• 한국정밀공학회지
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• 제33권7호
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• pp.565-570
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• 2016

This paper presents the characteristics related to needle insertion of a robotic device for the automated biopsy procedure. The automated biopsy device, a main component of the robotic needle insertion type intervention system, allows performance of the full biopsy procedure, except for anesthesia, without direct handling of a radiologist or a tele-operated control. In this study, the needle length parameters corresponding to various insertion depths and precision for needle insertion of the automated biopsy device, are discussed. There were two combinations of needle length parameters for appropriate needle insertion and motion capture-based measurement was performed; 0.156 mm error for the 90 mm length commanded insertion displacement was measured. The pre-defined goal is a maximum 1 mm error and thus our measured error is within the acceptable range. In the repeatability check, it was also shown that the device can implement a highly accurate insertion.

• 한국산림과학회지
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• 제57권1호
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• pp.39-44
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• 1982

우리 나라의 지리산(智異山), 덕유산(德裕山), 한라산(漢拏山)에 천연분포(天然分布)되어 있는 구상나무 집단(集團)의 침엽형질변이(針葉形質變異)를 구명(究明)하기 위하여 집단별(集團別), 집단내(集團內)의 개체별(個體別)로 조사(調査)하였던 바 그 결과(結果)를 요약(要約)하면 다음과 같다. 침엽장(針葉長), 기공열수(氣孔列數)에 있어서는 집단간(集團間)에 1%의 유의성(有意性)이 인정(認定)되었으며 집단내(集團內)의 개체간(個體間)에는 형질(形質) 모두 유의성(有意性)을 인정(認定)할 수 없었다. 모수(母樹)의 흉고직경(胸高直徑)과 침엽장(針葉長), 침엽폭(針葉幅) 간(間)에 있어서는 집단(集團) 모두 상관(相關)이 없었다. 침엽장(針葉長)과 침엽폭(針葉幅) 간(間)에서 덕유산(德裕山)과 한라산(漢拏山) 집단(集團)은 정(正)의 상관(相關)을 보였으나 지리산(智異山) 집단(集團)은 상관(相關)이 없었으며 침엽장(針葉長)과 기공열수(氣孔列數) 간(間)에서는 덕유산(德裕山) 집단(集團)이 정(正)의 상관(相關)을 보였다. 침엽폭(針葉幅)과 기공열수(氣孔列數) 간(間)에는 집단(集團) 모두 정(正)의 상관(相關)을 보였으나 침엽폭(針葉幅)과 거치밀도(鋸齒密度) 그리고 기공열수(氣孔列數)와 거치밀도(鋸齒密度) 간(間)에는 상관(相關)이 없었다. 거치밀도(鋸齒密度)의 변이계수(變異係數)는 다른 형질(形質)에 비(比)해 큰 경향(傾向)을 나타내었다.

• 전기의세계
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• 제26권3호
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• pp.69-72
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• 1977

The effects of sharpness of needle electode on the spark voltage in needle-plane and needle-needle spark gaps at atmospheric pressure was investigated experimentaly in this paper. As the sharpness of needle electrode increases, the spark voltage increases, and the rate of increase is greater in needle-needle electrode than in needle-plane gap. the effects of sharpness is greater in small gap length. These characteristics can be explained by the electric field strength at the needle tip depending on the sharpness of needle, electro-static capacity between the electrodes, and the polarity effect in needle-plane gap. These experimental results will be able to play an important roles on the design of needle-needle gap as high voltage measurement devices and of needle-plane gap as high voltage rectifier equipments.

• 전자공학회논문지SC
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• 제45권6호
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• pp.16-25
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• 2008

미세 탐침이란 프로브 카드(Probe Card)를 구성하는 초미세탐침을 의미한다. 이러한 미세 탐침은 그 크기가 상당히 미세하기 때문에 외관 이상 유무를 사람의 눈으로 검사하기가 상당히 어렵다. 반면, 프로브카드를 구성하는 미세 탐침의 이상 유무는 상당히 중요한 요소라고 볼 수 있다. 이에 본 연구에서는 사람의 눈으로 검사하기 어려운 미세 탐침의 불량 상태를 자동화된 비전 시스템으로 검사할 수 있는 방법을 개발하였다. 즉 탐침의 구부러진 각도, Tip Length, 종단 직경을 고속으로 자동 검사할 수 있는 비전 기술을 개발한 것이다 제안한 방법에 의한 실험결과, 사람의 육안에 위한 검사보다 검사의 정확도와 속도가 향상되었으며, 또한 조명환경에 대해서도 강건성(robustness)이 향상되었음을 알 수 있었다.

• 한국안전학회지
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• 제19권1호
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• pp.56-59
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• 2004

In this paper, we investigated the influence of gap length and tip radius on breakdown of mineral based insulation oil. Applied voltages were DC and AC voltage. Electrode system was needle-plane structure. The tip radius of needle electrode was 5, 10, 20 and 25${\mu}m$, respectively. We measured breakdown voltage for each of tip radius with increasing electrode gap, 2mm to 12mm. Electric breakdown strength at tip was calculated using Mason's equation contained geometric figure. As gap length increased, breakdown strength increased linearly. But, as tip radius of needle increased, breakdown strength decreased exponentially. It can be explained by the phenomenon that electron is easily injected, as tip radius increases, and effective work function decreases. When appling DC voltage, breakdown strength was higher when polarity of needle was negative than positive. It is because of the space charge effect in accordance with the influence of liquid motion.

