PubMed Health⌕ Search

Biomedical subjects

R Bedini

Publications and source records attributed to R Bedini.

14 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↗
PubMed1993

VAD Biomer blood sacs: mechanical tests and ultrastructural observations.

Ventricular Assist Devices (VADs) are a support to the heart function and are used as bridge to transplantation for a brief period in patients awaiting a donor heart. They consist of two sacs with two artificial valves that allow blood flow, the whole connected to a specific electronic equipment. This study examines the performance of a segmented-polyurethane elastomer, namely Biomer, that has been extensively used to manufacture pneumatically actuated VAD blood sacs. Specimens obtained from three VAD blood sacs explanted from three human patients and specimens from one unimplanted blood sac were investigated for mechanical performance of the material and for the changes it undergoes as a result of mechanical stress and interaction with the surrounding biological environment. The application of tensile strength at break yielded no relevant differences between unimplanted and explanted specimens. Biomer exhibited a high elongation at break for both groups, with somewhat lower values for explanted specimens. SEM observations carried out on the inner surface--in contact with blood--of unstressed explanted specimens showed no thrombotic deposits, calcifications, microbial contamination or structural changes. The complementary broken surfaces of stressed specimens showed a distinctive fracture pattern.

Biocompatible Materials↗
PubMed1992

'Ciliated' tumour cells in ascitic fluid from two cases of cystadenocarcinoma of the ovary.

We report two cases of primary carcinoma of the ovary in which 'ciliated' adenocarcinoma cells were found in the ascitic fluid. Transmission electron microscopy revealed that these were not true cilia but rather a prolific growth of abnormal microvilli. The cytological findings were compared with the histological appearances of the primary tumour. No ciliated cells were seen in the primary tumour, suggesting that the formation of the microvilli represented an independent proliferation of the cells in the fluid. Special staining reactions for mucin, alkaline phosphatase and epithelial membrane antigen were identical in the primary tumour and the cells in the ascitic fluid.

Adult↗
PubMed1991

Evaluation of an experimental periodontal ligament for dental implants.

To improve the devices used in dental implantology, a new experimental supporting element has been developed. The device, made of titanium, poly(methylmethacrylate) and Dacron tissue, has been tested for the osteointegrability of its outer Dacron coat by implants in mandibular bone of rabbits. The Dacron filamentous tissue became incorporated by the bone at 3 month post-implantation. This might provide a reliable mechanical anchorage of the device and a barrier against epithelial proliferation and microbial contamination. Preliminary results relating to in vitro evaluation of the poly(methyl methacrylate)-Dacron fixation strength predict favourable mechanical behaviour at this interface and in the complete implanted device.

Animals↗
PubMed1988

Pacemaker registration electronic-card. A proposal for a computerised system of storing of the pacemaker registration card.

This paper describes an example of a computerised system dedicated to store an Emergency Health Card into a compact and portable memory support such as the CMOS RAM CARD. Details are given from the system used and of the program developed for this task. In particular, patient, pacemaker and lead data are stored by the prototype system. The acquisition layout is similar to that of the European pacemaker registration card but some other sections are added. The possibilities of an introduction of a card system like this on E.E.C. countries is discussed.

Computer Systems↗
PubMed1976

Methods for the study of regional myocardial perfusion in patients with atherosclerotic coronary artery disease: findings at rest after nitroglycerin and during angina pectoris.

In patients with ischemic heart disease the evaluation of regional myocardial perfusion by 133Xenon intracoronary injection using a gamma camera computer system allows the detection of regional alterations of myocardial perfusion. While at rest a minority of the patients studied shows large alterations, during pacing induced angina a severe reduction of regional myocardial perfusion can be evidenced both in initial distribution scintigrams, when the injection is performed during angina, and on the washout curves when angina is induced immediately after the injection, during the course of the washout.

Angina Pectoris↗
PubMedDate not supplied

Effects of gamma-globulin therapy in severely epileptic children.

The effects of gamma-globulin therapy have been studied from clinical, immunological, and electrographic perspectives in 10 children affected by severe organic epilepsy. After the first or the second injection of large doses of IgG, an appreciable reduction in seizure frequency and an improvement in behavioral and psychological performance were observed in seven children. These clinical modifications were not correlated with an important decrease of the EEG epileptic elements, but in most cases they were associated to an increase in alpha activity and/or in power of the predominant EEG frequency. These changes were observed during the entire treatment period and tended to disappear when therapy was interrupted. No significant changes in both immunological data and plasma levels of antiepileptic drugs accompanied the clinical and EEG changes.

Adolescent↗