RFID-Assisted wireless sensor networks for cardiac tele-healthcare

As the baby boomers head into old age, America will see a dramatic increase in the number of elderly patients admitted to healthcare facilities, such as nursing homes. Due to this rising elderly population, it will be difficult for nursing home personnel to monitor all patients at once. One way to cut down on the amount of supervision by the staff is for patients to administer their own medication. This leads to new problems though, as a patient incorrectly administering one of their many medications could lead to a disastrous end. Technology to wirelessly transmit a patient’s electrocardiogram (ECG) has also been implemented to reduce supervision. Wireless transmissions are infamous for their error rate, but the ECG is a sensitive signal where every second of data matters and cannot tolerate such losses. Additionally, such existing networks employ an expensive communication infrastructure. Due to this healthcare crisis, the ability for a device to remotely monitor a patient’s medication intake and transmit accurate ECG readings, while being cost efficient, is a major innovation. To combat this crisis, this thesis focuses on a multi-hop wireless sensor network (WSN) composed of many wearable sensors, one for each patient, that host a radio frequency identification (RFID) reader and are capable of RF communication. Each wearable device is also assumed to contain an ECG sensor, though this was not implemented in this work. The system is responsible for two distinct features. The first is remotely supervised patient medication intake via RFID and a central workstation/database. The second is the accurate remote transmission of a patient’s ECG using the extended Kalman filter (EKF) for wireless error recovery

Challenges of the inconsistency regime: Novel debiasing methods for missing data models

We study semi-parametric estimation of the population mean when data is observed missing at random (MAR) in the $n < p$ "inconsistency regime", in which neither the outcome model nor the propensity/missingness model can be estimated consistently. Consider a high-dimensional linear-GLM specification in which the number of confounders is proportional to the sample size. In the case $n > p$, past work has developed theory for the classical AIPW estimator in this model and established its variance inflation and asymptotic normality when the outcome model is fit by ordinary least squares. Ordinary least squares is no longer feasible in the case $n < p$ studied here, and we also demonstrate that a number of classical debiasing procedures become inconsistent. This challenge motivates our development and analysis of a novel procedure: we establish that it is consistent for the population mean under proportional asymptotics allowing for $n < p$, and also provide confidence intervals for the linear model coefficients. Providing such guarantees in the inconsistency regime requires a new debiasing approach that combines penalized M-estimates of both the outcome and propensity/missingness models in a non-standard way.Comment: 89 pages, 6 figure

Design Requirements for Manned Orbital and Lunar Bases

Satisfaction of his physiological needs is the prime requirement for assuring man ! s performance in a short-duration space mission. Many authorities feel that long-duration missions will require essentially only an increase in requirements proportional to the length of the mission, based upon short-term figures. The authors contend, on the other hand, that considerations regarding the most efficient use of man in an actual space environment presume that all of the environmental requirements for human existance have been provided. These needs can be satisfied through appropriate design requirements, established early in the developmental program, so that man can exist and operate satisfactorily in an orbital or lunar base environment. This paper describes the essential habitability needs that allow man to perform for long periods of time

Maximum Mean Discrepancy Meets Neural Networks: The Radon-Kolmogorov-Smirnov Test

Maximum mean discrepancy (MMD) refers to a general class of nonparametric two-sample tests that are based on maximizing the mean difference over samples from one distribution $P$ versus another $Q$, over all choices of data transformations $f$ living in some function space $\mathcal{F}$. Inspired by recent work that connects what are known as functions of $\textit{Radon bounded variation}$ (RBV) and neural networks (Parhi and Nowak, 2021, 2023), we study the MMD defined by taking $\mathcal{F}$ to be the unit ball in the RBV space of a given smoothness order $k \geq 0$. This test, which we refer to as the $\textit{Radon-Kolmogorov-Smirnov}$ (RKS) test, can be viewed as a generalization of the well-known and classical Kolmogorov-Smirnov (KS) test to multiple dimensions and higher orders of smoothness. It is also intimately connected to neural networks: we prove that the witness in the RKS test -- the function $f$ achieving the maximum mean difference -- is always a ridge spline of degree $k$, i.e., a single neuron in a neural network. This allows us to leverage the power of modern deep learning toolkits to (approximately) optimize the criterion that underlies the RKS test. We prove that the RKS test has asymptotically full power at distinguishing any distinct pair $P \not= Q$ of distributions, derive its asymptotic null distribution, and carry out extensive experiments to elucidate the strengths and weakenesses of the RKS test versus the more traditional kernel MMD test

