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At least 109 records · Page 6Linked to original sources
PubMed1980

Evaluation of childhood pseudoseizures using EEG telemetry and video tape monitoring.

Pseudoseizures, clinical events that superficially resemble epileptic attacks but which are not associated with central nervous system paroxysmal activity, are often difficult to differentiate from epileptic seizures. To evaluate the frequency and clinical manifestations of pseudoseizures in children with intractable seizures, children admitted to a Comprehensive Epilepsy Unit received prolonged simultaneous EEG telemetry and video recording. Pseudoseizures occurred in 11 of 53 pediatric patients admitted during the study period. Eight of the 11 patients with pseudoseizures also had documented epileptic seizures. Clinical characteristics of pseudoseizures and epileptic seizures documented by TEEG-VR were compared. Degree and duration of the postictal state, incontinence, combativeness, relationship to stress, and response to anticonvulsant medication were useful differentiating criteria. Pseudoseizures are not unusual in pediatric patients, often occur concurrently with epileptic seizures, and may be difficult to diagnose. However, careful clinical observation may offer clues in differentiating pseudoseizures from epileptic seizures.

Adolescent↗
PubMed1996

Electrode positioning for reliable telemetry ECG recordings during social stress in unrestrained rats.

We describe a surgical procedure for optimizing the location of telemetry ECG leads in rats. The new location was aimed at obtaining an accurate representation of ECG features throughout the cardiac cycle by limiting the voltage instability usually observed during intense somatomotor activity and improving the signal-to-noise ratio. The two electrodes (wire loops) were fixed on the dorsal surface of the xiphoid process and in the anterior mediastinum close to the right atrium. The implantation procedure was fast, little invasive, and allowed animals to completely recover from intervention. The performance of the "improved" location (IL, n = 10) with respect to two subcutaneous (SC) positionings ("conventional positioning" CSP, n = 5; "updated location," USL, n = 5) was evaluated by comparing ECGs obtained in baseline, stress and recovery conditions and during different behavioral activities (immobility and grooming). The resident-intruder test (emotional/physical challenge) was chosen as experimental stress paradigm. The noise level of ECGs obtained from IL rats was lower than in CSP and USL animals, in all recording conditions. Percentages of correctly recognized beats (CRBs) over the total number of beats (TBs) were significantly higher in IL rats than in CSP and USL animals, both in baseline conditions (99% vs. 11% and 40%) and situations involving high somatomotor activity (stress: 97%, 5% and 16% recovery; 97%, 7% and 15%) (p < 0.01). The performance of IL as compared to CSP and USL was also better when percentages during grooming and immobility were considered (grooming: 93% vs. 4% and 23%: immobility: 97%, 6%, and 33%; p < 0.01).

Animals↗
PubMed1997

24-hour recordings of blood pressure, heart rate and behavioural activity in rabbits by radio-telemetry: effects of feeding and hypertension.

We used radio-telemetry to measure 24-hour rhythms of systolic, diastolic and mean blood pressure, heart rate and behavioural activity in conscious rabbits, which were maintained under normal day/night rhythms and restricted feeding. Over three consecutive days, all variables showed little change between day-period and night-period, except for a pronounced rise in the afternoon, coinciding with the presentation of pellet food. Mean blood pressure increased during this period from baseline values between 78-82 mm Hg to a peak of 89-91 mm Hg. At the same time heart rate rose from baseline values of 147-161 b/min to a peak of 206-234 b/min and behavioural activity scores rose from 11-31 counts/h to a peak of 52-81 counts/h. Changing the time at which pellet food was presented to the rabbits from the early afternoon to the early morning, caused a complete and immediate shift of the peak of blood pressure and heart rate to the morning period. Chronic intravenous infusion of angiotensin II caused a significant increase in blood pressure (24-hour average: 80 +/- 1 vs. 114 +/- 7 mm Hg) but did not alter basal heart rate or behavioural activity. The increase in heart rate and blood pressure seen with food presentation was attenuated with angiotensin II infusion. These data show that in rabbits diurnal changes in blood pressure, heart rate and activity were determined to a large extent by timed feeding. In addition, in rabbits with angiotensin-induced hypertension the food-induced changes in blood pressure and heart rate were blunted.

Angiotensin II↗
PubMed1997

A new protocol for the transmission of physiological signals by digital telemetry.

A method has been devised to transmit physiological signals from the brains of rats using a new digital telemetry transmission protocol. The chief advantage of the present system over existing systems is that the circuit only consumes power during the transmission of a brief pulse of information. This results in a very much extended battery life allowing the device to be implanted and recordings to be carried out over a longer period of time.

