Evidence map›Paper›PMID 30929120›Full record

ArticleJournal of pharmacokinetics and pharmacodynamics2019

Estimating parameters of nonlinear dynamic systems in pharmacology using chaos synchronization and grid search.

Nikhil Pillai, Sorell L Schwartz, Thang Ho, Aris Dokoumetzidis, Robert Bies, Immanuel Freedman

Abstract read
In one paragraph

Article in Journal of pharmacokinetics and pharmacodynamics, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

  1. Evaluation and analysis of clinical outcome prediction for trauma patients based on machine learning.Chinese journal of traumatology = Zhonghua chuang shang za zhi · 2026
    Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Nikhil PillaiComputational and Data-Enabled Science, University at Buffalo, Buffalo, USA.
Sorell L SchwartzDepartment of Pharmacology and Physiology, Georgetown University Medical Center, Georgetown, USA.
Thang HoVertex Pharmaceuticals, Boston, USA.
Aris DokoumetzidisDepartment of Pharmaceutical Technology, University of Athens, Athens, Greece.
Robert BiesComputational and Data-Enabled Science, University at Buffalo, Buffalo, USA.
Immanuel FreedmanFreedman Patent, Harleysville, PA, 19438, USA. freedman@freedmanpatent.com.ORCID 0000-0003-3382-173X

Funding

National Center for Theoretical Sciences UL1TR000006
6 · The paper itself

Abstract

Bridging fundamental approaches to model optimization for pharmacometricians, systems pharmacologists and statisticians is a critical issue. These fields rely primarily on Maximum Likelihood and Extended Least Squares metrics with iterative estimation of parameters. Our research combines adaptive chaos synchronization and grid search to estimate physiological and pharmacological systems with emergent properties by exploring deterministic methods that are more appropriate and have potentially superior performance than classical numerical approaches, which minimize the sum of squares or maximize the likelihood. We illustrate these issues with an established model of cortisol in human with nonlinear dynamics. The model describes cortisol kinetics over time, including its chaotic oscillations, by a delay differential equation. We demonstrate that chaos synchronization helps to avoid the tendency of the gradient-based optimization algorithms to end up in a local minimum. The subsequent analysis illustrates that the hybrid adaptive chaos synchronization for estimation of linear parameters with coarse-to-fine grid search for optimal values of non-linear parameters can be applied iteratively to accurately estimate parameters and effectively track trajectories for a wide class of noisy chaotic systems.

Indexed as

AlgorithmsComputer SimulationComputer SystemsHumansModels, StatisticalNonlinear DynamicsPharmacologyChaos synchronizationChaotic systemDelay differential equationLeast squaresParameter estimation

Identifiers

PMID30929120
PMCPMC6491657

What OpenQuestion holds

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LicenceCC BY
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.