Online drawings for dementia diagnose: in-air and pressure information analysis

In this paper we present experimental results comparing on-line drawings for control population (left and right hand) as well as Alzheimer disease patients. The drawings have been acquired by means of a digitizing tablet, which acquires time information angles and pressures. Experimental measures based on pressure and in-air movements appear to be significantly different for both groups, even when control population performs the tasks with the non-dominant hand

Parameterization of written signatures based on EFD

In this work we propose a method to quantify written signatures from digitalized images based on the use of Elliptical Fourier Descriptors (EFD). As usually signatures are not represented as a closed contour, and being that a necessary condition in order to apply EFD, we have developed a method that represents the signatures by means of a set of closed contours. One of the advantages of this method is that it can reconstruct the original shape from all the coefficients, or an approximated shape from a reduced set of them finding the appropriate number of EFD coefficients required for preserving the important information in each application. EFD provides accurate frequency information, thus the use of EFD opens many possibilities. The method can be extended to represent other kind of shapes

Features extraction scheme for behavioral biometric authentication in touchscreen mobile devices

Common authentication mechanisms in mobile devices such as passwords and Personal Identification Number have failed to keep up with the rapid pace of challenges associated with the use of ubiquitous devices over the Internet, since they can easily be lost or stolen. Thus, it is important to develop authentication mechanisms that can be adapted to such an environment. Biometric-based person recognition is a good alternative to overcome the difficulties of password and token approaches, since biometrics cannot be easily stolen or forgotten. An important characteristic of biometric authentication is that there is an explicit connection with the user's identity, since biometrics rely entirely on behavioral and physiological characteristics of human being. There are a variety of biometric authentication options that have emerged so far, all of which can be used on a mobile phone. These options include but are not limited to, face recognition via camera, fingerprint, voice recognition, keystroke and gesture recognition via touch screen. Touch gesture behavioural biometrics are commonly used as an alternative solution to existing traditional biometric mechanism. However, current touch gesture authentication schemes are fraught with authentication accuracy problems. In fact, the extracted features used in some researches on touch gesture schemes are limited to speed, time, position, finger size and finger pressure. However, extracting a few touch features from individual touches is not enough to accurately distinguish various users. In this research, behavioural features are extracted from recorded touch screen data and a discriminative classifier is trained on these extracted features for authentication. While the user performs the gesture, the touch screen sensor is leveraged on and twelve of the user‘s finger touch features are extracted. Eighty four different users participated in this research work, each user drew six gesture with a total of 504 instances. The extracted touch gesture features are normalised by scaling the values so that they fall within a small specified range. Thereafter, five different Feature Selection Algorithm were used to choose the most significant features subset. Six different machine learning classifiers were used to classify each instance in the data set into one of the predefined set of classes. Results from experiments conducted in the proposed touch gesture behavioral biometrics scheme achieved an average False Reject Rate (FRR) of 7.84%, average False Accept Rate (FAR) of 1%, average Equal Error Rate (EER) of 4.02% and authentication accuracy of 91.67%,. The comparative results showed that the proposed scheme outperforms other existing touch gesture authentication schemes in terms of FAR, EER and authentication accuracy by 1.67%, 6.74% and 4.65% respectively. The results of this research affirm that user authentication through gestures is promising, highly viable and can be used for mobile devices

Nuevas técnicas diagnósticas de las enfermedades respiratorias : análisis de imagen

