PubMed Health⌕ Search

Biomedical subjects

J Puentes

Publications and source records attributed to J Puentes.

7 recordsLinked to original sources
PubMed2000

Towards dynamic cardiac scenes interpretation based on spatial-temporal knowledge.

Cardiac motion analysis enables to identify pathologies related to myocardial anomalies or coronary arteries circulation deficiencies. Conventionally, bi-dimensional (2D) left ventricle contour images have been extensively used, to perform quantitative measurements and qualitative evaluations of the cardiac function. Nevertheless, there are other cardiac anatomical structures, the coronary arteries, imaged on routine procedures, upon which complementary motion interpretation can be conducted. This paper presents an experimental methodology to perform dynamic cardiac scenes interpretation, studying three-dimensional (3D) coronary arteries spatial-temporal behavior. Being an alternative way to approach computer assisted cardiac motion interpretation, it reveals a wide range of rarely explored spatial-temporal situations and proposes how to address them. Considering the challenges to achieve dynamic scene interpretation, it is explained how spatial and temporal knowledge, are connected to specialist knowledge and measured parameters, to obtain a dynamic scene interpretation. Global and local motion features are modeled according to cardiac motion and geometrical knowledge, before its transformation into symbols. Anatomical knowledge and spatial-temporal knowledge are applied, along with spatial-temporal reasoning schemes, to access symbols meaning. Experimental results obtained using real data are presented. Complexity of interpretation envisioning is discussed, taking the given results as an example.

Artificial Intelligence↗
PubMed1998

Understanding coronary artery movement: a knowledge-based approach.

The aim of this paper is to describe a knowledge-based system that interprets three-dimensional (3D) coronary artery movement, using data from digital subtraction angiography image sequences. Dynamic information obtained from artery centerline 3D reconstruction and optical flow estimation, is classified according to experimental evidence indicating that artery displacements are quasi-homogeneous by a segment analysis. Characteristic motion features like displacement direction, perpendicular/radial components, rotation direction, curvature and torsion are qualitatively described from an image sequence using symbolic labels. These facts are then related and interpreted using anatomical-functional knowledge provided by a specialist, as well as spatial and temporal knowledge, applying spatio-temporal reasoning schemes. Facts, knowledge and reasoning rules are stated in a declarative form. Detailed examples of local and global interpretation results, using a real reconstructed angiographic biplane image sequence are presented in order to illustrate how our system suitably interprets coronary artery dynamic behavior.

Angiography, Digital Subtraction↗
PubMed1998

Dynamic feature extraction of coronary artery motion using DSA image sequences.

This paper aims to define and describe features of the motion of coronary arteries in two and three dimensions, presented as geometrical parameters that identify motion patterns. The main left coronary artery centerlines, obtained from digital subtraction angiography (DSA) image sequences, are first reconstructed. Thereafter, global and local motion features are evaluated along the sequence. The global attributes are centerline and point trajectory lengths, displacement amplitude, and virtual reference point, while local attributes are displacement direction, perpendicular/radial components, rotation direction, and curvature and torsion. These kinetic features allow us to obtain a detailed quantitative description of the displacements of arteries' centerlines, as well as associated epicardium deformations. Our modeling of local attributes as quasi-homogeneous on a segment analysis, enables us to propose a novel numeric to symbolic image transformation, which provides the required facts for knowledge-based motion interpretation. Experimental results using real data are consistent with cardiac dynamic behavior.

Algorithms↗
PubMed1997

[Gastroesophageal reflux and obesity].

BACKGROUND: There is a possible relationship between gastroesophageal reflux and overweight, that has not been studied extensively. AIM: To study the association between overweight and gastroesophageal reflux in a group of patients and normal controls. SUBJECTS AND METHODS: Body mass index of 85 patients with gastroesophageal reflux and 100 patients with Barrett esophagus, was compared with that of 171 healthy controls. RESULTS: There were no differences in body mass index between healthy subjects and patients with gastroesophageal reflux. However, there was a higher proportion of overweight males and obese females with Barrett esophagus than among healthy controls. CONCLUSIONS: We did not find an association between overweight and gastroesophageal reflux, but patients with Barrett esophagus had a higher body mass index than normal controls.

Adolescent↗
PubMed1981

Tarsal tunnel syndrome in rheumatoid arthritis.

Recent reports suggest an increased incidence for the general population of tarsal tunnel syndrome (TTS) in rheumatoid arthritis (RA), similar to that previously reported for carpal tunnel syndrome. Proof of this supposition could be important in the diagnosis and management of pain in the feet of patients with RA. Thirty-nine patients with a classical diagnosis of RA by clinical and laboratory criteria had electrodiagnostic studies performed on both posterior tibial nerves and other nerves as indicated. These tests found a 15% incidence of peripheral neuropathy and a 5% incidence of TTS in patients with RA.

Adult↗
PubMed1976

Motor innervation of the flexor pollicis brevis: an electromyographic study.

Percutaneous stimulation of the ulnar and median nerves at the wrist, with simultaneous recording of action potentials on a standard electromyograph oscilloscope, was performed to observe the motor innervation of the flexor pollicis brevis muscle. Both the deep and the superficial heads of the muscle were studied in twenty-three subjects. Results showed that the most common pattern of innervation was exclusive ulnar nerve supply in both heads, with 52.4 percent of the subjects showing this pattern. Dual supply by both median and ulnar nerves occurred next in frequency with 19.0 percent showing this pattern in both heads of the muscle. Exclusive median nerve supply was observed in only 9.5 percent of the total cases studied. The remaining 19 percent showed varying patterns, with each head of the muscle supplied differently. If no differentiation between deep and superficial heads is made, this 19 percent may be considered as dual innervation of the muscle. In this case, it may be concluded that 38 percent of the muscles studied showed some type of dual innervation.

Adult↗