Purpose– The purpose of this paper is to describe conceptions of feasibility of a haptic navigation system for persons with a visual impairment (VI). Design/methodology/approach– Six persons with a VI who were white cane users were tasked with traversing a predetermined route in a corridor environment using the haptic navigation system. To see whether white cane experience translated to using the system, the participants received no prior training. The procedures were video-recorded, and the participants were interviewed about their conceptions of using the system. The interviews were analyzed using content analysis, where inductively generated codes that emerged from the data were clustered together and formulated into categories. Findings– The participants quickly figured out how to use the system, and soon adopted their own usage technique. Despite this, locating objects was difficult. The interviews highlighted the desire to be able to feel at a distance, with several scenarios presented to illustrate current problems. The participants noted that their previous white cane experience helped, but that it nevertheless would take a lot of practice to master using this system. The potential for the device to increase security in unfamiliar environments was mentioned. Practical problems with the prototype were also discussed, notably the lack of auditory feedback. Originality/value– One novel aspect of this field trial is the way it was carried out. Prior training was intentionally not provided, which means that the findings reflect immediate user experiences. The findings confirm the value of being able to perceive things beyond the range of the white cane; at the same time, the participants expressed concerns about that ability. Another key feature is that the prototype should be seen as a navigation aid rather than an obstacle avoidance device, despite the interaction similarities with the white cane. As such, the intent is not to replace the white cane as a primary means of detecting obstacles.

Purpose: The purpose of the presented field trial was to describe conceptions of feasibility of a haptic navigation system for persons with a visual impairment.Design/methodology/approach: Six persons with a visual impairment who were white cane users were tasked with traversing a predetermined route in a corridor environment using the haptic navigation system. To see whether white cane experience translated to using the system, the participants received no prior training. The procedures were video-recorded, and the participants were interviewed about their conceptions of using the system. The interviews were analyzed using content analysis, where inductively generated codes that emerged from the data were clustered together and formulated into categories.Findings: The participants quickly figured out how to use the system, and soon adopted their own usage technique. Despite this, locating objects was difficult. The interviews highlighted the desire to be able to feel at a distance, with several scenarios presented to illustrate current problems. The participants noted that their previous white cane experience helped, but that it nevertheless would take a lot of practice to master using this system. The potential for the device to increase security in unfamiliar environments was mentioned. Practical problems with the prototype were also discussed, notably the lack of auditory feedback. Originality/value: One novel aspect of this field trial is the way it was carried out. Prior training was intentionally not provided, which means that the findings reflect immediate user experiences. The findings confirm the value of being able to perceive things beyond the range of the white cane; at the same time, the participants expressed concerns about that ability. Another key feature is that the prototype should be seen as a navigation aid rather than an obstacle avoidance device, despite the interaction similarities with the white cane. As such, the intent is not to replace the white cane as a primary means of detecting obstacles.

Purpose: The purpose of this article is to present some guidelines on how different means of information presentation can be used when conveying spatial information non-visually. The aim is to further the understanding of the qualities navigation aids for visually impaired individuals should possess.Design/methodology/approach: A background in non-visual spatial perception is provided, and existing commercial and non-commercial navigation aids are examined from a user interaction perspective, based on how individuals with a visual impairment perceive and understand space.Findings: The discussions on non-visual spatial perception and navigation aids lead to some user interaction design suggestions. Originality/value: This paper examines navigation aids from the perspective of non-visual spatial perception. The presented design suggestions can serve as basic guidelines for the design of such solutions.

The white cane is used by many visually impaired individuals as the primary aid for avoiding obstacles. In this it is unparalleled, but it cannot provide a large-scale view of the surroundings the way vision does. This makes navigating independently a challenge for the visually impaired. We are developing the Virtual White Cane (VWC), a device that uses sensors and haptic technologies to complement the limited view of the cane. Sensors makes it possible to probe obstacles far beyond the range of the white cane, and haptic feedback is familiar to users of the regular cane. The purpose of this device is to act as a complement to the standard cane, providing information about the surroundings that are beyond the cane's reach. This kind of extended view not only helps in anticipating obstacles, but also to navigate. The presentation will focus on the hardware of the currently developed prototype, in addition to some initial user experiences.

In its current form, the white cane has been used by visually impaired people for almost a century. It is one of the most basic yet useful navigation aids, mainly because of its simplicity and intuitive usage. For people who have a motion impairment in addition to a visual one, requiring a wheelchair or a walker, the white cane is impractical, leading to human assistance being a necessity. This paper presents the prototype of a virtual white cane using a laser rangefinder to scan the environment and a haptic interface to present this information to the user. Using the virtual white cane, the user is able to "poke" at obstacles several meters ahead and without physical contact with the obstacle. By using a haptic interface, the interaction is very similar to how a regular white cane is used. This paper also presents the results from an initial field trial conducted with six people with a visual impairment.

