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Biomedical subjects

C J Overbeeke

Publications and source records attributed to C J Overbeeke.

8 recordsLinked to original sources
PubMed1999

Head-controlled laparoscopy: experiment, prototype, and preliminary results.

Depth perception is closely linked to the ability to explore. Previously described laboratory experiments showed the advantage of linking the motions of the laparoscope directly to the head movements of the surgeon. Additionally, it was found that the laparoscope should be mechanically supported instead of manually (by an assistant). This article describes three stages in the design and evaluation of a practical mechanism with which to link the motions of the laparoscope directly to the head movements of the surgeon. First, a description is given of the perceptual and technical considerations. Second, a laboratory experiment is described investigating the validity of the proposed suggestions. Last, a prototype was built that was tested in a practical setting.

Animals↗
PubMed1997

Cubby. A medical virtual environment based on multiscreen movement parallax.

In this paper a desktop virtual reality system named Cubby is described. Cubby is based on self-induced, head-coupled movement parallax on three orthogonal screens. It is argued that this system is better suited to medical practice than Immersive VR solutions or single screen Desktop VR systems. Whilst Cubby is currently limited to visualisation it opens up possibilities of direct instrumental manipulation and as such could prove useful as a medical simulator.

Computer Simulation↗
PubMed1997

Spatial perception during laparoscopy: implementing action-perception coupling.

Laparoscopy is a telepresence task since the surgeon has no direct contract with the patient. Performance of the surgeon will increase if his sense of telepresence is improved. This can be achieved by restoring the hampered action perception coupling. With respect to visual perception this means that the surgeon should be informed about the spatial lay-out of the environment; depth information and information about the location of observation. Both types of information can be provided by allowing the surgeon to explore. This paper describes our work on restoring the action perception coupling with respect to visual perception. It provides an overview of different technical solutions which balance between what information should be provided from an perceptual stand point and what information can be provided from a technical viewpoint.

Depth Perception↗
PubMed1991

The taste of desserts' packages.

This article reports an experiment on expressing the behavioural meaning of designed objects. Can a designer express the taste of a desert in the form of its packaging and can consumers match these forms when tasting the desserts? Analysis of responses of 12 adults indicates positive answers to these questions.

Adult↗
PubMed1989

Scent and sound of vision: expressing scent or sound as visual forms.

This article describes three experiments on the possibility of expressing scent or sound into visual forms made by design engineering students. The hypothesis tested was that people are able to pick up patterns in the energy flow that the students transposed from one perceptual sense to another. In Exp. 1 subjects were given different scents and were asked to choose a sculpture designed according these scents. In Exp. 2 subjects were given different musical pieces and asked to match them with portable cassette players designed according to this music. Exp. 3 was identical to Exp. 2 but different music selections, similar to the ones in Exp. 2, were used. In all three experiments subjects were indeed able to perform the tasks above chance level. Results are discussed within the framework of the theory of direct perception of Gibson.

Arousal↗
PubMed1987

Depth on a flat screen.

The hypothesis was tested that the coupling of parallax shifts between objects depicted on a monitor screen around a fixation point with the head movements of an observer viewing this screen monocularly around a point coinciding with the fixation point is sufficient to create a convincing depth impression and to enable the observer to make reliable estimations of depth. The estimates were based on monocular vision and involved the aligning of wedges. The investigation consisted of two analogous experiments carried out simultaneously, one on depth estimations virtually in the screen and one on depth estimations virtually in front of the screen. In each experiment three conditions were compared: an active condition in which the coupling of parallax shifts and observer's head movements operated, a passive condition in which it did not, and a real-life set-up to measure the maximum reliability in depth estimation. The hypothesis is confirmed: in the active condition the variances in the alignments are significantly smaller than in the passive condition and approach those in the real-life set-up. This holds not only for estimates in the screen but also for estimates in front of the screen, that is, we can make a thing apparently leap out of the screen towards the observer. Results are interpreted against the background of the debate between the direct and the indirect theories of perception.

Cues↗
PubMed1986

Changing the perception of behavioral properties by subliminal presentation.

Profiles designed by Pittenger and Shaw were used in a tachistoscopic experiment. Subjects were asked to make estimates of age of a profile of a 10-yr.-old boy preceded subliminally by an older (old group) or younger (young group) profile or by a blank card (control group). Results show the mean estimate of the young group to be significantly smaller than that of the control group. The mean estimate of the old group was not significantly greater than that of the control group. The results are discussed in the framework of the debate on direct versus indirect perception. Marcel's 1983 data and the present results indicate that higher level perceptual processing (the perception of behavioral properties) can precede lower level perceptual processing (the perception of physical properties). By assuming that people do perceive directly the behavioral properties of an event, the direct approach avoids the danger of putting too much emphasis on intelligence in perception and at the same time avoids the homunculus trap.

Humans↗