Olfactory Display Research Articles

A Review of Olfactory Display Designs for Virtual Reality Environments

The field of Virtual Reality continues to evolve to provide an ever-greater sense of immersion to the user. However, VR experiences are still primarily constrained through the human senses of vision and audition, with some interest in haptic (mainly vibrotactile) applications. Only recently have olfactory displays—technologies that generate and deliver scent stimuli—been examined to provide the sense of smell to the human olfactory organ in virtual environments. This article presents a classification and review of olfactory-enhanced virtual reality systems, particularly those that deployed a Head-mounted Display or Cave Automatic Virtual Environment system. In addition, the article provides a discussion of the various technological and design challenges for developing an olfactory display suitable for enhancing virtual reality experiences. Finally, the article proposes future perspectives on the field and includes a table summarizing the characteristics and features of the reviewed systems.

Optimization of Odor Blending for 20-component Olfactory Display

Optimization of Odor Blending for 20-component Olfactory Display

An Open-Source Olfactory Display to Add the Sense of Smell to the Metaverse

Abstract As the Metaverse gains popularity due to its use in various industries, so does the desire to take advantage of all its potential. While visual and audio technologies already provide access to the Metaverse, there is increasing interest in haptic and olfactory technologies, which are less developed and have been studied for a shorter time. Currently, there are limited options for users to experience the olfactory aspect of the Metaverse. This paper introduces an open-source kit that makes it simple to add the sense of smell to the Metaverse. The solution is modular, allowing for the simultaneous use of multiple odors and compatibility with both desktop and wearable applications. The details of the solution, including its technical specifications, are outlined to enable potential users to utilize, test, and enhance the project and make it available to the scientific community.

The Development of a Simple Projection-Based, Portable Olfactory Display Device.

Olfactory displays are digital devices designed to provide the controlled release of odours to users. In this paper, we report on the design and development of a simple vortex-based olfactory display for a single user. By employing a vortex approach, we are able to minimize the amount of required odour, whilst still producing a good user experience. The olfactory display designed here is based on a steel tube with 3D-printed apertures and solenoid valve operation. A number of different design parameters (such as aperture size) were investigated, and the best combination was combined into a functional olfactory display. User testing was undertaken with four volunteers who were presented with four different odours, at two concentrations. It was found that the time to identify an odour was not strongly related to concentration. However, the intensity of the odour was correlated. We also found that there was a wide variance in human panel results when considering the length of time for a subject to identify an odour to its perceived intensity. This is likely linked to the subject group receiving no odour training before the experiments. However, we were able to produce a working olfactory display, based on a scent project method, which could be applicable to a range of application scenarios.

An experimental paradigm for studying EEG correlates of olfactory discrimination.

Electroencephalography (EEG) correlates of olfaction are of fundamental and practical interest for many reasons. In the field of neural technologies, olfactory-based brain-computer interfaces (BCIs) represent an approach that could be useful for neurorehabilitation of anosmia, dysosmia and hyposmia. While the idea of a BCI that decodes neural responses to different odors and/or enables odor-based neurofeedback is appealing, the results of previous EEG investigations into the olfactory domain are rather inconsistent, particularly when non-primary processing of olfactory signals is concerned. Here we developed an experimental paradigm where EEG recordings are conducted while a participant executes an olfaction-based instructed-delay task. We utilized an olfactory display and a sensor of respiration to deliver odors in a strictly controlled fashion. We showed that with this approach spatial and spectral EEG properties could be analyzed to assess neural processing of olfactory stimuli and their conversion into a motor response. We conclude that EEG recordings are suitable for detecting active processing of odors. As such they could be integrated in a BCI that strives to rehabilitate olfactory disabilities or uses odors for hedonistic purposes.

A graspable olfactory display for virtual reality

The sense of smell, olfaction, is seldom engaged in digital interactive systems, but, supported by the proper technology, olfaction might open up new interaction domains. Human olfactory experience involves active exploration, directed sniffing and nuanced judgements about odour identity, concentrations, and blends, yet to date most compact olfactory displays do not directly support these experiences. We describe the development and validation of a compact, low-cost olfactory display fitted to the hand controller of the HTC Vive Virtual Reality (VR) system that employs stepless valves to enable control of scent magnitude and blending (Fig. 1). Our olfactory display allows for concealed (i.e., unknown to the user) combinations of odours with virtual objects and contexts, making it well suited to applications involving interactions with odorous objects in virtual space for recreational, educational, scientific, or therapeutic functions. Through a user study and gas sensor analysis, we have been able to demonstrate that our device presents clear and consistent scent output, is intuitive from a user perspective, and supports gameplay interactions. We present results from a smell training game in a virtual wine tasting cellar in which the initial task of identifying wine aroma components is followed by evaluating more complex blends, allowing the player to “level up” as they proceed to higher degrees of connoisseurship. Novice users were able to quickly adapt to the display, and we found that the device affords sniffing and other gestures that add verisimilitude to olfactory experience in virtual environments. Test-retest reliability was high when participants performed the task two times with the same odours. In sum, the results suggest our olfactory display may facilitate use in game settings and other olfactory interactions.

