• Journal of Biomedical Engineering Research
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• v.26 no.5
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• pp.309-317
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• 2005

It is expected that fully-implantable middle-ear hearing devices (FIMEHDs) will soon be available with the advantages of complete concealment, easy surgical implantation, and low power operation to resolve the problems of semi-implantable middle-ear hearing devices (SIMEHDs) such as discomfort of wearing an external device and replacement of battery. Over the last 3 years, a Korean research team at Kyungpook National University has developed an FIMEHD called ACRHS-1 based on a differential floating mass transducer (DFMT). The main research focus was functional improvement, the establishment of easy surgical procedures for implantation, miniaturization, and a low-power operation. Accordingly, this paper reviews the overall system architecture, functions, and experimental results for ACRHS-1 and its related accessories, including a wireless battery charger and remote controller.

• Korean Journal of Audiology
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• v.24 no.4
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• pp.210-213
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• 2020

Fungal balls consist of rounded conglomerates of fungal mycelia, which can form within a preexisting cavity. They are mostly found in the paranasal sinuses in the head and neck regions. Cholesterol granuloma is a fibrotic lesion that develops as a tissue response to a foreign body such as cholesterol crystals or hemosiderin and is often associated with chronic otitis media. We present the unusual case of a 62-year-old male who was treated for chronic otitis media, which was histologically confirmed as a fungal ball and cholesterol granuloma in the middle ear cavity following tympanomastoidectomy. This is the first reported case of synchronous fungal ball and cholesterol granuloma in the middle ear cavity.

• Journal of Audiology & Otology
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• v.24 no.4
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• pp.210-213
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• 2020

Fungal balls consist of rounded conglomerates of fungal mycelia, which can form within a preexisting cavity. They are mostly found in the paranasal sinuses in the head and neck regions. Cholesterol granuloma is a fibrotic lesion that develops as a tissue response to a foreign body such as cholesterol crystals or hemosiderin and is often associated with chronic otitis media. We present the unusual case of a 62-year-old male who was treated for chronic otitis media, which was histologically confirmed as a fungal ball and cholesterol granuloma in the middle ear cavity following tympanomastoidectomy. This is the first reported case of synchronous fungal ball and cholesterol granuloma in the middle ear cavity.

• Biomedical Science Letters
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• v.24 no.2
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• pp.116-124
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• 2018

Lysozyme is known as a key substance of the innate immunity and have antibacterial effect in the mucosal tissues, especially middle ear. Aquaporin (AQP) functions as water movement in the tissue and has been expected to be participated in the inflammatory responses. In the present study, we investigated to reveal association of lysozymes and AQPs in otitis media. The gene expression of lysozyme genes, homo sapiens lysozyme (hLYZ), homo sapiens lysozyme M (hLYZ M), and homo sapiens lysozyme G like-2 (hLYGH), and AQP genes (AQP 0 - AQP 12) were measured from postauricular skin, mastoid mucosa, inflamed mastoid mucosa, and middle ear mucosa. The hLYZ, hLYZ M and hLYGH gene were expressed in mastoid mucosa, inflamed mastoid mucosa, middle ear mucosa. Of AQP genes, all AQP gene except AQP 3 gene were expressed in the tissue of middle ear. Among them, AQP 4, AQP 8, AQP 9, AQP 10, AQP 11 and AQP 12 were highly expressed in the inflamed mastoid mucosa and normal mastoid mucosa (P<0.001). Interestingly, expression levels of AQP 4, AQP 9, and AQP 12 gene were significantly higher in the inflamed mastoid mucosa compared to normal middle ear mucosa (P<0.05). These results suggest that lysozyme and AQPs could be associated with inflammatory response in the middle ear.

• Clinical and Experimental Otorhinolaryngology
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• v.11 no.4
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• pp.233-241
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• 2018

Objectives. As endoscopic instrumentation, techniques and knowledges have significantly improved recently, endoscopic ear surgery has become increasingly popular. Transcanal endoscopic ear surgery (TEES) can provide better visualization of hidden areas in the middle ear cavity during congenital cholesteatoma removal. We aimed to describe outcomes for TEES for congenital cholesteatoma in a pediatric population. Methods. Twenty-five children (age, 17 months to 9 years) with congenital cholesteatoma confined to the middle ear underwent TEES by an experienced surgeon; 13 children had been classified as Potsic stage I, seven as stage II, and five as stage III. The mean follow-up period was 24 months. Recurrence of congenital cholesteatoma and surgical complication was observed. Results. Congenital cholesteatoma can be removed successfully via transcanal endoscopic approach in all patients, and no surgical complications occurred; only one patient with a stage II cholesteatoma showed recurrence during the follow-up visit, and the patient underwent revision surgery. The other patients underwent one-stage operations and showed no cholesteatoma recurrence at their last visits. Two patients underwent second-stage ossicular reconstruction. Conclusion. Although the follow-up period and number of patients were limited, pediatric congenital cholesteatoma limited to the middle ear cavity could be safely and effectively removed using TEES.

