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ObjectivesThe diagnosis of vocal fold cancer currently relies on invasive surgical biopsies, which can compromise laryngeal function. Distinguishing between different types of laryngeal lesions without invasive tissue sampling is therefore crucial. Autofluorescence spectroscopy (AFS) has proved to be efficient as a non-invasive detection technique but has yet to be fully exploited in the context of a multi-class tissue analysis. This study evaluates whether AFS can be used to discriminate between different types of laryngeal lesions in view of assisting in vocal fold surgery and preoperative investigations.Materials and methodsEx vivospectral autofluorescence scans were recorded for each sample using a 405-nm laser excitation. A total of 1308 spectra were recorded from 29 vocal fold samples obtained from 23 patients. Multiclass analysis was conducted on the spectral data, classifying lesions either as normal, benign, dysplastic, or carcinoma. The results were compared to histopathological diagnosis.ResultsThrough an appropriate selection of spectral components and a cascading classification approach based on artificial neural networks (ANN), a classification rate of 97% was achieved for each lesion class, compared to 52% using autofluorescence intensity.ConclusionThe study demonstrates the effectiveness of AFS combined with multivariate analysis for accurate classification of vocal fold lesions. Comprehensive spectral data analysis significantly improves classification accuracy, even in challenging situations such as distinguishing between malignant and premalignant or benign lesions. This method could provide a way to performin situmapping of tissue states for minimally-invasive biopsy and surgical resection margins.

International audience; Currently, the production of Advanced Therapy Medicinal Products is highly sensitive to any contamination sources and therefore takes place in clean and sterile environments. Several days are required for each production, making these products extremely expensive. Throughout the process, numerous quality controls must be performed. This is especially true during the expansion phase in order to monitor cell growth and to detect any contamination. Bioreactor’s content must periodically be sampled to perform these controls. Two major drawbacks can be identified: a delayed knowledge of the quality control result and an additional risk of new contaminations due to sampling. In this work, we present optical spectroscopy methods which can be used to drastically reduce the risk of contamination. They provide a real time control of what happens in the bioreactor in a closed system manner. Cell concentrations are measured with an accuracy below 5% and contamination can be detected about 3 h after it occurred. The real time operation leads to several tens of thousand dollars’ savings because it allows stopping the production as soon as a problem arises. Consequently, the price of these products should be greatly reduced and they may be proposed to more patients.

International audience

International audience; Fluorescent molecules like SNARF are principally used to measure pH in liquid media. pH can be deduced from the global fluorescence intensity or, often more recisely, by studying the fluorescence spectra. This allows numerical pH values to be calculated using some of the spectra shape features. Usually, the goal is to extract the contributions of the protonated and deprotonated forms of the pH indicator from the whole shape of the fluorescence spectrum and to deduce the pH value from these respective contributions. In this short paper, we show that analyzing the shape of the SNARF spectra differently allows specifying the intra-molecular origin of the processes responsible for the fluorescence emission.

We investigated the possibility to grow molecularly porous amino-silane layers on glass-like substrates. The goal of this work is to show that it is possible to substantially increase the sensitivity of a fluorescence sensor by adjusting the functionalization strategy. Two methods are studied, one using APTMS only and another one using both APTMS and APDMS. We show that, using the second method, sensor sensitivity is improved by a factor of about 5. In order to demonstrate this, we applied the technique to the grafting of fluorescein in order to build a fluorescence pH sensor.

This article presents a novel low cost force sensing platform for the mechanical characterisation of human oocytes. This platform is compatible with the specific context of Assisted Reproductive Technology (ART). The oocyte is placed inside a standard Petri dish filled with a culture medium. It is immobilized using a holding pipette. The disposable parts used to mechanically test each oocyte are made of glass. This configuration is very similar to the one used in IntraCytoplasmic Sperm Injection protocol excepted that the injection pipette is replaced by a glass indenter. This platform uses two passive and linear magnetic springs to measure the nanoforce applied to the oocyte. The stabilisation of the unstable magnetic springs is passively achieved using the reaction force generated by the compressed oocyte. Some preliminary results obtained with an experimental platform are presented. The global magnetic stiffness of the indenter, evaluated by simulation and experimentally identified, is about 0.0013 N m−1.

