New electrochromic systems: multicolored, semi-solid and easy-to-make

266 p.La presente tesis doctoral aborda la temática de los sistemas electrocromicos centrándose en la obtención de nuevas coloraciones, especialmente coloraciones neutras (gris y negro) así como dispositivos multielectrocrómicos de fácil fabricación y manteniendo configuraciones de dispositivos sencillas.Para alcanzar estos objetivos, el desarrollo técnico de la tesis se ha centrado en dos puntos principales: 1) la síntesis de nuevos materiales electrocrómicos, concretamente viológenos, con sustituyentes de diferente naturaleza para ampliar la gama de coloraciones y 2) el desarrollo de un nuevo concepto de electrolito basado en un fluido de naturaleza no-Newtoniana viscoelástico. En relación al primer punto, se han sintetizado viológenos tanto exentos de grupo de anclaje para ser incorporados en dispositivos de mezcla única (¿All-in-one¿), como provistos de un grupo de anclaje que les permita unirse covalentemente a una capa nanoestructurada de TiO2, (¿layered¿) presentando velocidades de adsorción muy rápidas. En relación al segundo punto, el desarrollo de un electrolito de base acuosa con propiedades viscoelásticas ha permitido mantener las buenas prestaciones de los electrolitos líquidos y sólidos actuales, pero mejorando algunas de sus limitaciones y permitiendo una fácil fabricación y manejo.IK4 CIDETE

Introducing keytagging, a novel technique for the protection of medical image-based tests

This paper introduces keytagging, a novel technique to protect medical image-based tests by implementing image authentication, integrity control and location of tampered areas, private captioning with role-based access control, traceability and copyright protection. It relies on the association of tags (binary data strings) to stable, semistable or volatile features of the image, whose access keys (called keytags) depend on both the image and the tag content. Unlike watermarking, this technique can associate information to the most stable features of the image without distortion. Thus, this method preserves the clinical content of the image without the need for assessment, prevents eavesdropping and collusion attacks, and obtains a substantial capacity-robustness tradeoff with simple operations. The evaluation of this technique, involving images of different sizes from various acquisition modalities and image modifications that are typical in the medical context, demonstrates that all the aforementioned security measures can be implemented simultaneously and that the algorithm presents good scalability. In addition to this, keytags can be protected with standard Cryptographic Message Syntax and the keytagging process can be easily combined with JPEG2000 compression since both share the same wavelet transform. This reduces the delays for associating keytags and retrieving the corresponding tags to implement the aforementioned measures to only ¿30 and ¿90. ms respectively. As a result, keytags can be seamlessly integrated within DICOM, reducing delays and bandwidth when the image test is updated and shared in secure architectures where different users cooperate, e.g. physicians who interpret the test, clinicians caring for the patient and researchers

Biometric authentication using the PPG: A long-term feasibility study

The photoplethysmogram (PPG) is a biomedical signal that can be used to estimate volumetric blood flow changes in the peripheral circulation. During the past few years, several works have been published in order to assess the potential for PPGs to be used in biometric authentication systems, but results are inconclusive. In this paper we perform an analysis of the feasibility of using the PPG as a realistic biometric alternative in the long term. Several feature extractors (based on the time domain and the Karhunen–Loève transform) and matching metrics (Manhattan and Euclidean distances) have been tested using four different PPG databases (PRRB, MIMIC-II, Berry, and Nonin). We show that the false match rate (FMR) and false non-match rate (FNMR) values remain constant in different time instances for a selected threshold, which is essential for using the PPG for biometric authentication purposes. On the other hand, obtained equal error rate (EER) values for signals recorded during the same session range from 1.0% for high-quality signals recorded in controlled conditions to 8% for those recorded in conditions closer to real-world scenarios. Moreover, in certain scenarios, EER values rise up to 23.2% for signals recorded over different days, signaling that performance degradation could take place with time

Oblivious Inspection: On the Confrontation between System Security and Data Privacy at Domain Boundaries

In this work, we introduce the system boundary security vs. privacy dilemma, where border devices (e.g., firewall devices) require unencrypted data inspection to prevent data exfiltration or unauthorized data accesses, but unencrypted data inspection violates data privacy. To shortcut this problem, we present Oblivious Inspection, a novel approach based on garbled circuits to perform a stateful application-aware inspection of encrypted network traffic in a privacy-preserving way. We also showcase an inspection algorithm for Fast Healthcare Interoperability Resources (FHIR) standard compliant packets along with its performance results. The results point out the importance of the inspection function being aligned with the underlying garbled circuit protocol. In this line, mandatory encryption algorithms for TLS 1.3 have been analysed observing that packets encrypted using Chacha20 can be filtered up to 17 and 25 times faster compared with AES128-GCM and AES256-GCM, respectively. All together, this approach penalizes performance to align system security and data privacy, but it could be appropriate for those scenarios where this performance degradation can be justified by the sensibility of the involved data such as healthcare scenarios