Animals↗
PubMed1981

A method for reviewing radio-telemetry paramedic calls.

A method is presented for reviewing the taped radio-telemetry records of paramedic calls managed by hospital-based emergency medicine residents. All paramedic calls to the LAC/USC base station are reviewed by an emergency medicine resident using a special tape review form which focuses on communication skills, initial paramedic field assessment, sense of urgency of the case, and the completeness of the filed report. Additional emphasis is placed on the base station physician's interpretation of the field presentation and his choice of therapy. Tapes demonstrating particular skills or pitfalls in prehospital management are selected for monthly tape review conferences. Such conferences provide a method by which each side of the prehospital care team can perceive the position of the other, encouraging physicians and paramedics to enhance their respective roles in providing effective prehospital emergency care.

Allied Health Personnel↗
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↗
PubMed1997

Implantation of a refillable glucose monitoring-telemetry device.

This study describes the components and short-term in vivo evaluation of an integrated implantable system consisting of an amperometric glucose biosensor, a miniature potentiostat, a FM signal transmitter, and a power supply. The device (dimensions: 5.0 x 7.0 x 1.5 cm) was implanted subcutaneously in healthy mongrel dogs. The biosensor performance was evaluated in vitro prior to implantation using standard solutions simulating the physiological environment. A linear response to glucose concentration was observed throughout the physiological and pathophysiological range (with an upper limit of 25 mM glucose, and a sensitivity of 0.5 microA/mM). The results of short-term subcutaneous implantation of the integrated system demonstrated good agreement between the glucose concentration measured by the biosensor and that obtained using standard glucose determination methods. The delay-time between the tissue glucose level (measured by the biosensor) and the blood glucose level (obtained by standard methodology) was 3-7 min. These results demonstrated the feasibility of data transmission by a telemetry system through the skin of a dog and allowed the commencement of chronic in vivo testing. During the chronic implantation the biosensor was refilled in vivo. A rejuvenation of the sensor's response after refilling was observed suggesting the potential of such sensors for long-term implantation.

Animals↗
PubMed1996

Short-term canine implantation of a glucose monitoring-telemetry device.

In this study we report the development and short-term in vivo evaluation of an integrated implantable device consisting of an amperometric glucose biosensor, a miniature potentiostat, a FM signal transmitter, and power supply. The device (dimensions: 5.0 x 7.0 x 1.5 cm) was implanted under the skin of medium-size anaesthetized dog. The experimental set-up included several methods for data collection: analog recording via wired X-T chart recorders; data collection by wearable microprocessor--data logger, and remote data collection via antenna and receiver linked to a computer-based data acquisition system. The device (sensor) performance was evaluated in vitro prior to implantation, using different model solutions simulating the physiological environment. A linear response to glucose concentration was obtained up to 25 mM glucose, with a sensitivity of 0.5 microA/mM. The results of short-term subcutaneous implantation of the integrated device reveal adequate monitoring of an artificially-induced glycaemia. The delay-time was 3-7 minutes. These tests demonstrate the feasibility of data transmission by the telemetry system through the skin of a medium-sized dog and allow the commencement of chronic in vivo experimentation.

Animals↗
PubMed1997

The Cosmed K4 telemetry system as an accurate device for oxygen uptake measurements during exercise.

The purpose of this study was to test the accuracy of oxygen uptake (VO2) measurements using the Cosmed K4 portable telemetry system. This system of higher technology than the original Cosmed K2 device, contains a CO2 electrode allowing measurements alternatively by either the Cosmed K4 system (K4) or the CPX Medical Graphics (CPX) during a maximum oxygen uptake (VO2max) ergocycle test, at rest and during several submaximal exercises (25, 50 and 75% of maximal work rate) in seven subjects. Heart rate values were comparable for exercise at the same work stage during gas collection using the two systems, indicating that the physiological stresses were similar. The VO2 values did not significantly differ at rest (4.40+/-0.83 vs 4.16+/-0.58ml x min(-1) x kg[-1]), at 25% Wmax (20.97+/-1.31 vs 21.32+/-2.54 ml x min(-1) x kg[-1]), at 50% Wmax (33.32+/-3.92 vs 33.50+/-3.51 ml x min(-1) x kg[-1]), at 75% Wmax (47.01+/-7.51 vs 47.49+/-7.11 ml x min(-1) kg[-1]) and at maximal intensities (62.07+/-8.48 vs 62.84+/-11.31 ml x min(-1) kg[-1]) using K4 and CPX devices, respectively. The results of this study indicated that the K4 system was accurate for all oxygen uptake measurements from rest to maximum exercise levels.