In the present thesis 3 detailed studies were carried out that spring from 3 different diagnostic techniques that include bronoscopy, tuberculine bacillus infection diagnosis, and the control of oxygen therapy in chronic patients. All three studies were based on image analysis. In the first study we applied ultrasound techniques through broncoscopy (EBUS) and evaluated the images of 12 malignant ganglios and 11 benign mediastine ones in patients suspected as having pulmonary neoplastic disease. A previous process was applied to improve the quality of the image and enhance their features. Morfologic and texture parameters were anaylized such as texture of the ultrasounds and fractal dimensión that express the relation between the area and the perimeter of the structures that appear in the image, as well as characteristics of internal structure convolucionated of the hiliary and mediastine structures. The fractal dimensión was lower in the malignant ganglios compared to non-malignant ones (1.47(0.09), 1.53(0.10) mean (SD), respectively, Mann Whitney U test p<0.005)). In conclusion the fractal dimensión of ultrasound images of the mediastine ganglios obtained through endobronquial ultrasound differ depending on whether they are benign or malignant. In the second study a new method of evaluation was implemented of the tuberculine skin reaction with an Infrared camera. In this study 34 subjects participated that had been in contact with people infected with the bacillus. (46.8± 16.9 years), (12/22 men/women). The test reading was performed by the standard exploratory method and after taking an image of the puncture site on the forearm, using an Infrared Fluke Camara (320x240) situated 40 cm above the forearm. The IR image was processed using conventional image processing techniques (Canny edge detection, Hough transformer). From the previously segmented regions the following parameters are extracted: Maximum temperature , mean and mínimum in Cº, surface area and diameter of the area of segmented reaction. Results: 3 areas of segmentation were established: Area 1, called "papule", area 2 "eritema" and area 3 "background". The differences in temp between areas 1 and 2 in the group with positive IR reaction were significant with a mean temp. difference of 0.45 Cº ( T Test, p<0.05). The difference between the mean temp. of the central area of both groups was 1.11 Cº (T Test, p<0.05). The regression coefficient between the diameter measured by examination was R=0.65, R2=0.42, ( p<0.001), in all subjects with a positive PPD. We can conclude that the tuberculine injection produces an inflammatory reaction that can be easily readed with a IR application. The third study yielded data regarding the effects that applied oxygen therapy over a short period to time has on the psychomotor status of patients with chronic hypoxemia. Eight patients (7 men and 1 woman, mean age 69.5 (9.9) years (mean SD) affected by Hypoxemia (Pa O2 62.2(6.9) mmHg, participated. They performed drawings: a house and a clock. The tests were undertaken before and after inhaling O2 during 30 minutes. Results: The speed of drawing increased after inhaling O2 while making the house drawing (speed 27.6(5.5) mm/s basal, 30.9(7.1) mm/s with O2, mean(SD), p<0.025, Wilcoxon Test). The drawing time "down" decreased (i.e. For the house; "down time" 20.7 (6.6) s basal, 17.4 (6.3) s with O2 , p<0.017, Wilcoxon Test). The drawing time "down" or the fraction of time that the pencil is in contact while performing the drawing decreased. ((i.e. For the house: "time down" 20.7(6.6) s basal, 17.4(6.3) s con O2 , p<0.017, Wilcoxon Test). In conclusion, this study shows that in patients with chronic hypoxemia, the administration of O2 at a low concentration during a short period of time produces changes in psychomotor function that can be measured through the drawing analysis.En esta tesis se han realizado tres estudios aplicando tres técnicas diagnósticas diferentes que incluyen broncoscopia, diagnóstico de la infección por el bacilo de la tuberculosis y el control de la oxigeno terapia en pacientes crónicos. Todos los estudios están basados en el análisis de imagen. En el primer estudio mediante la técnica de ultrasonografia a través de broncoscopio (EBUS) se evaluaron las imágenes de 12 ganglios mediastinitos malignos y 11 benignos en pacientes con sospecha de neoplasia pulmonar. Un procesamiento previo de la imagen fue aplicado para mejorar la cualidad de la misma. Se analizaron parámetros de textura y morfología así como la dimensión fractal que expresa la relación entre área y perímetro de las estructuras que aparecen en la imagen. La dimensión fractal fue más baja en los ganglios malignos comparados con los benignos (1.47(0.09), 1.53(0.10) (media(sd)) respectivamente. (Mann Whitney U test p<0.005). En conclusión la dimnensión fractal de las imágenes de ultrasonidos de los ganglios mediastinitos (EBUS) difieren dependiendo de si son o no malignos. En el segundo estudio se implemento un nuevo método de evaluación de la reacción dérmica a la tuberculina mediante una cámara de infrarrojos (IR). Participaron 34 sujetos que habían estado en contacto con pacientes infectados con el bacilo tuberculoso (46.8±16.9 años), (12/22 hombres/mujeres). La lectura fue realizada mediante exploración convencional y una cámara IR Fluke (320x240) situada a 40 cm del antebrazo en el lugar de punción. La imagen IR se proceso mediante detección Canny y la transformación de Hough). Resultados: Se describieron 3 áreas de segmentación, área 1 o pápula, área 2 o eritema y área 3 o background. Las diferencias de temperatura entre la 1 y 2 en el grupo IR positivo fue de 0.45 Cº (T test, p<0.05). La diferencia de Temp. Entre ambos grupos fue de 1.11 Cº (T test, p<0.05). El coeficiente de regresión entre ambos métodos fue de R=0.65, R20.42 (p<0.001) en los IR +. Concluimos que la inyección de tuberculina produce una reacción inflamatoria que puede ser medida por una cámara IR. En el tercer estudio se estudiaron los efectos de la oxigenoterapia a corto plazo sobre el estado psicomotor de los pacientes afectos de hipoxemia crónica. Participaron 8 pacientes afectos de hipoxemia (7/1 hombres/mujeres, edad 69.5(9.9) años (PaO2 62.2(6.9) mmHg). Desarrollaron dibujos (una casa y un reloj) antes y después de la inhlación de O2 durante 30 min. Resultados: La velocidad del trazado aumento con la casa((27.6(5.5) mm/s basal, 30.9(7.1) mm/s con O2 , p<0.025) Wilcoxon test). El tiempo abajo (contacto lapiz-tabla) disminuyo para la casa (20.7(6.6)s basal 17.4(6.3)s con O2, p<0.017, Wilcoxon test). En conclusión este estudio indica que en pacientes con hipoxemia crónica, la administración de O2 a bajas concentraciones durante un periodo corto de tiempo produce cambios en la función psicomotora que pueden ser medidos mediante el análisis del trazado de dibujosPostprint (published version

