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Biomedical subjects

G Palagi

Publications and source records attributed to G Palagi.

9 recordsLinked to original sources
PubMed1994

A PC-based generator of surface ECG potentials for computer electrocardiograph testing.

The system is composed of an electronic circuit, connected to a PC, whose outputs, starting from ECGs digitally collected by commercial interpretative electrocardiographs, simulate virtual patients' limb and chest electrode potentials. Appropriate software manages the D/A conversion and lines up the original short-term signal in a ring buffer to generate continuous ECG traces. The device also permits the addition of artifacts and/or baseline wanders/shifts on each lead separately. The system has been accurately tested and statistical indexes have been computed to quantify the reproduction accuracy analyzing, in the generated signal, both the errors induced on the fiducial point measurements and the capability to retain the diagnostic significance. The device integrated with an annotated ECG data base constitutes a reliable and powerful system to be used in the quality assurance testing of computer electrocardiographs.

Electrocardiography↗
PubMedDate not supplied

An effective algorithm for quick fractal analysis of movement biosignals.

The problem of numerically classifying patterns, of crucial importance in the biomedical field, is here faced by means of their fractal dimension. A new simple algorithm was developed to characterize biomedical mono-dimensional signals avoiding computationally expensive methods, generally required by the classical approach of the fractal theory. The algorithm produces a number related to the geometric behaviour of the pattern providing information on the studied phenomenon. The results are independent of the signal amplitude and exhibit a fractal measure ranging from 1 to 2 for monotonically going-forwards monodimensional curves, in accordance with theory. Accurate calibration and qualification were accomplished by analysing basic waveforms. Further studies concerned the biomedical field with special reference to gait analysis: so far, well controlled movements such as walking, going up and downstairs and running, have been investigated. Controlled conditions of the test environment guaranteed the necessary repeatability and the accuracy of the practical experiments in setting up the methodology. The algorithm showed good performance in classifying the considered simple movements in the selected sample of normal subjects. The results obtained encourage us to use this technique for an effective on-line movement correlation with other long-term monitored variables such as blood pressure, ECG, etc.

Algorithms↗
PubMedDate not supplied

On the contribution of biomedical engineering and technology to the understanding and the management of arterial hypertension.

There are several reasons why arterial blood pressure, i.e. the pressure within the large arterial vessels, is out of the physical parameters of the human body, one of the most frequently measured. Firstly, arterial blood pressure is a physiologically meaningful parameter, since it represents the driving pressure generated by the heart which maintains blood perfusion in the periphery. Secondly, it is a clinically important parameter: a decline of arterial blood pressure (e.g. in shock) may represent a life-threatening emergency which requires prompt recognition and correction; elevated blood pressure (hypertension) on the other hand is a very common condition, which bears a high risk of cardiovascular mortality and morbidity and can be controlled with appropriate pharmacological means. Thirdly, but not lastly, arterial blood pressure is easily measurable with a fair degree of accuracy by the standard manual sphygmomanometric method and, more recently, by non-invasive automatic techniques. This paper discusses some of the aspects related to arterial blood pressure measurement, in which, in the author's opinion, medical engineering and technology are expected to provide useful advancements. Two major areas will be considered. The first regards the methodologies for arterial blood pressure assessment; the second the identification and acquisition of information additional to blood pressure which would be helpful for a better understanding of blood pressure measurements and/or of risk profiling. For the purpose of this brief paper, we shall mainly use examples and reasonings from our own experience.

Biomedical Engineering↗