Detection of breast lesions in medical digital imaging using neural networks

The purpose of this article is to present an experimental application for the detection of possible breast lesions by means of neural networks in medical digital imaging. This application broadens the scope of research into the creation of different types of topologies with the aim of improving existing networks and creating new architectures which allow for improved detection.Applications in Artificial Intelligence - Learning and Neural NetsRed de Universidades con Carreras en Informática (RedUNCI

The role of pain catastrophizing in the provision of rescue analgesia by healthcare providers following major joint arthroplasty

After surgery, patient reports or health care professional evaluations of heightened acute pain intensity should lead to extra analgesia provision, which is designated by rescue analgesia (RA). Whether RA is administered or not, it is not directly dependent on the patient but rather on clinical decisions, which should be based on pain management guidelines. There is a general lack of studies focusing on pain-related decision-making regarding RA provision. OBJECTIVES: This study aimed to examine which pre and post-surgical factors, beyond acute post-surgical pain intensity, might influence clinical decisions on RA administration after major joint arthroplasties (MJA). METHODS: A consecutive sample of 110 patients undergoing MJA was fully assessed 24 hours before (T1) and 48 hours after (T2) surgery. Before surgery, baseline demographic, clinical, and psychological variables were evaluated and after surgery the main outcome was RA provision, with acute post-surgical pain intensity being also registered. STUDY DESIGN: Prospective observational cohort study. SETTING: Central hospital in northern Portugal. RESULTS: Logistic regression analysis revealed that RA provision, after MJA, is influenced by a patient-related psychological factor, pain catastrophizing (OR = 1.143; 95% CI 1.044 - 1.253, P = 0.004), above and beyond acute post-surgical pain intensity. Additionally, the type of arthroplasty (OR = 2.806; 95% CI 1.002 - 7.857, P = 0.050) also affected RA provision. Other patient-related factors such as gender, previous pain states, pre-surgical optimism, and post-surgical anxiety did not reveal any predictive role in RA administration. LIMITATIONS: This is a single-site study, only confined to MJA patients. CONCLUSIONS: The findings of this study shed light on the importance of psychological factors in determining RA provision following MJA. This encourages further reflection on acute post-surgical pain management by health care providers, namely by raising clinicians' awareness about the factors that influence patient-provider interactions, as well as their impact on decision-making regarding RA provision. A global assessment of patients, wherein psychological variables are taken into account, is warranted in order to improve the quality of surgical pain management. Finally, these findings provide support for the design of acute post-surgical pain management interventions directed at clinicians, in order to augment professionals' awareness about the potential influence of patient-related psychological factors on RA decisions

Persistent pain after total knee or hip arthroplasty : differential study of prevalence, nature, and impact

This study compares the incidence, nature, and impact of persistent post-surgical pain after total knee arthroplasty (TKA) and total hip arthroplasty (THA) and investigates differences between these procedures, with the focus on potential presurgical and post-surgical issues that could be related to the distinct persistent post-surgical pain outcomes between these two groups. A consecutive sample of 92 patients was assessed prospectively 24 hours before, 48 hours, and 4-6 months after surgery. The data show that TKA patients had a higher likelihood of developing persistent post-surgical pain, of reporting higher pain levels, and of using more neuropathic descriptors when classifying their pain. In addition, TKA patients more often reported interference from pain on functional domains, including general activity, walking ability, and normal work. Demographic factors, like gender and age, along with presurgical clinical factors like disease onset, existence of medical comorbidities, and other pain problems, may have contributed to these differences, whereas baseline psychologic factors and functionality levels did not seem to exert an influence. Heightened acute post-surgical pain experience among TKA patients could also be related to distinct outcomes for persistent post-surgical pain. Future prospective studies should therefore collect TKA and THA samples wherein patients are homogeneous for demographic and presurgical clinical issues. Overall, these findings contribute to a small but growing body of literature documenting persistent post-surgical pain after major arthroplasty, conducted in different countries and across different health care settings.This work was supported by a project grant (PTDC/SAU-NEU/108557/2008) from the Portuguese Foundation of Science and Technology, COMPETE (Thematic Operational Programme for Competitive Factors), and FEDER (European Fund for Regional Development). We also thank the patients who agreed to participate in this study

Clavo Gamma 3 (Stryker) para el tratamiento de fracturas trocantéreas: nuestra experiencia durante el año 2005