Usability in biometric recognition systems

Mención Internacional en el título de doctorBiometric recognition, which is a technology already mature, grows nowadays in several contexts, including forensics, access controls, home automation systems, internet, etc. Now that technology is moving to mobile scenarios, biometric recognition is being also integrated in smartphones, tablets and other mobile devices as a convenient solution for guaranteeing security, complementing other methods such as PIN or passwords. Nevertheless, the use of biometric recognition is not as spread as desired and it is still unknown for a wide percentage of the population. It has been demonstrated [1] that some of the possible reasons for the slow penetration of biometrics could be related to usability concerns. This could lead to various drawbacks like worst error rates due to systems misuses and it could end with users rejecting the technology and preferring other approaches. This Thesis is intended to cover this topic including a study of the current state of the art, several experiments analysing the most relevant usability factors and modifications to a usability evaluation methodology. The chosen methodology is the H-B interaction, carried out by Fernandez-Saavedra [2], based on the ISO/IEC 19795 [3], the HBSI [4], the ISO 9241-210 [5] and on Common Criteria [6]. Furthermore, this work is focused on dealing with accessibility concerns in biometric recognition systems. This topic, usually included into the usability field, has been addressed here separately, though the study of the accessibility has followed the same steps as the usability study: reviewing the state of the art, pointing and analysing the main influential factors and making improvements to the state of the art. The recently published standard EN 301 549 – “Accessibility requirements suitable for public procurement of ICT products and services in Europe” [7] has been also analysed. These two topics have been overcome through the well-known user-centric-design approach. In this way, first the influential factors have been detected. Then, they have been isolated (when possible) and measured. The results obtained have been then interpreted to suggest new updates to the H-B interaction. This 3-steps approach has been applied cyclically and the factors and methodology updated after each iteration. Due to technology and usability trends, during this work, all the systems/applications developed in the experiments have been thought to be mobile directly or indirectly. The biometric modalities used during the experiments performed in this Thesis are those pointed as suitable for biometric recognition in mobile devices: handwritten recognition signature, face and fingerprint recognition. Also, the scenarios and the applications used are in line with the main uses of biometrics in mobile environments, such as sign documents, locking/unlocking devices, or make payments. The outcomes of this Thesis are intended to guide future developers in the way of designing and testing proper usable and accessible biometrics. Finally, the results of this Thesis are being suggested as a new International Standard within ISO/IEC/JTC1/SC37 – Biometric Recognition, as standardization is the proper way of guaranteeing usability and accessibility in future biometric systems. The contributions of this Thesis include: • Improvements to the H-B interaction methodology, including several usability evaluations. • Improvements on the accessibility of the ICT (Information and Communications Technology) products by means of the integration of biometric recognition systems • Adaptation and application of the EN 301 549 to biometric recognition systems.El reconocimiento biométrico, que es una tecnología ya madura, crece hoy en día en varios contextos, incluyendo la medicina forense, controles de acceso, sistemas de automatización del hogar, internet, etc. Ahora que la tecnología se está moviendo a los escenarios móviles, el reconocimiento biométrico está siendo también integrado en los teléfonos inteligentes, tabletas y otros dispositivos móviles como una solución conveniente para garantizar la seguridad, como complemento de otros métodos de seguridad como el PIN o las contraseñas. Sin embargo, el uso del reconocimiento biométrico es todavía desconocido para un amplio porcentaje de la población. Se ha demostrado [1] que algunas de las posibles razones de la lenta penetración de la biometría podrían estar relacionadas con problemas de usabilidad. Esto podría dar lugar a diversos inconvenientes, ofreciendo un rendimiento por debajo de lo esperado debido al mal uso de los sistemas y podría terminar con los usuarios rechazando la tecnología y prefiriendo otros enfoques. Esta tesis doctoral trata este tema incluyendo un estudio del estado actual de la técnica, varios experimentos que analizan los factores de usabilidad más relevantes y modificaciones a una metodología de evaluación de la usabilidad, la "H-B interaction" [2] basada en la ISO / IEC 19795 [3], el HBSI [4], la ISO 9241 [5] y Common Criteria [6]. Además, este trabajo se centra también en los problemas de accesibilidad de los sistemas de reconocimiento biométrico. Este tema, que por lo general se incluye en el campo de la usabilidad, se ha tratado aquí por separado, aunque el estudio de la accesibilidad ha seguido los mismos pasos que el estudio de usabilidad: revisión del estado del arte, análisis de los principales factores influyentes y propuesta de cambios en la metodología H-B interaction. Han sido también analizados los requisitos de accesibilidad para las Tecnologías de la Información y la Comunicación (TIC) en Europa, bajo la norma EN 301 549 [7]. Estos dos temas han sido estudiados a través de un enfoque centrado en el usuario (User Centric Design - UCD). De esta manera, se han detectado los factores influyentes. A continuación, dichos factores han sido aislados (cuando ha sido posible) y medidos. Los resultados obtenidos han sido interpretados para sugerir nuevos cambios a la metodología H-B interaction. Este enfoque de 3 pasos se ha aplicado de forma cíclica a los factores y a la metodología después de cada iteración. Debido a las tendencias tecnológicas y de usabilidad, durante este trabajo, todos los sistemas / aplicaciones desarrolladas en los experimentos se han pensado para ser móviles, directa o indirectamente. Las modalidades utilizadas durante los experimentos realizados en esta tesis doctoral son las que se señalaron como adecuados para el reconocimiento biométrico en dispositivos móviles: la firma manuscrita, la cara y el reconocimiento de huellas dactilares. Además, los escenarios y las aplicaciones utilizadas están en línea con los principales usos de la biometría en entornos móviles, como la firma de documentos, el bloqueo / desbloqueo de dispositivos, o hacer pagos. Los resultados de esta tesis tienen como objetivo orientar a los futuros desarrolladores en el diseño y evaluación de la usabilidad y la accesibilidad en los sistemas de reconocimiento biométrico. Por último, los resultados de esta tesis doctoral se sugerirán como un nuevo estándar de ISO / IEC / JTC1 / SC37 - Biometric Recognition, ya que la normalización es la manera adecuada de garantizar la usabilidad y la accesibilidad en los futuros sistemas biométricos. Las contribuciones de esta tesis incluyen: • Mejora de la metodología de evaluación H-B interaction, incluyendo varias evaluaciones de usabilidad. • Mejora de la accesibilidad de los sistemas de información / electrónicos mediante la integración de sistemas biométricos y varias evaluaciones. • Adaptación y aplicación de la norma de accesibilidad EN 301 549 al campo de los sistemas biométricos.Programa Oficial de Doctorado en Ingeniería Eléctrica, Electrónica y AutomáticaPresidente: Patrizio Campisi.- Secretario: Enrique Cabellos Pardo.- Vocal: Marcos Faundez Zanu

