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At least 55 records · Page 3Linked to original sources
PubMed1985

Configuration of the fetal electrocardiogram in ambulatory women in labor monitored with wideband telemetry.

The fetal electrocardiogram (ECG) in 23 ambulatory women in labor was monitored successfully with a single-channel FM telemetry unit with a 0.5-100-Hz wideband receiver to improve the quality of the ECG complex. An inverted QRS complex was seen in a patient with a deceleration and an inverted T wave during a deceleration in a patient confined to bed. A maternal artifact was transmitted in a third. The ECG complex was identical when wired patients were switched to telemetry. Thus, fetal heart rate and ECG configuration can be monitored accurately in ambulatory pregnant women.

Ambulatory Care↗
PubMed1979

Evaluation of fetal monitoring by telemetry.

A radiotelemetry system for the direct monitoring of fetal heart rate and intrauterine pressure during labor has been evaluated at 5 different institutions. A conventional fetal scalp electrode and a special intrauterine pressure sensor are connected to a radio transmitter placed on the patient's thigh. The receiver can be located up to 50 feet away from the transmitter and is either a self-contained monitor or a unit that converts a conventional fetal monitor to a telemetric one. The telemetry recordings are of similar quality to those obtained from conventional monitors. Telemetry allows for greater patient comfort and mobility as well as greater convenience to the clinical staff. Continuous data can be obtained from patients while they are ambulatory or sitting in a chair as well as while they are in bed.

Electrodes↗
PubMed1979

Integrated power controllers and RF data transmitters for totally implantable telemetry.

Data transmitters and power/source controllers are common elements in all totally implantable instrumentation systems. Two custom-designed integrated circuits have been developed for these elements and have significant impact on the realization of compact reliable telemetry packages. The first is an elapsed-time power switch that can remotely turn on implanted battery-powered systems with a short RF burst; to prevent accidental battery drainage, it will automatically turn off after a preprogrammed time (1-5 min). The second is a precision RF transmitter capable of operation up to 125 MHz in either FM or pulse-coded format and requires only two nonintegrated inductors. These IC systems are basic building blocks for a large number of totally implantable telemetry applications.

Electric Power Supplies↗
PubMed1979

Applications of totally implantable telemetry systems to chronic medical research.

The motivation for the development of advanced totally implantable telemetry systems is to improve the quality of medical care through a more detailed understanding of basic physiological processes. Three research protocols in electrophysiology, hepatic hemodynamics, and cardiac pharmacology are described which rely on new implantable instrumentation; these devices allow chronic measurements in the conscious animal of such diverse parameters as aortic and ventricular pressures; atrial, ventricular, and bundle of HIS electrograms; aortic and coronary blood flow, and total hepatic blood flow by measuring velocity profiles in the portal vein and the hepatic artery. The compact size and high reliability now achievable with these telemetry systems provides new tools to the researcher for the study of the body in health and disease.

Animals↗
PubMed1980

Heart rate, multiple body temperature, long-range and long-life telemetry system for free-ranging animals.

A long-range and long-life telemetry system for heart rate and multiple body temperatures from free-ranging animals is described. This system includes an implantable transmitter, external receiver-retransmitter collar, and a signal conditioner interface circuit to assist in demodulation of receiver tone outputs before data processing. The size of the implant is suitable for animals with body weights of a few kilograms or more; further size reduction of the implant is possible. The ECG is sensed by electrodes designed for internal telemetry and to reduce movement artifacts. The R-wave characteristics are then specifically selected to trigger a short radio frequency pulse. Temperatures are sensed at desired locations by thermistors and then, based on a heart-beat counter, transmitted intermittently via pulse interval modulation. This modulation scheme includes first and last calibration intervals for a reference by ratios with the temperature intervals for as much as a range of 0-50 degrees C with a resolution of 0.1 degrees C. Pulse duration and pulse sequencing are used to discriminate between heart rate and temperature pulses as well as radio frequency interference. The implanted transmitter might be used alone for experiments on animals that frequent particular locations within a large territory, on animals in virtually any laboratory situation, or on animals in moderate-sized enclosures, such as those in a zoological garden. The implanted transmitter is otherwise interfaced with the receiver-retransmitter collar that employs commercial tracking equipment to achieve the long-range transmission. The objective of the design was to achieve a high degree of experimental flexibility and overall high quality in performance. The system was tested in prototype form on a dog.