Colorectal cancer surgery in the very elderly patient: a systematic review of laparoscopic versus open colorectal resection.

INTRODUCTION: Colorectal cancer is the second most common cause of death from neoplastic disease in men and third in women of all ages. Globally, life expectancy is increasing, and consequently, an increasing number of operations are being performed on more elderly patients with the trend set to continue. Elderly patients are more likely to have cardiovascular and pulmonary comorbidities that are associated with increased peri-operative risk. They further tend to present with more locally advanced disease, more likely to obstruct or have disseminated disease. The aim of this review was to investigate the feasibility of laparoscopic colorectal resection in very elderly patients, and whether there are benefits over open surgery for colorectal cancer. METHODS: A systematic literature search was performed on Medline, Pubmed, Embase and Google Scholar. All comparative studies evaluating patients undergoing laparoscopic versus open surgery for colorectal cancer in the patients population over 85 were included. The primary outcomes were 30-day mortality and 30-day overall morbidity. Secondary outcomes were operating time, time to oral diet, number of retrieved lymph nodes, blood loss and 5-year survival. RESULTS: The search provided 1507 citations. Sixty-nine articles were retrieved for full text analysis, and only six retrospective studies met the inclusion criteria. Overall mortality for elective laparoscopic resection was 2.92% and morbidity 23%. No single study showed a significant difference between laparoscopic and open surgery for morbidity or mortality, but pooled data analysis demonstrated reduced morbidity in the laparoscopic group (p = 0.032). Patients undergoing laparoscopic surgery are more likely to have a shorter hospital stay and a shorter time to oral diet. CONCLUSION: Elective laparoscopic resection for colorectal cancer in the over 85 age group is feasible and safe and offers similar advantages over open surgery to those demonstrated in patients of younger ages

Sexual dysfunction following rectal cancer surgery

INTRODUCTION: Sexual and urological problems after surgery for rectal cancer are common, multifactorial, inadequately discussed, and untreated. The urogenital function is dependent on dual autonomic sympathetic and parasympathetic innervation, and four key danger zones exist that are at risk for nerve damage during colorectal surgery: one of these sites is in the abdomen and three are in the pelvis. The aim of this study is to systematically review the epidemiology of sexual dysfunction following rectal cancer surgery, to describe the anatomical basis of autonomic nerve-preserving techniques, and to explore the scientific evidence available to support the laparoscopic or robotic approach over open surgery. METHODS: According to the PRISMA guidelines, a comprehensive literature search of studies evaluating sexual function in patients undergoing rectal surgery for cancer was performed in Medline, Scopus, Web of Science, Embase, and Cochrane Central Register of controlled trials. RESULTS: An increasing number of studies assessing the incidence and prevalence of sexual dysfunction following multimodality treatment for rectal cancer has been published over the last 30 years. Significant heterogeneity in the prevalence of sexual dysfunction is reported in the literature, with rates between 5 and 90%. CONCLUSIONS: There is no evidence to date in favor of any surgical approach (open vs laparoscopic vs robotic). Standardized diagnostic tools should be routinely used to prospectively assess sexual function in patients undergoing rectal surgery