• Journal of Korea Multimedia Society
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• v.21 no.6
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• pp.678-684
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• 2018

In order to broaden the indication of middle ear implant, research has been actively conducted on the reverse output method that stimulates the round window. However, it is very difficult to transmit the vibration output effectively because the indivisual anatomical difference of the round window niche is very large and also the visual field is not secured even by a skilled otolaryngologic surgeon. In this paper, we propose a new reverse stimulation method of middle ear implants that transmits energy to the inner ear by using air as a medium. This can compensate for the disadvantages of the conventional method of transmitting vibration energy and minimizes the energy transfer efficiency interference due to the combination of the excitation point and the output device. It was shown that forward and backward transfer characteristics were obtained by cadaveric experiments, and it was shown that it can overcome the acoustical impedance of high round window and transmit energy to inner ear. The receiver, which is the output device of the conventional hearing aids, can generate a constant volume velocity, so it can have a high output at a limited volume, such as a round window niche. So, suggested method can overcome the high acoustical impedance of the round window and deliver acoustic energy to the inner ear.

• Journal of the Korean Society of Food Culture
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• v.21 no.5
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• pp.473-480
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• 2006

The purpose of this study were to investigate middle and high school students' food habits and food attitudes, and to assess student's nutrient consumption. A self-administered questionnaire was developed based on review of literature. The questionnaire consisted of three sections (food habits, food attitudes, and food consumption). The questionnaires were distributed to 4,050 students enrolled in 34 middle and high schools located in Seoul, Gyeonggi, and Gyeongnam provinces. A final response rate was 88.2% (3,570) excluding responses that had significant missing data. Data of the food habits and food attitudes were analyzed with descriptive analysis, $x^2$-test, and t-test using SPSS WIN(ver.11.0). The student's self-reported food consumption data was converted into nutrient consumption using conversion factor. Many middle and high school students skipped breakfast and/or dinner. Approximately 29% of the students did not eat vegetables and fruits. Scores of the middle school student's attitudes(19.1) towards foods were significantly higher than those of the high school student's attitudes(18.7)(p<.001). Student's nutrient intakes were estimated according to the student's self-reported food consumption data. The nutrient intakes were compared with DRIs(Dietary Reference Intakes: DRIs) for their age groups. The result of EAR(Estimated Average Requirement: EAR) cut-point method demonstrated 57.7% of middle school boys, 64.4% of middle school girls, 70.2% of high school boys, and 71.0% of high school girls did not meet EAR for Calcium. Additionally, it showed that 39.0% of middle school boys, 23.7% of middle school girls, 58.4% of high school boys, and 24.4% of high school girls did not consume EAR for Vitamin $B_1$. 25.7% of middle school boys did not meet EAR for Vitamin $B_2$, while 44.4% high school boys did not satisfy EAR for Vitamin $B_2$.

• Journal of Animal Environmental Science
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• v.12 no.2
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• pp.61-66
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• 2006

This study was carried out to investigate the relationship between the physical dimensions of ear and age for swine. The physical dimensions of ear and weight for twenty pigs were investigated on 1, 20, 40, 90, 120, and 150 days of age, respectively. The thickness of ear was measured at the upper, middle, and lower part of fore perimeter, and the middle and lower part of hind perimeter. The length of ear was measured for width and height. The thickness of ear increased rapidly from 1 day to 20 days of age, then it developed gradually after that period of time. The thickness at the lower part of fore perimeter increased most rapidly from 1 day to 20 days of age. In the length of ear, width increased gradually whereas height increased rapidly from 1 day to 90 days of age and then they almost did not. All the regression equations between the physical dimensions of ear and age were best represented by $Y=a+b\;X^{0.5}$. These results suggest that RFID has to be installed on the middle part of hind perimeter and an ID chip has to be installed on the lower part of fore perimeter.

• Journal of Biomedical Engineering Research
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• v.32 no.4
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• pp.285-288
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• 2011

In this study, we developed an optical coherence tomography(OCT) using a sweep-source laser whose center wavelength is 1310 nm and a probe of hand-held type. The developed hand-held probe targets to diagnose the middle ear, so it is miniaturized for ease and convenience of control. For the first time, we performed in-vivo clinical experiments on tympanic membrane(TM) perforation patients not reported from previous studies about OCT. The high-resolution sectional images of tympanic membrane perforation can be obtained. There aren't many studies about diagnostic instrument of the middle ear and diagnosis with sectional image of the middle ear, so the developed OCT system and hand-held probe are applicable to tympanic membrane perforation and other pathologic diagnosis in the middle ear.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.1 no.1
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• pp.29-36
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• 2007

Recently, implantable middle ear hearing devices (IMEHDs) have been developed to overcome the problems of conventional hearing aids. In this paper, a piezoelectric floating mass transducer (PFMT) based on a PZT multi-layered actuator has been designed and implemented using the approximated mechanical vibration modeling for the PFMT and the analysis of vibration characteristics through the transformation into the equivalent electrical model. The implemented PFMT has been attached to the ossicle of a human cadaver's temporal bone and the in-vitro experiment has been performed. Through the experimental results, it has been verified that the PFMT applied into our developed implantable middle ear hearing device can be used for an IMEHD transducer.