4 research outputs found

    Desarrollo de sistema de Machine Learning para la prediccion de vía aérea a partir de imagen facial con dispositivo movil

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    El manejo de una vía aérea difícil (VAD) representa aún una causa importante de lesiones relacionadas con la anestesia, cuyas complicaciones son potencialmente mortales. El notable interés en la predicción de VAD ha provocado el desarrollo de modelos de predicción, algunos de los cuales ya incluyen algoritmos de Inteligencia Artificial a partir de imágenes. Se realizó un estudio observacional, de cohortes prospectivo, en el que se tomaron imágenes de los pacientes sometidos a una anestesia general, recogiendo la información pre-anestésica así como la información post-intubación. Nuestro equipo desarrolló un algoritmo automático de detección de puntos faciales de cara a la toma de medidas de variables ya validadas de predicción de VAD, que se integraron con el modelo predictivo de Naguib. La incidencia estimada de VAD en nuestra muestra de 503 pacientes fue de un 6,36%. La valoración subjetiva (pre-intervención) de los clínicos obtuvo una sensibilidad de 25.00%, con una especificidad de 93.63%. En comparación, nuestra herramienta alcanzó una sensibilidad del 53.12% y una especificidad del 79.83%. El AUC obtenida, o área bajo la curva ROC, fue de 0.680. Integrando nuestro sistema de medición IA-ML con el modelo de Naguib, los resultados muestran que estamos cerca de igualar la capacidad predictiva del clínico. El potencial del análisis facial en la predicción de VAD nos anima a seguir investigando y a desarrollar modelos propios. Creemos que proporcionará al anestesiólogo una herramienta de ayuda en la toma de decisiones automática, objetiva y accesible

    Automated location of orofacial landmarks to characterize airway morphology in anaesthesia via deep convolutional neural networks

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    Background:A reliable anticipation of a difficult airway may notably enhance safety during anaesthesia. In current practice, clinicians use bedside screenings by manual measurements of patients’ morphology. Objective:To develop and evaluate algorithms for the automated extraction of orofacial landmarks, which characterize airway morphology. Methods:We defined 27 frontal + 13 lateral landmarks. We collected n=317 pairs of pre-surgery photos from patients undergoing general anaesthesia (140 females, 177 males). As ground truth reference for supervised learning, landmarks were independently annotated by two anaesthesiologists. We trained two ad-hoc deep convolutional neural network architectures based on InceptionResNetV2 (IRNet) and MobileNetV2 (MNet), to predict simultaneously: (a) whether each landmark is visible or not (occluded, out of frame), (b) its 2D-coordinates (x, y). We implemented successive stages of transfer learning, combined with data augmentation. We added custom top layers on top of these networks, whose weights were fully tuned for our application. Performance in landmark extraction was evaluated by 10-fold cross-validation (CV) and compared against 5 state-of-the-art deformable models. Results:With annotators’ consensus as the ‘gold standard’, our IRNet-based network performed comparably to humans in the frontal view: median CV loss L=1.277·10-3, inter-quartile range (IQR) [1.001, 1.660]; versus median 1.360, IQR [1.172, 1.651], and median 1.352, IQR [1.172, 1.619], for each annotator against consensus, respectively. MNet yielded slightly worse results: median 1.471, IQR [1.139, 1.982]. In the lateral view, both networks attained performances statistically poorer than humans: median CV loss L=2.141·10-3, IQR [1.676, 2.915], and median 2.611, IQR [1.898, 3.535], respectively; versus median 1.507, IQR [1.188, 1.988], and median 1.442, IQR [1.147, 2.010] for both annotators. However, standardized effect sizes in CV loss were small: 0.0322 and 0.0235 (non-significant) for IRNet, 0.1431 and 0.1518 (p<0.05) for MNet; therefore quantitatively similar to humans. The best performing state-of-the-art model (a deformable regularized Supervised Descent Method, SDM) behaved comparably to our DCNNs in the frontal scenario, but notoriously worse in the lateral view. Conclusions:We successfully trained two DCNN models for the recognition of 27 + 13 orofacial landmarks pertaining to the airway. Using transfer learning and data augmentation, they were able to generalize without overfitting, reaching expert-like performances in CV. Our IRNet-based methodology achieved a satisfactory identification and location of landmarks: particularly in the frontal view, at the level of anaesthesiologists. In the lateral view, its performance decayed, although with a non-significant effect size. Independent authors had also reported lower lateral performances; as certain landmarks may not be clear salient points, even for a trained human eye.BERC.2022-2025 BCAM Severo Ochoa accreditation CEX2021-001142-S / MICIN / AEI / 10.13039/50110001103