International audience; One of the most feared transfusion accident is the haemolytic reaction. A majority of countries impose a compatibility test before each transfusion, at the patient’s bedside or in laboratory. Regardless of the test performed, it does not prevent human errors and nothing ensures an “error free” procedure. Complete crossmatch is the only test ensuring a complete blood compatibility between donors and patients. It relies on the direct or indirect detection of agglutinations which occur when the patient’s plasma is mixed with the red cells to be transfused. It requires extracting plasma. The work described here will help avoid all the immunologic incompatibilities by the use of a compatibility test without plasma extraction. It relies on an immuno- biochip technology in a microfluidic environment with fluorescence detection. This position paper presents preliminary results obtained with artificial samples together with comments on the state of industrial competition and the new device market positioning.

International audience; Organic functions of the human body are related to biological constants. Variations of these constants, among them pH, induce pathological troubles. The general goal of our work is to fabricate a fluorescent pH sensor at the end of an optical fiber for in vivo pH measurements. One difficulty using fluorescence indicators is the need to perform an accurate calibration. In this communication, we present methods used to simplify and potentially avoid calibration procedures of fluorescence indicators. The first method concerns the simplification of calibration procedures making them independent of the indicator’s concentration, path length and equipment used. The second method concerns modelling the fluorescence emission of the molecules as a function of pH only. This model is used to fit the exact shape of C-SNARF-1 fluorescence spectra obtained at any pH. Subsequently, the pH of a solution can be computed with an accuracy of 0.1 pH unit without the calibration procedure employed up to now. These methods constitute the first steps toward calibration free pH measurements. They can be applied to any fluorescent indicator exhibiting a dual emission peak. As a conclusion, this is the first time that fluorescence properties of C-SNARF-1 are fully mathematically described.

ABO mismatch between donor and patient’s blood is still the cause of accidents which are sometimes lethal. The main causes of mis-assignment are human errors and wrong identification of patients or blood product. Only a final compatibility test at the patient’s bedside can avoid these errors. In some countries, this test is performed using manual procedures. This does not prevent from human manipulation and interpretation errors. In this paper, we present a prototype able to automatically perform a final ABO compatibility test. It relies on the use of disposable antibodies grafted biochips inserted into a mobile reader/actuator. Red blood cells are selectively captured on biochips grafted with antibodies complementary of antigens present on the cells surface. Detection of captured cells is based on optical absorption techniques. So far, our device achieved blood compatibility test with 99.3% sensitivity and 97.9% specificity.

In the field of blood transfusion, there is a need to improve the bedside pre-transfusion ABO compatibility test. In France, this test is mandatory for each red cell concentrates transfusion. It is performed manually and serious transfusion accidents still occur, principally due to human errors. Therefore, an automated ABO compatibility test is required. Works concerning objective interpretation of ABO compatibility test have been reported but the proposed techniques cannot be easily translated to the patient's bedside. We propose a prototype device which demonstrates the easy use of biochip technology to perform this test: it contains a fluidic system, biochips (two to test the patient and two to test the red cell concentrates) and an optical absorbance detection module. When blood is applied to the biochips, red blood cells are trapped onto the surface if antigens and antibodies are complementary (positive chips). If they are not complementary, very little red blood cells are adsorbed (negative chips). Percentages of surface covered with red blood cells in negative biochips are 2% ± 2 (red cell concentrates) and 1% ± 1 (whole blood). This proves that the fluidic configuration leads to an optimum control of fluids flows with little retention of red blood cells in the circuitry. These percentages increase to 96% ± 3 and 82% ± 8 for red cell concentrates and whole blood respectively. This demonstrates a strong and specific immunocapture of red blood cells on positive chips. Furthermore, optical detection proves to be efficient at critical red blood cells concentrations (108 C/mL) and absorbance strongly correlates to the percentage of red blood cells captured by antibodies.

