Research

This NewScientistTech article reports US researchers claim a liquid that changes colour when exposed to a magnetic field could cheaply replace the colour components in conventional LCD monitors. From the article: "The liquid contains tiny iron oxide particles coated with plastic. It is cheap and easy to make, and could also be used in flexible, rewritable, electronic paper, the researchers say.

Yadong Yin and colleagues at the Department of Chemistry at University of California, Riverside, US, created the liquid by coating particles of iron oxide – each about 100 nanometres in diameter – with a polymer and suspending the mixture in water.

The plastic coating means that each particle has a highly charged surface.

"Concurrent Recording and Regeneration of Visual and Olfactory Information Using Odor Sensor"
Takao Yamanaka, Nitikarn Nimsuk, Takamichi Nakamoto
Presence: Teleoperators & Virtual Environments, June 2007, Vol. 16, No. 3, Pages 307-317.

In this paper, a method of concurrent recording and regeneration of visual and olfactory information is presented using electronic nose technology. To accomplish this objective, the sensor response patterns of odors in the atmosphere were measured using QCM (quartz crystal microbalance) odor sensors with partially overlapping specificities. Then the odors were identified from the response patterns using LVQ (learning vector quantization), a pattern classification algorithm of neural networks with supervised learning. Visual information, presented as a movie, was captured using a digital video camera; concurrently, odors using odor sensor responses were paired to the video. The recorded visual and olfactory information was evaluated by sensory tests to investigate the effectiveness of the proposed system. As a result, it was found that the olfactory information recorded using the proposed method was appropriate for odor regeneration associated with the movie.

"Multi-Fingered Grasping and Manipulation in Virtual Environments Using an Isometric Finger Device"
Gregorij Kurillo, Matjaž Mihelj, Marko Munih, Tadej Bajd
Presence: Teleoperators & Virtual Environments, June 2007, Vol. 16, No. 3, Pages 293-306.

In this article we present a new isometric input device for multi-fingered grasping in virtual environments. The device was designed to simultaneously assess forces applied by the thumb, index, and middle finger. A mathematical model of grasping, adopted from the analysis of multi-fingered robot hands, was applied to achieve multi-fingered interaction with virtual objects. We used the concept of visual haptic feedback where the user was presented with visual cues to acquire haptic information from the virtual environment. The virtual object corresponded dynamically to the forces and torques applied by the three fingers. The application of the isometric finger device for multi-fingered interaction is demonstrated in four tasks aimed at the rehabilitation of hand function in stroke patients. The tasks include opening the combination lock on a safe, filling and pouring water from a glass, muscle strength training with an elastic torus, and a force tracking task. The training tasks were designed to train patients' grip force coordination and increase muscle strength through repetitive exercises. The presented virtual reality system was evaluated in a group of healthy subjects and two post-stroke patients (early post-stroke and chronic) to obtain overall performance results. The healthy subjects demonstrated consistent performance with the finger device after the first few trials. The two post-stroke patients completed all four tasks, however, with much lower performance scores as compared to healthy subjects. The results of the preliminary assessment suggest that the patients could further improve their performance through virtual reality training.

Take a look at the MIT Dual Reality Media Lab. Researchers are using their Plug sensor/actuator network to link their actual lab space to a virtual lab space in the Second Life online virtual world. From the project website: ""Dual reality" is the concept of maintaining two worlds, one virtual and one real, that reflect, influence, and merge into each other by means of deeply embedded sensor/actuator networks. Both the real and virtual components of a dual reality are complete unto themselves, but are enriched by their mutual interaction. The dual reality Media Lab is an example of such a dual reality, as enabled the Plug sensor/actuator network that links our actual lab space to a virtual lab space in the Second Life online virtual world.

"MACVE: A Mobile Agent Based Framework for Large-Scale Collaborative Virtual Environments"
Liang Zhang, Qingping Lin
Presence: Teleoperators & Virtual Environments, June 2007, Vol. 16, No. 3, Pages 279-292.

