Number Of Taps Research Articles

An Evaluation Of The Foot Tapping Test (ftt) In A Health Population

Simple in nature, the foot tapping test (FTT) has potential as an objective measure of upper motor function. Despite this, the reliability of the FTT has not been well identified. Furthermore, it is uncertain as to how to best measure the FTT as number of foot taps may vary upon counting methods. In order to make the FTT more clinically relevant, more research must be done on the FTT in healthy individuals in order to determine if it is a reliable measure of foot tapping ability. PURPOSE: The purpose of the study was to investigate reliability measures of the FTT in a healthy population using a variety of different measurement and counting methods. By identifying the reliability of the different measurement methods we hope to be able to make recommendations for future FTT research. METHODS: 20 healthy individuals, ages of 18-31, completed a series of foot tapping trials over 4 visits. While seated, subjects tapped their foot repeatedly for 10 seconds while researchers counted the number of foot taps. Starting foot was randomized for each visit and tested twice with shoes ON and twice with shoes OFF (8 trials * 4 visits = 32 trials per subject). The number of foot taps was determined for each trial via visual inspection, video playback (slowed and normal speed), and with the use of a force plate. The mean values of the FTT trials were compared across days, dominant vs. non-dominant foot, the shoes ON/OFF conditions, and with the different counting methods. RESULTS: Significant differences were found in foot tapping rates in the shoes ON (mean: 54.3 taps) vs shoes OFF (mean: 53.4 taps) and dominate vs. non-dominant (mean: 51.1 taps) foot analyses (p<0.05). Furthermore it was found that a significant difference in the mean number of foot taps existed between visit 1 (mean: 51.2 taps) and visits 2, 3, and 4 (mean: 54.3, 53.5, and 46.7 taps respectively) (p>0.05). It was found that the FTT exhibited high test-retest reliability (Pearson r >0.80) and high Cronbach’s alpha (alpha >0.80) across the live, slowed video counts, and force plate measurements. CONCLUSION: It was found that the FTT exhibits a high level of reliability across the live, slowed video, and force plate measures with both the shoes ON and shoes OFF. Given the observed reliability, the use of force plate with the FTT offers an attractive alternative to live counting or video playback methods.

Improved Chopping in Continuous-Time Delta–Sigma Converters Using FIR Feedback and &lt;inline-formula&gt; &lt;tex-math notation="LaTeX"&gt;${N}$ &lt;/tex-math&gt; &lt;/inline-formula&gt;-Path Techniques

Chopping the operational transconductance amplifier (OTA) of the input integrator in a continuous-time delta–sigma modulator is an effective way of addressing ${1/f}$ noise. This, however, causes shaped noise to alias into the signal band. A solution to this problem is to chop at the sampling rate of the modulator. High-speed chopping reduces the OTA’s dc gain, and degrades its linearity. Alternatively, the OTA can be chopped at a low rate, and FIR feedback can be used to introduce spectral nulls in the feedback waveform, so that the components that alias into the signal band are attenuated. This brief combines chopping and FIR feedback with ${N}$ -path techniques, enabling a much lower chopping frequency than would otherwise be possible with a given number of FIR DAC taps. Simulation results confirming the theory are given.

Quantitative assessment of finger tapping characteristics in mild cognitive impairment, Alzheimer’s disease, and Parkinson’s disease

Fine motor impairments are common in neurodegenerative disorders, yet standardized, quantitative measurements of motor abilities are uncommonly used in neurological practice. Thus, understanding and comparing fine motor abilities across disorders have been limited. The current study compared differences in finger tapping, inter-tap interval, and variability in Alzheimer's disease (AD), Parkinson's disease (PD), mild cognitive impairment (MCI), and healthy older adults (HOA). Finger tapping was measured using a highly sensitive light-diode finger tapper. Total number of finger taps, inter-tap interval, and intra-individual variability (IIV) of finger tapping was measured and compared in AD (n = 131), PD (n = 63), MCI (n = 46), and HOA (n = 62), controlling for age and sex. All patient groups had fine motor impairments relative to HOA. AD and MCI groups produced fewer taps with longer inter-tap interval and higher IIV compared to HOA. The PD group, however, produced more taps with shorter inter-tap interval and higher IIV compared to HOA. Disease-specific changes in fine motor function occur in the most common neurodegenerative diseases. The findings suggest that alterations in finger tapping patterns are common in AD, MCI, and PD. In addition, the present results underscore the importance of motor dysfunction even in neurodegenerative disorders without primary motor symptoms.

