Telemetric Transmission Research Articles

Development and study of perspective versions of on-board antenna design for telemetric information transmission

Development and study of perspective versions of on-board antenna design for telemetric information transmission

Clinical validation of a novel wearable system for real-time telemetric transmission of transient changes of cardiac autonomic modulation induced by psychophysiological and physical stress

Abstract Background Although clinical assessment of cardiac autonomic modulation (CAM) usually relies on off-line heart rate variability analysis (HRVa), measured under stationary conditions according to guidelines, there is a growing interest, in sports medicine and psychophysiology, for the reliable evaluation of acute changes of CAM occurring under real-world dynamics (i.e. acute stress induced by competitions or critical situations). The aim of this study was to test, with a standardized clinical protocol inducing enhancement of sympathetic/vagal modulation, the reliability of a novel system for continuous monitoring and telemetric transmission of transient CAM changes, provided by real-time calculation of time-variant HRV parameters (HRVp) and Skin Potential Response (SPR). Methods All measurements were performed in the laboratory for clinical electrophysiology. The Vi-BioBox system consists of a wearable wireless mini-recording device connected to a textile electrode garment and hands electrodes. 3 ECG and 2 SPR signals are continuously recorded (1 kHz sampling-rate) and streamed in real-time to Wintax4 (Magneti-Marelli) data logging for real-time calculation and monitoring of spectral HRVp and of the Root Mean Square value of two SPR signals (SPRRMS) with a proprietary custom software. 10 healthy volunteers (mean age 32.4±16.8 y, 50% males) underwent a 5-steps protocol: 1) 10-minutes baseline supine; 2) 10-minutes Head-up tilting 70° (HUTT); 3) 10-minutes supine recovery); 4) 20-minutes mental stress (“Mensa” preliminary Tests); 5) exercise-test at bicycle-ergometer. 12-lead ECG was continuously recorded also with Mortara Surveyor/X-Scribe and Time-variant HRVp were also calculated off-line with Kubios (3.0.2) software. Statistical analysis was performed with SPSS 21. Results The quality of the Vi-BioBox signals was optimal for reproducible real-time calculation and monitoring of time-variant HRV parameters. Baseline SPRRMS activity ranged between 0.01 and 0.8 mV, with wide interindividual variability. A significant (p<0.05) increment (up to 2.6 mV) was induced by HUTT (example in Figure 1), but not by physical exercise. SPRRMS and LF/HF had similar trend along test session. Good agreement was found between HRVp calculated in real-time, their off-line recalculation with Kubios software and those obtained from Mortara telemetry. Conclusion Real-time monitoring of time-variant spectral HRVp and of SPRRMS was reliable and reproducible. SPRRMS is an independent sensitive marker of sympathetic activation, which anticipates increments of VLF, LF and is useful to interpret CAM underlying of LF/HF changes. Real-time monitoring of CAM may be useful to improve the mechanistic understanding of acute psychophysiological stress-reactions, dysautonomic syncope, arrhythmic events initiation and for telemedicine (i.e. continuous remote monitoring of CAM in patients with heart failure). Figure 1. Real-time monitoring of HRV-SPR Funding Acknowledgement Type of funding source: None

New technologies for intensive prevention programs after myocardial infarction: rationale and design of the NET-IPP trial.

Current health care data reveal suboptimal prevention in patients with coronary artery disease and an unmet need to develop effective preventive strategies. The New Technologies for Intensive Prevention Programs (NET-IPP) Trial will investigate if a long-term web-based prevention program after myocardial infarction (MI) will reduce clinical events and risk factors. In a genetic sub study the impact of disclosure of genetic risk using polygenic risk scores (PRS) will be assessed. Patients hospitalized for MI will be prospectively enrolled and assigned to either a 12-months web-based intensive prevention program or standard care. The web-based program will include telemetric transmission of risk factor data, e-learning and electronic contacts between a prevention assistant and the patients. The combined primary study endpoint will comprise severe adverse cardiovascular events after 2years. Secondary endpoints will be risk factor control, adherence to medication and quality of life. In a genetic sub study genetic risk will be assessed in all patients of the web-based intensive prevention program group by PRS and patients will be randomly assigned to genetic risk disclosure vs. no disclosure. The study question will be if disclosure of genetic risk has an impact on patient motivation and cardiovascular risk factor control. The randomized multicenter NET-IPP study will evaluate for the first time the effects of a long-term web-based prevention program after MI on clinical events and risk factor control. In a genetic sub study the impact of disclosure of genetic risk using PRS will be investigated.

