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At least 217 records · Page 12Linked to original sources
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↗
PubMed1998

The forces in the distal femur and the knee during walking and other activities measured by telemetry.

The forces and moments in the shaft of a distal femoral replacement were measured by telemetry for a subject during different activities, and calculations were then made of the forces at the knee. The axial force showed a small peak at heel-strike followed by two main peaks during stance. In level walking, the peak axial force was between 1,487 and 1,718 N (2.2-2.5 BW), the peak shear force was 269-368 N (0.4-0.54 BW) directed anteriorly on the tibia, the peak axial torque was 7 Nm internal, while the patellofemoral force was 466-571 N. The highest axial force was recorded for descending stairs (2.8 BW). Standing on one leg produced 2.4 BW, while lying supine and raising the leg produced 1.7 BW. The data produced may resemble that of a normal subject, and has application to basic joint mechanics, to joint reconstruction, and to total knee replacement design and evaluation.

Adult↗
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↗
PubMed1999

Long-term telemetry of heart rates and energy metabolic rate during the diurnal cycle in normothermic and torpid African blue-naped mousebirds (Urocolius macrourus).

Colies are one of the phylogenetically oldest groups among the modern birds; the earliest finds are from about 35 million years ago. In states of energy deficiency they can undergo torpor during the night when metabolic rate and body temperature are decreased drastically to save energy (up to 90%). Here, we report the first measurements of heart rate (HR) by long-term telemetry, in seven individuals of blue-naped mousebirds (Urocolius macrourus); simultaneously and continuously metabolic rate (MR) was determined. HR at night was about 20% below the range of expected values (246/310 bpm). Mean oxygen pulse (O2 output/stroke) in normothermic birds was in a range of 0.019-0.020 ml O2/stroke; during torpor nights this value decreased significantly to 0.0086. Mean cardiac output ranged from 724 to 1214 ml blood/kg per min; in torpid birds this value fell to 400 ml blood/kg per min. Cardiac regulation of metabolic demand within an activity phase (day or night) is mainly achieved by chronotropy. Inotropy contributes at most 25% to the differences in MR between day and night (ca. 40%). Entry into torpor is brought about mainly by changes in HR (decrease from 240 to 90 bpm); after torpor levels have been reached, there is an increase in HR (to 200 bpm) and a sharp decrease (-53%) in stroke volume. This regulation by inotropy is also characteristic of arousal from torpor.

Adaptation, Physiological↗
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↗
PubMed1998

Towards multi-patient leadless and wireless cardiotocography via RF telemetry.

During labour the condition of the fetus is monitored by a cardiotocograph which displays fetal heart rate and a measure of uterine contractions. Ultrasound and tocodynamometer transducers are placed on the mother's abdomen and connected to a bedside monitor and display unit via a cable. This paper describes a prototype wireless system aimed at demonstrating the potential elimination of the cable which is undesirable in a number of respects. The radio link utilised operates at a frequency of 418 MHz with data compression and time division multiplexing (TDM) employed to allow up to 10 units to operate simultaneously on the same frequency in the same area. Data compression is achieved by extracting the Doppler ultrasound signal envelope and representing the frequency content of the signal using a zero crossing counting technique. Two Medium Access Control (MAC) protocols were considered, with a synchronised time division multiplexing system shown to offer greater throughput and resistance to interference than Carrier Sense Multiple Access (CSMA). This wireless RF telemetry system could be readily adapted for other multi-patient monitoring applications.

Cardiotocography↗
PubMed2006

Neural response telemetry measures in patients implanted with Nucleus 24.

