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DYNAMIC LINEARITY OF VO2 RESPONSES DURING AEROBIC EXERCISE

EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1992年第2期64卷 139-144页

作者： HOFFMANN, U ESSFELD, D WUNDERLICH, HG STEGEMANN, J 1. Physiologisches Institut der Deutschen Sporthochschule K?ln Carl-Diem-Weg 6 W-5000 Cologne 41 Federal Republic of Germany

The multifrequent pseudorandom binary sequence (PRBS) technique is a useful tool for studying oxygen uptake (VO2) kinetics within the aerobic range. However, the validity of this multifrequent test may be limited by nonlinearities generated by the circulatory and pulmonary system. To check for such nonlinear effects, we compared the frequency responses computed from two PRBS protocols with the results of pure sinusoidal frequencies varying in amplitude and mean values (periods between 50 s and 450 s). According to our results the VO2 frequency response does not seem to depend on the type of testing - PRBS or sine - or the changes within each test, i.e. mean power and power amplitude of the sine tests and the switching frequency of the PRBS. In the range of higher frequencies small differences between the test conditions may have been obscured by the greater scatter of dynamic responses. It was concluded that the VO2 frequency response was quasi-linear for periods down to at least 100 s. However, even in this range nonlinearities can be provoked by rest-exercise transitions, by a varying contribution of lactate or by an insufficient noise reduction.

关键词： OXYGEN UPTAKE KINETICS FREQUENCY RESPONSE pseudorandom binary sequence SINUSOIDAL TESTING HUMANS

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NEW pseudorandom ENCODING TECHNIQUE FOR SHAFT ENCODERS WITH ANY DESIRED RESOLUTION

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ELECTRONICS LETTERS 1987年第10期23卷 507-509页

作者： PETRIU, EM Department of Electrical Engineering University of Ottawa Ottawa Canada

A new pseudorandom, two-track encoding procedure for absolute-type shaft encoders with any number of disc sectors has been developed. For n-bit resolution the new method requires only n + m reading heads, where 2m-1 &... 详细信息

关键词： pseudorandom encoding Spatial variables measurement angle measurement angular measurement n-bit resolution binary sequences disc sectors encoding shaft encoders reading heads Other digital circuits digital circuits two-track encoding pseudorandom binary sequence

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High-sensitivity and wide-dynamic-range 10Gbit/s APD/preamplifier optical receiver module

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ELECTRONICS LETTERS 2002年第13期38卷 650-651页

作者： Matsuda, H Miura, A Irie, H Tanaka, S Ito, K Fujisaki, S Toyonaka, T Takahashi, H Chiba, H Irikura, S Takeyari, R Harada, T OpNext Japan Inc Transmiss Module Ctr Totsuka Ku Yokohama Kanagawa 2448567 Japan Hitachi Ltd Cent Res Lab Kokubunji Tokyo 1858601 Japan OpNext Japan Inc Opt Dev Ctr Totsuka Ku Yokohama Kanagawa 2448567 Japan Hitachi Ltd Device Dev Ctr Ome 1988512 Japan Hitachi ULSI Syst Co Ltd Dept Adv Technol Dev Ome Japan

InAlAs avalanche photodiodes (APD) and SiGe-HBT preamplifier 10 Gbit/s optical receiver modules ha c been developed. The measured back-to-back minimum sensitivity and the optical overload with a pseudorandom binary sequence of 2(31)-1 at a bit error rate of 10(-0) are -29.5 and +0.4 dBm. respectively. The dynamic range is 29.9 dB. These results show the highest sensitivity and the widest dynamic range yet reported for 10 Gbit/s APD receivers.

关键词： aluminium compounds SiGe InAlAs III-V semiconductors pseudorandom binary sequence indium compounds Photoelectric devices binary sequences HBT preamplifier bit error rate APD/preamplifier optical receiver module optical overload Optical fibre networks Optical communication equipment Amplifiers avalanche photodiodes optical fibre communication sensitivity preamplifiers back-to-back minimum sensitivity optical receivers 10 Gbit/s dynamic range

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Aerobic system analysis based on oxygen uptake and hip acceleration during random over-ground walking activities

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AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY 2017年第1期312卷 R93-R100页

作者： Beltrame, Thomas Hughson, Richard L. Univ Waterloo Fac Appl Hlth Sci 200 Univ Ave West Waterloo ON N2L 3G1 Canada Conselho Nacl Desenvolvimento Cient & Tecnol Brasilia DF Brazil

