The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Rolf Müller - One of the best experts on this subject based on the ideXlab platform.
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Interplay of static and dynamic features in biomimetic smart ears
Bioinspiration & biomimetics, 2013Co-Authors: Mittu Pannala, Sajjad Z. Meymand, Rolf MüllerAbstract:Horseshoe bats (family Rhinolophidae) have sophisticated biosonar systems with outer ears (pinnae) that are characterized by static local shape features as well as dynamic non-rigid changes to their overall shapes. Here, biomimetic prototypes fabricated from elastic rubber sheets have been used to study the impact of these static and dynamic features on the acoustic device characteristics. The basic shape of the prototypes was an obliquely truncated horn augmented with three static local shape features: vertical ridge, pinna-rim incision and frontal flap (Antitragus). The prototype shape was deformed dynamically using a one-point actuation mechanism to produce a biomimetic bending of the prototype’s tip. In isolation, the local shape features had little impact on the device beampattern. However, strong interactions were observed between these features and the overall deformation. The further the prototype tip was bent down, the stronger the beampatterns associated with combinations of multiple features differed from the upright configuration in the prominence of sidelobes. This behavior was qualitatively similar to numerical predictions for horseshoe bats. Hence, the interplay between static and dynamic features could be a bioinspired principle for affecting large changes through the dynamic manipulations of interactions that are sensitive to small geometrical changes.
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Time-variant biomimetic beamforming baffle prototypes augmented with local shape features
The Journal of the Acoustical Society of America, 2011Co-Authors: Mittu Pannala, Ojili Praveen Kumar Reddy, Sajjad Z. Meymand, Rolf MüllerAbstract:Horseshoe bats are known to exhibit non-rigid pinna deformations as part of their biosonar behaviors. During these deformation cycles, the pinnae of the animals alternate between upright and bent shape configurations that differ in their overall geometry as well as in the shapes and relative positions of local shape features. Artificial baffle prototypes have been designed to emulate these deforming bat pinnae. The prototype shapes were designed by augmenting an obliquely truncated cone with biomimetic local shape features. The prototype was implemented using elastic (synthetic rubber) materials. The deformation of the structure was accomplished through a simple actuation mechanism that was inserted on the back side of the artificial pinna. Features of the horseshoe bat pinna that have been evaluated for this study include a prominent vertical ridge that runs along the entire inner pinna surface, the Antitragus along with the lateral incisions that separate it from the back portion of the pinna, and a pin...
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Numerical insights into the mechanisms of biosonar beamforming
The Journal of the Acoustical Society of America, 2006Co-Authors: Rolf MüllerAbstract:The pronounced interspecific variability in the outer ear and nose shapes of bats suggests that the beamforming action of these structures is functionally important to the animals’ biosonar systems. Numerical methods bring three major advantages to the study of the underlying mechanisms: efficiency in producing high‐resolution directivity estimates, exploration of wave properties in the near field, and integration with digital shape manipulations. High‐resolution directivity estimates reveal the shape of main‐ and sidelobes as well as their interplay over frequency. In two case studies, sidelobes were found to be prominent directivity features with significant sensitivity. In one case, they were even part of a dynamic pattern in which the maximum sensitivity alternates between mainlobe and sidelobes over frequency. Shape manipulations can be applied to the study of such features as the tragus or Antitragus and prominent ledges around the pinna rim. These features can either be digitally removed or continu...
Chiara Benedetto - One of the best experts on this subject based on the ideXlab platform.
