Jacques Destiné

Midsagittal Jaw Movement Analysis for the Scoring of Sleep Apneas and Hypopneas

Given the importance of the detection and classification of sleep apneas and hypopneas (SAHs) in the diagnosis and the characterization of the SAH syndrome, there is a need for a reliable noninvasive technique measuring respiratory effort. This paper proposes a new method for the scoring of SAHs based on the recording of the midsagittal jaw motion (MJM, mouth opening) and on a dedicated automatic analysis of this signal. Continuous wavelet transform is used to quantize respiratory effort from the jaw motion, to detect salient mandibular movements related to SAHs and to delineate events which are likely to contain the respiratory events. The classification of the delimited events is performed using multilayer perceptrons which were trained and tested on sleep data from 34 recordings. Compared with SAHs scored manually by an expert, the sensitivity and specificity of the detection were 86.1% and 87.4%, respectively. Moreover, the overall classification agreement in the recognition of obstructive, central, and mixed respiratory events between the manual and automatic scorings was 73.1%. The MJM signal is hence a reliable marker of respiratory effort and allows an accurate detection and classification of SAHs.

Midsagittal Jaw Movements as a Sleep/Wake Marker

The seriousness of the obstructive sleep apnea/hypopnea syndrome is measured by the apnea-hypopnea index (AHI), the number of sleep apneas and hypopneas over the total sleep time (TST). Cardiorespiratory signals are used to detect respiratory events while the TST is usually assessed by the analysis of electroencephalogram traces in polysomnography (PSG) or wrist actigraphy trace in portable monitoring. This paper presents a sleep/wake automatic detector that relies on a wavelet-based complexity measure of the midsagittal jaw movement signal and multilayer perceptrons. In all, 63 recordings were used to train and test the method, while 38 recordings constituted an independent evaluation set for which the sensitivity, the specificity, and the global agreement of sleep recognition, respectively, reached 85.1%, 76.4%, and 82.9%, compared with the PSG data. The AHI computed automatically and only from the jaw movement analysis was significantly improved (p < 0.0001 ) when considering this sleep/wake detector. Moreover, a sensitivity of 88.6% and a specificity of 83.6% were found for the diagnosis of the sleep apnea syndrome according to a threshold of 15. Thus, the jaw movement signal is reasonably accurate in separating sleep from wake, and, in addition to its ability to score respiratory events, is a valuable signal for portable monitoring.

Mandible Behavior in Obstructive Sleep Apnea Patients Under CPAP Treatment

Aim: To investigate whether obstructive sleep apnea (OSA) patients present different behaviors of mandible movements before and under CPAP therapy. Materials and Methodology: In this retrospective study, patients were selected according to inclusion criteria: both the di- agnostic polysomnography recording showing an OSA with an apnea-hypopnea index (AHI) greater than 25 (n/h) and the related CPAP therapy control recordings were available, presence of mandible movement and mask pressure signals in the recordings, and tolerance to the applied positive pressure. Statistical analysis on four parameters, namely the apnea- hypopnea index (AHI), the arousal index (ArI), the average of the mandible lowering during sleep (aLOW), and the aver- age amplitude of the oscillations of the mandible movement signal (aAMPL), was performed on two sets of recordings: OSA and CPAP therapy. Results: Thirty-four patients satisfied the inclusion criteria, thus both OSA and CPAP groups included thirty-four record- ings each. Significant difference (p < 0.001) was found in the OSA group compared with the CPAP group when consider- ing either the four parameters or only the two ones related to mandible movements. Conclusions: When an efficient CPAP pressure is applied, the mouth is less open and presents fewer broad sharp closure movements, and oscillating mandible movements are absent or very small.

Evaluation of Aerosol Jet Printing (AJP) technology for electronic packaging and interconnect technique

We evaluated suitability of AJP (Aerosol Jet Printing) deposited silver layer on variety of organic substrates for the most common interconnect techniques used for electronic packaging. Specifically, we checked if the AJP silver layer can be electrically interconnected by Au and Al wires bonding technique. We also evaluated suitability of AJP silver layer for surface-mount technology (SMT). We performed electrical characterization of the AJP silver layer. We realized a fully functional working prototype of Autonomous Wireless Sensor Node system using AJP silver conductive track as an electrical interconnection.