P4336Evaluation of acute psycho-physiological reaction to law enforcement operational stress and tactical driving. 20 years of prospective Italian research

Abstract Background “Fight-or-flight” reaction to perceived danger may affect operational efficiency of police officers (POs), with negative impact on public safety. Therefore, there is a growing interest for methods to investigate stress occurring during highly-demanding operations. Stress-induced reactions are studied in psychophysiology integrating multiple parameters (ECG, EEG, respiration, electrodermal activity, salivary cortisol ...), most of them unrecordable in real-world dynamic situations. Instead ECG, recordable also during physical activity, quantifies stress-related autonomic modulation (AM) through the analysis of heart rate (HR) and its variability (HRVa). We used ECG and a miniaturized wearable wireless telemetric device (mWTD) to monitor AM changes during realistic police tactical training (rPTT), police tactical driving (PTD), oleoresin capsicum exposure (OCE) and live-fire shooting competitions (LFSC). 20 years of research, aimed to understanding of mechanisms underlying human response in force-on-force scenarios and to design more efficient training methods for POs, are reported. Method We selected data of 185 healthy POs (33.6±4.4 years old) investigated during rPTT with different psycho-physiological impact. Until 2015, ECG was recorded with standard ECG-Holter, then the novel mWTD connected to a standard textile sensors garment (Nuubo) has been used featuring simultaneous recording of 3 ECG and 2 Skin potential responses (SPR) for real-time assessment of transient variation of AM with a novel fast algorithm for integration of time-variant HRV spectral parameters (HRVp) and of Root Mean Square value of the two SPR signals (SPRRMS). Results HR increment varied significantly among individuals undergoing the same tasks. Highest HR values (>180 bpm in 66%) were observed during LFSC, often associated with poor operational score. Standard short-term HRVa was inadequate to evidence short-lasting transient changes of AM response due to acute stress (dominant LF at the beginning of task and at medium workload, relative dominance of HF and inversion of LF/HF ratio at the zenith of HR, in high-stress tasks). Under OCE, 83% of POs were able to perform their tasks, despite typical physical symptoms, high HR increment (peak 161 bpm) and HRV decrement with LF prevalence. Discriminant Analysis of HRVp differentiated between physical and psychological stress (accuracy >80%). During PTD good correlation was found between stress-induced increment of SPR activity and driving demands. Conclusion The mWTD is reliable for on-duty compatible recordings and telemetric transmission of AM during highly-demanding operations of POs. Real-time calculation and monitoring of time-varying spectral HRVp with SPRRMS provide immediate multimodal information on AM response to emotional and physical stress reactions to tactical demands. Discriminant Analysis of HRVp is useful to differentiate psychological and physical stress during police operational activity.

Distributed system of protection and diagnostics of support structural elements of high-voltage power lines

