Augmented visual feedback counteracts the effects of surface muscular functional electrical stimulation on physiological tremor

Grimaldi, Giuliana; Fernandez, Alfredo Tavares; Manto, Mario

doi:10.1186/1743-0003-10-100

Cited by 5 publications

(7 citation statements)

References 41 publications

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“…Further, respiratory motion is semi periodic in nature with slow-varying characteristics (frequency range < 1 Hz). Physiological tremor is a quasi periodic signal and lies in the high frequency range (6)(7)(8)(9)(10)(11)(12)(13)(14). Together with the nonstationary characteristics, the multistep prediction becomes much more challenging with LS-SVM compared to the other physiological motions like respiratory motions.…”

Section: B Methodsmentioning

confidence: 98%

“…It has multiple dominant frequencies usually distributed between 6 to 14 Hz with an amplitude of 50 to 100 μm in each principal axis [1]- [4]. The dominant frequencies of physiological tremor are usually limited to 4 Hz bandwidth (for e.g., [8][9][10][11][12] Hz for a typical healthy subject) [4]- [8]. The analysis conducted on physiological tremor time series in [4]- [6] and [9]- [12] suggested that tremor is nonstationary in nature and exhibits significant variations in amplitude, frequency, and bandwidth over the time.…”

Section: Introductionmentioning

confidence: 99%

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Multistep Prediction of Physiological Tremor Based on Machine Learning for Robotics Assisted Microsurgery

Tatinati

Veluvolu

Ang

2015

IEEE Trans. Cybern.

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For effective tremor compensation in robotics assisted hand-held device, accurate filtering of tremulous motion is necessary. The time-varying unknown phase delay that arises due to both software (filtering) and hardware (sensors) in these robotics instruments adversely affects the device performance. In this paper, moving window-based least squares support vector machines approach is formulated for multistep prediction of tremor to overcome the time-varying delay. This approach relies on the kernel-learning technique and does not require the knowledge of prediction horizon compared to the existing methods that require the delay to be known as a priori. The proposed method is evaluated through simulations and experiments with the tremor data recorded from surgeons and novice subjects. Comparison with the state-of-the-art techniques highlights the suitability and better performance of the proposed method.

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Section: B Methodsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Multistep Prediction of Physiological Tremor Based on Machine Learning for Robotics Assisted Microsurgery

Tatinati

Veluvolu

Ang

2015

IEEE Trans. Cybern.

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“…Patients were comfortably seated in an armchair, and equipped with 2 triaxial accelerometers, located at the right index finger and at the right metacarpal region (see Grimaldi et al, 2013 ). They were asked to maintain the upper limbs motionless horizontally in front of them and parallel to the floor.…”

Section: Methodsmentioning

confidence: 99%

Marked reduction of cerebellar deficits in upper limbs following transcranial cerebello-cerebral DC stimulation: tremor reduction and re-programming of the timing of antagonist commands

Grimaldi

Taib

Manto

et al. 2014

Front. Syst. Neurosci.

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Cerebellar ataxias represent a very heterogeneous group of disabling disorders for which we lack effective symptomatic therapies in most cases. There is currently an intense interest in the use of non-invasive transcranial DC stimulation (tDCS) to modulate the activity of the cerebellum in ataxic disorders. We performed a detailed laboratory assessment of the effects of transcranial cerebello-cerebral DC stimulation (tCCDCS, including a sham procedure) on upper limb tremor and dysmetria in 2 patients presenting a dominant spinocerebellar ataxia (SCA) type 2, one of the most common SCAs encountered during practice. Both patients had a very similar triplet expansion size in the ATXN2 gene (respectively, 39 and 40 triplets). tCCDCS reduced both postural tremor and action tremor, as confirmed by spectral analysis. Quadratical PSD (power spectral density) of postural tremor dropped to 38.63 and 41.42% of baseline values in patient 1 and 2, respectively. The integral of the subband 4–20 Hz dropped to 46.9 and 62.3% of baseline values, respectively. Remarkably, tCCDCS canceled hypermetria and reduced dramatically the onset latency of the antagonist EMG activity associated with fast goal-directed movements toward 3 aimed targets (0.2, 0.3, and 0.4 rad). Following tCCDCS, the latency dropped from 108–98 to 63–57 ms in patient 1, and from 74–87 to 41–46 ms in patient 2 (mean control values ± SD: 36 ± 8 to 45 ± 11 ms), corresponding to a major drop of z scores for the 2 patients from 7.12 ± 0.69 to 1.28 ± 1.27 (sham procedure: 6.79 ± 0.71). This is the first demonstration that tCCDCS improves upper limb tremor and hypermetria in SCA type 2. In particular, this is the first report of a favorable effect on the onset latency of the antagonist EMG activity, a neurophysiological marker of the defect in programming of timing of motor commands. Our results indicate that tCCDCS should be considered in the symptomatic management of upper limb motor deficits in cerebellar ataxias. Future studies addressing a tDCS-based neuromodulation to improve motor control of upper limbs are required (a) in a large group of cerebellar disorders, and (b) in different subgroups of ataxic patients. The anatomical location of the cerebellum below the skull is particularly well suited for such studies.

