Robust Modelling of Biological Neuroregulators (original) (raw)
Related papers
2002
The robustness that shows the biological regulation of the human lower urinary tract provides a suggestive paradigm for the artificial control. The biological regulator consists of a heterogeneous group of nervous centres that act cooperatively, in a distributed way. That regulation conforms a behaviour of several types (autonomous work or conscious one) and it reduces the consequences in situations of bad operation. Related to that system, we propose a model of the paradigm of heterogeneous and distributed control that can be found in biological systems. The objective is to artificially reproduce the benefits of robustness in order to use it in the control of natural systems and artificial devices. The distributed aspects have been obtained using multiple intelligent agents, each one of which represents one of the biological centres. The interaction pattern among agents provides a heuristic based on the OAM neural network (Orthogonal Associative Memory). The knowledge has been added to the system by training, using correct patterns of behaviour of the urinary tract and wrong behaviour patterns due to the inoperability in up to two of the agents (representing deficiencies in up to two nervous centres at the same time). The experiments show that the model is robust and it satisfies the expectations of providing a model of the regulator system that allows to break into fragments the problem, in simple modules with own entity each.
Modeling the Distributed Control of the Lower Urinary Tract Using a Multiagent System
Lecture Notes in Computer Science, 2004
In this article a model of the biological neuronal regulator system of the lower urinary tract is presented. The design and the implementation of the model has been carried out using distributed artificial intelligence, more specifically a system based on agents that carry out tasks of perception, deliberation and execution. The biological regulator is formed by neuronal centres. In the model, each agent is modeled so that its behaviour is similar to that of a neuronal centre. The use of the agent paradigm in the model confers it important properties: adaptability, distributed computing, modularity, synchronous or asynchronous functioning. This strategy also allows a complex systems approach formed by connected elements whose interaction is partially well-known. We have simulated and tested the model comparing results with clinical studies.
A Computer model of the neural control of the lower urinary tract
Neurourology and Urodynamics, 1998
Better understanding of the underlying working mechanism of the neural control of the lower urinary tract will facilitate the treatment of dysfunction with a neurogenic cause. We developed a computer model to study the effect of a neural control system on lower urinary tract behavior. To model the mechanical properties and neural control, assumptions had to be made. These assumptions were based, as much as possible, on knowledge and hypotheses taken from the literature. With valid assumptions, it should be possible to simulate normal as well as pathological behavior. To test the computer model, first, normal behavior of the lower urinary tract was simulated, and secondly, the known features of bladder outlet obstruction were simulated after the properties of the urethra were changed. The simulation results are comparable with measured data, so the assumptions on which the model is based could be valid. If the assumptions are valid, the feedback loops used in the model are also important feedback loops in vivo, and the model can be used to gain insight into the underlying mechanism of neural control.
Comparison of different computer models of the neural control system of the lower urinary tract
Neurourology and Urodynamics, 2000
This paper presents a series of five models that were formulated for describing the neural control of the lower urinary tract in humans. A parsimonious formulation of the effect of the sympathetic system, the pre-optic area, and urethral afferents on the simulated behavior are included. In spite of the relative simplicity of the five models studied, behavior that resembles normal lower urinary tract behavior as seen during an urodynamic investigation could be simulated. The models were tested by studying their response to disturbances of the afferent signal from the bladder. It was found that the inhibiting reflex that results from including the sympathetic system or the pre-optic area (PrOA) only counteracts the disturbance in the storage phase. Once micturition has started, these inhibiting reflexes are suppressed. A detrusor contraction that does not result in complete micturition similar to an unstable detrusor contraction could be simulated in a model including urethral afferents. Owing to the number of uncertainties in these models, so far no unambiguous explanation of normal and pathological lower urinary tract behavior can be given. However, these models can be used as an additional tool in studies of the mechanisms of the involved neural control.