A study of odor reproduction using multi‐component olfactory display

AbstractA sensory test experiment (triangle difference test) was conducted using the 20‐component olfactory display to confirm odor reproduction based on odor components. The essential oils used were lemon, palmarosa, carrot seed, elemi, lavender, cypress and mentha arvensis. Each one was selected from seven essential oil categories. The sensory test reveals that it was difficult to distinguish between the reproduced odor and the target one. Thus, the odor reproduction by olfactory display based on odor components was generally possible. Furthermore, we found that the participants used its features or intensities as clues to distinguish between the blended odor and the target one from a survey of the free comments on the questionnaire sheets.

Prototyping of an Olfactory Display supported by CFD Simulations

Computer-Aided Design and Applications is an international journal on the applications of CAD and CAM. It publishes papers in the general domain of CAD plus in emerging fields like bio-CAD, nano-CAD, soft-CAD, garment-CAD, PLM, PDM, CAD data mining, CAD and the internet, CAD education, genetic algorithms and CAD engines. The journal is aimed at all developers and users of CAD technology to ptovide CAD solutions for various stages of design and manufacturing. The journal publishes all about Computer-Aided Design and Computer-Aided technologies.

An olfactory display for virtual reality glasses.

Olfaction has not been explored in virtual reality environments to the same extent as the visual and auditory senses. Much less research has been done with olfactory devices, and very few of them can be easily integrated into virtual reality applications. The inclusion of odor into virtual reality simulations using a chemical device involves challenges such as possible diffusion into undesired areas, slow dissipation, the definition of various parameters (e.g., concentration, frequency, and duration), and an appropriate software solution for controlling the diffusion of the odor. This paper aims to present a non-intrusive, mobile, low cost and wearable olfactory display, and a software service that allows the developer to easily create applications that include olfactory stimuli integrated with virtual reality headset glasses. We also present a case study conducted with 32 people to evaluate their satisfaction when using the olfactory display. Our findings indicate that our solution works as expected, producing odor properly and being easy to integrate to applications.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00530-022-00908-8.

An Overview of Olfactory Displays in Education and Training

This paper describes an overview of olfactory displays (human–computer interfaces that generate and diffuse an odor to a user to stimulate their sense of smell) that have been proposed and researched for supporting education and training. Past research has shown that olfaction (the sense of smell) can support memorization of information, stimulate information recall, and help immerse learners and trainees into educational virtual environments, as well as complement and/or supplement other human sensory channels for learning. This paper begins with an introduction to olfaction and olfactory displays, and a review of techniques for storing, generating and diffusing odors at the computer interface. The paper proceeds with a discussion on educational theories that support olfactory displays for education and training, and a literature review on olfactory displays that support learning and training. Finally, the paper summarizes the advantages and challenges regarding the development and application of olfactory displays for education and training.

A Method for Computerized Olfactory Assessment and Training Outside of Laboratory or Clinical Settings.

There are currently few ways to reliably and objectively assess olfaction outside of the research laboratory or clinic. The COVID-19 pandemic has highlighted the need for remote olfactory assessment; in particular, smell training at home is a promising method for olfactory rehabilitation, but further methodological advances might enhance its effectiveness and range of use. Here, we present Exerscent, a portable, low-cost olfactory display designed primarily for uses outside of the laboratory and that can be operated with a personal computer. Exerscent includes Radio Frequency Identification (RFID) tags that are attached to odor stimuli and read with a MFRC522 module RFID reader/antenna that encodes the odor in order to provide adaptive challenges for the user (e.g., an odor identification task). Hardware parts are commercially available or 3D printed. Instructions and code for building the Exerscent are freely available online (https://osf.io/kwftm/). As a proof of concept, we present a case study in which a participant trained daily to identify 54 odors, improving from 81% to 96% accuracy over 16 consecutive days. In addition, results from a laboratory experiment with 11 volunteers indicated a very high level of perceived usability and engagement. Exerscent may be used for olfactory skills development (e.g., perfumery, enology), and rehabilitation purposes (e.g., postviral olfactory loss), but it also allows for other forms of technological interactions such as olfactory-based recreational interactions.

