Geert Langereis

Contactless EMG sensors embroidered onto textile

To obtain maximum unobtrusiveness with sensors for monitoring health parameters on the human body, two technical solutions are combined. First we propose contactless sensors for capacitive electromyography measurements. Secondly, the sensors are integrated into textile, so complete fusion with a wearable garment is enabled. We are presenting the first successful measurements with such sensors.

Contactless sensors for Surface Electromyography.

Muscle activity can be monitored by measuring the surface electromyography (SEMG) signal at the surface of the body. The SEMG signal is a combination of several activation signals sent through the muscle fibers triggering the contraction of the muscle. SEMG enables to access those signals non-invasively. Usually, metal plate electrodes in combination with electrolytic gel are placed in direct contact with the skin to measure SEMG. For prolonged monitoring of the muscle activity, this type of electrodes is not comfortable and can cause skin irritation. In this paper, we demonstrate capacitive electrodes capable of sensing the SEMG signal. These contactless electrodes do not require direct contact with the skin and thus they can be suitable for prolonged monitoring of the muscle activity

Thermally Balanced Writing for High-Speed Compact Disc Recordable (CD-R) Recording

A thermally balanced write strategy has been developed for high-speed recording of CD-recordable (CD-R). It is adopted in the recent multi-speed CD-R standard as the media testing condition. The write strategy accounts for the effects of thermal interference and heat accumulation during the recording process. Detailed thermal calculations of the resulting pit shapes and sizes support the approach. CD-R recording speeds of up to 40X are demonstrated using this Thermally Balanced Write Strategy.

34 GB Multilevel-Enabled Rewritable System Using Blue Laser and High-Numeric Aperture Optics.

Multilevel (ML) technology increases storage capacity and data transfer rates of an optical data storage system. ML is shown to be a strong candidate for use with a high numeric aperture (NA) and blue-laser system by demonstrating good margin performance.

Unobtrusive Sensing of Psychophysiological Parameters

The quantification of the human perception of experiences can be achieved by the sensing of specific psychophysiological parameters. A growing interest develops for the daily life use of these quantification techniques by unobtrusive and unnoticeable data collection. Remote and non invasive sensing technologies are discussed for the sensing of the following psychophysiological parameters: heart rate variability, and muscle stress. A generic miniature platform for miniature wireless sensing applications is described as an important enabler for unobtrusive and unnoticeable sensing. The technology no longer seems to be a limiting factor for unobtrusive and unnoticeable sensing. Initially the sensors will be worn on the body, but ultimately implantable sensors will become widely accepted, allowing access to new parameters, such as hormone levels and body core temperature.

An Implementation of Limited Multi-Level (LML) Optical Recording

Multi-level pits and lands are mastered compatible with the compact disc (CD) format in a sub-channel on top of the original Runlength-Limited (RLL) channel, which remains unaffected. By introducing multi-level effects only in long pit and land runlengths of the main RLL channel, two additional Limited Multi-Level (LML) channels are created. Via the restriction of the multi-level modulation to relatively long runlengths, it is realized that the jitter in the original channel is not affected and that separate (independent) slicers for all pit multi-level effects and for the land multi-level effects can be used. An additional achievement is that a slicer is devised for retrieving the LML-bits which is optimized for maintaining a maximum capacity in the multi-level channel. The LML system is evaluated using both simulations and experiments on read-only discs.

Recording CD-R up to 56x

The most important performance parameter for CD-R recording is the recording speed. We have achieved recording speeds of up to 56X on CD-R with a data-to-data jitter of 25 ns that is well within Orange Book specification. This jitter is achieved at zero asymmetry and with a write power margin of 20% of the optimum recording power. In this paper, we present results on a number of CD-R media. Furthermore, we discuss the influence of write strategy parameters, such as laser power level, laser pulse length, pulse shape, etc., on the recording performance of high speed CD-R.