A distributed system of protection and diagnostics of support structural elements of high-voltage power lines (HVPL) on 500 kV voltage was developed at Karaganda State technical university: - current monitoring of leakage currents of bunches of suspension insulators; - detection ice-rime depositions; - cathode protection of underground elements of support constructions; - information transfer from the sensors placed on supports on the control office on telemetric channels; - creation of the passport of each support on SCADA – system basis. The system contains set of local subsystems constructively placed on the HVPL support, telemetry subsystem providing processing and information transfer from the sensors placed on support, a subsystem of processing and information storage on the control offices of different level. Power supply of local subsystems is provided from the directed energy of electromagnetic fields. The local subsystem consists of three identical, hybrid sensors of a leakage current of suspension insulators, Ice-rime depositions detection is carried out by the indirect methods based on the current monitoring of support reaction to wind and ice loads, and also temperatures and air humidity. Information from sensors allows to control the integral values of a leakage current of the industrial frequency and surface currents of the partial discharges proceeding through insulators bunches, and also to define the time point which is optimum for ice-rime depositions. Radio modem, cellular, and also satellite communication with an automatic channels choice of communication in the conditions of the powerful electromagnetic fields having significant effect on an opportunity and transmission quality of information is used for telemetric information transmission to the control office The passport of each controlled section support of HVPL which has the information archive on technical elements condition of HVPL construction support, trends of leakage currents, about the current alert conditions with localization of the place, time and a type of an alert condition was created in the control office.

Design of a High Speed Data Acquisition System for a Transient Rotor-Dynamic Test Rig

Rotor test rigs which simulate transient dynamic events such as blade tip rub with inner surface of casing require high frequency data acquisition capability. Data acquisition from a rotating component is conventionally done with a slipring arrangement or telemetric transmission. While slip rings introduce noise into the signal, the telemetric transmission works out to be very expensive. As an alternate solution, a novel data acquisition system is designed in order to acquire and store data for a short duration of time and at a high sampling rate of 35 kHz. This system is calibrated through standard tests and provides a simple and efficient mode of data capture. By virtue of being mounted on the rotor, it eliminates the need of transreceiver system and hence the associated signal noise. The system is designed and tested to sustain centrifugal loads corresponding to a maximum speed of 2000 rpm.

Corneal thickness after overnight wear of an intraocular pressure fluctuation contact lens sensor

To assess the effect of overnight wear of a contact lens-based sensor (CLS) for monitoring of 24-hr intraocular pressure (IOP) fluctuations on central corneal thickness (CCT). Changes in the CCT, mid-peripheral corneal thickness and central corneal radius (CCR) during overnight CLS wear in 20 eligible patients with ocular hypertension or established glaucoma were prospectively studied using ultrasound pachymetry and topography. Corneal thickness and CCR changes were evaluated from pre-to-postsleep, with the fellow eye as control. Paired t-test or Wilcoxon signed-rank test was used as appropriate and with α = 0.05. Relationship between the IOP profile recorded by the CLS and the pre-to-postsleep corneal thickness differences was assessed using the Spearman correlation coefficient. After CLS wear, mean CCT had changed from 523 to 537 μm (p = 0.015) in the study eye and from 518 to 522 (p = 0.206) in the fellow eye (n = 15). There was no difference in CCT change between eyes (p = 0.075). There were no statistically significant changes in horizontal or vertical CCR in either eye (p > 0.05 for all). No correlation was found between the pre-to-postsleep differences in the CLS signal and the pre-to-postsleep differences in ultrasound CCT measurements (p = 0.974). The continuous IOP monitoring does not appear to be affected by differences in corneal thickness that occur during overnight CLS wear, although the CLS did induce some corneal swelling. This effect was not statistically significantly different from the control eye and does not seem to influence the CLS IOP profile.

Telemetric transmission of energy and data for implantable systems.

Telemetric transmission of energy and data for implantable systems.