Deteriorated aerobic response to moderate exercise might precede the manifestation of clinical symptoms of non-communicable diseases. The purpose of the current study was to verify that the use of current wearable technologies for analysis of pulmonary oxygen uptake ((V) over dotO(2)) dynamics during a pseudorandom ternary sequence (PRTS) over-ground walking protocol is a suitable procedure for the investigation of the aerobic response in more realistic settings. A wearable accelerometer located at the hip assessed the magnitude of the input changes delivered to the aerobic system. Eight adults (24 +/- 4 yr old, 174 +/- 7 cm, and 71.4 +/- 7.4 kg) performed two identical PRTS over-ground walking protocols. In addition, they performed on the cycle ergometer two identical pseudorandom binary sequence (PRBS) protocols and one incremental protocol for maximal ((V) over dotO(2)) determination. In the frequency domain, mean normalized gain amplitude (MNG in %) quantified ((V) over dotO(2)) dynamics. The MNG during PRTS was correlated (r = -0.80, P = 0.01) with the ((V) over dotO(2)) time constant (tau) obtained during cycling. The MNG estimated during PRBS was similar to the MNG estimated during PRTS (r = 0.80, P = 0.01). The maximal ((V) over dotO(2)) correlated with the MNG obtained during the PRBS (r = 0.79, P = 0.01) and PRTS (r = 0.78, P = 0.02) protocols. In conclusion, PRTS over-ground walking protocol can be used to evaluate the aerobic system dynamics by the simultaneous measurement of ((V) over dotO(2)) and hip acceleration. In addition, the aerobic response dynamics from PRBS and PRTS were correlated to maximal ((V) over dotO(2)). This study has shown that wearable technologies in combination with assessment of MNG, a novel indicator of system dynamics, open new possibilities to monitor cardiorespiratory health under conditions that better simulate activities of daily living than cardiopulmonary exercise testing performed in a medical environment.

关键词： oxygen uptake kinetics wearables accelerometer pseudorandom binary sequence pseudorandom ternary sequence

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Visual evoked Potentials elicited by pseudorandom stimulation from patients with macular degeneration

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JAPANESE JOURNAL OF OPHTHALMOLOGY 2002年第1期46卷 108-113页

作者： Nemoto, N Mori, H Kiyosawa, M Wang, WF Mochizuki, M Momose, K Tokyo Med & Dent Univ Grad Sch Dept Ophthalmol & Visual Sci Bunkyo Ku Tokyo 1138591 Japan Kanagawa Inst Technol Dept Informat & Network Engn Atsugi Kanagawa Japan

Purpose: To investigate the effect of a central scotoma on the amplitude, implicit time (IT), and temporal frequency characteristics (TFC) of the visual evoked potentials (VEPs) elicited by a pseudorandom binary sequence (PRBS) stimulus in age-related macular degeneration (,A,[D) patients. Methods: Twenty-six patients with AMD, 17 eves with visual acuity of less than 20/100, and 9 eyes with Visual acuity between 20/70 and 20/50, were examined. Nine eyes of age-matched healthy volunteers served as controls. To elicit the PRBS-VEPs, one eye was stimulated with a PRBS stimulus. The first-order kernel was calculated from a cross-correlation between the PRBS and the VEPs. The Fourier transformed first-order kernel was used as the TFC of the visual system. Results: The mean IT of P2 (second positive peak) of the first-order kernel was significantly delayed (t-test, P < .05), and the P2-N2 (peak-to-peak of P2 and second negative peak N2) amplitude was significantly reduced (t-test. P < .01) in eves with AMD. A depression of the TFC values in the 6-18 Hz band was prominent in patients with AMD (t-test, P < .01). Conclusion: PRBS-VEPs demonstrated a prolonged IT and reduced amplitude of the first-order kernel, and reduced TFC with a reduction of visual acuity in patients with macular degeneration. (C) 2002 Japanese Opthalmological Society.

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A novel absolute displacement detecting magnetic sensor

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Journal of Harbin Institute of Technology(New Series) 2011年第2期18卷 81-85页

作者：郝双晖刘勇宋宝玉郝明晖 School of Mechatronic Engineering Harbin Institute of Technology

A novel magnetic grating based on calibration was *** tracks,look-up track and index track,were used to realize absolute *** of look-up track were magnetized according to N-S-N-S,and magnetic field was sensed by 6 linear Hall *** signals whose phase shift is 120° were obtained through difference,and the offset of magnetic head in a signal period could be obtained by look-up table;Magnets of index track were magnetized according to pseudorandom binary *** sensors were used to get the absolute offset of the signal period to which the magnetic head is *** magnetic grating was calibrated using a higher resolution optical grating:output of optical grating and signals from magnetic grating were sampled at the same time and transmitted to computer,the relation between them could be got and stored in MCU for *** displacement was got according to Hall signals while in working state.A magnetic grating prototype was made,and it could realize absolute detecting in 2048 mm and the resolution could achieve to 0.001 *** structure is simple,cost is very low and it is suitable for mass production.