SPICE Circuit Simulation of the Electrical Response of a Semiconductor Membrane to a Single-Stranded DNA Translocating Through a Nanopore

In this paper, we describe a circuit-element model for the electric detection of biomolecules in translocation through a nanopore in a semiconductor-oxide-semiconductor (SOS) membrane. The biomolecules are simulated as a superposition of individual charges moving through the nanopore and inducing a charge variation on the membrane electrodes that is modeled as a current source. The SOS membrane is discretized into interconnected elementary circuit elements. The model is tested on the translocation of 11 base single-stranded C3AC7 DNA molecule, for which the electric signal shows good qualitative agreement with the multiscale device approach of Gracheva et al., while quantifying the low-pass filtering in the membrane. Overall, the model confirms the possibility of identifying the sequence of the DNA bases electrically.

High vibration sensors: Modelling, design and integration

Since many years, the University of Liège is involved in micro-electronics and micro-electromechanical systems modelling, design and integration. Recently, the University of Liege had received the opportunity to build a brand new infrastructure (clean rooms - ISO 7) with specific equipments for packaging and MEMS characterisation. This new facility (clean rooms and equipments) enables the University to be very well positioned in the nano/micro-electronics modelling, analysis and packaging world and is now able to answer specific research and related industrial needs. In this paper we consider the design of a vibration sensor in its significantly vibrating surroundings and investigate in its dynamical behaviour. Environmental vibrations affect the sensor part of the MEMS device and influence the choice of the “best” packaging methods for the application. Within the framework of packaging, we consider a simple test application ensuring best interconnection technology. Dynamical investigations include a preliminary analysis of the packaging and a separate finite-element analysis of the MEMS device (inside the package), testing the device under the condition of a harsh environment (high vibration spectral level). Computations are proposed in combination with experimental observations.

Power Lines Real Time Monitoring

Nowadays, the electricity demand keeps increasing. To adapt to this request, an increase in the production of electricity, as well as in transmission and distribution capacities is necessary. Whereas the construction of a new site of energy production is relatively easy, it is extremely long and difficult to manage to build new overhead lines. Consequently, electricity companies are searching for means to maximize the transport capacity of their lines while preserving the minimal distances to the ground and the mechanical reliability of the lines. Real time monitoring of the line ampacity is one of the means which make it possible to optimize the use of high voltage lines.Copyright

Low temperature assembly method of microfluidic bio-molecules detection device

We developed a microfluidic device for the detection of bio-molecules. The active part of the device is a biofunctionalized interdigitated capacitive sensor. The microsystem consists of a sensor on silicon chip, a microfluidic channel formed by photo-patternable resist and a plastic cover. We implemented a low temperature packaging process to assemble the sensor and prevent the biological material from degradation.

Simulation of Electronic Sensing of Biomolecules in Translocation Through a Nanopore in a Semiconductor Membrane

A two-level computational model for simulation of the electric signal detected on the electrodes of a Semiconductor-Oxide-Semiconductor (SOS) capacitor forming a nanoscale artificial membrane, and containing a nanopore with translocating DNA are presented. At the device level, a three-dimensional self-consistent scheme involving snapshots of the DNA charge distribution, as well as the electrolytic charge and the charge in the semiconductor membrane compute the electrostatic potential over the whole solid-liquid system. With this numerical approach we investigate the possibility of resolving individual nucleotides as well as their types in the absence of conformational disorder. At the system level, we develop a circuit-element model for the SOS semiconductor membrane where the membrane is discretized into interconnected elementary circuit elements to assess the response of the DNA away from the pore. The model is tested on the translocation of 11 base single-stranded C3AC7 DNA molecule, for which the electric signal shows good qualitative agreement with the multi-scale device approach of Gracheva et al. also described in the first part of this chapter (Gracheva et al., Nanotech. 17, 622–633, 2006), while quantifying the low-pass filtering in the membrane.