From Scent Projection to Respiratory Protection: Designing Digital Olfactory Interactions for Fashion Wearables

ABSTRACT In recent times, environmental and psychological threats revive protective dress forms, specifically the mask. Threats such as the COVID-19 pandemic, and technological infrastructures of surveillance capitalism, materially shape social realities. This paper explores current doctoral research, the AURA case study, which accounts for the cultural, contextual undercurrents and hidden operations of these threats, and how they refashion wearables practice. AURA is a series of Internet of Things (IoT) connected, olfactory wearables that render sensor-captured data into digital scent display. The author argues that bodies, as the subject of and venue for data extraction, are invested in, and fashioned by, bio-political power structures of systemic surveillance. A critical approach examines how bodies are materially re-crafted by physiological and psychological hazards—proposing an expanded understanding of technology as a bodily matter of the social practice of dress. The focus is to lend the notion of bodily matters as an analytical filter for reading important insights from fashion, and Human-Computer Interaction (HCI) studies through one another while proposing a subversive reworking of olfactory interfaces for wearables. This research employs critical fashion practice to embed wireless communication technologies and digital olfactory data visualisation for a spectrum of purposes, from wearable scent displays to protective forms that shield the body from airborne contaminants. Thoughtful dialogue in temporary public forums and workshops gathers specific issues of automated olfactory display where capitalised technology applications and a global pandemic converge. Community-defined perceived harms and external threats warrant personal protection. The olfactory sense is a way to access emotion-based, ecological and ethical connections across spatial and temporal scales in speculative wearables design. This paper outlines changing roles and practices for multi-sensory wearables innovation, working to suggest new modes beyond current technology development paradigms, for empowered and meaningful interactions in networked data infrastructures.

Clustered Digital Air Cannon: A Novel Device for Projection-based Olfactory Display

Clustered Digital Air Cannon: A Novel Device for Projection-based Olfactory Display

ReminiScentia: shaping olfactory interaction in a personal space for multisensory stimulation therapy

Recently, multimodal interfaces are incorporating smell as an additional means of interaction. Devices called olfactory displays have been designed to improve applications with various objectives, such as notifying or alerting through scents, increasing immersion in virtual or augmented reality applications, or learning and enhancement of mental functions. Based on the potential of olfactory memory to evoke memories and emotions to benefit health and well-being, we propose ReminiScentia as an olfactory display to generate and deliver scents. This work presents an evaluation of the effectiveness of ReminiScentia in evoking brain responses similar to those generated by manually delivered scents. To achieve this, we monitored the hemodynamic responses during manual and ReminiScentia olfactory stimulation over the prefrontal cortex (PFC) by using a functional near-infrared spectroscopy (fNIRS) device in 33 healthy subjects. Among the results, it was found that when ReminiScentia was used to deliver the olfactory stimuli, there is no statistically significant difference in the magnitude of concentration changes of OxyHb in the PFC between manual deliver and ReminiScentia (Wilcoxon: p > 0.05). The effectiveness of the use of ReminiScentia has allowed us not only its application for the evocation of memories in a multisensory therapy but also to propose an olfactory interaction design space where olfactory stimuli are used to provide feedback or instructions in multisensory stimulation activities that could support the training of higher mental functions such as memory and learning in patients with cognitive disabilities.

Evaluation of Temporal Characteristics of Olfactory Displays with Different Structures

Evaluation of Temporal Characteristics of Olfactory Displays with Different Structures

Towards Smart Gaming Olfactory Displays.

Olfaction can enhance the experience of music, films, computer games and virtual reality applications. However, this area is less explored than other areas such as computer graphics and audio. Most advanced olfactory displays are designed for a specific experiment, they are hard to modify and extend, expensive, and/or can deliver a very limited number of scents. Additionally, current-generation olfactory displays make no decisions on if and when a scent should be released. This paper proposes a low-cost, easy to build, powerful smart olfactory display, that can release up to 24 different aromas and allow control of the quantity of the released aroma. The display is capable of absorbing back the aroma, in an attempt to clean the air prior to releasing a new aroma. Additionally, the display includes a smart algorithm that will decide when to release certain aromas. The device controller application includes releasing scents based on a timer, text in English subtitles, or input from external software applications. This allows certain applications (such as games) to decide when to release a scent, making it ideal for gaming. The device also supports native connectivity with games developed using a game development asset, developed as part of this project. The project was evaluated by 15 subjects and it was proved to have high accuracy when the scents were released with 1.5 minutes’ delay from each other.

On the Tutorials, Sniffest Competition, and Special Session on Olfactory Displays in ISOEN 2019

On the Tutorials, Sniffest Competition, and Special Session on Olfactory Displays in ISOEN 2019

Development of a Thermal-Based Olfactory Display for Aroma Sensory Training

The digital replication of smell – so-called olfactory displays, remains one of the least advanced sensory technologies. Recent developments have focused heavily on virtual reality. However, there remains a need for olfactory displays targeted towards aroma training. In this paper, we present a thermal-based olfactory display, using Peltier heating elements. The unit is fully computer-controlled and holds up to 12 ‘aroma capsules’. Each capsule contains an individual aroma that can either be activated on its own or with others to create richer experiences. The unit has been designed as part of a wine aroma game to promote sensory training. The portable device has been tested with 15 volunteers to test the detection and recognition times of 6 aromas associated with red or white wines.

Subjective and Objective Evalution of Emotions Cased by Olfactory Display

Subjective and Objective Evalution of Emotions Cased by Olfactory Display

Olfactory Display and its Application

Olfactory Display and its Application