The Fast Time Frequency Transform (F.T.F.T.): A Novel On-line Approach To The Instantaneous Spectrum

Martens,

doi:10.1109/iembs.1992.592902

Cited by 12 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…low sensitivity to sedentary activities and inability to register static exercise (BOUTEN et al, 1997;MATTHEWS and FREEDSON, 1995). in addition, the signals of the two forearm sensors in this study were closely related (correlation o f 0.81).…”

mentioning

confidence: 77%

“…The frequency feature was based upon a bandpass filtered derivative (0.3-2.0 Hz for the legs; 0.6-4.0 Hz for the think), also using finite impulse response filters. This bandpassed signal was the input of the fast time frequency transform (FTFT) procedure (MARTENS, 1992). if this signal met the pre-set criteria, a valid frequency was assigned and compressed to 1 Hz.…”

Section: Detection Method" Signal Processing and Analysismentioning

confidence: 99%

See 1 more Smart Citation

Ambulatory measurement of upper limb usage and mobility-related activities during normal daily life with an upper limb-activity monitor: A feasibility study

2002

View full text Add to dashboard Cite

The aim of this research was to assess the ability of an upper limb-activity monitor (ULAM) to discriminate between upper limb usage and non-usage in healthy and disabled subjects during normal daily life. The ULAM was based on ambulatory accelerometry and consisted of several acceleration sensors connected to a small recorder worn around the waist. While wearing this ULAM, four healthy and four disabled subjects performed an activity protocol representing normal daily life upper limb usage or non-usage. The motility feature (derived from the raw acceleration signals) was used as a measure of the extent of upper limb usage. Agreement scores between ULAM output and videotape recordings (reference method) were calculated. ULAM data that were of special interest for rehabilitation were detected satisfactorily (overall agreement 83.9%). There were no systematic differences in the agreement percentages between healthy and disabled subjects for mobility-related activities (p = 0.345) and the different forms of upper limb usage or non-usage (p= 0.715). The ULAM can be used in future studies in subjects with upper limb disorders to discriminate between upper limb usage and non-usage during performance of mobility-related activities to determine activity limitations.

show abstract

mentioning

confidence: 77%

Section: Detection Method" Signal Processing and Analysismentioning

confidence: 99%

Ambulatory measurement of upper limb usage and mobility-related activities during normal daily life with an upper limb-activity monitor: A feasibility study

2002

View full text Add to dashboard Cite

show abstract

“…For sleep spindle detection and analysis, the EEGs were subjected to instantaneous spectral analysis using a fast time frequency transform (FTFT) (Martens, 1992). The FTFT calculates instantaneous amplitude, frequency, and bandwidth in eight frequency bands from 0 -4, 4 -8, 8 -12, 12-16, 16 -18, 18 -22, 22-24, 24 -28, and 28 -32 Hz.…”

Section: Methodsmentioning

confidence: 99%

Encoding Difficulty Promotes Postlearning Changes in Sleep Spindle Activity during Napping

et al. 2006

View full text Add to dashboard Cite

Learning-dependent increases in sleep spindle density have been reported during nocturnal sleep immediately after the learning session. Here, we investigated experience-dependent changes in daytime sleep EEG activity after declarative learning of unrelated word pairs. At weekly intervals, 13 young male volunteers spent three 24 h sessions in the laboratory under carefully controlled homeostatic and circadian conditions. At approximately midday, subjects performed either one of two word-pair learning tasks or a matched nonlearning control task, in a counterbalanced order. The two learning lists differed in the level of concreteness of the words used, resulting in an easier and a more difficult associative encoding condition, as confirmed by performance at immediate cued recall. Subjects were then allowed to sleep for 4 h; afterward, delayed cued recall was tested. Compared with the control condition, sleep EEG spectral activity in the low spindle frequency range and the density of low-frequency sleep spindles (11.25-13.75 Hz) were both significantly increased in the left frontal cortex after the difficult but not after the easy encoding condition. Furthermore, we found positive correlations between these EEG changes during sleep and changes in memory performance between pre-nap and post-nap recall sessions. These results indicate that, like during nocturnal sleep, daytime sleep EEG oscillations including spindle activity are modified after declarative learning of word pairs. Furthermore, we demonstrate here that the nature of the learning material is a determinant factor for sleep-related alterations after declarative learning.

show abstract

“…The plethysmography method for BR registered the excursions of the thorax associated with breathing as an oscillatory signal, from which the BR of the subject was derived by means of instantaneous frequency analysis (Martens, 1992). With this type of analysis, small changes in the oscillatory signal can be detected immediately using the phase angle and instantaneous amplitude per sample to calculate the instantaneous frequency, and subsequently transform it into BR per minute.…”

Section: Data Analysis and Reductionmentioning

confidence: 99%

Subjective and physiological responses to emotion-eliciting pictures in male schizophrenic patients

Hempel

Tulen

Beveren

et al. 2007

International Journal of Psychophysiology

View full text Add to dashboard Cite

The Fast Time Frequency Transform (F.T.F.T.): A Novel On-line Approach To The Instantaneous Spectrum

Cited by 12 publications

References 0 publications

Ambulatory measurement of upper limb usage and mobility-related activities during normal daily life with an upper limb-activity monitor: A feasibility study

Ambulatory measurement of upper limb usage and mobility-related activities during normal daily life with an upper limb-activity monitor: A feasibility study

Encoding Difficulty Promotes Postlearning Changes in Sleep Spindle Activity during Napping

Subjective and physiological responses to emotion-eliciting pictures in male schizophrenic patients

Contact Info

Product

Resources

About