The Collaborative Virtual Environment (CVE) is a promising technology which provides an online shared virtual world for geographically dispersed people to interact with each other. However, the scalability of existing CVE systems is limited due to the constraints in processing power and network speed of each participating host. In this paper, a mobile agent based framework for large-scale CVE, MACVE, is proposed to support a large number of concurrent participants in a CVE with a large amount of evolving virtual entities. In MACVE, the CVE system is decomposed into a group of collaborative mobile agents, each of which is responsible for an independent system task. These agents can migrate or clone dynamically at any suitable participating host including traditional servers and qualified user hosts to avoid the potential bottleneck, which can improve the scalability of CVE. Our prototype system has demonstrated the feasibility of the proposed framework.

"Perceived Instability of Virtual Haptic Texture: III. Effect of Update Rate"
Seungmoon Choi, Hong Z. Tan
Presence: Teleoperators & Virtual Environments, June 2007, Vol. 16, No. 3, Pages 263-278.

This study investigates the effect of update rate on the quality of haptic virtual textures, with the goal to develop a guideline for choosing an optimal update rate for haptic texture rendering. Two metrics, control stability and perceived quality of the virtual haptic texture, were used. For control stability, we examined the effect of update rate on the “buzzing” of virtual haptic textures. For perceived quality, we measured the discriminability of virtual haptic textures rendered at different update rates. Our study indicates that update rates much higher than the conventional 1 kHz are needed in order to achieve a stable rendering of “clean and hard” textured surfaces. We also found that our ability to distinguish textures rendered with different update rates depends on whether the virtual textures contain perceived instability. Based on these results, we provide a general guideline for selecting an optimal update rate for rendering virtual textured surfaces.

"The Benefit of Force Feedback in Surgery: Examination of Blunt Dissection"
Christopher R. Wagner, Nicholas Stylopoulos, Patrick G. Jackson, Robert D. Howe
Presence: Teleoperators & Virtual Environments, June 2007, Vol. 16, No. 3, Pages 252-262.

Force feedback is widely assumed to enhance performance in robotic surgery, but its benefits have not yet been systematically assessed. In this study we examine the effects of force feedback on a blunt dissection task. Twenty subjects used a telerobotic system to expose an artery in a synthetic model while viewing the operative site with a video laparoscope. Subjects were drawn from a range of surgical backgrounds, from inexperienced to attending surgeons. Performance was compared between three force feedback gains: 0% (no force feedback), 37%, and 75%. The absence of force feedback increased the average force magnitude applied to the tissue by at least 50%, and increased the peak force magnitude by at least 100%. The number of errors that damage tissue increased by over a factor of 3. The rate and precision of dissection were not significantly enhanced with force feedback. These results hold across all levels of previous surgical experience. We hypothesize that force feedback is helpful in this blunt dissection task because the artery is stiffer than the surrounding tissue. This mechanical contrast serves to constrain the subject's hand from commanding inappropriate motions that generate large forces.

This ScienceDaily article reports that researchers from Rensselaer Polytechnic Institute obtained a a $2 million grant from the National Institutes of Health (NIH) for developing a physics-based virtual model that can simulate a patient's breathing in real time. From the article: "X. George Xu, professor of nuclear and biomedical engineering, and Suvranu De, associate professor of mechanical engineering, have formed a multidisciplinary collaboration with clinical colleagues at the Cancer Therapy & Research Center in San Antonio, Texas, to develop the 4-D Visible Photographic Man (VIP-Man).

This NewScientistTech article is about the use of brain-computer interfaces in virtual worlds. It also presents the European consortium PRESENCCIA that has the goal of creating a virtual world through which a person can navigate using just their imagination. From the article: "A simulated world that can be explored simply by thinking about putting one foot in front of the other might offer new rehabilitation possibilities for disabled patients.

This is the vision behind a project that connects a brain-computer interface (BCI) to an immersive virtual world.

This medGadget article take a look at the University of Calgary CAVEman project: a 4D high-resolution model of a functioning human made for their CAVE. From the article: "Your anatomy textbooks are 2D. CAVEman is 4D, meaning it's as cool as your average text book squared. Of course, if your text book's coolness is <1, then that means CAVEman isn't very cool at all...so maybe the math doesn't hold up, cut us some slack, it's Thursday. Oh, the research, right: The University of Calgary unveiled their 4D (that's typical 3D + time) high-resolution model of a functioning human.