TapOnce: a novel authentication method on smartphones

PurposeSecurity technology on mobile devices is increasingly more important as smartphones are becoming more versatile and, thus, store more sensitive information. Among the three indispensable factors of owner authentication technologies on mobile devices, security, usability and system efficiency, usability is considered the key factor. This paper aims to challenge the limits of usability on mobile device authentication technology with respect to input size.Design/methodology/approachThis paper introduces one tap authentication as a novel authentication method on mobile devices. A user just has to tap the screen of a smartphone once, and he or she will be authenticated.FindingsOne tap authentication is proven possible in this paper. The average equal error rate among 10 owners against 25 unauthorized users is as low as 3.8.Research limitations/implicationsThis paper focuses on verifying the possibility on one tap authentication. However, the application to various environments, such as when standing or walking or on a train, is not explored.Originality/valueThis research explores tap authentication with a single tap for the first time in the field. To the best of the authors’ knowledge, the minimum number of taps required in tap authentication has been 4.

Degrees of Freedom and Achievable Rate of Wide-Band Multi-Cell Multiple Access Channels With No CSIT

This paper considers a $K$-cell multiple access channel with inter-symbol interference. The primary finding of this paper is that, without instantaneous channel state information at the transmitters (CSIT), the sum degrees-of-freedom (DoF) of the considered channel is $\frac{\beta -1}{\beta}K$ with $\beta \geq 2$ when the number of users per cell is sufficiently large, where $\beta$ is the ratio of the maximum channel-impulse-response (CIR) length of desired links to that of interfering links in each cell. Our finding implies that even without instantaneous CSIT, \textit{interference-free DoF per cell} is achievable as $\beta$ approaches infinity with a sufficiently large number of users per cell. This achievability is shown by a blind interference management method that exploits the relativity in delay spreads between desired and interfering links. In this method, all inter-cell-interference signals are aligned to the same direction by using a discrete-Fourier-transform-based precoding with cyclic prefix that only depends on the number of CIR taps. Using this method, we also characterize the achievable sum rate of the considered channel, in a closed-form expression.

Estimating Angle of Arrival (AOA) for Wideband Signal by Sensor Delay Line (SDL) and Tapped Delay Line (TDL) Processors

Angle of arrival (AOA) estimation for wideband signal becomes more necessary for modern communication systems like Global System for Mobile (GSM), satellite, military applications and spread spectrum (frequency hopping and direct sequence). Most of the researchers are focusing on how to cancel the effects of signal bandwidth on AOA estimation performance by using a transversal filter (tap delay line) (TDL). Most of the researchers were using two elements array antenna to study these effects. In this research, a general case of proposed (M) array elements is used. A transversal filter (TDL) in phase adaptive array antenna system is used to calculate the optimum number of taps required to compensate these effect. The proposed system uses a phase adaptive array antenna in conjunction with LMS algorithm to work an angle of arrival (AOA) estimator for wideband signals rather than interference canceller. An alternative solution to compensate for the effect of signal bandwidth is proposed by using sensor delay line (SDL) instead of fixed delay unit since it has variable time sampling in the time domain and not fixed time delay, depending on the angle of arrival of received signals. The proposed system has the ability to estimate two parameters for received signals simultaneously (the output Signal to Noise Ratio (SNR) and AOA), unlike others systems which estimate AOA only. The comparison of the simulation results with Multiple Signal Classification (MUSIC) technique showed that the proposed system gives good results for estimating AOA and the output SNR for wideband signals. (SDL) processor shows better performance result than (TDL) processor. MUSIC technique with both (SDL) and (TDL) processors shows unacceptable results for estimating (AOA) for the wideband signal. &#x0D;

