Specifications
 
 
Advantages of VariaCardio® TF5 over long-term HRV recordings
   
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 Sustained HRV recordings over 24 hours usually include many artefacts due to inevitable changes to the autonomic system reflecting changing external stimuli.
   
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 When compared with non-stationary long-term data, short HRV recordings obtained under controlled environmental conditions are generally free of artefacts and noise, hence more reproducible and, therefore, more reliable and sensitive to small changes.
   
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 Short-term spectral analysis of HRV performed under standardised conditions allows the differentiation and quantification of both main branches of autonomic control.
   
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 In short-term orthostatic manipulation, both frequency spectrum components are related to the corresponding components obtained in long-term monitoring (standing vs. low frequency, supine vs. high frequency)27. Short-term HRV data have been shown to correlate well with outcomes of sustained recording periods28,29.
   
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 Recent studies suggest there is no need to control the breathing rate during the test to interpret the parasympathetic component of HRV in identification of high-risk cardiac patients30.
 
VariaCardio® TF5 Advantages
   
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 High sampling rate; 1000Hz -- uniquely accurate using forward error checking.
   
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 Unique R wave detection algorithm; high accuracy and reproducibility of computational algorithms.
R-R interval detection in the sensor unit, no further retransformation minimises random errors and non-linearities.
   
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 Integral electrode strap, avoids the need to undress the patient, thus minimising patient stress during testing, with the added advantage of no disposable electrodes, gels or other ongoing costs.
   
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 Real-time ECG display and full-time recording allows full overview & record of ECG behaviour throughout the test; crucial for avoiding errors due to artefacts.
   
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 Real-time HRV display; necessary for online studies of
instantaneous autonomic response, e.g. for angina treatment and/or stress management.
   
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 Standardised test protocol including pre-defined analytical epochs (300 seconds) and frequency analysis bands (very low 0.01-0.05 Hz/optionally/, low 0.05-0.15 Hz and high 0.15-0.40 Hz) -- increases reproducibility and reliability of results.
   
• Combination of visual and automated artefact detection & handling options.
   
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 Software stores both, original and "filtered" (artefacts processing etc.) data files for further applications.
Most system parameters are "user definable"; according to requirements.
   
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 High processing speed provides instant results based on time and frequency domain analysis, providing quick and accurate results.
   
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 Statistics includes information on stationarity of data to avoid misinterpretations.
   
• True 3D graphical data display provides easily understood results in unique format.
   
• Prints a standardised medical report with all relevant data, including your comments.
   
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 Thorough data and system protection via specific dongle, user-adjustable passwords and license/access rights schemes where applicable.
 
Key Features
   
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 Quick 15 minute orthostatic test can replace traditional 24-hour Holter evaluation of HRV1.
   
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 Advanced sophisticated telemetric technology produces accurate repeatable results. It allows the subject to be tested in a quiet, separate room to avoid "white coat" syndrome and other environmental disturbances that may induce spurious autonomic activity2.
   
• Fully validated method using evidence based medicine. System independently tested & used worldwide3.
   
• Reproducible due to controlled, physiological test conditions.
   
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 Standardised reflex test battery4 and/or modified orthostatic load protocol that requires minimum patient co-operation.
   
• Wide range of tests offered.
   
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 Cardiovascular reflex test battery.
   
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 Time domain & spectral (frequency) domain analysis during modified orthostatic test
   
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 Long-term telemetric HRV data with single channel ECG on-line monitoring & recording is possible (up to 24 hours in one setting).
   
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 Simple recording procedure - Examination can be performed by a technician. Easy interpretation based on true 3D & 2D graphics and sophisticated statistics.
   
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 Safe, portable instrumentation using rechargeable battery, allows mobile diagnostics facilities and home examination.
   
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 Patient friendly device enhances compliance for regular checks & prospective studies. Motivates the patient to relax during investigation.
   
• Remote Analysis Service for customer support via Internet.
   
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 Applications; human and veterinary medicine, sports, occupational & health care services, psychology, stress management, prevention, population screening, risk assessment.
 

References / Advantages

27. Fei L et al: Relationship between short- and long-term measurements of heart rate variability in patients at risk of sudden cardiac death. Pacing Clin Electrophysiol 1994; 17 (11 Pt2): 2194-200.
28. Bigger JT Jr et al: The ability of several short-term measures of RR variability to predict mortality after myocardial infarction. Circulation 1993; 88: 927-34.
29. Fei L et al: Short- and long-term assessment of heart rate variability for risk stratification after acute myocardial infarction. Am J Cardiol 1996; 77/9: 681-684.
30. Bloomfield DM et al: Comparison of spontaneous vs. metronome-guided breathing on assessment of vagal modulation using RR variability. Am J Physiol Heart Circ Physiol 2001; 280: H1145-H1150.

References / Key Features

1. Fei L et al: Short- and long-term assessment of heart rate variability for risk stratification after acute myocardial infarction. Am J Cardiol 1996; 77/9: 681-684.
2. Siche JP: Factors of variation of heart rate. Ann Cardiol Angeiol (Paris) m1998; 47(6): 415-9.
3. Data on file
4. Ewing DJ et al: The value of cardiovascular autonomic function tests: 10 years experience in diabetes. Diabetes Care 1985; 8/5: 491-8.
 
 
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VariaCardio® and VariaPulse are registered trademarks of AMDG Ltd. This product is protected by patents owned by AMDG Ltd.

Manufactured for AMDG by MIE Medical Research Ltd (an ISO13488 accredited company). AMDG and MIE Research Ltd reserve the right to amend specifications without notice in accordance to their policy of continual product improvement.
 
© 2001-5 Advanced Medical Diagnostics Group Ltd. All Rights Reserved.
 

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