René Farcy

Indoor Navigation System for the Visually Impaired Using One Inertial Measurement Unit (IMU) and Barometer to Guide in the Subway Stations and Commercial Centers

The main research about indoor navigation is about the use of Wi-Fi, Bluetooth or Ultra Wide band technology for locating one person in a building. These systems give an absolute position of the person; however, it is mandatory to put the hotspots of every technology in the building for calculating this position. An Inertial Measurement Unit is usually placed on the foot because, it is easier to compute the distance. The aim of this work is to use inexpensive sensors which come in a Smart Phone, which are handheld, or belt mounted for guiding one visually impaired in two main tests: the subway station and the commercial center. We are not intending neither to put any hotspot or landmarks on the place nor to use the IMU on the foot for ergonomic reasons. The results and performances are better in the subway stations than in the commercial centers.

Towards an optical biopsy for the diagnosis of breast cancer in vivo by endogenous fluorescence spectroscopy

The techniques of medical imaging allow the detection of suspect lesions in the breast, but they do not always evidence the malignant nature of these lesions. Breast biopsies and histological analyses are therefore implemented to establish a diagnosis. In order to reduce the number of these invasive procedures, a portable clinical system was designed based upon the excitation of Endogenous Fluorescence in vivo at 405 nm via a fiber-optics probe included in a disposable needle of small diameter (<1 mm). From the fluorescence signal, the authors are able to discriminate between diseased and healthy areas of human breast biopsies. Stronger fluorescence intensity and systematic spectral red shift of the tumor areas were observed. These results are confirmed by confocal microscopy. This new instrument is promising for the minimally invasive diagnosis of breast tumors in vivo with an appreciable limitation of patient trauma and of operational and financial cost.

Aides électroniques pour le déplacement des personnes non-voyantes: vue d'ensemble et perspectives

In this paper, we present an overview of current electronic locomotion aids for the blind and perspectives for future systems. We start with the two main issues raised by locomotion assistance for the blind : how to capture and present information. Then, we explain how these issues have been dealt with in existing devices, and we describe the techniques that have been used to solve them : infrared, ultrasonic and laser sensors to capture information; tactile and audio modalities to present information. After that, we expose some current ideas and results about a new generation of context-aware, semantics-enhanced locomotion assistance devices, that are expected to provide higher-level information than current ones do.

Tactile interface to steer electric wheelchairs

In the framework of improving assistive technologies for people with disabilities, this project aims to design, develop and evaluate a tactile interface to control an electric wheelchair. It targets users who have a difficulty using a joystick, the most common control device for electric wheelchairs. We propose a new steering system with a tactile tablet or smartphone (Android). We have developed a prototype that we tested with a group of disabled users. The results were encouraging. The feedback we collected then lead to developing a second prototype which will soon be in the testing phase.

Tactile Interface for Electric Wheelchair

In the framework of an augmented multimodal electric wheelchair for people with multiple disabilities, we propose a new user interface based on an Android application on a tablet to steer the wheelchair. The proposed system aims at overcoming some of the problems encountered with the traditional joystick interface like the involuntary arm extensions due to spasticity conditions. These often lead to unwanted movement of the chair and, in many cases, to accidents. The application uses different output modalities to allow the user keep his/her attention on the navigation task without having to visually focus on the tablet screen. We conducted some preliminary tests with some people with disabilities to engage them in the design process and get their feedback on the first prototype. The general impression was positive with insight on future improvements to the system.

Indoor navigation with smart phone IMU for the visually impaired in university buildings

Purpose The purpose of this paper is to design and test effective indoor navigation solutions for visually impaired people in situations where GPS, bluetooth or Wi-Fi signals are unavailable. The authors use the inertial measurement units (IMU), the compass and the barometer of a smart phone. Design/methodology/approach The authors have used commercial Android smart phones with IMU, compass and barometer to record a path and to give navigation instructions in an adapted way using a mobility-specific vocabulary. The method proposed is to save paths taking into account different indoor waypoints such as the stairs (change from one floor to another) and the change of direction of the trajectory of the path (e.g. one-fourth turn right or left), recording data from the IMU sensor’s, compass and barometer of the smart phone. Having this information and the characteristics of the each segment (distance, azimuth to the north and pressure) of the path, it is possible to provide functional navigation guidance to the visually impaired subject. Three different visually impaired people (one partially sighted and two fully blind) and three sighted people have tested the paths. The efficiency of the navigation is analyzed in terms of distance and time using the comparison between blind and sighted people. Findings The main finding is that it is possible to guide visually impaired people some hundreds of meters just using the sensors of a smart phone under certain conditions: the visually impaired person has to understand the guidance instructions and respect some strategies (e.g. not to walk diagonally across vast spaces). Additionally it is observed that the visually impaired participants walked distances, which are not much different to the optimal values. On the other hand; because of their hesitations using their white cane to find free paths, they take in some cases 50 percent more time to arrive (for a few minutes path, this time is not critical and even more efficient than looking for a guide). One thing to highlight is that even with this hesitation, the subjects arrived to the final destination. Originality/value This paper demonstrates how an IMU coupled to a compass and a barometer from a Smart Phone employing a spoken mobility language (e.g. next corridor to the left; at the end of the stairs turn right, turn left, etc.) can guide visually impaired people inside buildings.