Staggered CAP—A New Spectrally Efficient Modulation Format for Optical Communications

In this letter, staggered carrierless amplitude phase (sCAP), a new spectrally efficient modulation format, is proposed for optical transmission. By staggering the in-phase and quadrature components of the CAP modulation, simultaneous transmission of two additional pulse amplitude modulation signals is possible: the first one being baseband and the second one lower sideband. The new modulation format has several advantages: 100% bandwidth efficiency, rectangular-shaped spectrum, minimum tap number shaping filters, minimum requirements for analog-to-digital conversion sampling rate, low peak-to-average power ratio, and capability of bit and power loading. The experimental results in vertical cavity surface emitting laser multimode fiber link indicate that the new format by far outperforms regular CAP.

The positive effect of venlafaxine on central motor conduction

ObjectivesUsing the triple stimulation technique (TST) and conventional transcranial magnetic stimulation (TMS), this study was designed to investigate the effect of venlafaxine on central motor conduction in healthy adults. Patients and MethodsIn this crossover, self-controlled trial, eight healthy adult volunteers were randomly divided into groups A and B. In group A, the volunteers were administered 1 venlafaxine capsule once daily for 7 consecutive days, followed by a 3-day break. Next, volunteers in this group received 1 placebo capsule once daily for 7 consecutive days. Group B received the treatments in the opposite order. The index finger tapping test, grip strength test, TST and conventional TMS examination for each hand were recorded before and one week after the administration of venlafaxine or placebo. ResultsCompared to the placebo stage, in the venlafaxine stage, the number of index finger taps was significantly increased for both hands, and the TST amplitude and area ratios were significantly increased. The improvement in the TST amplitude ratio was significantly and positively correlated with the improvements in performance on the index finger tapping test. ConclusionVenlafaxine positively regulates central motor conduction in healthy adults.

Tablet-Based Application for Objective Measurement of Motor Fluctuations in Parkinson Disease

Background: The motor subscale of the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS-III) has limited applicability for the assessment of motor fluctuations in the home setting. Methods: To assess whether a self-administered, tablet-based application can reliably quantify differences in motor performance using two-target finger tapping and forearm pronation-supination tasks in the ON (maximal dopaminergic medication efficacy) and OFF (reemergence of parkinsonian deficits) medication states, we recruited 11 Parkinson disease (PD) patients (age, 60.6 ± 9.0 years; disease duration, 12.8 ± 4.1 years) and 11 healthy age-matched controls (age, 62.5 ± 10.5 years). The total number of taps, tap interval, tap duration, and tap accuracy were algorithmically calculated by the application, using the more affected side in patients and the dominant hand in healthy controls. Results: Compared to the OFF state, PD patients showed a higher number of taps (84.2 ± 20.3 vs. 54.9 ± 26.9 taps; p = 0.0036) and a shorter tap interval (375.3 ± 97.2 vs. 708.2 ± 412.8 ms; p = 0.0146) but poorer tap accuracy (2,008.4 ± 995.7 vs. 1,111.8 ± 901.3 pixels; p = 0.0055) for the two-target task in the ON state, unaffected by the magnitude of coexistent dyskinesia. Overall, test-retest reliability was high (r >0.75) and the discriminatory ability between OFF and ON states was good (0.60 ≤ AUC ≤ 0.82). The correlations between tapping data and MDS-UPDRS-III scores were only moderate (–0.55 to 0.55). Conclusions: A self-administered, tablet-based application can reliably distinguish between OFF and ON states in fluctuating PD patients and may be sensitive to additional motor phenomena, such as accuracy, not captured by the MDS-UPDRS-III.

