The Measurement of 2D Curvature of In-Vivo Human Ear Canal

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P103-P103
Author(s):  
Jen-Fang Yu ◽  
Fan Chung-chieh ◽  
Chin-Kuo Chen
Keyword(s):  
3D Model ◽  
External Auditory Meatus ◽  
Slice Thickness ◽  
Inferior Wall ◽  
Ear Canal ◽  
High Resolution Computed Tomography ◽  
Non Invasive ◽  
External Canal ◽  
Human Ear

Problem To non-invasively measure the 2D curvature of human ear canal and produce the earmold by the non-invasive 3D ear impression. Methods The images of external ear were scanned by high-resolution computed tomography (HRCT). The resolution for each slice was 512⋉512 pixels. The pixel size was 0.188⋉0.188mm and the slice thickness was 0.625mm. The boundary between tympanic membrane and external auditory meatus was enhanced by image processing. Additionally, 3D model of ear canal was reconstructed by 2D images. The length and angle of first and second bends of canal were measured based on the 3D model. 2D curvature of first and second bends of canal was then computed by sine and cosine laws. Results The volume of ear canal was 862.0 cubic mm. The angle and curvature of superior wall of first bend at axial view were 121.5 degrees and 0.0685; of inferior wall of first bend were 246 degrees and −0.1102; of superior wall of second bend were 227.8 degrees and −0.0332; of inferior wall of second bend were 143.1 degrees and 0.0130 respectively. 2D curvature of superior and inferior wall of first and second bends was diagrammed. Conclusion The 2D curvature of ear canal at first and second bends could be measured and produce the ear impression non-invasively. The geometry of canal changed by tumors is a common syndrome in ear disease. Therefore, the geometry of ear canal can be tracked after the otoplasty. Significance The 3D geometry of canal can help physicians diagnose the syndrome of external canal before otoplasty. Moreover, the hearing aid earmold can be made by non-invasive ear impression instead of invasive ear impression.

NON-INVASIVE TECHNIQUE FOR IN VIVO HUMAN EAR CANAL VOLUME MEASUREMENT

2012 ◽  
Vol 12 (04) ◽  
pp. 1250064 ◽  
Author(s):  
JEN-FANG YU ◽  
GO-LONG TSAI ◽  
CHUNG-CHIEH FAN ◽  
CHING-I CHEN ◽  
CHIA-CHI CHENG ◽  
...  
Keyword(s):  
Water Injection ◽  
Three Dimensional ◽  
Volume Measurement ◽  
Invasive Technique ◽  
Slice Thickness ◽  
High Resolution Computed Tomography ◽  
Two Dimensional Image ◽  
Non Invasive ◽  
The Mean

This prospective study is to develop a new non-invasive in vivo technique for the measurement of the human external auditory canal (EAC) volume using high resolution computed tomography (HRCT). Eighteen ears of nine male volunteers, with an age range of 20–30, were measured. The EAC volume was measured using three different methods: tympanometry, water injection, and HRCT. Two dimensional image slices of the EAC, in vivo, were obtained from the raw HRCT data. Each 2D CT image slice was composed of 512 × 512 pixels, with a 0.5 mm slice thickness, and a 0.175 × 0.175 × 0.5 mm3 voxel size. HRCT images were processed with Amira® software (Visage Imaging, Inc., San Diego, USA). Three-dimensional images of the EAC were reconstructed using an unconstrained smoothing mode. The resulting volume of the 3D model of the EAC was calculated using a voxel gate stacked tool. Using tympanometry, the mean measured EAC volume, averaged over all ears, was 766.66 mm3 (Standard Deviation, SD = 194.03 mm3). Using water injection, the mean measured EAC volume was 1102.77mm3 (SD = 121.60 mm3). Using HRCT, the mean measured EAC volume was 1082.22 mm3 (SD = 119.63 mm3). As evident from the SD values, variability was greater in the tympanometry group than in the water injection and HRCT groups. This study successfully developed a new technique to measure the EAC volume using HRCT imaging. This non-invasive technique for in vivo EAC volume measurement was less variable than tympanometry, and avoided the intrusive aspect of measurement by water injection. The technique allows effective, non-invasive assessment of the EAC volume pre-canalplasty, providing a predictor of EAC volume post-canalplasty.

The sensitivity of hearing by the resonance in in vivo human ear canal.

2009 ◽  
Vol 125 (4) ◽  
pp. 2721-2721
Author(s):  
Wei‐De Cheng ◽  
Jen‐Fang Yu ◽  
Kuo‐Wei Huang ◽  
Shang‐Peng Chang ◽  
Chin‐Kuo Chen
Keyword(s):  
Ear Canal ◽  
Human Ear

scholarly journals Non-invasive diagnostics in fossils - Magnetic Resonance Imaging of pathological belemnites

2005 ◽  
Vol 2 (2) ◽  
pp. 133-140 ◽  
Author(s):  
D. Mietchen ◽  
H. Keupp ◽  
B. Manz ◽  
F. Volke
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Soft Tissue ◽  
Clinical Diagnostics ◽  
Resonance Imaging ◽  
Non Invasive ◽  
Physiological Processes ◽  
Magnetic Resonance Imaging Mri ◽  
Invasive Diagnostics