Pulmonary Endogenous Fluorescence Allows the Distinction of Primary Lung Cancer from the Perilesional Lung Parenchyma.

Background Pre-therapeutic pathological diagnosis is a crucial step of the management of pulmonary nodules suspected of being non small cell lung cancer (NSCLC), especially in the frame of currently implemented lung cancer screening programs in high-risk patients. Based on a human ex vivo model, we hypothesized that an embedded device measuring endogenous fluorescence would be able to distinguish pulmonary malignant lesions from the perilesional lung tissue. Methods Consecutive patients who underwent surgical resection of pulmonary lesions were included in this prospective and observational study over an 8-month period. Measurements were performed back table on surgical specimens in the operative room, both on suspicious lesions and the perilesional healthy parenchyma. Endogenous fluorescence signal was characterized according to three criteria: maximal intensity (Imax), wavelength, and shape of the signal (missing, stable, instable, photobleaching). Results Ninety-six patients with 111 suspicious lesions were included. Final pathological diagnoses were: primary lung cancers (n = 60), lung metastases of extra-thoracic malignancies (n = 27) and non-tumoral lesions (n = 24). Mean Imax was significantly higher in NSCLC targeted lesions when compared to the perilesional lung parenchyma (p<0,0001) or non-tumoral lesions (p<0,0001). Similarly, photobleaching was more frequently found in NSCLC than in perilesional lung (p<0,0001), or in non-tumoral lesions (p<0,001). Respective associated wavelengths were not statistically different between perilesional lung and either primary lung cancers or non-tumoral lesions. Considering lung metastases, both mean Imax and wavelength of the targeted lesions were not different from those of the perilesional lung tissue. In contrast, photobleaching was significantly more frequently observed in the targeted lesions than in the perilesional lung (p≤0,01). Conclusion Our results demonstrate that endogenous fluorescence applied to the diagnosis of lung nodules allows distinguishing NSCLC from the surrounding healthy parenchyma and from non-tumoral lesions. Inconclusive results were found for lung metastases due to the heterogeneity of this population.

GPS and IMU (inertial measurement unit) as a navigation system for the visually impaired in cities

Purpose – The aim of this work is to improve navigation solutions for the visually impaired, specifically problems with the heading given by the current GPS antennas. This heading is not reliable when the speed of the pedestrian or of the car is less than 10 km/h. The solution proposed is the use of one inertial measurement unit (IMU) coupled to a GPS, giving the navigation information in the way of heading and distance to the final destination.Design/methodology/approach – The authors have developed their system using their IMU (compass, gyroscope and accelerometer) developed in the laboratory. They have also developed the user interface in one Smart Phone in the Android operating system coupled to the IMU using the Bluetooth transmission. Furthermore, the authors have tested their system in bad GPS reception conditions in Paris. They also used two other GPS systems (Navigon and Ariadne GPS) for testing the best way of giving the information: either “car navigation information: turn left or right at 100 ...

Tactile Interface to Steer Power Wheelchairs: A Preliminary Evaluation with Wheelchair Users

Power Wheelchairs can be a necessity for many people to have a certain level of mobility. Unfortunately, some of them may not be able to use one because they cannot safely manipulate a joystick. In a previous study, we proposed a tactile interface to steer power wheelchairs and started a first round of experimentation with able-bodied users. In this paper, we present recent tests of our steering interface in both formal and informal settings with some users with mobility impairment from different profiles. In the formal tests, two wheelchair users performed three different common tasks: straight line following, 90° corner and doorway passing with both our tactile steering interface and a joystick. The steering performance of the tactile interface was close or similar to that of the joystick. We also outline lessons that we learned from these tests for future improvements.

25 gauge fibered-needle for label-free fluorescence analysis of breast masses: a first in vivo study

Breast lesions diagnosis and characterization need additional cost-effective techniques to avoid unnecessary invasive procedures, such as core needle biopsies, in the case of benign tumors. Endogenous fluorescence is an effective method to highlight in situ metabolic and/or structural changes between cancerous and non-cancerous lesions. In this context, we developed an original set-up, consisting of a 405 nm laser diode transmitting light through a 25 Gauge (0.45 mm x 50mm) 14° sharp fibered needle to excite intranodular fluorophores around the needle tip and providing real-time labelfree fluorescence spectral analysis of lesions from 450 nm to 650 nm. The objective was to help radiologists to classify suspicious masses in vivo and in real-time within the lesion. We reported the results of spectral differences between 14 invasive lobular carcinomas and 6 intraductal papilloma enrolled in a clinical study.