UNLABELLED: Cochlear implantation has been recommended for children under 24 months of age. The use of objective measures is needed to help speech processor programming. The electrically evoked compound potential (EAP), which can be assessed by neural response telemetry (NRT), is one of those objective measures. AIM: to determine how often the EAP can be recorded by NRT system during surgery and to describe the responses. STUDY DESIGN: Clinical with transversal cohort. MATERIAL AND METHOD: The impedances and NRT were measured in a group of 17 Nucleus 24 implant users. The responses were analyzed and compared to the etiology, hearing loss duration and electrode array position. RESULTS: The EAP was easily recorded in the apical electrodes and, in otosclerosis and meningitis cases the EAP threshold was higher than in the other etiology cases. CONCLUSIONS: The NRT can be found in 82% of the cases during surgery. The responses obtained may vary according to etiology and the position of electrodes along the cochlea.

Action Potentials↗
PubMed2002

Continuous real-time monitoring of phosphine concentrations in air using electrochemical detectors interfaced by radio telemetry.

This work involves the novel use of a radio telemetry-based system that continuously monitors phosphine using two different types of electrochemical detectors (ECD/RT). The ECD/RT units were used to monitor phosphine inside and at varying distances from large tobacco storage warehouses. A master controller unit transferred the data to a personal computer that received and displayed the data. Supervisory control and data acquisition software assimilated the data from each ECD/RT unit, displayed and updated it as new transmissions were received, and stored the data in secure databases. Phosphine concentrations outside five warehouses simultaneously under fumigation and at the facility boundaries were <0.3 parts per million (ppm). Phosphine levels ranged from 0 to 580 ppm inside sealed warehouses. A comparison was made between the data collected at an ECD/RT unit approximately 4 m downwind of a sealed warehouse and a colorimetric tube at the same location. The final phosphine concentration from the colorimetric method was 0.05 ppm and the average over the 20-minute collection period for the ECD/RT was 0.13 ppm. This system allows for continuous, remote monitoring around warehouses under fumigation and superior time resolution allowing timely response to fugitive emissions of phosphine.

Air Pollution, Indoor↗
PubMed2003

Use of a telemetry system to examine recovery of the cardiovascular system after excitement induced by handling stress in a conscious cynomolgus monkey (Macaca fascicularis).

The aim of this study was to determine the time required for the cardiovascular system of a conscious cynomolgus monkey, in which a telemetry had been implanted, to recover from excitement induced by handling stress. With enforcement of guidelines regarding safety pharmacological studies, cardiovascular studies in primates have become more important. However, as macaque monkeys are promptly excited under experimental procedures, it is often difficult to evaluate the drug effects on the cardiovascular system. Therefore, we tested monkey chair restraint and intravenous injection of saline. After monkey chair restraint and intravenous injection, approximately 30 minutes were required for recovery of both heart rate and blood pressure to their pre-treatment level; however, ECG parameters such as PR, QRS interval, and QTc did not drastically change. Based on our current results and with sufficient consideration of autonomic nervous effects, accurate evaluation of drug effects on the cardiovascular system should now be possible.

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↗
PubMed2006

Accelerometry combined with heart rate telemetry in the assessment of total energy expenditure.

The aim of the present study was: (1) to develop a new method for total energy expenditure (TEE) assessment, using accelerometry (ACC) and heart rate (HR) telemetry in combination; (2) to validate the new method against the criterion measure (DLW) and to compare with two of the most common methods, FLEX-HR and ACC alone. In the first part of the study VO(2), HR and ACC counts were measured in twenty-seven subjects during walking and running on a treadmill. Considering the advantages and disadvantages of the HR and ACC methods an analysis model was developed, using ACC at intensities of low and medium levels and HR at higher intensities. During periods of inactivity, RMR is used. A formula for determining TEE from ACC, HR and RMR was developed: TEE = 1.1x(EQ(HR) x TT(HR) + EQ(ACC1) x TT(ACC1) + EQ(ACC2) x TTACC2 + RMR x TT(RMR)). In the validation part of the study a sub-sample of eight subjects wore an accelerometer, HR was logged and TEE was measured for 14 d with the DLW method. Analysis of the Bland-Altman plots with 95 % CI indicates that there are no significant differences in TEE estimated with HR-ACC and ACC alone compared with TEE measured with DLW. It is concluded that the HR-ACC combination as well as ACC alone has potential as a method for assessment of TEE during free-living activities as compared with DLW.