Hondatze kognitibo arinaren detekzio goiztiarrerako hizketa ezagutza automatikoan oinarrituriko ekarpenak

302 p.Alzheimerdun gaixoengan, mintzamena ez ezik, erantzun emozionala ere kaltetu egiten da. Emozioak giza gogoaren arkitekturarekin zerikusia dituzten prozesu kognitiboak dira, eta erabakiak hartzearekin eta oroimenaren kudeaketa edota arretarekin zerikusia dute, eta aldi berean ere, horiek hertsiki lotuta dauden komunikazioarekin. Hortaz, erantzun eta kudeaketa emozionalak ere badira gaitzaren hasierako fase horietan nahasten diren beste komunikazio-elementu batzuk, eta disfluentzia bezala, emozio-erantzuna narriadura kognitiboa neurtzeko adierazlea izan daiteke.Hortaz, zenbait atazaren bidez sortutako ahots-laginen azterketak direla medio, disfluentzia eta emozio-erantzuna jaso daitezke. Hizkuntzarekiko independenteak diren parametroak bildu eta horien hizkeraren nahasmenduak ezaugarritu badaitezke, ekarpena lagungarria izan daiteke diagnostikoa egingo duten espezialistentzat.Lehengaiak ahots-laginak direnez, ingurune kliniko zein etxeko ingurunean egindako ataza desberdinen bidez grabazioak egin eta datu-baseak osatu dira, osasun-guneen irizpide etikoak kontuan hartuta eta. Datu-base horien ikerketaren bidez, galera kognitiboaren garapena neurtu, kuantifikatu, balioztatu eta sailkatu nahi da. Gaitzaren etapa desberdinak hautematen laguntzeko ekarpena egin nahi da, eta horretarako, hizkuntzarekiko independenteak diren parametroen azterketa automatikorako teknika eta metodologiak garatu dira. Mintzamen automatikoaren analisian oinarritutako multi-hurbilketa ez-lineala egin da, zeinak hizketa-analisian erabiltzen diren denborazko serieen konplexutasunaren neurtze kuantitatiboa eman diezaguke