Publications de Assim Boukhayma

Optical Urea Sensing in Sweat for Kidney Healthcare by Sensitive and Selective Non-enhanced Raman Spectroscopy

Christian Enz, Sandro Carrara, Assim Boukhayma, Ata Jedari Golparvar, Mattia Petrelli

Sweat biomarker analysis has attracted much interest in applications ranging from sports to wearable healthcare. Among all the sweat biomolecules, abnormal urea levels have been linked to several complications, particularly renal dysfunction. Here, we repo ...

SPIE-INT SOC OPTICAL ENGINEERING2023

Third-harmonic generation monitoring of femtosecond-laser-induced in-volume functional modifications

Christian Enz, Yves Bellouard, Olivier Bernard, Assim Boukhayma, Andrea Kraxner

During the last two decades, ultrafast in-volume laser-based processing of transparent materials has emerged as a key 3D-printing method for manufacturing a variety of complex integrated photonic devices and micro-parts. Yet, identifying suitable laser pro ...

2023

Rapid, Sensitive and Selective Optical Glucose Sensing with Stimulated Raman Scattering (SRS)

Christian Enz, Sandro Carrara, Assim Boukhayma, Ata Jedari Golparvar

Optical blood glucose sensing offers pain-free, non-invasive, continuous monitoring with minimum risk of infection since it does not require breaking the skin barrier. Among various optical detection and spectroscopic techniques, only Raman scattering offe ...

IEEE2022

Comparison of Two in Pixel Source Follower Schemes for Deep Subelectron Noise CMOS Image Sensors

Christian Enz, Minhao Yang, Assim Boukhayma, Antonino Caizzone, Daniel Mathias Bold, Andrea Kraxner

This paper compares two in-pixel source follower stage designs for low noise CMOS image sensors embedded both on a same 5 mm by 5 mm chip fabricated in a 180 nm CIS process. The presented chip embeds two pixel variants, one based on a body-effect-canceled ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

Very Selective Detection of Low Physiopathological Glucose Levels by Spontaneous Raman Spectroscopy with Univariate Data Analysis

Christian Enz, Sandro Carrara, Assim Boukhayma, Antonino Caizzone, Ata Jedari Golparvar

After decades of research on non-invasive glucose monitoring, invasive devices based on finger blood sampling are still the predominant reference for diabetic patients for accurately measuring blood glucose levels. Meanwhile, research continues improving p ...

2021

Optimized Detection of Hypoglycemic Glucose Ranges in Human Serum by Raman Spectroscopy with 532 nm Laser Excitation

Christian Enz, Sandro Carrara, Assim Boukhayma, Ata Jedari Golparvar

Raman scattering-based biomedical detection has usually been proposed with near-infrared laser sources. However, a low-cost CMOS imager's quantum efficiency is optimum around green wavelength, and their sensitivity substantially decreases in near-infrared ...

SCITEPRESS2021

Design and Optimization of Low Power and Low Light Sensor

Christian Enz, Assim Boukhayma, Antonino Caizzone, Raffaele Capoccia

The current trend towards embedding more and more light sensors in portable and wearable devices is calling for higher integration and reuse of the sensor interface electronics. In many applications, the light needs to be generated locally, which becomes t ...

IEEE2020

Multispectral image sensor and method for fabrication of an image sensor

Assim Boukhayma

The present invention relates to a multispectral image sensor having a pixel array for detecting images with light components in different wavelength ranges, comprising a plurality of imaging layers each embedded in a semiconductor substrate, wherein in ea ...

2020

Time-of-flight device and 3d optical detector

Christian Enz, Assim Boukhayma, Antonino Caizzone

A Time-of-flight optical device and a 3D optical detector comprising a CMOS integrated circuit with an array of photosensitive pixels that are, at least in part, interconnected to form macro-pixels (180). Each macro-pixel (180) groups a plurality of indivi ...

2020

Experimental Verification of the Impact of Analog CMS on CIS Readout Noise

Christian Enz, Assim Boukhayma, Raffaele Capoccia

In this article, the impact of the combination of the column-level gain and the correlated multiple sampling (CMS) on the noise of CMOS image sensor (CIS) readout chains is first analyzed. The theory is then validated experimentally with CIS readout chains ...

2020

A CMOS Image Sensor Pixel Combining Deep Sub-Electron Noise With Wide Dynamic Range

Christian Enz, Assim Boukhayma, Antonino Caizzone

This letter introduces a 5-transistors (5T) implementation of CMOS Image Sensors (CIS) pixels enabling the combination of deep sub-electronnoise performance with wide dynamic range (DR). The 5T pixel presents a new technique to reduce the sense node capaci ...

Institute of Electrical and Electronics Engineers2020

Non-invasive glucose sensor

Assim Boukhayma

An optical device for the in noninvasive determination of the concentration of glucose or another analyte in blood using a combination of Raman spectrometry and PPG. The device includes an optical detector, preferably a CMOS imager including pinned photodi ...

2020

A 2.6 μW Monolithic CMOS Photoplethysmographic (PPG) Sensor Operating With 2 μW LED Power for Continuous Health Monitoring

Christian Enz, Assim Boukhayma, Antonino Caizzone

2019

AC/DC Ratio Enhancement in Photoplethysmography Using a Pinned Photodiode

Christian Enz, Assim Boukhayma, Antonino Caizzone

Photoplethysmography (PPG) enables non-invasive vitals monitoring. Nevertheless, it is intrinsically limited by the extremely small AC/DC ratio, also called perfusion-index (PI). This increases the dynamic-range requirements to reliably process the PPG wav ...

Institute of Electrical and Electronics Engineers2019

A 2.6μW Monolithic CMOS Photoplethysmographic Sensor Operating with 2μW LED Power

Christian Enz, Assim Boukhayma, Antonino Caizzone

IEEE2019

Compact Modeling of Charge Transfer in Pinned Photodiodes for CMOS Image Sensors

Christian Enz, Farzan Jazaeri, Assim Boukhayma, Raffaele Capoccia

In this paper, we propose a physics-based compact model of the pinned photodiode (PPD) combined with the transfer gate. A set of analytical expressions is derived for the 2-D electrostatic profile, the PPD capacitance, and the charge transfer current. The ...

2019

Pixel sensor cell for cmos image sensors with enhanced conversion gain at high dynamic range capability

Assim Boukhayma

The present invention relates to a pixel sensor cell (1) for a CMOS sensor device comprising: - a photodiode (11) for generating photoelectrons; - a first transfer transistor (12) coupling the photodiode (11) with an intermediate node (IN) and configured t ...

2019

An Ultra-Low Power PPG and mm-Resolution ToF PPD-Based CMOS Chip Towards All-in-One Photonic Sensors

Christian Enz, Assim Boukhayma, Antonino Caizzone

This paper presents a CMOS photonic sensor covering multiple applications from ambient light sensing to time resolved photonic sensing. The sensor is made of an array of gated pinned photodiodes (PPDs) averaged using binning and passive switched-capacitor ...

2019

A kTC Noise Analysis in a Passive Switched-Capacitor CMS Circuit for CIS

Christian Enz, Assim Boukhayma, Raffaele Capoccia

ICLAB2019

Health monitoring device

Christian Enz, Assim Boukhayma, Antonino Caizzone

The invention relates to a photoplethysmography (PPG) sensing device comprising - a pulsed light source, - at least one pixel to create photo-generated electrons, synchronized with said pulsed light source. It is mainly characterized in that each pixel com ...

2019