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Ear acupuncture in the treatment of migraine attacks: a randomized trial on the efficacy of appropriate versus inappropriate acupoints
Neurological Sciences, 2011Co-Authors: Gianni Allais, Marco Romoli, Sara Rolando, Ilaria Castagnoli Gabellari, Gisella Airola, Rita Allais, Chiara BenedettoAbstract:Ear acupuncture can be a useful mean for controlling migraine pain. It has been shown that a technique called the Needle Contact Test (NCT) can identify the most efficacious ear acupoints for reducing current migraine pain through just a few seconds of needle contact. The majority of the points were located on the antero-internal part of the Antitragus (area M) on the same side of pain. The aim of this study was to verify the therapeutic value of area M and to compare it with an area of the ear (representation of the sciatic nerve, area S) which probably does not have a therapeutic effect on migraine attacks. We studied 94 females suffering from migraine without aura, diagnosed according to the ICHD-II criteria, during the attack. They were randomly subdivided into two groups: in group A, tender points located in area M, positive to NCT were inserted; in group B, the unsuitable area (S) was treated. Changes in pain intensity were measured using a VAS scale at various times of the study. During treatment, there was a highly significant trend in the reduction of the VAS value in group A (Anova for repeated measures: p
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Ear acupuncture in unilateral migraine pain
Neurological Sciences, 2010Co-Authors: Gianni Allais, Marco Romoli, Sara Rolando, Ilaria Castagnoli Gabellari, Chiara BenedettoAbstract:The needle contact test (NCT) is a diagnostic technique useful to identify, through the contact of the needle on the skin of the ear, the most efficacious points for reducing pain during a migraine attack. The aim of this study was to identify the most important auricular zones for pain control by applying the NCT in a group of 15 women during a unilateral attack of migraine without aura. We also assessed how effective the insertion of a semi-permanent needle in these zones was in reducing the migraine pain during the next 24 h. The most effective tender points in pain control were located on the antero-internal part of the Antitragus, the anterior part of the lobe and the upper auricular concha ipsilateral to the side of pain. The insertion of a semi-permanent needle in these zones allowed stable control of the migraine pain, which occurred within 30 min and persisted at the same levels 24 h later (ANOVA for repeated measures: p
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Ear acupuncture in unilateral migraine pain.
Neurological Sciences, 2010Co-Authors: Gianni Allais, Marco Romoli, Sara Rolando, Ilaria Castagnoli Gabellari, Chiara BenedettoAbstract:The needle contact test (NCT) is a diagnostic technique useful to identify, through the contact of the needle on the skin of the ear, the most efficacious points for reducing pain during a migraine attack. The aim of this study was to identify the most important auricular zones for pain control by applying the NCT in a group of 15 women during a unilateral attack of migraine without aura. We also assessed how effective the insertion of a semi-permanent needle in these zones was in reducing the migraine pain during the next 24 h. The most effective tender points in pain control were located on the antero-internal part of the Antitragus, the anterior part of the lobe and the upper auricular concha ipsilateral to the side of pain. The insertion of a semi-permanent needle in these zones allowed stable control of the migraine pain, which occurred within 30 min and persisted at the same levels 24 h later (ANOVA for repeated measures: p < 0.01). Pain was tested by using a visual analogue scale; the values recorded were the following: 7.6 ± 1.6 at baseline and 4.3 ± 1.7; 4.1 ± 1.9; 3.9 ± 1.8; 3.4 ± 1.8; 2.3 ± 1.6 after, respectively, 15, 30, 60, 120 min and 24 h.
Ha Fen - One of the best experts on this subject based on the ideXlab platform.
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Congenital auricular deformity consisting of cleft concha and transposition of the earlobe and Antitragus.
Plastic and reconstructive surgery, 1996Co-Authors: Zhang Jia-yi, Ha FenAbstract:We have reported a patient with a congenital auricular deformity consisting of cleft concha transposition of the earlobe and Antitragus. This is an extremely rare entity. We have named it congenital auricular deformity consisting of cleft concha and transposition of the earlobe and Antitragus because the case we described is a congenital cleft auricle and transposition of the earlobe and Antitragus in terms of position of the deformity.
Dirk Vandermeulen - One of the best experts on this subject based on the ideXlab platform.
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An investigation of matching symmetry in the human pinnae with possible implications for 3D ear recognition and sound localization.