Finger and foot tapping sensor system for objective motor assessment

Background/Aim. Finger tapping test is commonly used in neurological examinations as a test of motor performance. The new system comprising inertial and force sensors and custom proprietary software was developed for quantitative estimation and assessment of finger and foot tapping tests. The aim of this system was to provide diagnosis support and objective assessment of motor function. Methods. Miniature inertial sensors were placed on fingertips and used for measuring finger movements. A force sensor was placed on the fingertip of one finger, in order to measure the force during tapping. For foot tapping assessment, an inertial sensor was mounted on the subject?s foot, which was placed above a force platform. By using this system, various parameters such as a number of taps, tapping duration, rhythm, open and close speed, the applied force and tapping angle, can be extracted for detailed analysis of a patient?s motor performance. The system was tested on 13 patients with Parkinson?s disease and 14 healthy controls. Results. The system allowed easy measurement of listed parameters, and additional graphical representation showed quantitative differences in these parameters between neurological patient and healthy subjects. Conclusion. The novel system for finger and foot tapping test is compact, simple to use and efficiently collects patient data. Parameters measured in patients can be compared to those measured in healthy subjects, or among groups of patients, or used to monitor progress of the disease, or therapy effects. Created data and scores could be used together with the scores from clinical tests, providing the possibility for better insight into the diagnosis.

OFDM for 4G Wireless Communications

Orthogonal frequency division multiplexing(OFDM) is the multiple access scheme for the fourth generation(4G) wireless communications. This paper analyzes the performance of OFDM through the Bit Error Rate(BER), Outage Probability, and ergodic capacity with flat delay profile as well as linearly increasing power decay factor. The probability density function(PDF) obtained in a Rayleigh fading channel is used to derive a closed-form expression for the outage probability, error rates and ergodic capacity of OFDM signals. The exact error rate values are similar to those obtained from simulation results. The performance improves with more number of channel taps

On the Selection of Optimum Threshold Bound of Body Surface to External Communication in Body Area Network

This article investigates the optimum threshold bounds for the signal travelling through a body surface to external nodes of a body area network. An ultra-wideband system ranging from 3.1-10.6 GHz is used for the observations of the signal transmitting through different body directions using NICT's statistical model. Through simulative investigation, the link performance is evaluated by calculating outage probability using sub-optimum Rake receivers, which are based on either partial combining (P-Rake) or selective combining (S-Rake). The optimum numbers of Rake taps are also identified. The obtained results give an assessment to better understand the effect of body direction and Rake structure on the selection of optimum threshold bounds for a channel model CM4 of body area communication.

Relation between Manual Dexterity and the Accuracy of Cavity Preparation

Background: Manual dexterity is important for dentists. However, few studies have investigated the relation between dental skills and manual dexterity. The hypothesis of the present study is that an association exists between manual dexterity and the accuracy of cavity preparation.Methods: Fifty-two dental students (25 males, 27 females) participated in this study. All subjects completed manual dexterity tasks (i.e., grip strength, pinch force, and number of taps made by fingers of the right hand) and a preparation accuracy test using Virtual Reality Systems (VRS, Simodont®). For the preparation test, the cross-block body in Simodont's Manual Dexterity section was used. The associations between erroneous preparations (i.e., errors in the lateral and vertical directions) and the results of manual dexterity tasks were then analyzed and examined.Result: The results revealed that grip strength and number of taps made by the fingers correlated with lateral direction errors. In particular, the number of taps in the first 10 s from the start of tapping made by the third finger, which the participants used as a finger rest during preparation, demonstrated a significant correlation with lateral direction errors.Conclusion: In this work, tapping was revealed to be associated with manual dexterity by quantifying the accuracy of preparation. In addition, the agility of the third finger used as a finger rest appeared to affect accuracy in the lateral direction. VRS is useful not only in developing teaching strategy but also in research on cavity preparation. DOI: 10.21276/aohdr.1828

The BRAIN test: a keyboard-tapping test to assess disability and clinical features of multiple sclerosis

