PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Analog-Digital Conversion”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed1978

A method for continuous electrocardiodynamic monitoring.

A new method is presented for the monitoring of cardiac time intervals, e.g. in clinical and industrial work investigation. The methods yields 'on-line' the electrocardiodynamic time profile during rest as well as effort, and has applications in health care, sports and occupational medicine. By means of analog processing of an electrocardiographic signal, ear densitogram and beat-by-beat display of the measured cardiac time intervals as amplitude-modulated pulses, an 'electrocardiodynamic time profile' is obtained. In order to estimate the accuracy and the limitations of the method, a comparison with computerized methods was performed. In an ergonomic experiment carried out by a Romanian-Swedish research team, analog and digital methods for the detection of cardiac time intervals showed good agreement.

Adolescent↗
PubMed1979

Apperceptive signals demonstrating the dynamic disturbance of myocardial ischemia.

Analog pressure signals (catheter-tip manometers) from the left atrium, left ventricle, and aorta and a flow signal from the arota were obtained in 25, open-chest, anesthetized dogs in which 115 episodes of ischemia were produced in an area of the left ventricle subtended by the distal left anterior descending coronary artery and its last major diagonal branch. The left ventricular pressure and its first derivative (dP/dt) were displayed as an X-Y loop. The character of this loop went through a unique series of dynamic changes in 110 of the 115 ischemic episodes, indicating that this is a useful tool for monitoring myocardial ischemia. Spectrum pairs of the above signals were analyzed with digital computational transfer functions in 14 ischemic episodes of three experiments and preliminary assessment reveals unique pole and zero changes in many pairs during each episode which also may prove to be a useful indicator of the hemodynamic disturbance incurred during myocardial ischemia.

Analog-Digital Conversion↗
PubMed1976

International standard (C.C.I.T.T.) for transmitting biomedical analogue and digital data on the public telephone network.

Analogue transmission of biomedical signals over the public telephone network has advantages from the economic point of view over digitalized transmission. This paper deals with the special problems encountered with the transmission of biomedical signals. Furthermore, the new international transmission standard C.C.I.T.T. recommendation V. 16 is introduced. This standard has recently been adopted by the relevant study group and has been presented to the Plenary Assembly of the C.C.I.T.T. for final approval. This standard is compatible with the existing public telephone networks. The technical specifications of this standard allow the transmission of the three-channel ECG for diagnostic purposes, e.g., remote processing and computer-assisted evaluation, as well as the transmission of the one-channel ECG with acoustic coupling, e.g., in emergency cases and for pace maker monitoring.

Analog-Digital Conversion↗
PubMed1975

[A hybrid system for documentation of pathological findings (author's transl)].

Considerations on the theory of communication point to the importance of "redundant" data in medicine. These usually arise from texts such as catamneses, descriptions of findings etc., and escape digital data pooling and storage on organizational and financial grounds. Here, microfilm is available as an economical storage medium taking little room. Developments in recent years enable integration of automatic analog storage into digital information systems. The use of such a hybrid system in the field of pathology is described.

Analog-Digital Conversion↗
PubMedDate not supplied

A dual-processor computer for arrhythmia analysis.

In order to facilitate the analysis of 24-hour tape recordings of ECG for rhythm by the AZTEC technique, we have configured a dual-processor system. It samples the ECG signal from a tape playback unit at a rate of 7501.88 Hz, allowing analysis at 30 x real time. An approach to error recognition and containment for the program, which utilizes the sampling of events, is discussed. Steps are taken to reduce errors caused by human sampling of "high risk" regions of the record.

Analog-Digital Conversion↗
PubMed1976

Analog vs. digital photogrammetry for optic cup analysis.

This report compares the reproducibility of analog and digital photogrammetry for topographical analysis of the optic cup. Ten simultaneous stereophotographs of each of three optic discs were taken with the Zeiss fundus camera plus a twin-prism stereoseparator. Digital processing produced photogrammetric contours of the optic cup and estimates of its geometry. Optic cup contours from the same stereopairs were also drawn with an analog stereoplotter and were analyzed by manual planimetry. The reproducibility of digital photogrammetry and analysis for estimation of cup depth, cup width, cup cross sectional area, and cup volume was concluded to be generally superior to the reproducibility of analog photogrammetry and manual analysis.

Analog-Digital Conversion↗