Objetivos: estudiar los resultados del sistema de enclavado Gamma 3 en el tratamiento de las fracturas trocantéreas durante el año 2005. Material y Métodos: 73 pacientes con fractura trocantérea mayores de 60 años tratados mediante enclavado céfalo-medular Gamma 3 durante el año 2005 con un seguimiento de 8 a18 meses. Edad media 80 años, 40% de los pacientes deambulantes de forma independiente previo a la fractura, 50% ASA III y IV. Resultados: tiempo quirúrgico 90 minutos, 54% de pacientes transfundidos con una media de 0,89 concentrados por paciente sin diferencias estadisticamente significativas entre aquellos en lo que se colocó y tapón y los que no; 63% de los pacientes deambulan si ayuda en el pstoperatorio. Conclusiones: el sistema Gamma 3 proporciona resultados fiables y reproducible en cualquier variedad de fractura trocanterea y nos parece un sistema eficaz y válido para el tratamiento de este tipo de fracturas.Objectives: to study the results of Gamma 3 for the treatment of trochanteric fractures. Material and Methods: 73 patients older than 60 years old with trochanteric fracture tre- ated using Gamma 3 nailing during year 2005. Follow-up 8-18 months. Mean age 80 years old, 40% preoperative walking without help, 50% ASA III and IV. Results: surgical time 90 minutes, 54% of the patients need blood transfusion with 0,89 concentrates per patients mean. No difference was found in blood transfusion with the use of end cup. 63% walking wit- hout help of with cane postoperatively. Conclusions: Gamma 3 nail is a valid system for the treatment of all types of tro- chanteric fractures

Detection of breast lesions in medical digital imaging using neural networks

The purpose of this article is to present an experimental application for the detection of possible breast lesions by means of neural networks in medical digital imaging. This application broadens the scope of research into the creation of different types of topologies with the aim of improving existing networks and creating new architectures which allow for improved detection.Applications in Artificial Intelligence - Learning and Neural NetsRed de Universidades con Carreras en Informática (RedUNCI

3D point cloud registration based on a purpose-designed similarity measure

This article introduces a novel approach for finding a rigid transformation that coarsely aligns two 3D point clouds. The algorithm performs an iterative comparison between 2D descriptors by using a purpose-designed similarity measure in order to find correspondences between two 3D point clouds sensed from different positions of a free-form object. The descriptors (named with the acronym CIRCON) represent an ordered set of radial contours that are extracted around an interest-point within the point cloud. The search for correspondences is done iteratively, following a cell distribution that allows the algorithm to converge toward a candidate point. Using a single correspondence an initial estimation of the Euclidean transformation is computed and later refined by means of a multiresolution approach. This coarse alignment algorithm can be used for 3D modeling and object manipulation tasks such as "Bin Picking" when free-form objects are partially occluded or present symmetries

Accurate estimation of airborne ultrasonic time-of-flight for overlapping echoes

In this work, an analysis of the transmission of ultrasonic signals generated by piezoelectric sensors for air applications is presented. Based on this analysis, an ultrasonic response model is obtained for its application to the recognition of objects and structured environments for navigation by autonomous mobile robots. This model enables the analysis of the ultrasonic response that is generated using a pair of sensors in transmitter-receiver configuration using the pulse-echo technique. This is very interesting for recognizing surfaces that simultaneously generate a multiple echo response. This model takes into account the effect of the radiation pattern, the resonant frequency of the sensor, the number of cycles of the excitation pulse, the dynamics of the sensor and the attenuation with distance in the medium. This model has been developed, programmed and verified through a battery of experimental tests. Using this model a new procedure for obtaining accurate time of flight is proposed. This new method is compared with traditional ones, such as threshold or correlation, to highlight its advantages and drawbacks. Finally the advantages of this method are demonstrated for calculating multiple times of flight when the echo is formed by several overlapping echoes.This work has been supported by the Spanish Government projects DPI2006-15313 and DPI2012-36959

A taxonomic and biogeographic review of the fossil tapirs from Bolivia

Fossil remains of South American tapirs are often fragmentary and scarce compared with those of other mammals that entered South America during the "Great American Biotic Interchange". Here, we review and add to the Pleistocene tapir remains from the Tarija Valley (Bolivia), and provide a taxonomic re-evaluation of Tapirus tarijensis. T. tarijensis was a large-sized animal, approximating the size of the living Malaysian T. indicus and the extinct North American T. haysii. The geographical distribution of Pleistocene records of Tapirus in South America indicates that T. tarijensis was the only known species inhabiting the Tarija Valley during this time.Facultad de Ciencias Naturales y Muse