Adult↗
PubMed2005

Effect of peri-modiolar cochlear implant positioning on auditory nerve responses: a neural response telemetry study.

CONCLUSIONS: There was no evidence that a reduction in current was needed for nerve stimulation as a result of modiolar placement of a cochlear implant. However, modiolus hugging did reduce the spread of excitation for the basal and apical electrodes. This improved stimulation selectivity may result in improved speech discrimination by implant users. OBJECTIVE: To test the effect of modiolar placement of a cochlear implant on stimulation thresholds, and to confirm whether peri-modiolar electrode placement resulted in the hypothesized reduced spread of excitation. MATERIAL AND METHODS: Auditory nerve responses were measured by means of neural response telemetry (NRT) in 14 subjects. All subjects received a Nucleus CI24R(CS) Contour implant. For each subject, the stimulation threshold and response growth rate were determined on all the odd-numbered electrodes, using a masker-and-probe paradigm. In addition, the spatial spread of excitation was measured on electrodes 1, 6, 11, 16 and 20, using a variable-masker paradigm. All NRT measurements were performed intra-operatively, both before and after peri-modular placement of the electrode by removal of surgical stylet. RESULTS: Removal of the stylet had no significant effect on the threshold and growth rate of NRT responses. It caused a reduction in the spread of excitation for electrodes 1, 6 and 20, but not for electrodes 11 and 16.

Adolescent↗
PubMed2001

Intra-operative recordings of electrically evoked auditory nerve action potentials in young children by use of neural response telemetry with the nucleus C124M cochlear implant.

The electrically evoked action potential (EAP) was recorded intra-operatively by use of neural response telemetry (NRT) on the Nucleus C124M cochlear implant. The aim of the present study was to investigate the EAP in young children immediately following implant surgery and whilst the children were still anaesthetized. The effect of data collection parameters on the reliability of the EAP was assessed and the relationships of the EAP findings to the intra-operative electrical auditory brainstem response (EABR) and early behavioural threshold levels (T-levels) were also investigated. The study data comprised intra-operative recordings in 60 children. Age at implantation was less than five years in 42 (70%) of the children. Aetiology of deafness was congenital in the majority of children (55, 92%), meningitic in four children and of unknown origin in one child. Optimum test parameters for the intra-operative EAP were an amplifier gain of 40 dB and a delay of 50 micros in order to minimize the effects of amplifier saturation due to stimulus artefact and to maximize the identification of the N1 component. An intra-operative protocol was established which involved recording four stimulus levels on each of the 22 electrodes of the electrode array, the range of stimulus levels being tailored towards the expected EAP thresholds and T-levels so as to identify response threshold. There was significant correlation between the intraoperative EAP thresholds and the early T-levels (Pearson's r = 0.93 ;p<0.01) when a correction factor was introduced based on a reliable behavioural measure of the threshold of electrical stimulation on electrode 10. The intra-operative EAP threshold, when combined with a limited amount of behavioural data, may therefore be used to predict the T-level with a useful degree of accuracy. This result is also supported by the significant correlation observed between the intra-operative thresholds of the EAP and EABR.

Auditory Threshold↗
PubMed2004

Longitudinal behaviour of neural response telemetry (NRT) data and clinical implications.

Neural response telemetry (NRT) data from 63 subjects equipped with the Nucleus CI24M Cochlear Implant System generally exhibited little change over up to 4 years. Larger changes, when they occurred, were seen only within the first 15 months postoperatively, and these changes diminished over time. Intraoperative NRT data were generally stable enough to be used for assisting in the initial speech processor fitting sessions. It was not possible to predict changes in the subjective map threshold and comfortable loudness levels (T and C levels, respectively) based on observed changes in the NRT data. The long-term stability of the neural response amplitude and the neural response threshold, however, implies that NRT may be useful as a routine diagnostic tool to detect changes to the neural periphery over time.

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↗