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Publications

Publications by Miguel Coimbra

2018

A New Method for the Anterior Mitral Leaflet Segmentation in Echocardiography Videos using the Virtual M-mode Space

Authors
Sultan, MS; Martins, N; Costa, E; Veiga, D; Ferreira, MJ; Silva Mattos, Sd; Coimbra, MT;

Publication
40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2018, Honolulu, HI, USA, July 18-21, 2018

Abstract

2016

Modular Health Kiosk for Health Self-Assessment

Authors
Soares, E; Oliveira, C; Maia, J; Almeida, R; Coimbra, M; Brandao, P; Prior, R;

Publication
2016 IEEE SYMPOSIUM ON COMPUTERS AND COMMUNICATION (ISCC)

Abstract
We describe the architecture, problems and lessons learned from building a Health Kiosk from commercial, off-the shelf Personal Health Devices and a computer with a touch-screen interface. The kiosk is used autonomously by patients to measure vital data prior to a consultation, in the scope of a population screening, or for routinely monitoring. The prototype was tested in multiple events with different user groups, aided by observer reporting and user questionnaires to assess problems and difficulties with the interface and device usage.

2014

Noninvasive Blood Pressure and the Second Heart Sound Analysis

Authors
Castro, A; Mattos, SS; Coimbra, MT;

Publication
2014 36TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)

Abstract
Heart sound characteristics are linked to blood pressure, and its interpretation is important for detection of cardiovascular disease. In this study, heart sounds' auscultation, acquired from children patients (27 patients, 10.2 +/- 3.9 years, 35.7 +/- 20.8 kg, 132.3 +/- 25.5 cm), were automatically segmented to extract the two main components: the first sound (S1) and the second sound (S2). Following, a set of time, frequency, and wavelet based features, were extracted from the S2, and analyzed in relation to the noninvasive cuff-based measures of blood pressure (mean blood pressure of 78 +/- 8.8 mmHg). A multivariate regression analysis was performed for each S2 feature set to determine which features better related to the blood pressure measurements. The best results, in the leave-one-out evaluation, were obtained using the frequency features set, with a MAE of 6.08 mmHg, a MAPE of 7.85%, and a ME of 0.31 mmHg, in the estimation of the mean blood pressure.

2017

A Preliminary Approach for the Segmentation of Mitral Valve Regurgitation Jet in Doppler Ecocardiography Images

Authors
Costa, E; Martins, N; Sultan, MS; Veiga, D; Ferreira, MJ; Mattos, S; Coimbra, M;

Publication
PROCEEDINGS OF THE 10TH INTERNATIONAL JOINT CONFERENCE ON BIOMEDICAL ENGINEERING SYSTEMS AND TECHNOLOGIES, VOL 2: BIOIMAGING

Abstract
Rheumatic Fever and Rheumatic Heart Disease remain a major burden among children in developing countries. Echocardiography with colour flow Doppler is key to early diagnosis. However, the technique requires time and experienced operators, which are scarce resources in the affected areas. Automatic segmentation of colour Doppler regurgitation jets could, potentially, reduce the cost of screening, and spread diagnostic accessibility for a larger number of patients. Ultrasound processing is very challenging due to speckle noise and similarity of representation of all kinds of tissue. Region-based active contours are suitable tools for the segmentation in cases of intensity heterogeneities, which makes them interesting algorithms for left atrium segmentation. HSV colour space describes colour in terms of hues and saturation, which may facilitate the translation of medical interpretation of the Doppler pseudo-colour into mathematical expression for colour segmentation. A total of 979 frames from 20 sequences were manually annotated and used to validate the proposed pipeline. Overall, the results for colour pattern segmentation are promising (sensitivity=0.91 false detection rate=0.10), but further developments are required for the atrium segmentation (sensitivity=0.80, false detection rate=0.28).

2015

A proposal to incorporate digital auscultation and its processing into an existing electronic health record

Authors
Gomes, P; Frade, S; Castro, A; Cruz Correia, R; Coimbra, M;

Publication
HEALTHINF 2015 - 8th International Conference on Health Informatics, Proceedings; Part of 8th International Joint Conference on Biomedical Engineering Systems and Technologies, BIOSTEC 2015

Abstract
This paper aims to describe and discuss a proposal to incorporate digital auscultation and its processing into an existing EHR. The architecture was planned to be used in both primary and hospital care, and includes a digital stethoscope; an exam collection module; an integration module; an EHR web service; and an EHR. Special attention was given to standardize communications using HL7 and openEHR. The proposed implementation uses a commercial stethoscope, an android app to collect the data, a mirth integration engine that communicates using HL7 or openEHR through REST or SOAP calls. The signal processing of the sounds is also included. The auscultation sound files are made available to the EHR users. This solution will open the possibility to have richer patient records than can be very important for patient care, research and medical teaching. It also raises issues regarding ethical and legal concerns that must be considered in future research.

2019

Quantification of the difference between Cardiac Magnetic Resonance signals in perfusion studies with and without motion correction algorithms

Authors
Moreira, T; Almeida, N; Bettencourt, N; Coimbra, M;

Publication
2019 6TH IEEE PORTUGUESE MEETING IN BIOENGINEERING (ENBENG)

Abstract
In studies requiring respiratory apnea, such as the cardiac magnetic resonance (CMR) perfusion sequence, it is sometimes difficult for patients to perform such a requirement. In the medical imaging market, motion correction algorithms have emerged, such as motion correction (MoCo) from Siemens, as computational tools capable of correcting this dilemma. It is important to verify, by the signal intensity of the images, if the images of the sequences with the application of the algorithm do not differ significantly from the images without any post-processing. An experimental study was carried out to measure signal intensity by region of interest (ROI) marking, one of which was located in the cardiac chamber and another in the segment with ischemia in thirteen individuals (n = 13) with a diagnosis of ischemia of the anterior descendent artery who performed the perfusion sequence by CMR. Statistical analysis with the values resulting from these measurements was performed using the statistical analysis software IBM SPSS Statistics 24. Signal strength measurements were performed at the Alfena Private Hospital with Siemens Syngo MR D14 software. It is verified that there are no statistically significant differences in the signal intensity measurements in the images without and with the motion correction algorithm.

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