Mobile wireless monitoring system for prehospital emergency care.

BACKGROUND: Latest achievement technologies allow engineers to develop medical systems that medical doctors in the health care system could not imagine years ago. The development of signal theory, intelligent systems, biophysics and extensive collaboration between science and technology researchers and medical professionals, open up the potential for preventive, real-time monitoring of patients. With the recent developments of new methods in medicine, it is also possible to predict the trends of the disease development as well the systemic support in diagnose setting. Within the framework of the needs to track the patient health parameters in the hospital environment or in the case of road accidents, the researchers had to integrate the knowledge and experiences of medical specialists in emergency medicine who have participated in the development of a mobile wireless monitoring system designed for real-time monitoring of victim vital parameters. Emergency medicine responders are first point of care for trauma victim providing prehospital care, including triage and treatment at the scene of incident and transport from the scene to the hospital. Continuous monitoring of life functions allows immediate detection of a deterioration in health status and helps out in carrying out principle of continuous e-triage. In this study, a mobile wireless monitoring system for measuring and recording the vital parameters of the patient was presented and evaluated. Based on the measured values, the system is able to make triage and assign treatment priority for the patient. The system also provides the opportunity to take a picture of the injury, mark the injured body parts, calculate Glasgow Coma Score, or insert/record the medication given to the patient. Evaluation of the system was made using the Technology Acceptance Model (TAM). In particular we measured: perceived usefulness, perceived ease of use, attitude, intention to use, patient status and environmental status. METHODS: A functional prototype of a developed wireless sensor-based system was installed at the emergency medical (EM) department, and presented to the participants of this study. Thirty participants, paramedics and doctors from the emergency department participated in the study. Two scenarios common for the prehospital emergency routines were considered for the evaluation. Participants were asked to answer the questions referred to these scenarios by rating each of the items on a 5-point Likert scale. RESULTS: Path coefficients between each measured variable were calculated. All coefficients were positive, but the statistically significant were only the following: patient status and perceive usefulness (ß = 0.284, t = 2.097), environment (both urban a nd rural) and perceive usefulness (ß = 0.247, t = 2.570; ß = 0.329, t = 2.083, respectively), and perceive usefulness and behavioral intention (ß = 0.621 t = 7.269). The variance of intention is 47.9%. CONCLUSIONS: The study results show that the proposed system is well accepted by the EM personnel and can be used as a complementary system in EM department for continuous monitoring of patients' vital signs.

Automated breast-region segmentation in the axial breast MR images.

PURPOSE: The purpose of this study was to develop a robust breast-region segmentation method independent from the visible contrast between the breast region and surrounding chest wall and skin. MATERIALS AND METHODS: A fully-automated method for segmentation of the breast region in the axial MR images is presented relying on the edge map (EM) obtained by applying a tunable Gabor filter which sets its parameters according to the local MR image characteristics to detect non-visible transitions between different tissues having a similar MRI signal intensity. The method applies the shortest-path search technique by incorporating a novel cost function using the EM information within the border-search area obtained based on the border information from the adjacent slice. It is validated on 52 MRI scans covering the full American College of Radiology Breast Imaging-Reporting and Data System (BI-RADS) breast-density range. RESULTS: The obtained results indicate that the method is robust and applicable for the challenging cases where a part of the fibroglandular tissue is connected to the chest wall and/or skin with no visible contrast, i.e. no fat presence, between them compared to the literature methods proposed for the axial MR images. The overall agreement between automatically- and manually-obtained breast-region segmentations is 96.1% in terms of the Dice Similarity Coefficient, and for the breast-chest wall and breast-skin border delineations it is 1.9mm and 1.2mm, respectively, in terms of the Mean-Deviation Distance. CONCLUSION: The accuracy, robustness and applicability for the challenging cases of the proposed method show its potential to be incorporated into computer-aided analysis systems to support physicians in their decision making.

Characterization of spatiotemporal changes for the classification of dynamic contrast-enhanced magnetic-resonance breast lesions.

OBJECTIVE: The early detection of breast cancer is one of the most important predictors in determining the prognosis for women with malignant tumours. Dynamic contrast-enhanced magnetic-resonance imaging (DCE-MRI) is an important imaging modality for detecting and interpreting the different breast lesions from a time sequence of images and has proved to be a very sensitive modality for breast-cancer diagnosis. However, DCE-MRI exhibits only a moderate specificity, thus leading to a high rate of false positives, resulting in unnecessary biopsies that are stressful and physically painful for the patient and lead to an increase in the cost of treatment. There is a strong medical need for a DCE-MRI computer-aided diagnosis tool that would offer a reliable support to the physician's decision providing a high level of sensitivity and specificity. METHODS: In our study we investigated the possibility of increasing differentiation between the malignant and the benign lesions with respect to the spatial variation of the temporal enhancements of three parametric maps, i.e., the initial enhancement (IE) map, the post-initial enhancement (PIE) map and the signal enhancement ratio (SER) map, by introducing additional methods along with the grey-level co-occurrence matrix, i.e., a second-order statistical method already applied for quantifying the spatiotemporal variations. We introduced the grey-level run-length matrix and the grey-level difference matrix, representing two additional, second-order statistical methods, and the circular Gabor as a frequency-domain-based method. Each of the additional methods is for the first time applied to the DCE-MRI data to differentiate between the malignant and the benign breast lesions. We applied the least-square minimum-distance classifier (LSMD), logistic regression and least-squares support vector machine (LS-SVM) classifiers on a total of 115 (78 malignant and 37 benign) breast DCE-MRI cases. The performances were evaluated using ten experiments of a ten-fold cross-validation. RESULTS: Our experimental analysis revealed the PIE map, together with the feature subset in which the discriminating ability of the co-occurrence features was increased by adding the newly introduced features, to be the most significant for differentiation between the malignant and the benign lesions. That diagnostic test - the aforementioned combination of parametric map and the feature subset achieved the sensitivity of 0.9193 which is statistically significantly higher compared to other diagnostic tests after ten-experiments of a ten-fold cross-validation and gave a statistically significantly higher specificity of 0.7819 for the fixed 95% sensitivity after the receiver operating characteristic (ROC) curve analysis. Combining the information from all the three parametric maps significantly increased the area under the ROC curve (AUC) of the aforementioned diagnostic test for the LSMD and logistic regression; however, not for the LS-SVM. The LSMD classifier yielded the highest area under the ROC curve when using the combined information, increasing the AUC from 0.9651 to 0.9755. CONCLUSION: Introducing new features to those of the grey-level co-occurrence matrix significantly increased the differentiation between the malignant and the benign breast lesions, thus resulting in a high sensitivity and improved specificity.