关键词： displacement detecting absolute output pseudorandom binary sequence

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Effect of renal perfusion pressure on responses of intrarenal blood flow to renal nerve stimulation in rabbits

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CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY 2004年第1-2期31卷 35-45页

作者： Guild, SJ Malpas, SC Eppel, GA Nguang, SK Evans, RG Univ Auckland Dept Physiol Circulatory Control Lab Auckland New Zealand Univ Auckland Dept Elect & Elect Engn Auckland New Zealand Monash Univ Dept Physiol Melbourne Vic 3168 Australia

1. We investigated how sympathetic nerve activity and renal perfusion pressure (RPP) interact in controlling renal haemodynamics in pentobarbitone-anaesthetized rabbits. 2. Renal blood flow (RBF) was reduced by electrical renal nerve stimulation (0.5-8 Hz), with RPP set using an extracorporeal circuit to 65, 100 and 135 mmHg. 3. Responses of RBF and cortical laser Doppler flux to renal nerve stimulation were blunted by increased RPP. For example, 4 Hz stimulation reduced RBF by 68 +/- 7% with baseline perfusion pressure approximately 65 mmHg, but only by 22 +/- 3% at approximately 135 mmHg. Medullary laser Doppler flux was less responsive than cortical laser Doppler flux to renal nerve stimulation and its response was not dependent on perfusion pressure. 4. When perfusion pressure was clamped at its baseline level during renal nerve stimulation, responses of RBF and cortical laser Doppler flux, but not medullary laser Doppler flux, were still blunted with increased baseline perfusion pressure. 5. A frequency rich stimulus was applied to assess the effects of perfusion pressure on dynamic neural control of RBF. Renal blood flow responded similarly at each level of perfusion pressure, as a low-pass filter with a pure time delay. 6. Our results suggest that, in the rabbit extracorporeal circuit model, increased RPP blunts the ability of steady state renal nerve stimulation to reduce cortical, but not medullary perfusion. However, in this model the level of RPP appears to have little impact on dynamic neural control of RBF.

关键词： laser Doppler flowmetry medullary blood flow pseudorandom binary sequence renal blood flow sympathetic nervous system

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Response allocation in a rapid-acquisition concurrent-chains procedure: Effects of overall terminal-link duration

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BEHAVIOURAL PROCESSES 2009年第2期81卷 233-237页

作者： Christensen, Darren R. Grace, Randolph C. Univ Canterbury Dept Psychol Christchurch 1 New Zealand Univ Arkansas Med Sci Little Rock AR 72205 USA

Four pigeons were exposed to a concurrent-chains procedure in which the initial link was constant (variable-interval 10s) while the terminal-link delays changed across sessions according to a pseudo-random binary series. In the short condition, the left terminal link was a fixed-interval 8s and the right terminal link was either fixed-interval 4s or fixed-interval 16s;in the long condition, the left terminal link was fixed-interval 16 sand the right terminal link was either fixed-interval 8s or fixed-interval 32 s. Multiple regression showed that response allocation was sensitive to the current session immediacy ratio, with greater sensitivity in the long than the short condition. This replicates the terminal-link effect [MacEwen, D., 1972. The effects of terminal-link fixed-interval and variable-interval schedules on responding under concurrent-chained schedules. J. Exp. Anal. Behav. 18,253-261] in a pseudorandom binary series design. Grace and McLean's [Grace, R.C., McLean, A., 2006. Rapid acquisition in concurrent chains: evidence for a decision model. J. Exp. Anal. Behav. 85, 181-202] decision model provided a good description of the data and predicted the terminal-link effect. Estimates of the criterion parameter increased in the long condition but less than proportionally, and were close to the expected values based on the programmed schedule durations, as predicted by the decision model. These results provide additional support for the decision model as an account of choice in concurrent chains. (C) 2009 Elsevier B.V. All rights reserved.