Animals↗
PubMed1977

Evaluation of the model 78100A adult telemetry unit for use in fetal heart rate monitoring.

A commercially available adult telemetry unit was adapted for use in fetal heart rate monitoring. Advantages included permitting the mother to ambulate during labor, monitoring the fetus while the mother was in transit from the labor to the delivery area and reducing electrical noise levels. Patient as well as physician acceptance has been uniformly excellent. Patients who normally would not have accepted monitoring acceded to the use of the telemetry system when informed that they could move about while in labor. The equipment is easy to adapt, widely available, relatively inexpensive and simple to use.

Electrocardiography↗
PubMed1988

Development of a telemetry system for measuring oxygen uptake during sports activities.

A new system for continuous measurement of oxygen uptake by means of a telemeter has been developed. Oxygen uptake and pulmonary ventilation during rest and exercise were determined using a portable oxygen consumption meter (Oxylog). A small interface circuit between the Oxylog and the transmitter of a frequency modulated bio-telemeter system was designed and installed inside the Oxylog. Data from the transmitter were passed to a receiver and were fed into a microcomputer system. The microcomputer system displayed and printed out minute values of ventilation and oxygen uptake. The accuracy and reliability of the new system were checked by comparison with the traditional (Douglas bag) method. In the range less than 80 l.min-1 of ventilation and less than 2 l.min-1 of oxygen uptake, the system was not inferior to the Douglas bag method. The new system was applied for field continuous measurement of oxygen uptake during a doubles tennis game. The results of the application indicate that the telemetry system developed here is a very practical and useful way of measuring oxygen uptake during sports activities.

Adult↗
PubMed1981

Telemetry of several biological signals from behaving animals.

A telemetry device is described for recording ECG, EMG, EEG, multiple and single unit activity from central nervous system. It implies the use of a FET input operational amplifier and an FM oscillator. It can be used with different electrodes and in many animal species when behavioral studies and completely unrestrained subjects are requested.

Animals↗
PubMed1984

Telemetry of electrophysiologic variables from conscious dogs: system design, validation, and serial studies.

The necessity for conscious animal models in the study of cardiac physiology has been established for hemodynamics. The characterization of the electrophysiologic properties of the heart has not been performed in a serial fashion in a conscious animal model. Implanted telemetry sensing devices for recording atrial, ventricular, and His electrograms and stimulation systems for both atrium and ventricle allowed serial evaluation of eight dogs for up to 4 months. There were significant fluctuations in some electrophysiologic variables with time, particularly heart rate, sinus node recovery time, and pacing rate for induction of Wenckebach block. This variability did not appear to deviate with time after implantation, and no significant differences in the basal electrophysiologic state were found between the period early after surgery (0 to 2 1/2 weeks) and later (3 to 8 weeks).

Animals↗
PubMed1991

128-channel cable-telemetry EEG recording system for long-term invasive monitoring.

A 128-channel cable-telemetry EEG monitoring system has been developed for use on patients undergoing intensive neurodiagnostic monitoring with invasive intracranial electrodes. A unique head mounted preamplifier/multiplexor design allows continuous recording from any combination of intracerebral, subdural, epidural or surface electrodes. A computer is used to delay or buffer all 128 channels by 2 min or more. This computer is connected to a fileserver via a local area network and is used exclusively for data acquisition. Seizure files created by the activation of the seizure/event push button or detected by a second computer containing on-line seizure/spike detection algorithms are written directly on to the fileserver by the acquisition computer. The 128 channels of EEG recorded on the fileserver can then be remotely reviewed on a high resolution graphics terminal, printed out on a laser jet printer, archived or played out on paper, 16 channels at a time on any EEG machine. A time of day signal is also generated by the computer to permit time correlation with a continuous audio/video VCR unit which permits comparison of the EEG and clinical events. This system allows continuous EEG monitoring of extensive multichannel arrays not previously possible with conventional 16-, 32- or even 64-channel systems.

Electroencephalography↗
PubMed1991

Four-channel telemetry system for in vivo measurement of hip joint forces.