Feasibility of in utero Telemetric Fetal ECG Monitoring in a Lamb Model

Objectives: If fetal ECG (fECG) devices could be miniaturized sufficiently, one could consider their implantation at the time of fetal surgery to allow permanent monitoring of the fetus and timely intervention in the viable period. We set up an experiment to evaluate the feasibility of in utero direct fECG monitoring and telemetric transmission using a small implantable device in a lamb model. Methods: A 2-lead miniature ECG sensor (volume 1.9 cm³; weight 3.9 g) was subcutaneously implanted in 2 fetal lambs at 122 days gestation (range 119–125; term 145 days). The ECG sensor can continuously register and transmit fECG. The signal is captured by an external receiving antenna taped to the maternal abdominal wall. We developed dedicated software running on a commercial laptop for on-line analysis of the transmitted fECG signal. This was a noninterventional study, i.e. daily readings of the fECG signal were done without clinical consequences to the observations. Results: fECG could be successfully registered, transmitted by telemetry and analyzed from the moment of implantation till term birth in one case (24 days). In the second case, unexplained in utero fetal death occurred 12 days after implantation. In this subject, agonal fECG changes were recorded. Conclusion: An implanted miniature (<2 ml) ECG sensor can be used to retrieve, process and transmit continuously a qualitative fECG signal in third-trimester fetal lambs. The telemetric signal could be picked up by an external antenna located within a 20-cm range. In this experiment, this was achieved through taping the external receiver to the maternal abdomen. Any acquired signal could be transmitted to a commercially available laptop that could perform on-line analysis of the signal.

New technologies in the optimization of CRT programming

After implanting a CRT device, consistent and scheduled patient follow-up is mandatory. Besides determining electrode parameters and reviewing arrhythmic episodes, these follow-ups focus on monitoring and optimizing congestive heart failure therapy. Therefore new CRT devices present methods for heart failure surveillance and telemetric transmission of the acquired data, which allows the physician to respond immediately to the varying needs of the respective heart failure patient. In addition to cardiac resynchronization, optimization of atrioventricular (AV) and interventricular (VV) delay provide major hemodynamic benefits. As echocardiographic optimization of AV and VV delay is time consuming it is often not feasible during daily clinical practice. Therefore implemented algorithms that automatically determine and adapt AV and VV delays with respect to the fluctuating needs of the patients are essential. This article presents the current state of monitoring and optimization methods in CRT devices.

Advances in telecommunications concerning epilepsy.

Telemedicine is a rapidly expanding discipline. Looking back on a long tradition of telemetric measurement and transmission of brain electrical data, one might ask how relevant telecommunication techniques have become for clinical work in epileptology. In principle, communication can be either between patient and doctor or between doctor and doctor. The former includes telephone reports on frequency and severity of seizures and on mental and physical state. Because of the special problems of patients with epilepsy, the need for traveling should be minimized. To maintain close contact, telemetric transmission of electroencephalograms (EEG), seizure video-registration, and monitoring of anti-epileptic drug (AED) blood levels from home are desirable, but the technical tools now available are not of sufficiently high performance for these applications. However, physicians and medical units can communicate using high-rate data transfer. There are major problems with this technology. Transfer rates using the internet are not fixed. Moreover, using six digital telephone lines simultaneously, good-quality transmission of a 3-min video may take more than 1 h, restricting interactivity. In contrast to imaging (e.g., magnetic resonance imaging), there is no generally accepted protocol for handling EEG/electrocorticography data. There are also legal problems relating to the responsibility for failures and safety of personal or medical data. Nevertheless, the expenses of installation and use of such equipment appear justified by the expected benefits, for the patients (avoiding travel and multiple investigations, checking diagnosis and therapy, amending quality of life), for the physician (sparing equipment and manpower, accelerating and improving diagnosis), for the epilepsy center (increased database for expert systems, improved logistic and data storage) and, finally, for insurance providers (reduced overall costs). When the neurosurgical procedure is remote from the place of presurgical evaluation, telecommunication should be obligatory.

Telemetric Small Intestinal Motility Recording in Awake Rats

Introduction: Ideally, gastrointestinal motility recording should be done in freely moving, stress-free animals. However, no such method is currently available for rats. Methods: Two NiCr electrodes were sutured to the jejunum and connected to an implantable electromyographic (EMG) transmitter in rats. EMG signals were radio-transmitted to a receiver placed at the bottom of the rats’ home cages. Results: Fasting and postprandial jejunal EMG signals could be detected by telemetry. Phase III contractions of the MMC were easy to identify visually and occurred at a rate of about 4.8 per hour. Feeding disrupted the phasic contraction pattern 15 min after the start of food intake and lasted for 2 h. The motility index (MI, area under the curve) was calculated and increased postprandially. Conclusion: Telemetric transmission of rat gastrointestinal EMG signals is feasible and results are comparable to those given in the literature.