BackgroundThe BRadykinesia Akinesia INcordination (BRAIN) test is an online keyboard-tapping test previously validated as a sensitive tool for detecting signs of Parkinson’s disease.ObjectivesTo determine whether the BRAIN test can measure disability in MS and identify the presence of pyramidal or cerebellar dysfunction.MethodsKinesia scores (KS, number of key taps in 30 s), akinesia times (AT, mean dwell time on each key) and incoordination scores (IS, variance of travelling time between keys) were calculated in 39 MS patients. These were correlated against the Expanded Disability Status Scale (EDSS) scores, pyramidal and cerebellar functional system scores and 9-hole peg test scores.ResultsEDSS correlated with KS (r = − 0.594, p < 0.001), AT (r = 0.464, p = 0.003) and IS (r = 0.423, p = 0.007). 9-HPT scores strongly correlated with KS (r = 0.926, p < 0.001). Pyramidal scores correlated with KS (r = − 0.517, p < 0.001). Cerebellar scores correlated with KS (r = − 0.665, p < 0.001), AT (r = 0.567, p < 0.001) and IS (r = 0.546, p = 0.007). Receiver operating characteristic curves demonstrate that KS can distinguish between the presence or absence of pyramidal and cerebellar dysfunction with area under curve 0.840 (p < 0.001) and 0.829 (p < 0.001), respectively.ConclusionsThe BRAIN test can remotely measure disability in MS. Specific scores differ according to the presence and severity of pyramidal or extrapyramidal dysfunction. It demonstrates huge potential in monitoring disease progression in clinical trials.

Development of a video-simulation instrument for assessing cognition in older adults

BackgroundCommonly used methods to assess cognition, such as direct observation, self-report, or neuropsychological testing, have significant limitations. Therefore, a novel tablet computer-based video simulation was created with the goal of being valid, reliable, and easy to administer. The design and implementation of the SIMBAC (Simulation-Based Assessment of Cognition) instrument is described in detail, as well as informatics “lessons learned” during development.ResultsThe software emulates 5 common instrumental activities of daily living (IADLs) and scores participants’ performance. The modules were chosen by a panel of geriatricians based on relevance to daily functioning and ability to be modeled electronically, and included facial recognition, pairing faces with the correct names, filling a pillbox, using an automated teller machine (ATM), and automatic renewal of a prescription using a telephone. Software development included three phases 1) a period of initial design and testing (alpha version), 2) pilot study with 10 cognitively normal and 10 cognitively impaired adults over the age of 60 (beta version), and 3) larger validation study with 162 older adults of mixed cognitive status (release version). Results of the pilot study are discussed in the context of refining the instrument; full results of the validation study are reported in a separate article. In both studies, SIMBAC reliably differentiated controls from persons with cognitive impairment, and performance was highly correlated with Mini Mental Status Examination (MMSE) score.Several informatics challenges emerged during software development, which are broadly relevant to the design and use of electronic assessment tools. Solutions to these issues, such as protection of subject privacy and safeguarding against data loss, are discussed in depth. Collection of fine-grained data (highly detailed information such as time spent reading directions and the number of taps on screen) is also considered.ConclusionsSIMBAC provides clinicians direct insight into whether subjects can successfully perform selected cognitively intensive activities essential for independent living and advances the field of cognitive assessment. Insight gained from the development process could inform other researchers who seek to develop software tools in health care.

GSC 구조의 시공간 모노펄스 시스템

For a target echo containing interference, it is very difficult to improve the performance of a monopulse radar with spatial domain processing, because the statistical property of interference cannot be exclusively obtained. This paper proposes a monopulse system that has a generalized sidelobe canceller(GSC) filter-based time domain processor as a preprocessor prior to conventional monopulse spatial processing. We analytically show the procedure of time-space signal processing running in the system, and assess its performance through simulation. In particular, the performance dependence on the number of taps in the main channel filter and the estimation error in Doppler frequency are assessed by comparison with those of existing systems.

200 Gb/s transmission using a dual-polarization O-Band silicon photonic intensity modulator for Stokes vector direct detection applications.