Adult↗
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↗
PubMed1995

[Preliminary study of an implantable device powered by an inductive link for telemetry of the epicardial electrocardiogram and the radionuclide activity of the left ventricle].

In nuclear cardiology, radionuclide data concerning the cardiac function are presently collected using external detectors, providing scintigraphic images or activity curves with respect to time. This paper presents a new approach to the latter kind of instruments, which are often called nuclear stethoscopes. This proposed system is composed of a cardiac implant, a miniature transmitter positioned externally on the chest and a remote receiver system allowing the processing of the cardiac function data. The transcutaneous magnetic link permits the power transfer in order to energize the electronic implant, and permits the telemetry of the electrocardiogram and the radionuclide data between the implant and the external receiver system. The nuclear activity measured by a photodiode for gamma rays based on cadmium telluride, with pulse width modulation, constitutes the carrier of the electrocardiographic activity. The composite signal is transmitted by means of the implant impedance modulation. The use of this transmission concept reduces to a minimum the volume of the implant. Furthermore, this system, allowing the correct positioning of the external transmitter facing the left ventricle, increases the performance of the global transmission system. Theoretical results on the design of the magnetic link are presented.

Electrocardiography↗
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↗
PubMed1977

Urine marking and territoriality in Galago alleni (Waterhouse, 1837--Lorisoidea, Primates)--a field study by radio-telemetry.

A wild population of Galago alleni was controlled by trapping and followed by radio-tracking in the equatorial rainforest of Gaboon during three study periods of 3 months each in 1972, 73 and 75. The disposition of territories and the social organization are described, as well as their evolution through time. A new technique of radio telemetry permitted identification and localization of urine marking in wild galagos. Urine marking took place throughout the territory, with a fourfold increase in frequency in zones where there is a slight overlap with neighbouring territories (female--female or male--male). The function of urine washing (wetting of the soles of the feet with urine) is discussed in relation to five hypotheses proposed by different authors, and th data obtained in the field in Gaboon. We interpret this behaviour as a means of dispersal of urine marks (social signals) in a three-dimensional milieu where displacement by a combination of leaping and running creates numerous pathways.

Animals↗
PubMed1975

Electrical activity of grafted myometrium and its recording by radio-telemetry in unrestrained rabbits.

1. The electrical activity in myometrial grafts in fifty-one female rabbits with ear chambers fitted with pick-up electrodes has been monitored. An FM telemetry system has made long-term studies possible in the freely moving animal. 2. Two distinct patterns of electrical activity were observed either arising spontaneously or provoked by oxytocin. These were the 'long-duration burst' containing about 50-150 spikes, and the 'short-duration burst' containing 1-10 spikes. 3. The spike frequency within the long-duration bursts varied between 0-9 and 1-3 spikes sec-1 and was fairly constant during the first half of the burst. The frequency of the bursts in the long series of short-duration bursts was about 2-3 min-1. 4. When activity from grafts in two chambers in the same animal was monitored for long periods, spontaneous activity occurred at random throughout the day in each graft, indicating that the spontaneous activity was probably myogenic.

Animals↗
PubMed1985

An optical telemetry device to identify which dolphin produces a sound.

A small telemetry device, called a "vocalight," was designed for attachment to a dolphin's head using a suction cup. The vocalight lights up a variable number of light-emitting diodes depending upon the loudness of sounds received at a hydrophone within the suction cup. If vocalights matched for sensitivity are put on each dolphin within a captive group, observers can identify which dolphin produces a vocalization. Use of vocalights indicates that source levels of whistles from captive bottlenosed dolphins, Tursiops truncatus, range from approximately 125 to over 140 dB re: 1 microPa at 1 m.

Animals↗
PubMed1979

A multichannel telemetry system for recording cardiovascular neural signals.

A multichannel telemetry system was developed for use with chronically instrumented unrestrained cats. This system can simultaneously record efferent and afferent cardiovascular neural signals, bioelectrical noise arising near the electrode recording the neural signals, EEG, ECG, and a standard calibration signal. The miniature (18 cm3), lightweight (24 g), telemeter is a five-channel, time-multiplexed, pulse width modulation (PWM)/FM device employing a high frequency subcarrier (60 kHz) and two sampling frequencies (30 kHz and 6 kHz). The device is powered by two small 120 mA . h silver oxide cells; it has an indoor transmission range of 10 m and can operate for 48 h. One channel transmits a standard signal (a square wave of 100 Hz and 200 mVp-p) used to monitor and regulate the system's performance. When the variation in either the amplitude or frequency of the standard signal is greater than 10% of the control value, the transmitted bioelectrical signals are automatically discarded.

Animals↗