International audience; The goal of this work concerns a new method to substantially increase the sensitivity of a fluorescence pH sensor. The method is based on a double silanization method. Two methods are compared: one using APTMS (3-Aminopropyl)trimethoxysilane) only and another one using both APTMS and APDMS (3-Aminopropyl)dimethoxymethylsilane). Using the second method, sensor’s sensitivity is improved by more than 500 %.

International audience; We present a simple optical micro-system used to measure the transmission spectra of oocytes in order to qualify their maturation stage. Two applications of the device are possible: (i) the evaluation of the maturation stages of oocytes, and (ii) the development of a fertilization indicator. For the first application, CV, MI and MII oocytes were also analysed. Transmission spectra allow the 3 maturation stages to be identified but cannot be used to estimate the maturity of an unknown oocyte. Oocytes are subject to continuous development. This is why spectral separation of the 3 maturation stages cannot be made although they can be visually identified. However, the visual observation remains biologist-dependent. We therefore investigated the temporal maturation evolution of the oocytes in terms of transmission spectra and probability analysis. Results show that oocytes to be fertilized should not only be chosen in the MII stage, but also at the right time during the MII stage. This particular aspect requires further investigation. However, spectral measurements could be used as a technique for monitoring the maturation evolution of the oocytes. Fertilized oocytes exhibiting fertilization abnormalities were also tested. The device proved to be an efficient fertilization indicator.

International audience; We report Gold/Silica biochips for low cost biosensor devices. Firstly, the study of biochemical interactions on silica by means of Surface Plasmon Resonance (SPR) is presented. Secondly, Gold/Silica biochips are employed to reduce the strong quenching that occurs when a fluorophore is close to the gold surface. Furthermore, the control of the Silica-like thickness allows optimizing the distance between the metallic surface and the fluorophore in order to enhance the fluorescent signal. These results represent the first steps towards highly sensitive, specific and low cost biosensors based, for example, on Surface Plasmon Coupled Emission (SPCE) techniques.

International audience; In vitro Fertilisation (IVF) is one of the therapeutic techniques offered to patients suffering from reproduction difficulties. Among the various steps involved in gamete manipulation, especially in intra cytoplasmic sperm injection (ICSI), the determination of the cell to be fertilised is critical. Usually, the choice of the oocyte relies on a visual checking of the maturity of the cell and on its morphological properties. Our current work deals with the fabrication of labs-on-chip (LOC), devoted to the characterisation of the cells before fertilisation. They consist of a platform that includes different analysis tools and a system that allows the accurate displacement between the different analysis bays. The first issue that must be addressed is the capture, the transportation and the trapping of a single oocyte on the LOC surface.We recently proposed a system based on micro-translators used for long distance transportation and micro-fluidics for accurate trapping. In this paper, we demonstrate a full micro-fluidic system which allows both, the long range displacement and the accurate trapping of a single oocyte. This simplifies the LOC because there is no more need for any micro-motor or complex mechanical systems.We also demonstrate the first optical sensor that quantifies the degree of maturity of the cell to be fertilised. This sensor can also be used as a fertilisation indicator.

International audience; In blood transfusion, accidents still occur because of ABO mismatch between donor and patient’s blood. These errors, sometimes lethal, are principally due to wrong identification of patient and/or blood product or to human errors. The best way to avoid these errors is to perform an ultimate ABO compatibility test at the patient’s bedside immediately prior to transfusion. Ideally, this test should be performed automatically, without human interpretation and with minimum blood exposure for nurses. This ideal and ultimate method is not yet employed because of the lack of suitable device. In this paper, we propose a system that may fulfil the above mentioned requirements. It is based on selective blood capture on biochip surfaces in a device which automatically drives the different fluids, performs optical detection of captured red cells and finally interprets the optical reading in terms of ABO compatibility. So far, our device achieved blood compatibility test with 99.3 % sensitivity and 97.9 % specificity.

