Estimation of the Second Derivative of Kinematic Impact Signals Using Fractional Fourier Domain Filtering

Georgakis, Apostolos; Subramaniam, Suba R.

doi:10.1109/tbme.2008.2006507

Cited by 18 publications

(12 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Forward and reverse pass filtering was used to avoid time-shift distortions. The values for the parameters of the triangle were determined empirically [4] as: X 1 = 12 Hz, W 1 =0.111s, W 2 = 0.111s, and H = 36 Hz. The accelerations ) ( t α were computed using the second-order forward differences of the filtered signals.…”

Section: Resultsmentioning

confidence: 99%

“…The height H of the triangle corresponds to the impact-induced expansion of the frequency content. The physical relevance of the above parameters to the actual motion enables the development of application-specific methods to estimate them, such as the empirical algorithms used in [4].…”

Section: B Description Of the Algorithmmentioning

confidence: 99%

“…The presented method, Manuscript originally introduced in [4], achieves this by drawing upon the unique relationship between the fractional Fourier transform (FrFT) of a signal and its time-frequency (TF) representation to design a time-varying cut-off threshold for low-pass filtering. In this paper, we illustrate the differences of the method from classical low-pass filtering by contrasting their frequency responses in the TF plane.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A simple filter circuit for denoising biomechanical impact signals

Subramaniam

Georgakis

2009

2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society

View full text Add to dashboard Cite

We present a simple scheme for denoising non-stationary biomechanical signals with the aim of accurately estimating their second derivative (acceleration). The method is based on filtering in fractional Fourier domains using well-known low-pass filters in a way that amounts to a time-varying cut-off threshold. The resulting algorithm is linear and its design is facilitated by the relationship between the fractional Fourier transform and joint time-frequency representations. The implemented filter circuit employs only three low-order filters while its efficiency is further supported by the low computational complexity of the fractional Fourier transform. The results demonstrate that the proposed method can denoise the signals effectively and is more robust against noise as compared to conventional low-pass filters.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: B Description Of the Algorithmmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A simple filter circuit for denoising biomechanical impact signals

Subramaniam

Georgakis

2009

2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society

View full text Add to dashboard Cite

show abstract

“…As described in our recent study, 21 with the IIM-2010A, the fourth derivative of radial pulse was calculated by the new algorithm based on the B-spline wavelet, with better accuracy and anti-noise capability, while with the HEM-9000AI, numerical differentiation was used, which might amplify noise, especially at high frequencies. 26 Less variation has also been shown in radial SEVR measured by the IIM-2010A compared with carotid SEVR. The reason might be that the radial pulse waveform was easier to measure than the carotid pulse waveform.…”

Section: Discussionmentioning

confidence: 99%

“…One possible explanation was the technical difference in detecting the shoulder point of radial pulse waveform, which was the key point for calculating AIx. As described in our recent study, with the IIM‐2010A, the fourth derivative of radial pulse was calculated by the new algorithm based on the B‐spline wavelet, with better accuracy and anti‐noise capability, while with the HEM‐9000AI, numerical differentiation was used, which might amplify noise, especially at high frequencies . Less variation has also been shown in radial SEVR measured by the IIM‐2010A compared with carotid SEVR.…”

Section: Discussionmentioning

confidence: 99%

A New Tonometric Device for Radial Augmentation Index and Subendocardial Viability Ratio: Potential Use in Health Screening

Wang

Zhang

et al. 2014

J of Clinical Hypertension

View full text Add to dashboard Cite

Augmentation index (AIx) and subendocardial viability ratio (SEVR) are widely accepted indices of wave reflection and myocardial oxygen demand relative to supply. This study aimed to validate a new tonometric device (IIM‐2010A) for obtaining AIx and SEVR from radial artery. A total of 68 outpatients (32 men and 36 women) aged 20 to 76 years (44.7±16.6 years) recruited from a health screening center participated in the study. AIx was obtained from radial pressure using the HEM‐9000AI and IIM‐2010A devices, while SEVR was measured from carotid pressure with the tonometric method and from radial pressure by the IIM‐2010A device. In a subgroup of 24 patients, the measurements of AIx and SEVR were repeated after an interval of 10 minutes. The correlation of radial AIx between the IIM‐2010A and HEM‐9000AI devices was highly significant (r=0.956, P<.01). Radial SEVR determined from IIM‐2010A was also highly related to carotid SEVR (r=0.864, P<.01), although the value was about 13.1% lower. There was no statistically significant difference between the repeated measurements of both indices. The lower coefficient of variation (2.9% vs 4.3% for AIx, 3.3% vs 4.1% for SEVR) and higher intraclass correlation coefficient (0.96 vs 0.91 for AIx, 0.93 vs 0.86 for SEVR) of IIM‐2010A confirmed better short‐term reproducibility, compared with the HEM‐9000AI device and carotid tonometry. The new tonometric device IIM‐2010A is effective and reproducible in calculating radial AIx and SEVR and has potential use in health screening.

