Correlation between cephalometric variables and obstructive sleep apnoea severity in children.

Aim Alterations in craniofacial growth have been associated with obstructive sleep apnoea in children. The main objectives of this study were to analyse the correlation between cephalometric variables and Obstructive Apnea/Hypopnea Index (OAHI) in order to investigate if craniofacial features may influence the severity of obstructive sleep apnoea and to study the correlation between upper nasopharyngeal width and maxillomandibular skeletal discrepancy in sagittal and vertical plane. Materials and methods Study Design: Correlations between cephalometric variables and obstructive sleep apnoea/hypopnea index and between upper airways space and maxillomandibular skeletal discrepancy were investigated. Forty-seven children with obstructive sleep apnoea diagnosed by overnight sleep study (polysomnography) underwent a lateral radiograph, orthodontic and ear-nose-throat examinations. Cephalometric analysis according to Kirjavainen has been performed to define skeletal and upper airways variables. Statistics: Spearman’s correlation analysis was performed between OAHI and all cephalometric variables. Pearson’s correlation analysis was performed between cephalometric variables of upper airway space and cephalometric variables related to maxillomandibular discrepancy. Chi-square test was used to compare occlusal features with adenoidal and tonsillar hypertrophy. Kruskal-Wallis rank test was used to compare OAHI with occlusal variables and adenotonsillar hypertrophy. Results The results show a positive correlation between OAHI and maxillomandibular discrepancy measured by ANB angle (rho=0.32; p=0.023). A significant correlation was found between upper nasopharyngeal width and vertical maxillomandibular skeletal discrepancy: 1) ad1-PNS were correlated to Mandibular Plane/SellaNasion angle (r=-0.36; p=0.012), Palatal Plane/Mandibular Plane angle (r=-0.39; p=0.007), and Posterior-Anterior Facial Height % (r=0.29; p=0.045); 2) ad2-PNS was correlated to Palatal Plane/Mandibular Plane angle (r=-0.39; p=0.007). No statistically significant differences were found in non-parametric tests between OAHI and occlusal variables or adenoidal and tonsillar hypertrophy. Conclusions The present study shows a significant correlation between maxillomandibular discrepancy and the severity of OSA. Moreover, the reduction of nasopharyngeal width was correlated to maxillomandibular hyperdivergent growth pattern. These results support the presence of a correlation between sleep-disordered breathing and craniofacial features even if the cause-effect relation is still unclear. Based on these evidences, we suggest the importance of orthodontic evaluation in the management of paediatric OSA

A CMOS integrated focal plane array for ultra low-cost infrared applications

A prototype of 34x34 pixels vision sensor with on focal plane image processing is presented. The sensor perform a wide range of image filtering over a 3x3 pixel kernel, based on two operations: Absolute Value of the Difference (AVD) between two signals and Signal Accumulation (SA). These two functions are implemented at pixel-level thanks to a high pixel connectivity, allowing both pixel parallel comp utation with large flexibility in coefficients assignment. The pixel occupies 35x35 um2 of chip area with a fill factor of 20%. The total dynamic range of the sensor is 98 dB. The array was fabricated in 0.35 um CMOS technology and consumes 6 mW @ 3.3 V

An uncooled infrared focal plane array for low-cost applications fabricated with standard CMOS technology

This paper reports the design, fabrication and assessment of a low-cost uncooled infrared imager that has been conceived as a general purpose system to be used in a wide range of infrared applications. The imager has been fabricated using the AMS 0.8 μm CYE CMOS process together with a compatible front-side bulk micromachining post-process provided by the CMP service of the TIMA laboratory. The adopted fabrication approach does not involve any lithography step, material deposition or particular etch-stop technique after the CMOS process, so that the imager cost is almost equal to the CMOS chip cost. The infrared imager is composed of a focal plane array (FPA) with 16 × 16 thermopile pixels, which are monolithically integrated with the addressing and readout electronics. Each pixel consists of a thermally isolated micromachined membrane suspended by two arms that contain the polysilicon/aluminium thermocouples of the embedded thermopile sensor. The pixel membrane also includes a heating resistor intended to implement a self-test function that allows an electrical test of the FPA without need of specific infrared equipment. Since the voltage levels generated by the thermopile pixels are in the range of a few μV the readout channel consists of a low-noise voltage amplifier with a high variable gain that can be tuned for different operation conditions. The readout circuit makes use of the chopper principle and the correlated double sampling technique to reduce the noise floor and the amplifier offset levels. Optical measurements performed with the fabricated prototypes have shown a pixel responsivity of 15.0 V/W, a noise equivalent power of 1.37 nW and a normalized detectivity of 1.05 × 107 cm Hz1/2 W−1, values that are in line with current state of the art. The readout channel features a maximum gain of 85 dB with a 4.3 kHz bandwidth and an equivalent input noise of 22 nV/Hz1/2. An infrared imager based on the FPA has been build and thermal imaging has been demonstrated

An uncooled infrared focal plane array for ultra low-cost applicatons fabricated with standard CMOS technology

This paper reports the design, fabrication and assessment of a low-cost uncooled infrared imager that has been conceived as a general purpose system to be used in a wide range of infrared applications. The imager has been fabricated using the AMS 0.8 m CYE CMOS process together with a compatible front-side bulk micromachining post-process provided by the CMP service of the TIMA laboratory. The adopted fabrication approach does not involve any lithography step, material deposition or particular etch-stop technique after the CMOS process, so that the imager cost is almost equal to the CMOS chip cost. The infrared imager is composed of a focal plane array (FPA) with 16×16 thermopile pixels, which are monolithically integrated with the addressing and readout electronics. Each pixel consists of a thermally isolated micromachined membrane suspended by two arms that contain the polysilicon/aluminium thermocouples of the embedded thermopile sensor. The pixel membrane also includes a heating resistor intended to implement a self-test function that allows an electrical test of the FPA without need of specific infrared equipment. Since the voltage levels generated by the thermopile pixels are in the range of a few V the readout channel consists of a low-noise voltage amplifier with a high variable gain that can be tuned for different operation conditions. The readout circuit makes use of the chopper principle and the correlated double sampling technique to reduce the noise floor and the amplifier offset levels. Optical measurements performed with the fabricated prototypes have shown a pixel responsivity of 15.0 V/W, a noise equivalent power of 1.37nW and a normalized detectivity of 1.05×107 cm Hz1/2W−1, values that are in line with current state of the art. The readout channel features a maximum gain of 85 dB with a 4.3 kHz bandwidth and an equivalent input noise of 22 nV/Hz1/2. An infrared imager based on the FPA has been build and thermal imaging has been demonstrated

A micromachined flow sensor for monitoring and evaluation of urinary disfunction

The field of medicine has evolved significantly, in part, due to advances made in other realms of modern technology. One such example includes health microsystems, where small-scale measurement devices, integrated with electronic support circuitry, are microfabricated for use in-home or in clinical/hospital settings. Silicon micromachining technology has allowed fabrication of novel, miniaturized sensors leading towards innovative applications in next generation, portable analysis and diagnostic instruments. This paper reports on the development of a silicon flow microsensor which, in conjunction with a pressure microsensor, is used for real-time urodynamic evaluation of urinary dysfunction. It is known that variations in urodynamic pressure-flow patterns can be used to differentiate between constrictive and compressive obstructions by simultaneously measuring both bladder pressure and urine flow rate as a function of time. This device can allow for convenient, year long in-home monitoring, allowing an urologist to subsequently assess potential urinary dysfunction