Microprocessors and Microsystems, 2022
The human neuroregulator system is a complex nervous system composed of a heterogeneous group of nerve centres distributed along the spinal cord. These centres act autonomously, communicate through nerve interconnections, and govern and regulate the behaviour of human beings' organs and systems. For over twenty years, our research group has been studying the neuroregulatory system of the lower urinary tract (LUT), which controls the organs and systems involved in the urination process. Based on the study of the behaviour and composition of the LUT, we have succeeded in isolating the centres involved in its functioning. The goal has been to understand the individual role played by each centre in order to create a general model of the neuroregulator system capable of operating at the level of the nerve centre. The model has been created and formalised based on Multi-Agent Systems (MAS) theory: each agent thus models the behaviour of a nerve centre. This latter proposal is a step forward regarding current black box models. Its fine granularity opens up the possibility of acting at the level of the centre, of particular interest to treat dysfunctions. The present study enriches this theoretical model with an architectural model that makes it suitable to implement in hardware. Based on this new model, we propose a System on Chip (SoC) design of a specific processor capable of performing a nerve centre's functions. Although this processor can be entirely configured and programmed to adjust to the functioning of the different centres, the present work aimed at facilitating the understanding and validation of the proposal. We thus focused on the Cortical-Diencephalic (CD) centre, responsible for voluntary micturition. The research adopted an original approach with the aim of creating a configurable chip, capable of developing any neuroregulatory function, implantable in the body and being able to function in a coordinated way with the biological neuroregulator system.
Hardware design of the cortical-diencephalic centre of the lower urinary tract neuroregulator system
Computers in Biology and Medicine, 2016
The neuroregulatory system in humans, governs and regulates the behavior of their organs and systems. This system is composed of a set of neuronal centers, distributed along the spinal cord, which operate independently, along with their interconnections nerve. In previous research, through the study of the functioning and composition of the neuroregulatory system of the lower urinary tract, we have been able to isolate the centers involved in this function with the objective of understanding their individual operation and be able to create as well a general model of neuroregulatory system capable of operating at the level of neuronal center. The longterm objective of the research is the development of a system on chip (SoC) capable of behaving as a fully programmable neuroregulatory system. In this paper we take the next step in the research studying the feasibility of the hardware design of one of these centers neuroregulatory, in particular the center Cortical-Diencephalic, achieving a first prototype and architectural proposal. To do this, it has been isolated the behavior of this center, has proposed a design hardware implemented on FPGA to create a prototype, has been constructed a simulation environment for your evaluation and, finally, the results have been analyzed, verifying that their functional behavior is set to the expected in a human being and that operational requirements necessary for their implementation are technical and architecturally feasible.
Computational framework for behavioural modelling of neural subsystems
Neurocomputing, 2009
This paper presents a new approach to the problem of modelling living system dynamics. Our point of view claims the fact that behind the biological apparent complexity, a hidden simplicity may appear when a suitable modelling is developed. The framework is inspired on the computing features of biological systems by involving a set of elementary standard behaviours that can be combined in order to emulate more complex behaviours. The algebraic formalization is based on both a recursive primitive operation defined by a table which models the elementary behaviours and a multilevel operating mode that carries out behaviour combinations. A parametric architecture implements the model, providing a good trade-off between time delay calculation and memory requirements. In this paper, the simulation of neural subsystems is considered as an application. The comparison with other simulation techniques outlines the capabilities of our method to provide an accurate modelling together with a very simple circuit implementation.
Challenges in modeling the neural control of LUT
2020
1. Overview The lower urinary tract (LUT) in mammals consists of the urinary bladder, external urethral sphincter (EUS) and the urethra. Control of the LUT is achieved via a neural circuit which integrates two distinct components. One component of the neural circuit is ‘reflexive’ in that it relies solely on input from sensory neurons in the bladder and urethra that is fed back via spinal neurons to the LUT. The second neural component is termed ‘top-down’ and is a conditioned input that comes from structures such as Pontine Micturition center (PMC), and Pontine storage center (PSC), that also receive the afferent sensory input from the LUT relayed through periaqueductal gray (PAG). The reader is referred to excellent references such as [1-3] from de Groat’s group for the top down control, which is not discussed here. This chapter focuses primarily on outlining the challenges in the development of computational model of the neural circuit that controls the LUT. Section 2 describes t...
Modelling of urological dysfunctions with neurological etiology by means of their centres involved
Applied Soft Computing, 2011
Artificial neural networks Modelling biological systems Urology Expert systems in medicine Artificial intelligence Decision support systems a b s t r a c t Urinary incontinence is a considerable problem which is clearly reflected in the number of patients affected by it. Moreover, it is extremely difficult to obtain an accurate diagnosis as the urinary incontinence very often is related to the neurological system. In this article a model with capabilities for urological diagnosing is proposed. This model is specialized towards the diagnosis of urological dysfunctions with neurological etiology. For this reason the model explores all the neural centres involved in both the urological phases, voiding and micturition. Once these centres have been studied it becomes possible to establish a direct relation between neural centres which present an anomalous functioning and neurological dysfunctions.