Journal of anatomy, 2014Co-Authors: Peter Claes, Jonas Reijniers, Mark D. Shriver, Jonathan Snyders, Paul Suetens, Joachim Nielandt, Guy De Tré, Dirk VandermeulenAbstract:The human external ears, or pinnae, have an intriguing shape and, like most parts of the human external body, bilateral symmetry is observed between left and right. It is a well-known part of our auditory sensory system and mediates the spatial localization of incoming sounds in 3D from monaural cues due to its shape-specific filtering as well as binaural cues due to the paired bilateral locations of the left and right ears. Another less broadly appreciated aspect of the human pinna shape is its uniqueness from one individual to another, which is on the level of what is seen in fingerprints and facial features. This makes pinnae very useful in human identification, which is of great interest in biometrics and forensics. Anatomically, the type of symmetry observed is known as matching symmetry, with structures present as separate mirror copies on both sides of the body, and in this work we report the first such investigation of the human pinna in 3D. Within the framework of geometric morphometrics, we started by partitioning ear shape, represented in a spatially dense way, into patterns of symmetry and asymmetry, following a two-factor anova design. Matching symmetry was measured in all substructures of the pinna anatomy. However, substructures that ‘stick out’ such as the helix, tragus, and lobule also contained a fair degree of asymmetry. In contrast, substructures such as the conchae, Antitragus, and antihelix expressed relatively stronger degrees of symmetric variation in relation to their levels of asymmetry. Insights gained from this study were injected into an accompanying identification setup exploiting matching symmetry where improved performance is demonstrated. Finally, possible implications of the results in the context of ear recognition as well as sound localization are discussed.
Mittu Pannala - One of the best experts on this subject based on the ideXlab platform.
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Interplay of static and dynamic features in biomimetic smart ears
Bioinspiration & biomimetics, 2013Co-Authors: Mittu Pannala, Sajjad Z. Meymand, Rolf MüllerAbstract:Horseshoe bats (family Rhinolophidae) have sophisticated biosonar systems with outer ears (pinnae) that are characterized by static local shape features as well as dynamic non-rigid changes to their overall shapes. Here, biomimetic prototypes fabricated from elastic rubber sheets have been used to study the impact of these static and dynamic features on the acoustic device characteristics. The basic shape of the prototypes was an obliquely truncated horn augmented with three static local shape features: vertical ridge, pinna-rim incision and frontal flap (Antitragus). The prototype shape was deformed dynamically using a one-point actuation mechanism to produce a biomimetic bending of the prototype’s tip. In isolation, the local shape features had little impact on the device beampattern. However, strong interactions were observed between these features and the overall deformation. The further the prototype tip was bent down, the stronger the beampatterns associated with combinations of multiple features differed from the upright configuration in the prominence of sidelobes. This behavior was qualitatively similar to numerical predictions for horseshoe bats. Hence, the interplay between static and dynamic features could be a bioinspired principle for affecting large changes through the dynamic manipulations of interactions that are sensitive to small geometrical changes.
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Effects of local shape features on the beampatterns of a dynamic biomimetic baffle
The Journal of the Acoustical Society of America, 2012Co-Authors: Mittu Pannala, Sajjad Z. Meymand, Rolf MuellerAbstract:Horseshoe bats have mobile pinnae that can change their shapes as a result of active actuation. A common pattern is an alteration between an upright and a bent-tip geometrical configuration. Numerical predictions of reception beampatterns associated with these different shape geometries have indicated that the upright configurations are associated with beampatterns dominated by a single mainlobe whereas the bent-tip configurations have prominent sidelobes. Using a biomimetic baffle prototype, we have found that this effect can be reproduced qualitatively with just a plain obliquely truncated cone that is fabricated from flexible material (rubber) and bent at the tip. However, local shape features can have a strong impact on the quantitative expression of this effect. The three features studied here were a vertical ridge, an equivalent to the bat's Antitragus, and a lateral incision into the baffle rim. The effects of these features on the beampatterns where found to interact with each other and also depen...
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Time-variant biomimetic beamforming baffle prototypes augmented with local shape features
The Journal of the Acoustical Society of America, 2011Co-Authors: Mittu Pannala, Ojili Praveen Kumar Reddy, Sajjad Z. Meymand, Rolf MüllerAbstract:Horseshoe bats are known to exhibit non-rigid pinna deformations as part of their biosonar behaviors. During these deformation cycles, the pinnae of the animals alternate between upright and bent shape configurations that differ in their overall geometry as well as in the shapes and relative positions of local shape features. Artificial baffle prototypes have been designed to emulate these deforming bat pinnae. The prototype shapes were designed by augmenting an obliquely truncated cone with biomimetic local shape features. The prototype was implemented using elastic (synthetic rubber) materials. The deformation of the structure was accomplished through a simple actuation mechanism that was inserted on the back side of the artificial pinna. Features of the horseshoe bat pinna that have been evaluated for this study include a prominent vertical ridge that runs along the entire inner pinna surface, the Antitragus along with the lateral incisions that separate it from the back portion of the pinna, and a pin...