate over time.

1 July 2019 in Automation in Construction
Verified
Journal Article
Closed access
RKRui de Klerk
Rui de Klerk
ADAndré Mendes Duarte
André Mendes Duarte
DMDaniel Pires Medeiros
Daniel Pires Medeiros
José P. Pinto DuarteJosé P. Pinto Duarte
José P. Pinto Duarte
Joaquim JorgeJoaquim Jorge
Joaquim Jorge
DLDaniel Simões Lopes
Daniel Simões Lopes

26 May 2015 in ACM Computing Surveys
Verified
Journal Article
Open access
BAB. R. de Araújo
B. R. de Araújo
DLDaniel Simões Lopes
Daniel Simões Lopes
PJPauline Jepp
Pauline Jepp
Joaquim JorgeJoaquim Jorge
Joaquim Jorge
BWBrian Wyvill
Brian Wyvill
Implicit surfaces (IS) are commonly used in image creation, modeling environments, modeling objects, and scientific data visualization. In this article, we present a survey of different techniques for fast visualization of IS. The main classes of visualization algorithms are identified along with the advantages of each in the context of the different types of IS commonly used in computer graphics. We focus closely on polygonization methods, as they are the most suited to fast visualization. Classification and comparison of existing approaches are presented using criteria extracted from current research. This enables the identification of the best strategies according to the number of specific requirements, such as speed, accuracy, quality, or stylization.

2 May 2017
Verified
Conference Paper
Open access
MSMaurício Sousa
Maurício Sousa
DMDaniel Mendes
Daniel Mendes
SPSoraia Paulo
Soraia Paulo
Nuno MatelaNuno Matela
Nuno Matela
JJJoaquim Jorge
Joaquim Jorge
DLDaniel Simões Lopes
Daniel Simões Lopes
Reading room conditions such as illumination, ambient light, human factors and display luminance, play an important role on how radiologists analyze and interpret images. Indeed, serious diagnostic errors can appear when observing images through everyday monitors. Typically, these occur whenever professionals are ill-positioned with respect to the display or visualize images under improper light and luminance conditions. In this work, we show that virtual reality can assist radiodiagnostics by considerably diminishing or cancel out the effects of unsuitable ambient conditions. Our approach combines immersive head-mounted displays with interactive surfaces to support professional radiologists in analyzing medical images and formulating diagnostics. We evaluated our prototype with two senior medical doctors and four seasoned radiology fellows. Results indicate that our approach constitutes a viable, flexible, portable and cost-efficient option to traditional radiology reading rooms.

5 September 2010 in Multibody System Dynamics
Verified
Journal Article
Closed access
PDF file
DLDaniel Simões Lopes
Daniel Simões Lopes
MSMiguel Tavares da Silva
Miguel Tavares da Silva
JAJorge A. Ambrósio
Jorge A. Ambrósio
PFPaulo Flores
Paulo Flores

1 April 2021 in The Breast
Verified
Journal Article
Open access
PGPedro F. Gouveia
Pedro F. Gouveia
JCJoana Costa
Joana Costa
PMPedro Morgado
Pedro Morgado
RKRonald Kates
Ronald Kates
DPDavid Pinto
David Pinto
MCMaria João Cardoso
Maria João Cardoso
Innovations in 3D spatial technology and augmented reality imaging driven by digital high-tech industrial science have accelerated experimental advances in breast cancer imaging and the development of medical procedures aimed to reduce invasiveness. A 57-year-old post-menopausal woman presented with screen-detected left-sided breast cancer. After undergoing all staging and pre-operative studies the patient was proposed for conservative breast surgery with tumor localization. During surgery, an experimental digital and non-invasive intra-operative localization method with augmented reality was compared with the standard pre-operative localization with carbon tattooing (institutional protocol). The breast surgeon wearing an augmented reality headset (Hololens) was able to visualize the tumor location projection inside the patient's left breast in the usual supine position. This work describes, to our knowledge, the first experimental test with a digital non-invasive method for intra-operative breast cancer localization using augmented reality to guide breast conservative surgery. In this case, a successful overlap of the previous standard pre-operative marks with carbon tattooing and tumor visualization inside the patient's breast with augmented reality was obtained. Breast cancer conservative guided surgery with augmented reality can pave the way for a digital non-invasive method for intra-operative tumor localization.