Compensation techniques for producing well defined corner in KOH-etched (1 0 0) silicon have widely been proposed. However, the case of apertures connected with V-grooves has apparently not yet been published. In this paper, we present a compensation technique used in order to produce well defined square apertures connected with V-grooves. A full description of the KOH etching process, simulation methods as well as experimental confirmations are presented here. The technique is very easy to use and is convenient for any size of apertures and V-grooves. The structure obtained with this technique are of interest in many micro-machining domains, especially in the field of micro-fluidics and micro-biology.

International audience; ince rubella vaccine was established, cytomegalovirus infection has become the most frequent cause of congenital infections. The French Health Authority is urging a diagnosis at birth for newborns. Since no screening device is commercially available, a consortium has been established to set-up an original device. The project has been funded by the French National Research Agency. The device consists of a disposable cartridge containing the biological sample and the reactive liquids required for immuno-fluorescencence detection on a functionalized surface. It also consists of a mobile reader used to drive the fluids onto the biosensor and to ensure the optical measurement. Positive and negative samples can be discriminated with a fluorescence intensity ratio of 3.

A Mach–Zehnder unbalanced LiNbO3 integrated modulator with independent control of the phase of each arm is incorporated into the reference arm of a low coherence interferometer set-up. Using different RF modulation frequency and processing electronics tuned to these frequencies, the system can be used for simultaneous interrogation of the signal reflected from two different depths in tissue or from two different axial positions in profilometry. When a pair of XY scanning mirrors are incorporated into the sensing arm, then two en-face images from different axial positions can be simultaneously produced. The depth separation between the axial positions of the points or layers interrogated is equal to half of the modulator path difference. The operation of the system is illustrated by displaying simultaneously two images from a coin.

In this paper, we present a new keying structure which enhances the secrecy of an already relatively secure coherence modulation method we developed recently. The originality of the method consists in using an encrypting key composed of a large amplitude – low frequency part and a low amplitude – high frequency part. These two components ensure that the spectrum, as well as the signal tapped by an eavesdropper, are efficiently corrupted. When the key is applied simultaneously to both the encoder and the decoder, the signal is correctly restored. Both theoretical aspects and experimental confirmations are presented in this paper.

International audience; This paper deals with mutual information-based registration of multimodal images for laser phonomicrosurgery of the vocal folds. The images to be registered are white light images (white light camera) versus fluorescence images. This work is carried out within the framework of the European project RALP which involves the use of microrobotic system for endoluminal laser phonosurgery. The designed system includes two fiber bundles connected to a high speed camera and one fiber bundle used for fluorescence image. Using the mutual information based registration method, it will be possible to represent the visible information in the fluorescence image and use it in the other image.

International audience; We report the formation of a 2D waveguide induced by a self-trapped vortex beam in a photorefractive-photovoltaic medium. Demonstrations are performed by monitoring the self-trapping dynamic of an annular vortex beam in a LiNbO(3):Fe crystal. Control of the experimental observations is consistent with the underlying physics revealed by a numerical model.

International audience; The work described here concerns the fabrication of cost-effective biosensors that permit to amplify a fluorescence signal without a complex nano-structuration of the surface. The idea is to put to profit the natural pseudo nano-structuring that is observed when depositing metallic layers by various micro-fabrication techniques. This new architecture consists of a glass substrate. A gold film is deposited on the top of it and a silica layer onto the gold. A dye (Cy5) is then absorbed onto the surface and the fluorescence intensity is measured. This intensity depends on the distance between the dye and the metal. It also depends on the properties of the metallic film. The goal of the work is to determine which gold deposition method leads to the highest fluorescence amplification and which silica thickness is required to achieve this amplification.

International audience; The early screening and diagnosis is one of the most critical steps in the curing of skin cancers and mainly melanomas. We present here a complete platform which deals from screening to therapy via diagnosis in a collaborative manner. The screening is made with a computing collaborative platform consisting of a photograph of the incriminated skin region, its sending to a server devoted to image processing as an aid to the dermatologist who will examine the photograph and the results given by image processing. If there is a doubt, the patient will be proposed to go at a dermatologist’s office for diagnosing the eventual cancer by using an optical probe developed in our laboratory. Then, in case of a cancer, the dermatologist will be able to cure the cancer by phototherapy by using the same optical probe.