Development and evaluation of a microservice-based virtual assistant for chronic patients support

Los asistentes virtuales (también conocidos como chatbots) son programas que interactúan con los usuarios simulando una conversación humana a través de mensajes de texto o de voz. Los asistentes virtuales destinados al cuidado de la salud ofrecen servicios, herramientas, asesoramiento, ayuda, soporte y gestión de diferentes enfermedades. Los usuarios de este tipo de asistente virtual pueden ser, por ejemplo, pacientes, cuidadores y profesionales sanitarios, los cuales poseen diferentes necesidades y requerimientos. Los pacientes con enfermedades crónicas podrían beneficiarse de los asistentes virtuales que se encargan de realizar seguimientos de su condición, proporcionar información específica, fomentar la adherencia a la medicación, etc. Para realizar estas funciones, los asistentes virtuales necesitan una arquitectura de software adecuada. Esta tesis doctoral propone el diseño de una arquitectura específica para el desarrollo de asistentes virtuales destinados a proporcionar soporte a pacientes crónicos. Hoy en día, las personas interactúan entre sí diariamente utilizando plataformas de mensajería. Para alinear este tipo de interacción con la arquitectura del asistente virtual, proponemos el uso de plataformas de mensajería para la interacción asistente virtual-paciente, prestando especial atención a las cuestiones de seguridad y privacidad (es decir, el uso de plataformas de mensajería seguras con cifrado de extremo a extremo).Los asistentes virtuales pueden implementar sistemas conversacionales para que la interacción con los pacientes sea más natural. Los sistemas conversacionales en escenarios de atención médica complejos, como la gestión de enfermedades, deben ser capaces de poder comprender oraciones complejas utilizadas durante la interacción. La adaptación de nuevos métodos con el procesamiento de lenguaje natural (NLP, por su nombre en inglés, Natural Language Processing) puede aportar una mejora a la arquitectura del asistente virtual. Los word embeddings (incrustación de palabras) se han utilizado ampliamente en NLP como entrada en las redes neuronales. Tales word embeddings pueden ayudar a comprender el objetivo final y las palabras clave en una oración. Por ello, en esta tesis estudiamos el impacto de diferentes word embeddings entrenados con corpus generales y específicos utilizando el entendimiento del lenguaje natural conjunto (Joint NLU, por su nombre en inglés, Joint Natural Language Understanding) en el dominio de la medicación en español. Los datos para entrenar el modelo NLU conjunto se generan usando plantillas. Dicho modelo se utiliza para la detección de intenciones, así como para el slot filling (llenado de ranuras). En este estudio comparamos word2vec y fastText como word embeddings y ELMo y BERT como modelos de lenguaje. Para entrenar los embeddings utilizamos tres corpus diferentes: los datos de entrenamiento generados para este escenario, la Wikipedia en español como dominio general y la base de datos de medicamentos en español como datos especializados. El mejor resultado se obtuvo con el modelo ELMo entrenado con Wikipedia en español.Dotamos al asistente virtual de capacidades de gestión de medicamentos basadas en NLP. En consecuencia, se analiza el impacto del etiquetado de slots y la longitud de los datos de entrenamiento en modelos NLU conjuntos para escenarios de gestión de medicamentos utilizando asistentes virtuales en español. En este estudio definimos las intenciones (propósitos de las oraciones) para escenarios centrados en la administración de medicamentos y dos tipos de etiquetas de slots. Para entrenar el