Data set 004

Description

The very weak and noisy trigeminal somatosensory evoked potentials (TSEPs) are considered, which are successfully evoked by electrical stimulation of the trigeminal nerve of patients with endosseous oral implants. The registration of these TSEPs is performed by means of surface electrodes on the skull, which are positioned in such a way that 4 cortical areas are investigated (Fpz-C5', C75-C6', Fpz-C3', Fpz-C6').

As TSEP analysis provides an objective means of assessing neuronal function, it is considered to be a promising tool for investigating tactile sensation through the anchoring implant in the bone. Since TSEPs are severely contaminated by background ongoing electrical activities of the brain, a methodology has to be developed for detecting the transient signal (TSEP) in the biological noise (EEG).

A good filtering method, which separates out the TSEPs from the background EEG, increases the signal-to-noise ratio of the recorded signals significantly and improves the extraction of the characteristic components of the TSEPs, is very useful. The characteristic components of a TSEP signal are peak latencies (= the time (msec) between the onset of the stimulus and the signal peak).

Data format

The data is stored in Matlab format. The folowing files are available:

id0998.mat: TSEP (trigeminal somatosensory evoked potentials) registration with stimulation of the gingiva near the implant. During stimulation of the gingiva, the electrode carried an intensity of 4 mA, which caused a motor respons of the lip. The sensitivity level of this subject was 0.64 mA.
id2501.mat: TSEP registration at the implant. Positioning of the electrode on the gingiva, where an intensity of 4.5 mA is given.
id0398.mat: TSEP registration with stimulation of the gingiva on the same level as the implant. During the stimulation of the gingiva, the electrode carried an intensity of 3.5 mA. This subject had a sensitivity level of 0.9 mA.

These three files "idxxxx" contain two arrays with the following content:

dataxxxx:
column 1 and 5: two TSEP measurements of channel 1 (Fpz-C5')
column 2 and 6: two TSEP measurements of channel 2 (C75-C6')
column 3 and 7: two TSEP measurements of channel 3 (Fpz-C3')
column 4 and 8: two TSEP measurements of channel 4 (Fpz-C6')
eegxxxx:
column 1 and 5: two EEG measurements of channel 1 (Fpz-C5')
column 2 and 6: two EEG measurements of channel 2 (C75-C6')
column 3 and 7: two EEG measurements of channel 3 (Fpz-C3')
column 4 and 8: two EEG measurements of channel 4 (Fpz-C6')

 

Remarks:
in eeg2501, the last column is missing, simply because the second measurement of channel 4 was not available.

Publications in which this data set is used

  1. Swinnen A., Van Huffel S., Van Loven K., Jacobs R., ``Advanced signal processing techniques for trigeminal somatosensory evoked potentials'', in Proc. of the Advances in Medical Signal and Information Processing, Bristol, UK, Sep. 2000, pp. 142-149.
  2. Swinnen A., Van Huffel S., Van Loven K., Jacobs R., ``Detection and multichannel SVD based filtering of trigeminal somatosensory evoked potentials'', Medical & Biological Engineering & Computing, 2000, Vol. 38,
    p. 297-305.