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1.
BMC Med Inform Decis Mak ; 23(1): 205, 2023 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-37803440

RESUMO

This research aims to develop a diagnostic tool that can quickly and accurately detect prostate cancer using electronic nose technology and a neural network trained on a dataset of urine samples from patients diagnosed with both prostate cancer and benign prostatic hyperplasia, which incorporates a unique data redundancy method. By analyzing signals from these samples, we were able to significantly reduce the number of unnecessary biopsies and improve the classification method, resulting in a recall rate of 91% for detecting prostate cancer. The goal is to make this technology widely available for use in primary care centers, to allow for rapid and non-invasive diagnoses.


Assuntos
Nariz Eletrônico , Neoplasias da Próstata , Masculino , Humanos , Neoplasias da Próstata/diagnóstico , Biópsia , Redes Neurais de Computação , Probabilidade
2.
Artigo em Inglês | MEDLINE | ID: mdl-11570762

RESUMO

An extended Butterworth-Van Dyke (EBVD) model with frequency-independent parameters for the characterization of a resonant compound formed by a quartz crystal in contact with a finite viscoelastic layer contacting a semi-infinite viscoelastic medium is extracted by analysis of the lumped element model. The formulation of the EBVD model is compared with the complete expression of the electrical admittance of the loaded quartz derived from the transmission line model (TLM). Relative deviations between them do not exceed 3% around 1% bandwidth near resonance. An extended Martin & Granstaff's model and an explicit expression for the frequency shift that supposes an extension of Kanazawa's model for viscoelastic media are obtained. An analysis of the errors associated with the extraction of shear parameters of the coating for different materials prove that, to obtain an error less than 5% in the shear parameters determination, the viscoelastic contribution, defined as the relative error in the thickness computed from the frequency shift by Sauerbrey equation, must be greater than a limit that depends on Q, which is defined as the ratio of the shear storage modulus (G') to shear loss modulus (G"). In the materials studied, polymers in the transition range or in the rubbery state with Q = 1 and 10, the viscoelastic contribution must be higher than 15% and 50%, respectively, for a 5% limit error in the shear parameters extraction. A criterion for a practical determination of the appropriate viscoelastic regimes is indicated.

3.
Artigo em Inglês | MEDLINE | ID: mdl-11370377

RESUMO

A new electronic design for continuous motional series resonant frequency monitoring of loaded quartz crystal resonators is presented. Using this circuit, a low-cost method for a simple determination of equivalent circuit parameters of quartz crystal resonators is described. Measurements made with the proposed system on typical AT cut quartz crystals are in good agreement with those of an Impedance Analyzer.

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