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“…The 30-s time series were segmented into 10 segments of 3 s. Auto-spectra of 10 sequential 3 s data epochs were averaged to produce smoothed auto-spectra, with mean removal and a Hamming window for each data segment ( 17 ). The following spectral parameters were extracted, and means were computed for the three experimental conditions: maximal PSD, peak frequency of power spectra, center frequency (median value of the area below the power spectrum), and frequency dispersion (frequency width of the interval around the center frequency that contains 66% of the total power spectrum) ( 19 , 20 ). Composite data (square root of the sum of the accelerations squared for all three axes) were processed as reported earlier ( 20 , 21 ).…”

Section: Transcranial Cerebello-cerebral Direct Current Stimulation (mentioning

confidence: 99%

“…The following spectral parameters were extracted, and means were computed for the three experimental conditions: maximal PSD, peak frequency of power spectra, center frequency (median value of the area below the power spectrum), and frequency dispersion (frequency width of the interval around the center frequency that contains 66% of the total power spectrum) ( 19 , 20 ). Composite data (square root of the sum of the accelerations squared for all three axes) were processed as reported earlier ( 20 , 21 ). Data presented in Section “ Results ” are mean ± SD of the three recordings performed in each experimental condition.…”

Section: Transcranial Cerebello-cerebral Direct Current Stimulation (mentioning

confidence: 99%

A Postural Tremor Highly Responsive to Transcranial Cerebello-Cerebral DCS in ARCA3

Bodranghien¹,

Taib²,

Maldergem

et al. 2017

Front. Neurol.

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Background and objectivesCerebellar ataxias are disabling disorders that impact the quality of life of patients. In many cases, an effective treatment is missing. Despite the increasing knowledge on the pathogenesis of cerebellar disorders including genetic aspects, there is currently a gap in the therapeutical management of cerebellar deficits. Cerebellar ataxia associated with ANO10 mutation (ARCA3) presents a disabling cerebellar syndrome. The aim of this study is to report a patient with a marked postural tremor responding to transcranial cerebello-cerebral direct current stimulation (tCCDCS).MethodsWe applied tCCDCS using anodal stimulation over the cerebellum with a return electrode on the contralateral motor cortex. We performed a clinical rating, accelerometry studies, and recordings of voluntary movements at baseline, after sham, and after active tCCDCS.ResultsA dramatic response of postural tremor was observed after tCCDCS, with a major drop of the power spectral density to 26.12% of basal values.DiscussionThe postural tremor of cerebellar ataxia associated with ANO10 mutation was highly responsive to tCCDCS in our patient. This case illustrates that tCCDCS is a novel therapeutic option in the treatment of cerebellar deficits and might represent a promising tool to reduce tremor in ARCA3.

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Augmented visual feedback counteracts the effects of surface muscular functional electrical stimulation on physiological tremor

Cited by 5 publications

References 41 publications

Multistep Prediction of Physiological Tremor Based on Machine Learning for Robotics Assisted Microsurgery

Multistep Prediction of Physiological Tremor Based on Machine Learning for Robotics Assisted Microsurgery

Marked reduction of cerebellar deficits in upper limbs following transcranial cerebello-cerebral DC stimulation: tremor reduction and re-programming of the timing of antagonist commands

A Postural Tremor Highly Responsive to Transcranial Cerebello-Cerebral DCS in ARCA3

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