The analogue time expansion technique, where the time interval to be measured is stretched by a factor k, can be realized with current integration. This kind of time stretcher can be used as a time domain amplifier to improve the precision of the time to digital conversion. Two specific circuit techniques have been investigated for the realization of a time stretcher in a CMOS technology. A comparison has been made between a Miller and an open-loop integrator based time stretcher with respect to the available linearity, power consumption and circuit area. The simulations show that the open loop approach with carefully optimized circuit configurations may lead to a compact and low power single photon avalanche diode pixel configuration with the required time amplification property. The application field for the studied techniques in this work is the on-pixel-based time interval measurement unit in 3D time-of-flight cameras based on a 2D single photon avalanche diode array.

Vi planerar att utveckla ett enradschip i CMOS och därefter bygga en TOF-kamera baserad på detta chip.

Projektet syftar till att göra det möjligt för personer med funktionsnedsättning, som inte själva har full förmåga att styra en rullstol, att ändå nyttja den. Sensorer på rullstolen upptäcker automatiskt hinder i omgivningen och ger därmed den rörelsehindrade hjälp med styrningen.En virtuell blindkäpp som består av en haptisk robotarm kopplad till en laser som mäter avstånd till föremål i omgivningen har även tagits fram. Utifrån informationen skapas en 3D-bild som brukaren av den virtuella blindkäppen kan känna på med robotarmen.Fortsatt forskning kommer att fokusera på den virtuella vita käppen som kommer att ha en mycket längre räckvidd än en vanlig vit käpp. Vi avser att göra den handhållen så att rullstolen inte behövs som bärare av laserskanner och haptisk robot. En mycket viktig del i vår forskning är att åstadkomma en bra användarupplevelse. Synskadade, som har stor erfarenhet av den vanlig vita käppen, skall snabbt lära sig att använda den virtuella vita käppen.

In its current form, the white cane has been used by visually impaired people for almost a hundred years. It is an intuitive device that helps visually impaired people navigate independently. For people who, in addition to a visual impairment, also have impaired movement, this independence is not as certain. If a wheelchair or a walker is needed, human assistance might be a necessity.MICA (Mobile Internet Connected Assistant) is a computerized wheelchair that has been equipped with a laser rangefinder that can measure the distance to obstacles in the environment. This information has been used to make the wheelhair able to drive on its own, avoiding obstacles, so that users unable to drive a wheelchair themselves are able to use it.The latest addition to MICA - a virtual white cane - allows visually impaired wheelchair users to virtually touch obstacles in their environment, and thus navigate in a similar way to those using a regular white cane. This is accomplished by generating a simplified 3D model based on the data acquired from the laser rangefinder, and sending this data to a haptic device, allowing users to feel the 3D model.The virtual white cane is still in an early development stage. The first test drive of MICA with the virtual white cane (together known as "The Sighted Wheelchair") was performed on 2011-05-10. A short video called "The Sighted Wheelchair" can be found on YouTube.Future work will focus on developing the software that communicates with the laser rangefinder and the haptic device to improve the user experience. Efforts will also be made to overcome the limitations of the laser rangefinder, improving the 3D model.

Den vita käppen har använts av synskadade i snart hundra år. Den är ett intuitivt hjälpmedel med vars hjälp en synskadad person självständigt kan ta sig fram. För rörelsehindrade personer som också är synskadade är denna självständighet inte lika självklar. Om en rullstol eller rollator behövs blir käppen opraktisk, vilket innebär att mänsklig assistans kan bli nödvändig.MICA (Mobile Internet Connected Assistant) är en datoriserad rullstol som utrustats med en laserskanner som, i laserns svep-plan, mäter avstånd till hinder i omgivningen. Denna information har använts för att bland annat få rullstolen att på egen hand ta sig runt hinder, med avsikten att användare som inte har full förmåga att styra en rullstol ändå skall kunna använda den.Med det senaste tillskottet till MICA – en virtuell vit käpp – är tanken att synskadade personer med begränsad rörelseförmåga skall kunna känna sig fram i sin omgivning och därmed navigera självständigt. Detta åstadkoms genom att laserns mätningar av omgivningen genererar en förenklad 3D-modell av omgivningen. Denna modell skickas sedan till en haptisk robot som gör det möjligt för brukaren att känna på det lasern mäter upp, och på så vis upptäcka hinder på samma sätt som med en vanlig käpp.Utvecklingen av den virtuella vita käppen är ännu i sitt inledningsskede. Första offentliga demonstrationen av MICA utrustad med den virtuella käppen, även kallad ”Den seende rullstolen”, skedde 2011-05-10. En kort film om ”The sighted wheelchair” finns nu YouTube. Fortsatt arbete kommer bestå i att vidareutveckla mjukvaran som kommunicerar med lasern och roboten för att få en bättre användarupplevelse, samt att kringgå laserns begränsning att bara mäta i ett plan så att en mer realistisk modell av omgivningen kan byggas upp.