关键词： Reinforcer delay Acquisition Concurrent chains Choice Pigeons Hysteresis Terminal-link effect pseudorandom binary sequence

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FREQUENCY-DOMAIN ANALYSIS OF VENTILATION AND GAS-EXCHANGE KINETICS IN HYPOXIC EXERCISE

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JOURNAL OF APPLIED PHYSIOLOGY 1991年第6期71卷 2394-2401页

作者： XING, HC COCHRANE, JE YAMAMOTO, Y HUGHSON, RL UNIV WATERLOO DEPT KINESIOL WATERLOO N2L 3G1 ONTARIO CANADA

The kinetics of O2 uptake (VO2), CO2 output (VC(O2)), ventilation (VE), and heart rate (HR) were studied during exercise in normoxia and hypoxia [inspired O2 fraction (FI(O2)) 0.14]. Eight male subjects each completed 6 on- and off-step transitions in work rate (WR) from low (25 W) to moderate (100-125 W) levels and a pseudorandom binary sequence (PRBS) exercise test in which WR was varied between the same WRs. Breath-by-breath data were linearly interpolated to yield 1-s values. After the first PRBS cycle had been omitted as a warm-up, five cycles were ensemble-averaged before frequency domain analysis by standard Fourier methods. The step data were fit by a two-component (three for HR) exponential model to estimate kinetic parameters. In the steady state of low and moderate WRs, each value of VO2, VCO2, VE, and HR was significantly greater during hypoxic than normoxic exercise (P < 0.05) with the exception of VCO2 (low WR). Hypoxia slowed the kinetics of VO2 and HR in on- and off-step transitions and speeded up the kinetics of VCO2 and VE in the on-transition and of VE in the off-transition. Frequency domain analysis confined to the range of 0.003-0.019 Hz for the PRBS tests indicated reductions in amplitude and greater phase shifts in the hypoxic tests for VO2 and HR at specific frequencies, whereas amplitude tended to be greater with little change in phase shift for VCO2 and VE during hypoxic tests. There were significant higher-frequency components in all variables (less-than-or-equal-to 0.89 Hz) with no differences due to hypoxia. These data indicate that both step and PRBS exercise tests can show the effects of hypoxia on dynamic cardiorespiratory responses.

关键词： pseudorandom binary sequence OXYGEN UPTAKE CARBON DIOXIDE OUTPUT VENTILATION HEART RATE MODELING FOURIER ANALYSIS TOTAL LAG TIME

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LONG-LASTING VENTILATORY RESPONSE OF HUMANS TO A SINGLE BREATH OF HYPERCAPNIA IN HYPEROXIA

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JOURNAL OF APPLIED PHYSIOLOGY 1992年第1期72卷 242-250页

作者： MODARRESZADEH, M BRUCE, EN CASE WESTERN RESERVE UNIV DEPT BIOMED ENGNCLEVELANDOH 44106 CASE WESTERN RESERVE UNIV DEPT MEDCLEVELANDOH 44106

It has often been assumed that under normoxia, closed-loop ventilatory responses to transient CO2 stimulation (i.e., lasting for 1-3 breaths) are less likely to be mediated by the slow-responding central (medullary) chemoreflex. This assumption, however, has not been quantitatively examined in humans. We hypothesized that in the closed-loop respiratory chemical feedback system [in which the centrally mediated ventilatory response to transient changes in the arterial PCO2 levels (Pa(CO2)) will in turn affect the pulmonary CO2 and hence Pa(CO2)], the contribution of the central chemoreflex pathways to brief disturbances in blood gases may be more important than considered previously. Using the technique of pseudorandom binary CO2 stimulation, we quantified the ventilatory response of normal humans to brief disturbances in arterial CO2 during hyperoxia. Tidal volume (VI), inspiratory ventilation (VI), inspiratory time (TI), expiratory time (TE), and end-tidal CO2 fraction (FET(CO2)) were measured in subjects who inhaled a mixture that was pseudorandomly switched between 95% O2-5% CO2 and 100% O2 (63 breath sequences). From these data, we calculated the responses of VI, VI, TI, TE, and FET(CO2), to a single-breath inhalation of 1% CO2 in O2. Our results showed that in response to a brief increase of 0.75 Torr in alveolar CO2, VI showed a transient increase (average peak response of 0.12 l/min) that persisted for greater-than-or-equal-to 80 s in every subject. The response of VI was similar to that of VI, whereas TI and TE showed no consistent changes. Using these results we calculated that central chemoreflex pathways may contribute significantly to typical transient CO2 stimulation tests in hyperoxic and normoxic humans.

关键词： CENTRAL CHEMOREFLEX TRANSIENT VENTILATION CLOSED-LOOP RESPONSE pseudorandom binary sequence

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