3 research outputs found
Multimodel Approaches for Plasma Glucose Estimation in Continuous Glucose Monitoring. Development of New Calibration Algorithms
ABSTRACT
Diabetes Mellitus (DM) embraces a group of metabolic diseases which main characteristic is the presence of high glucose levels in blood. It is one of the diseases with major social and health impact, both for its prevalence and also the consequences of the chronic complications that it implies.
One of the research lines to improve the quality of life of people with diabetes is of technical focus. It involves several lines of research, including the development and improvement of devices to estimate "online" plasma glucose: continuous glucose monitoring systems (CGMS), both invasive and non-invasive. These devices estimate plasma glucose from sensor measurements from compartments alternative to blood. Current commercially available CGMS are minimally invasive and offer an estimation of plasma glucose from measurements in the interstitial fluid
CGMS is a key component of the technical approach to build the artificial pancreas, aiming at closing the loop in combination with an insulin pump. Yet, the accuracy of current CGMS is still poor and it may partly depend on low performance of the implemented Calibration Algorithm (CA). In addition, the sensor-to-patient sensitivity is different between patients and also for the same patient in time.
It is clear, then, that the development of new efficient calibration algorithms for CGMS is an interesting and challenging problem.
The indirect measurement of plasma glucose through interstitial glucose is a main confounder of CGMS accuracy. Many components take part in the glucose transport dynamics. Indeed, physiology might suggest the existence of different local behaviors in the glucose transport process.
For this reason, local modeling techniques may be the best option for the structure of the desired CA. Thus, similar input samples are represented by the same local model. The integration of all of them considering the input regions where they are valid is the final model of the whole data set.
Clustering is tBarceló Rico, F. (2012). Multimodel Approaches for Plasma Glucose Estimation in Continuous Glucose Monitoring. Development of New Calibration Algorithms [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/17173Palanci
Geometrical codification for clustering mixed categorical and numerical databases
[EN] This paper presents an alternative to cluster mixed databases. The main
idea is to propose a general method to cluster mixed data sets, which is not very
complex and still can reach similar levels of performance of some good algorithms.
The proposed approach is based on codifying the categorical attributes and use a
numerical clustering algorithm on the resulting database. The codification proposed
is based on polar or spherical coordinates, it is easy to understand and to apply,
the increment in the length of the input matrix is not excessively large, and the
codification error can be determined for each case. The proposed codification
combined with the well known k-means algorithm showed a very good performance
in different benchmarks and has been compared with both, other codifications and
other mixed clustering algorithms, showing a better or comparable performance in
all cases.The authors acknowledge the partial funding of this work by the National projects DPI2007-66728-C02-01 and DPI2008-06737-C02-01.Barceló Rico, F.; Diez, J. (2012). Geometrical codification for clustering mixed categorical and numerical databases. Journal of Intelligent Information Systems. 39(1):167-185. https://doi.org/10.1007/s10844-011-0187-yS16718539