We present a dual-polarization O-band silicon photonic (SiP) transmitter for intra-datacenter optical interconnects. The transmitter is built using two identical O-band traveling wave Mach-Zehnder modulators with an average VπL and a bandwidth at 1.5 V bias voltage of 2.88 V.cm and 24.5 GHz, respectively. We experimentally demonstrate the transmitter in a Stokes vector direct-detection (SV-DD) system for dual-polarization intensity modulated signals with 2-level and 4-level pulse amplitude modulation (DP-PAM2 and DP-PAM4) formats. The direct-detection Stokes vector receiver (DD-SVR) followed by offline digital signal processing (DSP) is implemented for SOP de-rotation. We characterize the performance of the SV-DD system versus number of taps, received signal power, state of polarization (SOP), reach, and bit rate. Results reveal that 112 Gb/s DP-PAM2 can be transmitted over 10 km of single mode fiber (SMF) at a bit error rate (BER) below 10-5 at -1 dBm received signal power irrespective of the SOP. Moreover, a 168 Gb/s (42 Gbaud) DP-PAM4 signal can be transmitted over 2 km and 10 km at a BER below the 7% hard-decision forward error correction (HD-FEC) threshold (i.e., 3.8 × 10-3) at 0 dBm and 2 dBm, respectively. Furthermore, 224 Gb/s and 200 Gb/s DP-PAM4 are successfully received at a BER below the HD-FEC in the back-to-back and 2 km cases, respectively. Finally, we compare the performance of the 6 × 2 multiple-input multiple-output (MIMO) equalization to a simpler 4 × 2 MIMO equalization and explain the superior performance of the 6 × 2 in the presence of SVR imperfections.

Comparison of NRZ and duo-binary format in adaptive equalization assisted 10G-optics based 25G-EPON

We investigate and compare the requirements of FFE/DFE based adaptive equalization techniques for NRZ and Duo-binary based 25-Gb/s transmission, which are two of the most promising schemes for 25G-EPON. A 25-Gb/s transmission system based on 10G optical transceivers is demonstrated and the performance of only FFE and combination of FFE and DFE with different number of taps are compared with two modulation formats. The FFE/DFE based Duo-binary receiver shows better performance than NRZ receiver. For Duo-binary receiver, only 13-tap FFE is needed for BtB case and the combination of 17-tap FFE and 5-tap DFE can achieve a sensitivity of −23.45 dBm in 25 km transmission case, which is ∼0.6 dB better than the best performance of NRZ equalization. In addition, the requirements of training sequence length for FFE/DFE based adaptive equalization is verified. Experimental results show that 400 symbols training length is optimal for the two modulations, which shows a small packet preamble in up-stream burst-mode transmission.

Adaptive Time Taps of STAP Under Channel Mismatch for GNSS Antenna Arrays

Although antenna arrays can effectively suppress interference and maintain the navigation signal integrity, interference suppression performance is limited by channel mismatch. However, a space-time adaptive processor (STAP) can reduce channel mismatch by introducing time taps within each element, which will further suppress the interference and improve the performance. However, interference suppression depends significantly on the number of time taps. This paper presents a proportion differentiation (PD) algorithm for the adaptive control of time taps based on the antenna arrays output power is presented. The effectiveness of the proposed algorithm is verified through simulations and measured data. The STAP with adaptive time taps has achieved excellent performance for interference suppression performance without increasing the computational load.

Hardware Approach to Demodulate Satellite Relayed Video Signals

The Finite Impulse Response is utilized for satellite video signal demodulation because of one of a kind properties and the utilization of limited exactness and coefficients to speak to signals for higher accuracy and SNR. The Perks MxClellan Alorithm is utilized to create ideal Low Pass Filter utilizing Remez Command utilizing large number of taps for accurate modeling. To overcome the area overhead of computationally concentrated multipliers that are utilized as a part of existing filters, a LUT based equipment multiplier generates optimized filter regarding range and number of computations. The FIR filter was designed in MATLAB and Xilinx ISE10.1i Tools, from which the coefficients separated, were thought about. The FPGA picked was Spartan3E, rationale enhanced 90nm XC3S500E-5FG320 CMOS innovation FPGA. The LUT based FIR Filter enhances territory by 20% and deferral by 4% roughly.