modelo, generamos cuatro conjuntos de datos, combinando oraciones largas o cortas con slots largos o cortos. Para el análisis comparativo, elegimos seis modelos NLU conjuntos (SlotRefine, stack-propagation framework, SF-ID network, capsule-NLU, slot-gated modeling y joint SLU-LM) de la literatura existente. Tras el análisis competitivo, se observa que el mejor resultado se obtuvo utilizando oraciones y slots cortos. Nuestros resultados sugirieron que los modelos NLU conjuntos entrenados con slots cortos produjeron mejores resultados que aquellos entrenados con slots largos para la tarea de slot filling.En definitiva, proponemos una arquitectura de microservicios genérica válida para cualquier tipo de gestión de enfermedades crónicas. El prototipo genérico ofrece un asistente virtual operativo para gestionar información básica y servir de base para futuras ampliaciones. Además, en esta tesis presentamos dos prototipos especializados con el objetivo de mostrar cómo esta nueva arquitectura permite cambiar, añadir o mejorar diferentes partes del asistente virtual de forma dinámica y flexible. El primer prototipo especializado tiene como objetivo ayudar en la gestión de la medicación del paciente. Este prototipo se encargará de recordar la ingesta de medicamentos a través de la creación de una comunidad de apoyo donde los pacientes, cuidadores y profesionales sanitarios interactúen con herramientas y servicios útiles ofrecidos por el asistente virtual. La implementación del segundo prototipo especializado está diseñada para una enfermedad crónica específica, la psoriasis. Este prototipo ofrece teleconsulta y almacenamiento de fotografías.Por último, esta tesis tiene como objetivo validar la eficacia del asistente virtual integrado en las plataformas de mensajería, destinado al cuidado de la salud. Por ello, esta tesis incluye la evaluación de los dos prototipos especializados. El primer estudio tiene como objetivo mejorar la adherencia a la medicación en pacientes con diabetes mellitus tipo 2 comórbida y trastorno depresivo. Para ello, se diseñó y posteriormente se realizó un estudio piloto de nueve meses. En el estudio analizamos la Tasa de Posesión de Medicamentos (MPR, por su nombre en inglés, Medication Possession Ratio), obtuvimos la puntuación del Cuestionario sobre la Salud del Paciente (PHQ-9, por su nombre en inglés, Patient Health Questionnaire) y medimos el nivel de hemoglobina glicosilada (HbA1c), en los pacientes antes y después del estudio. También realizamos entrevistas a todos los participantes. Un total de trece pacientes y cinco enfermeras utilizaron y evaluaron el asistente virtual propuesto. Los resultados mostraron que, en promedio, la adherencia a la medicación de los pacientes mejoró. El segundo estudio tiene como objetivo evaluar un año de uso entre el asistente virtual y pacientes con psoriasis y dermatólogos, y el impacto en su calidad de vida. Para ello se diseñó y realizó un estudio prospectivo de un año de duración con pacientes con psoriasis y dermatólogos. Para medir la mejora en la calidad de vida, en este estudio analizamos los cuestionarios de Calidad de Vida de los Pacientes con Psoriasis (PSOLIFE, por su nombre en inglés, Psoriasis Quality of Life) y el Índice de Calidad de Vida en Dermatología (DLQI, por su nombre en inglés, Dermatology Life Quality Index). Además, realizamos encuestas a todos los participantes y obtuvimos el número de consultas médicas realizadas a través del asistente virtual. Se incluyeron en el estudio un total de 34 participantes (30 pacientes diagnosticados con psoriasis moderada-grave y cuatro profesionales sanitarios). Los resultados mostraron que, en promedio, la calidad de vida mejoró.<br /