Technischer Aufbau, Kalibrierung und Ergebnisse mit einem neuen intraokularen Drucksensor mit telemetrischer Übertragung1

Presently intraocular pressure is measured indirectly by applanation or impression of the cornea. Only isolated values are available with this method. We present a new implantable system for direct and continuos measurement of the intraocular pressure. An implantable system consisting of a miniaturized sensor and a telemetric unit was integrated in an intraocular lens. The eye pressure is determined by the sensor, modulated and transduced by the telemetric system. By an extracorporal receiver the signal is demodulated. The electric supply of the intraocular system is achieved by external electromagnetic induction. The telemetric transmission of the intraocular pressure can be achieved with an accuracy of +/- 1 mm Hg and a frequency of registration of 3 values per second. Clinical application necessitates further animal trials in vivo.

Analysis of free forward flight ofSchistocerca gregaria employing telemetric transmission of muscle potentials

The free flight of mature female Schistocerca gregaria loaded with a transmitter device has been video-monitored for short periods of time in the laboratory. Several flight parameters, such as body angles to horizontal and to flight path, ascent angle, and flight speed, have been analysed. These flight parameters and their interrelationships coincide with those revealed during steady free flight in the field (Baker et al. 1981. J Comp Physiol 141:233–237). Therefore, these short free flights in the laboratory represent free autonomous flight performance, but offer the possibility of controlling environmental conditions. During free flight, the firing patterns of four selected powerful depressor and elevator muscles of the fore- and hindwings were obtained by a transmitter device fixed to the prothorax of the locust. Based on the recruitment of individual motor units, a correlation of the muscle-specific activity with the aerodynamic flight parameters can be accomplished. Wing-beat frequency is positively correlated to ascent angle and to speed. The recruitment of the motor units of the forewing muscles shows a correlation with some of the flight parameters, whereas the hindwing muscles are activated in a rather immutable pattern. This argues for the importance of the forewings for maneuvering, whereas the hindwings mainly serve to provide the basic power output in flight. J. Exp. Zool. 284:119–129, 1999. © 1999 Wiley-Liss, Inc.

Analysis of free forward flight of Schistocerca gregaria employing telemetric transmission of muscle potentials

The free flight of mature female Schistocerca gregaria loaded with a transmitter device has been video-monitored for short periods of time in the laboratory. Several flight parameters, such as body angles to horizontal and to flight path, ascent angle, and flight speed, have been analysed. These flight parameters and their interrelationships coincide with those revealed during steady free flight in the field (Baker et al. 1981. J Comp Physiol 141:233–237). Therefore, these short free flights in the laboratory represent free autonomous flight performance, but offer the possibility of controlling environmental conditions. During free flight, the firing patterns of four selected powerful depressor and elevator muscles of the fore- and hindwings were obtained by a transmitter device fixed to the prothorax of the locust. Based on the recruitment of individual motor units, a correlation of the muscle-specific activity with the aerodynamic flight parameters can be accomplished. Wing-beat frequency is positively correlated to ascent angle and to speed. The recruitment of the motor units of the forewing muscles shows a correlation with some of the flight parameters, whereas the hindwing muscles are activated in a rather immutable pattern. This argues for the importance of the forewings for maneuvering, whereas the hindwings mainly serve to provide the basic power output in flight. J. Exp. Zool. 284:119–129, 1999. © 1999 Wiley-Liss, Inc.