Abstract. For more than a decade, Magnetic Resonance Imaging (MRI) has been routinely employed in clinical diagnostics because it allows non-invasive studies of anatomical structures and physiological processes in vivo and to differentiate between healthy and pathological states, particularly of soft tissue. Here, we demonstrate that MRI can likewise be applied to fossilized biological samples and help in elucidating paleopathological and paleoecological questions: Five anomalous guards of Jurassic and Cretaceous belemnites are presented along with putative paleopathological diagnoses directly derived from 3D MR images with microscopic resolution. Syn vivo deformities of both the mineralized internal rostrum and the surrounding former soft tissue can be traced back in part to traumatic events of predator-prey-interactions, and partly to parasitism. Besides, evidence is presented that the frequently observed anomalous apical collar might be indicative of an inflammatory disease. These findings highlight the potential of Magnetic Resonance techniques for further paleontological applications.

scholarly journals Non-invasive skin sampling of tryptophan/kynurenine ratio in vitro towards a skin cancer biomarker

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Skaidre Jankovskaja ◽  
Johan Engblom ◽  
Melinda Rezeli ◽  
György Marko-Varga ◽  
Tautgirdas Ruzgas ◽  
...  
Keyword(s):  
Skin Cancer ◽  
Relative Increase ◽  
Cancer Biomarker ◽  
Cancer Diagnostics ◽  
Sampling Time ◽  
Skin Permeability ◽  
Experimental Conditions ◽  
Non Invasive

AbstractThe tryptophan to kynurenine ratio (Trp/Kyn) has been proposed as a cancer biomarker. Non-invasive topical sampling of Trp/Kyn can therefore serve as a promising concept for skin cancer diagnostics. By performing in vitro pig skin permeability studies, we conclude that non-invasive topical sampling of Trp and Kyn is feasible. We explore the influence of different experimental conditions, which are relevant for the clinical in vivo setting, such as pH variations, sampling time, and microbial degradation of Trp and Kyn. The permeabilities of Trp and Kyn are overall similar. However, the permeated Trp/Kyn ratio is generally higher than unity due to endogenous Trp, which should be taken into account to obtain a non-biased Trp/Kyn ratio accurately reflecting systemic concentrations. Additionally, prolonged sampling time is associated with bacterial Trp and Kyn degradation and should be considered in a clinical setting. Finally, the experimental results are supported by the four permeation pathways model, predicting that the hydrophilic Trp and Kyn molecules mainly permeate through lipid defects (i.e., the porous pathway). However, the hydrophobic indole ring of Trp is suggested to result in a small but noticeable relative increase of Trp diffusion via pathways across the SC lipid lamellae, while the shunt pathway is proposed to slightly favor permeation of Kyn relative to Trp.

scholarly journals Prevalence and Photobiology of Photosynthetic Dinoflagellate Endosymbionts in the Nudibranch Berghia stephanieae

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2200
Author(s):  
Ruben X. G. Silva ◽  
Paulo Cartaxana ◽  
Ricardo Calado
Keyword(s):  
Food Deprivation ◽  
Photosynthetic Efficiency ◽  
Rapid Decrease ◽  
Complete Loss ◽  
Symbiotic Association ◽  
Non Invasive ◽  
Sea Slugs ◽  
Non Destructive ◽  
Over Time

Berghia stephanieae is a stenophagous sea slug that preys upon glass anemones, such as Exaiptasia diaphana. Glass anemones host photosynthetic dinoflagellate endosymbionts that sea slugs ingest when consuming E. diaphana. However, the prevalence of these photosynthetic dinoflagellate endosymbionts in sea slugs appears to be short-lived, particularly if B.stephanieae is deprived of prey that host these microalgae (e.g., during bleaching events impacting glass anemones). In the present study, we investigated this scenario, along with food deprivation, and validated the use of a non-invasive and non-destructive approach employing chlorophyll fluorescence as a proxy to monitor the persistence of the association between sea slugs and endosymbiotic photosynthetic dinoflagellates acquired through the consumption of glass anemones. Berghia stephanieae deprived of a trophic source hosting photosynthetic dinoflagellate endosymbionts (e.g., through food deprivation or by feeding on bleached E. diaphana) showed a rapid decrease in minimum fluorescence (Fo) and photosynthetic efficiency (Fv/Fm) when compared to sea slugs fed with symbiotic anemones. A complete loss of endosymbionts was observed within 8 days, confirming that no true symbiotic association was established. The present work opens a new window of opportunity to rapidly monitor in vivo and over time the prevalence of associations between sea slugs and photosynthetic dinoflagellate endosymbionts, particularly during bleaching events that prevent sea slugs from incorporating new microalgae through trophic interactions.

In Vivo Wireless Brain Stimulation via Non-invasive and Targeted Delivery of Magnetoelectric Nanoparticles

2021 ◽  
Author(s):  
Tyler Nguyen ◽  
Jianhua Gao ◽  
Ping Wang ◽  
Abhignyan Nagesetti ◽  
Peter Andrews ◽  
...  
Keyword(s):  
Brain Stimulation ◽  
Targeted Delivery ◽  
Non Invasive
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