Macular pigment optical density and photophobia light threshold

AbstractLight absorption by macular pigment may attenuate visual discomfort, or photophobia, for targets composed of short-wavelength light. Macular pigment optical density (MPOD) and photophobia light thresholds were measured psychophysically in 10 subjects. The energy necessary to induce photophobia for a short-wavelength target relative to a long-wavelength target was linearly related to MPOD, as well as estimates of peak MPOD and integrated macular pigment. In four subjects who consumed lutein supplements, increases in MPOD corresponded to increases in photophobia light thresholds. Light absorption by macular pigment appears to influence the amount of short-wavelength light necessary to elicit photophobia

Identificación de un elemento de volumen representativo para la simulación del comportamiento mecánico de fundiciones de grafito esferoidal

La Fundición de Grafito Esferoidal (FGE) es una aleación metálica de Fe-C-Si que presenta una microestructura conformada por nódulos de grafito embebidos en una matriz metálica de ferrita y perlita. Estas características microestructurales hacen de la FGE un material compuesto “natural”. La micromecánica computacional es una de las alternativas que permiten la determinación del comportamiento macroscópico de materiales con microestructura heterogénea. Un aspecto crucial de la micromecánica es la identificación del dominio microestructural que permita representar adecuadamente al material, denominado Elemento de Volumen Representativo (EVR) (T. Kanit et al., Int. J. Solids Struct., 40: 3647–3679 (2003)). La determinación del EVR involucra tanto la representación de la geometría y del comportamiento constitutivo de las fases, como la especificación del tamaño del dominio microestructural para que sea representativo. En el presente trabajo, se identificó un EVR de forma cúbica con Condiciones de Borde Periódicas (CBP) para la simulación del comportamiento mecánico de una FGE. La microestructura de la FGE se representó mediante partículas esféricas posicionadas aleatoriamente dentro del dominio cúbico, rodeadas por la matriz. Se consideraron el comportamiento elásto-plástico de la matriz metálica y la baja cohesión de la intercara matriz-nódulos, tal como se reporta en la literatura. Mediante el método de elementos finitos se analizaron dominios microestructurales con cantidades crecientes de nódulos en su interior. En base a este análisis y considerando tanto la precisión de los resultados como el costo computacional, se determinó un domino microestructural que es un EVR adecuado para la FGE. El EVR establecido se probó comparando resultados numéricos del modelo con resultados de ensayos experimentales. Se observó un buen acuerdo entre ambos resultados indicando una adecuada definición del EVR.Publicado en: Mecánica Computacional vol. XXXV, no. 24Facultad de Ingenierí

Analysis of the Part Distortions for Inconel 718 SLM: A Case Study on the NIST Test Artifact

The present paper evaluates the misalignment and geometry distortion of the standard National Institute of Standards and Technology (NIST) test artifact in Inconel 718 alloy, when several layers with and without supports are employed to manufacture it by the Selective Laser Melting (SLM) process. To this end, a coordinate-measuring machine (CMM) is used to measure the geometrical distortion in each manufacturing configuration, following the same measurement protocol. The results show that the laser path strategy favors a thermal gradient which, consequently, induces geometrical distortions in the part. To prove this hypothesis, a numerical simulation is performed to determine the thermal gradient and the pattern of the residual stresses. It was found that the geometrical distortion certainly depends on the position of the feature position and laser strategy, where thermal cycles and residual thermal stresses had an impact in the end-part geometry, especially if a high strength-to-weight ratio commonly used in aeronautics is present.This work is supported by the Serra Húnter program (Generalitat de Catalunya) reference number [UPC-LE-304 (2018)] and by the Aeronautics Advanced Manufacturing Center (CFAA) in the JANO—Joint action toward digital transformation project framework. Diego Celentano acknowledges Pontificia Universidad Católica de Chile (PUC), Wallonie-Bruxelles International (WBI) and National Council for Scientific and Technological Research CONICYT (FONDECYT Projects No. 3180006 and 1180591) for the financial supports provided for this work