show abstract

Robust and nonlinear control literature survey (No. 13)

2009

Intl J Robust & Nonlinear

View full text Add to dashboard Cite

In order to keep readers up-to-date, the journal will contain a list of recently published journal articles relevant to the fields of robust and nonlinear control six times a year. This list is compiled from a wide range of journals. Please note that even though the list has been broadly categorized these classifications are by no means strict, and are there to assist the reader. Please also note that inclusion in the list is not an endorsement of a papers quality. If you have any suggestions or comments, please email Leonardo Giovanini at lgiovanini@fich.unl.edu.ar. THEORETICAL DEVELOPMENTS IN ROBUST CONTROLFleming A, Wills A. Optimal periodic trajectories for band-limited systems. IEEE Transaction on Control Systems Technology 2009; 17(3):552-562. Ghosh S, Das S, Ray G. Decentralized stabilization of uncertain systems with interconnection and feedback delays: an LMI approach. IEEE Transaction on Automatic Control 2009; 54(4):905-912. Guo L, Yin L. Robust PDF control with guaranteed stability for non-linear stochastic systems under modelling errors. IET Control Theory and Applications 2009; 3(5):575-582. Huang G, Wang S. Use of predicted information to improve the control performance of systems with uncertainties. Journal of Process Control 2009; 19(3):457-463. Jetto L, Orsini V. Some remarks on the robust Schur stability analysis of interval polynomials. International Journal of Control 2009; 82(3):493-496. Karafyllis I, Kravaris C. Robust global stabilisability by means of sampled-data control with positive sampling rate. International Journal of Control 2009; 82(4):755-772. Khadra A, Liu X, Shen X. Analyzing the robustness of impulsive synchronization coupled by linear delayed impulses. IEEE Transaction on Automatic Control 2009; 54(4):923-928. Nobakhti A, Brown M, Wang H. On the sensitivity of the control structure selection problem in largescale multivariable systems. IET Control Theory and Applications 2009; 3(5):533-550. Ou L-L, Zhang W-D, Yu L. Low-order stabilization of LTI systems with time delay. IEEE Transaction on Automatic Control 2009; 54(4):774-787. Sun J, Djouadi S. Robust stabilization over communication channels in the presence of unstructured uncertainty. IEEE Transaction on Automatic Control 2009; 54(4):830-834. Wallin R, Hansson A, Johansson J. A structure exploiting preprocessor for semidefinite programs derived from the Kalman-Yakubovich-Popov Lemma. IEEE Transaction on Automatic Control 2009; 54(4):697-704. Zhang X-N, Yang G-H. Control synthesis via state feedback with finite frequency specifications for time-delay systems. International Journal of Control 2009; 82(3):508-516. 2. THEORETICAL DEVELOPMENTS IN NONLINEAR CONTROL Alamir M, Welsh J, Goodwin G. Redundancy versus multiple starting points in nonlinear system related inverse problems. Automatica 2009; 45(4): 1052-1057. Ambrosino R, Calabrese F, Cosentino C, De Tommasi G. Sufficient conditions for finite-time stability of impulsive dynamical systems. IEEE Transaction on Automatic Control 2009; 54(4): 861-865. Costa E, do Val J. Uni...

show abstract

Estimation of the Second Derivative of Kinematic Impact Signals Using Fractional Fourier Domain Filtering

Cited by 18 publications

References 23 publications

A simple filter circuit for denoising biomechanical impact signals

A simple filter circuit for denoising biomechanical impact signals

A New Tonometric Device for Radial Augmentation Index and Subendocardial Viability Ratio: Potential Use in Health Screening

Robust and nonlinear control literature survey (No. 13)

Contact Info

Product

Resources

About