Validation of a Virtual Assistant for Improving Medication Adherence in Patients with Comorbid Type 2 Diabetes Mellitus and Depressive Disorder

Virtual assistants are programs that interact with users through text or voice messages simulating a human-based conversation. The development of healthcare virtual assistants that use messaging platforms is rapidly increasing. Still, there is a lack of validation of these assistants. In particular, this work aimed to validate the effectiveness of a healthcare virtual assistant, integrated within messaging platforms, with the aim of improving medication adherence in patients with comorbid type 2 diabetes mellitus and depressive disorder. For this purpose, a nine-month pilot study was designed and subsequently conducted. The virtual assistant reminds patients about their medication and provides healthcare professionals with the ability to monitor their patients. We analyzed the medication possession ratio (MPR), measured the level of glycosylated hemoglobin (HbA1c), and obtained the patient health questionnaire (PHQ-9) score in the patients before and after the study. We also conducted interviews with all participants. A total of thirteen patients and five nurses used and evaluated the proposed virtual assistant using the messaging platform Signal. Results showed that on average, the medication adherence improved. In the final interview, 69% of the patients agreed with the idea of continuing to use the virtual assistant after the study

All-in-One Gel-Based Electrochromic Devices: Strengths and Recent Developments

Electrochromic devices (ECDs) have aroused great interest because of their potential applicability in displays and smart systems, including windows, rearview mirrors, and helmet visors. In the last decades, different device structures and materials have been proposed to meet the requirements of commercial applications to boost market entry. To this end, employing simple device architectures and achieving a competitive electrolyte are crucial to accomplish easily implementable, high-performance ECDs. The present review outlines devices comprising gel electrolytes as a single electroactive layer (“all-in-one”) ECD architecture, highlighting some advantages and opportunities they offer over other electrochromic systems. In this context, gel electrolytes not only overcome the drawbacks of liquid and solid electrolytes, such as liquid’s low chemical stability and risk of leaking and soil’s slow switching and lack of transparency, but also exhibit further strengths. These include easier processability, suitability for flexible substrates, and improved stabilization of the chemical species involved in redox processes, leading to better cyclability and opening wide possibilities to extend the electrochromic color palette, as discussed herein. Finally, conclusions and outlook are provided.This work has been partially supported by the European Union’s Horizon 2020 research and innovation program under the INNPAPER project (grant agreement No. 760876)

Microservice chatbot architecture for chronic patient support

Chatbots are able to provide support to patients suffering from very different conditions. Patients with chronic diseases or comorbidities could benefit the most from chatbots which can keep track of their condition, provide specific information, encourage adherence to medication, etc. To perform these functions, chatbots need a suitable underlying software architecture. In this paper, we introduce a chatbot architecture for chronic patient support grounded on three pillars: scalability by means of microservices, standard data sharing models through HL7 FHIR and standard conversation modeling using AIML. We also propose an innovative automation mechanism to convert FHIR resources into AIML files, thus facilitating the interaction and data gathering of medical and personal information that ends up in patient health records. To align the way people interact with each other using messaging platforms with the chatbot architecture, we propose these very same channels for the chatbot-patient interaction, paying special attention to security and privacy issues. Finally, we present a monitored-data study performed in different chronic diseases, and we present a prototype implementation tailored for one specific chronic disease, psoriasis, showing how this new architecture allows the change, the addition or the improvement of different parts of the chatbot in a dynamic and flexible way, providing a substantial improvement in the development of chatbots used as virtual assistants for chronic patients

Lessons learned after a three-year store and forward teledermatology experience using internet: Strengths and limitations

Purpose This paper presents a three-year teledermatology evaluation experience. The aim is to explain the methodology followed, present the evaluation results, discuss critically the issues that emerged during the experience and report the main lessons learned. Methods A complete design and evaluation methodology was conducted to fully address significant issues arising from other previous teledermatology experiences. First, system-design requirements and image quality issues were studied. Then, a detailed clinical concordance study was undertaken to determine the accuracy of diagnoses made using teledermatology in order to assess different dermatological clinics. Finally, an impact study on the health system was performed. Furthermore, clinical, technical, social and alignment outcomes were analyzed during the study and at the end of it, in order to understand how emerging factors affected the final setup of the teledermatology system. Results The most important results reported in this study can be summarized as follows. (1) A complete web-based environment for teledermatology support was developed as a result of a dynamic evaluation process with clinical personnel. (2) A total of 120 teleconsultations (82 pediatric and 28 adult) were made during the clinical concordance study. Concordance analysis was carried out for each dermatological disease group. High concordance rates were found in pediatrics for inflammatory dermatoses (76%) and also for adults (75%) with infections and infestations. (3) Physicians were satisfied with the teledermatology system but the time dedicated to consultation in primary care was a limiting factor (19 min for each teleconsultation). (4) An extensive discussion about the successful and the limiting aspects of the teledermatology experience revealed the reasons behind the final decision not to proceed with its implementation. It was considered not to be aligned with Health Care Organization (HCO) strategy and consequently did not achieve high-level support for its long-term implementation. Conclusions A high degree of diagnostic accuracy both for pediatric and adult consultations was achieved using the teledermatology system with affordable technical requirements. Its usefulness for filtering dermatological referrals was also demonstrated in the study. Nevertheless, other factors such as the reorganization required for the physicians’ time schedule, remuneration issues, absence of EHR (electronic health record) integration and lack of interaction with the HCO were important limiting factors. This led to the conclusion that under the evaluation conditions long-term set-up was not possible. It was also concluded that HCO participation would have been essential for both the evaluation study and the long-term set-up of the system. Highlights This paper reports a realistic experience in the design and evaluation of a telemedicine solution for remote dermatology consultation (tele-dermatology) in Aragón, Spain. ► This study takes a different approach discussing the strengths and limitations of a teledermatology experience in a realistic manner. ► A list of lessons learned is provided for future teledermatology implementations. Many pediatricians are involved in the experience providing in this way a detailed concordance analysis for children dermatological clinics