• 분석과학
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• 제33권2호
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• pp.76-85
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• 2020

A stainless-steel needle (Hamilton 90022, 22 gauge, 718-㎛ o.d., 413-㎛ i.d., 51-mm length, bevel tip) with an electrochemically coated polyaniline layer having a microbore tunnel was newly prepared as a device for headspace in-needle microextraction. For designing the needle, the polyaniline layer length was optimized, and to evaluate the extraction efficiency for polycyclic aromatic hydrocarbons, numerous cyclic voltammetry scans were conducted. In addition, the optimization of the analytical conditions (including the adsorption and desorption parameters) and the validation of the analytical method were conducted. The optimized adsorption and desorption conditions were 40 ℃ for 30 min and 230 ℃ for 60 s, respectively. Finally, in this study, a polyaniline layer was electrochemically deposited on the in-needle surface, and it exhibited good thermal stability. The needle with the polyaniline layer was repeatedly used more than 200 times during this study. This method has some advantages in terms of the extraction time, extraction efficiency, and analysis cost.

• Restorative Dentistry and Endodontics
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• 제37권1호
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• pp.24-28
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• 2012

Objectives: The aim of this study was to test the hypothesis, that the effectiveness of irrigation in removing smear layer in the apical third of root canal system is dependent on the depth of placement of the irrigation needle into the root canal and the enlargement size of the canal. Materials and Methods: Eighty sound human lower incisors were divided into eight groups according to the enlargement size (#25, #30, #35 and #40) and the needle penetration depth (3 mm from working length, WL-3 mm and 9 mm from working length, WL-9 mm). Each canal was enlarged to working length with Profile.06 Rotary Ni-Ti files and irrigated with 5.25% NaOCl. Then, each canal received a final irrigation with 3 mL of 3% EDTA for 4 min, followed by 5 mL of 5.25% NaOCl at different level (WL-3 mm and WL-9 mm) from working length. Each specimen was prepared for the scanning electron microscope (SEM). Photographs of the 3mm area from the apical constriction of each canal with a magnification of ${\times}250$, ${\times}500$, ${\times}1,000$, ${\times}2,500$ were taken for the final evaluation. Results: Removal of smear layer in WL-3 mm group showed a significantly different effect when the canal was enlarged to larger than #30. There was a significant difference in removing apical smear layer between the needle penetration depth of WL-3 mm and WL-9 mm. Conclusions: Removal of smear layer from the apical portion of root canals was effectively accomplished with apical instrumentation to #35/40 06 taper file and 3 mm needle penetration from the working length.

• 대한간호학회지
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• 제40권6호
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• pp.844-851
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• 2010

Purpose: This study was conducted to assess optimal needle length for gluteal intramuscular injections (IM) via simple skinfold thickness (SFT). Methods: For this study, 190 healthy adults were recruited and grouped into eight groups according to gender and body mass index (BMI) (kg/$m^2$). The Korean Society for the Study of Obesity criteria defines a BMI under 20 as underweight, 20.1-22.9 as normal, 23-24.9 as overweight and over 25 as obese. For each participant, the SFT of dorsoguteal (DG) and ventrogluteal (VG) sites were measured using a caliper. Subcutaneous tissue thickness was acquired through ultrasonic images. Results: For men in the overweight and obese groups at the DG site, for the obese group at the VG site, and for women in the normal weight, overweight and obese groups at both sites, the mean subcutaneous tissue thickness exceeded 1.84 cm, the minimal length for a 1 inch needle used for IM. At the DG site, optimal intramuscular needle length (OINL) was 1.4 times in women and 1.0 times in men compared to SFT. At the VG site, OINL was 1.3 times in women and 0.9 times in men compared to SFT. Conclusion: The results of this study suggest that SFT is a reliable index to determine optimal needle length with minimal effort prior to IM.

• 한국분무공학회지
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• 제6권2호
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• pp.9-15
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• 2001

The internal flow characteristics of a gasoline direct injector have been studied to improve fuel economy and reduce exhaust emissions. Computational Fluid Dynamics (CFD) is used to examine the internal flow of the GDI with the purpose of designing the optimum geometry of the injector. This study tests orifice length, cone angle, swirl angle, orifice diameter and needle lift. The results show that optimum sizes of the orifice length, cone angle, swirl angle, orifice diameter and needle lift are 0.8mm, $140^{\circ},\;120^{\circ},\;80mm\;and\;70{\mu}m$, respectively. The size of the lift does not affect the formation of the air core signficantly near the tip of the needle compared to the ball-type needle. The vena contracta phenomenon near the orifice inlet can be released by smoothing the edge.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 춘계학술대회 논문집
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• pp.250-253
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• 2004

Sharpness of the tip of micro needle is very Important quality that should be controlled in the manufacturing processes. Acupuncture needle is one of the most widely used micro-needle. And the tip sharpness of acupuncture needle Is usually checked by the magnitude of resisting force obtained through sharpness test. In this study, some sharpness tests of acupuncture needle were done and the relationship between the misalignment of specimen and the magnitude of resisting force. The diameter of the needle used in the test was $250\;{\mu}m$ and the length of it was 40 mm.