The application of a strain gauge technique to the measurement of the power characteristics of five impellers

The work described in this paper establishes the accuracy with which the power number can be measured within a mixing vessel and presents measurements for five impellers (Rushton, “bucket”, 45°-pitched blade, 60°-pitched blade and hyperboloid) as a function of rotational speed. The technique uses strain gauges and the telemetric transmission of the strain and is, therefore, more accurate than methods which involve mechanical determination of torque and that allows power measurements to be carried out in relatively small and more cost-effective models of mixing vessels. In the cases where previous data exists the results of this study compare well. This work provides new data for the “bucket”, 45°-pitched blade and hyperboloid (low Reynolds numbers) impellers and represented a systematic study for all five impellers with one measurement system.

High resolution cryogenic quartz thermometer and application towireless measurement

The high quality synthetic single crystal quartz resonator mounted in a casing of 3 mm diameter with 8 mm length has been developed for the cryogenic temperature sensor covering with the wide range from 400 K to 4.2 K under thickness shear mode operation about 28 MHz through either extended cable connection or wireless radio echo telemetric transmission from the resonator. A wireless echo sensor system of quartz cryogenic temperature sensor system has been constructed and tested for an application to cryogenic temperature control.

Telemetric transmission system for in vivo measurement of the stress load of an internal spinal fixator

For stabilizing fractures of the spine, a number of implantable devices are available. However, not much is known about the loads acting on these devices. In order to measure the forces and moments within the implant, the Dick internal fixation device was modified and fitted out with a hermetically sealed inductively powered telemetry unit. An integrated 8-channel telemetry chip was specially developed to measure the signals of six strain gauge sensors, the temperature of the implant and the supply voltage. Since the internal fixation devices are always implanted in pairs, two telemetry units are operated at the same time. This article details the function of the implanted electronic circuit and the external system components.

Cardiac pacing in the 1980s: Treatment and techniques in transition

The pacemaker of the 1980s is designed to maintain atrioventricular synchrony through dual-chamber pacing. This pacemaker is multiprogrammable and capable of telemetric transmission of biologic, electronic and electrophysiologic data. Several developments have made this therapeutic modality possible: 1) the cumulative survival rate of many lithium-battery pacemakers exceeds 95% at 5 years; 2) lead and connector problems are rare; 3) atrial and ventricular electrode malfunctions occur in less than 2% of implants; and 4) new introducer techniques have simplified implantation (mortality and major morbidity rates are 0.5 and 0.4%, respectively). With multiprogrammability, pacemaker function can be optimized for the patient's needs, and about 20% of reoperations can be avoided.Ninety-six dual-chamber (DDD) pacemakers, 55 of which have been followed up for more than 3 months, have provided trouble-free performance and have yielded salutary clinical results, particularly when implanted to replace previous ventricular inhibited units. Problems with these pacemakers have included unusual pacing electrocardiograms, pacemaker eccentricities, programmer maintenance, pacing and follow-up complexities and costs.In the 1980s, effort will be required to find a balance between rapidly evolving technology and the clinical need for complex pacing systems. From 1978 to 1981, the rate of pacemaker implantation grew from 309 to 513 implants per million population per year, and there are now approximately 500,000 patients with implanted pacemakers living in the United States. Indications for pacing are ill-defined, because in many cases the assessment of clinical response to pacing is largely subjective, lacking satisfactory quantitative indexes. This decade will be a time of reappraisal of the extent of clinical applicability of new techniques, particularly the multi-programmable dual-chamber system which, after 3 years of clinical trial, shows promise of being the predominant pacemaker of the immediate future.

Effect of internal fixation on the strain environment of the canine femur.

Strain gauge technology and telemetric transmission were utilized to investigate the dynamic strain patterns along the cortical surface of bone and the response to internal fixation, in vivo. Application of a tension band plate resulted in conversion of normal tensile strain into compressive strain which verified the tension band principle of internal fixation. Creation of a transverse osteotomy did not alter this response, provided that the fragments were rigidly fixed. The plate caused an appreciable decrease in normal surface strain measured from the lateral and medial cortices, illustrating the concept of stress protection.