    Opportunistic infections and AIDS malignancies early after initiating combination antiretroviral therapy in high-income countries

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    Background: There is little information on the incidence of AIDS-defining events which have been reported in the literature to be associated with immune reconstitution inflammatory syndrome (IRIS) after combined antiretroviral therapy (cART) initiation. These events include tuberculosis, mycobacterium avium complex (MAC), cytomegalovirus (CMV) retinitis, progressive multifocal leukoencephalopathy (PML), herpes simplex virus (HSV), Kaposi sarcoma, non-Hodgkin lymphoma (NHL), cryptococcosis and candidiasis. Methods: We identified individuals in the HIV-CAUSAL Collaboration, which includes data from six European countries and the US, who were HIV-positive between 1996 and 2013, antiretroviral therapy naive, aged at least 18 years, hadCD4+ cell count and HIV-RNA measurements and had been AIDS-free for at least 1 month between those measurements and the start of follow-up. For each AIDS-defining event, we estimated the hazard ratio for no cART versus less than 3 and at least 3 months since cART initiation, adjusting for time-varying CD4+ cell count and HIV-RNA via inverse probability weighting. Results: Out of 96 562 eligible individuals (78% men) with median (interquantile range) follow-up of 31 [13,65] months, 55 144 initiated cART. The number of cases varied between 898 for tuberculosis and 113 for PML. Compared with non-cART initiation, the hazard ratio (95% confidence intervals) up to 3 months after cART initiation were 1.21 (0.90-1.63) for tuberculosis, 2.61 (1.05-6.49) for MAC, 1.17 (0.34-4.08) for CMV retinitis, 1.18 (0.62-2.26) for PML, 1.21 (0.83-1.75) for HSV, 1.18 (0.87-1.58) for Kaposi sarcoma, 1.56 (0.82-2.95) for NHL, 1.11 (0.56-2.18) for cryptococcosis and 0.77 (0.40-1.49) for candidiasis. Conclusion: With the potential exception of mycobacterial infections, unmasking IRIS does not appear to be a common complication of cART initiation in high-income countries. © 2014 Wolters Kluwer Health | Lippincott Williams &amp; Wilkins

    Opportunistic infections and AIDS malignancies early after initiating combination antiretroviral therapy in high-income countries

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    Background: There is little information on the incidence of AIDS-defining events which have been reported in the literature to be associated with immune reconstitution inflammatory syndrome (IRIS) after combined antiretroviral therapy (cART) initiation. These events include tuberculosis, mycobacterium avium complex (MAC), cytomegalovirus (CMV) retinitis, progressive multifocal leukoencephalopathy (PML), herpes simplex virus (HSV), Kaposi sarcoma, non-Hodgkin lymphoma (NHL), cryptococcosis and candidiasis. Methods: We identified individuals in the HIV-CAUSAL Collaboration, which includes data from six European countries and the US, who were HIV-positive between 1996 and 2013, antiretroviral therapy naive, aged at least 18 years, hadCD4+ cell count and HIV-RNA measurements and had been AIDS-free for at least 1 month between those measurements and the start of follow-up. For each AIDS-defining event, we estimated the hazard ratio for no cART versus less than 3 and at least 3 months since cART initiation, adjusting for time-varying CD4+ cell count and HIV-RNA via inverse probability weighting. Results: Out of 96 562 eligible individuals (78% men) with median (interquantile range) follow-up of 31 [13,65] months, 55 144 initiated cART. The number of cases varied between 898 for tuberculosis and 113 for PML. Compared with non-cART initiation, the hazard ratio (95% confidence intervals) up to 3 months after cART initiation were 1.21 (0.90-1.63) for tuberculosis, 2.61 (1.05-6.49) for MAC, 1.17 (0.34-4.08) for CMV retinitis, 1.18 (0.62-2.26) for PML, 1.21 (0.83-1.75) for HSV, 1.18 (0.87-1.58) for Kaposi sarcoma, 1.56 (0.82-2.95) for NHL, 1.11 (0.56-2.18) for cryptococcosis and 0.77 (0.40-1.49) for candidiasis. Conclusion: With the potential exception of mycobacterial infections, unmasking IRIS does not appear to be a common complication of cART initiation in high-income countries
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