The long-term loosening of artificial hip joints remains a serious clinical problem. Optimization of implant design and material will improve the fixation, but it requires a detailed knowledge of the forces which act on the implant. A four-channel telemetric transmitter was developed and arranged completely inside a hermetically closed artificial hip joint. This permits long term in vivo measurements of the three-dimensional forces without endangering the patient. The external telemetry system consists of an inductive power supply, an RF receiver, a microcomputer with hardware extension and a VHS video system. The personal computer offers real-time data processing of three orthogonal force components as well as slow motion analysis of recorded measurements. After several years of animal tests, two instrumented prostheses were implanted in the first patient (male) in May and August of 1988. In March 1990 a third prosthesis was implanted in a second patient (female). Joint force measurements have regularly been performed from the first post-operative day until now for several kinds of activity.

Biomechanical Phenomena↗
PubMed1976

An inexpensive receiver for ECG telemetry.

A simple, inexpensive ECG demodulator circuit has been described which may be used in conjunction with an ECG telephone transmitter, telephone amplifier, and ECG recorder to form a telemetry system capable of ECG monitoring.

Electrocardiography↗
PubMed1977

Cardiac telemetry exercise program.

To train cardiac consultants who interpret electrocardiogram rhythm strips from the field, we designed a series of prerecorded telemetered rhythms and discussions which can be sent into telemetry consoles. The patterns represent cardiac arrhythmias (eg, ventricular tachycardia, complete heart block, etc), as well as equipment problems (loose leads, misplaced leads, etc). We selected and modified some of the patterns of "Arrhythmia Resusci Anne" (Laerdal Medical Corporation), sent these through ambulance radios (to create a tone), recorded the signal on a standard tape recorder and dubbed in the monologue. The physician is asked to interpret the pattern and give instructions to the ambulance attendant. The answers and response times are recorded by the technician running the taped exercise. At the end of the quiz, the rhythms are replayed along with a discussion of each pattern.

Ambulances↗
PubMedDate not supplied

[A comparative study of standard electroencephalographic techniques and telemetry (author's transl)].

The authors have used radio-telemetry to perform long duration studies and to study the variations in cerebral electrical activity. They presented a quantitative study of the distribution of paroxysmal activity in the epileptic, based on an experimental observation and confirmed as a result of the methods used. They were able to show a relationship between the severity and temporal distribution of paroxysmal activity which was confirmed statistically. Further observations were made on the distribution and onset of epileptic discharges but more detailed analysis is required before general electrophysiological conclusions can be made.

Adolescent↗
PubMed1975

An intra-oral telemetry system for the continuous recording of vertical jaw movement.

Continuous measurement of the separation between upper and lower dental arches, the so-called interocclusal distance (10D), is of interest in dentistry. Criteria for making such measurements by radio telemetry are discussed. It is concluded that a transmitter small enough to fit in a molar tooth gap is necessary in order to minimize interference with normal function; other design factors are related to obtaining adequate frequency stability, on which measurement accuracy depends. A transmitter fulfilling these requirements is described which sensed the instantaneous value of 10D by the frequency change produced when a metallic object (dental filling, gold crown, shorted turn of wire or piece of ferrite) in one dental arch moved relative to the transmitter in the other. Errors due to lateral and protrusive jaw movements were measured. Careful design and the use of high grade ceramic chip capacitors resulted in a transmitter of good frequency stability (+/- 0.03% in 10 h, +/- 0.02%/degrees c) and small size (10 X 7 X 5 mm). An example is given illustrating 10D movements due to swallowing, speech and respiration.

Humans↗
PubMed1985

Polysomnographic telemetry using Telediagnostic and Oxford Medilog 9000 systems.

Sleep was recorded in 24 normal adult sleepers (21-42 years of age) for 4 consecutive nights (2 nights in the laboratory and 2 nights in the home environment) using one of two commercially available telemetry systems, either the Telediagnostic or the Oxford Medilog 9000. Modifications to each system were necessary to approximate standard laboratory techniques for polysomnography. With comparability in recording techniques between systems, there were no qualitative or quantitative differences in standard electroencephalogram sleep parameters recorded in either the home or laboratory environment.

Adult↗