• The Korean Journal of Pain
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• 제10권2호
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• pp.225-230
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• 1997

Background: Authors modified the traditional continuous axillary brachial plexus block technique of Selander for purpose of increasing success rate and decreasing complications by use of commercial epidural anesthesia set. Method: Thirty-nine patients scheduled for upper extremity operations were injected with 40 ml of anesthetic solution by axillary perivascular technique, using 23~25G immobile needle at 2 cm from the pectoralis major. Tuohy needle was immediately introduced at 4 cm from the pectoralis major and pierced the expanded neurovascular sheath at an angle of 30 degree to the skin. The "pop" was well noted well. Needle was advanced 0.5 to 3.0 cm and epidural catheter introduced through the needle. After removal of needle, occlusive dressing was done. Tip of catheter and spread of solution were demonstrated by fluoroscopy with contrast dye after completion of procedure. Result: Catheter insertion was successful at first attempt for all case. Total length of insertion was from 6 to 13($10.0{\pm}1.7$) cm. Tip of catheter was placed in infraclavicular space(66.7%), about the humeral head(17.9%) and in upper arm in 3 cases as U-shape(7.9%). Catheters were maintained for $6.7{\pm}2.6$(3-12) days. There were no complications such as: perforation of major vessels, needle trauma to nerve, infection, bleeding or hematoma. Conclusion: This study demonstrated continuous axillary brachial plexus block with epidural anesthesia set is safe, easy and convenient modification of technique of Selander.

• Journal of Dental Anesthesia and Pain Medicine
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• 제23권5호
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• pp.281-285
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• 2023

Background: Dentists bend needles prior to certain injections; however, there are concerns regarding needle fracture, lumen occlusion, and sharps handling. A previous study found that a 30-gauge needle fractures after four to nine 90° bends. This fatigue life study evaluated how many 90° bends a 30-gauge dental needle will sustain before fracture when bent using a needle guide. Methods: Two operators at Element Materials Technology, an independent testing, inspection, and certification company tested 48 30-gauge needles. After applying the needle guide, the operators bent the needle to a 90° angle and expressed the anesthetic from the tip. The needle was then bent back to a 0° angle, and the functionality was tested again. This process was repeated until the anesthetic failed to pass through the end of the needle due to fracture or obstruction. Each operator tested 24 needles (12 needles from each lot), and the number of sustained bends before the needle fracture was recorded. Results: The average number of sustained bends before needle failure was 40.33 (95% confidence interval = 37.41-43.26), with a minimum of 20, median of 40, and a maximum of 54. In each trial, the lumen remained patent until the needle fractured. The difference between the operators was statistically significant (P < 0.001). No significant differences in performance between needle lots were observed (P = 0.504). Conclusion: Our results suggest that using a needle guide increases the number of sustained bends before needle fracture (P < 0.000001) than those reported in previous studies. Future studies should further evaluate the use of needle guides with other needle types across a variety of operators. Furthermore, additional opportunities lie in exploring workplace safety considerations and clinical applications of anesthetic delivery using a bent needle.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제36회 춘계학술대회논문집
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• pp.249-252
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• 2011

고체로켓추진기관의 추력조절을 위해 핀틀 기술이 사용된다. 아직까지 핀틀 유동에 대해 근본적인 물리적 이해를 돕는 연구가 공개되지 않아, 이 연구에서 다양한 형상의 needle형 핀틀에 따른 유동구조에 대한 수치적 연구를 진행하였다. 2차원 축대칭, 압축성을 고려하여, 상용 열유체 해석 프로그램인 FLUENT 6.2를 사용하여 해석을 수행하였다. 난류 모델을 검증하기 위해 기 수행된 실험 결과와 비교하였다. 핀틀 각도(tip angle)가 작아질수록 노즐에서 유동 박리점이 하류로 이동하며, 핀틀에서 발생하는 끝단 충격파가 약해진다. 핀틀 반경(tip radius)이 작아질수록 핀틀에서 발생하는 끝단 충격파가 하류로 이동하며, 크기는 약해진다. 핀틀 형상(contour)은 유동 박리 지점에 직접적인 영향을 미친다.

• Journal of Chest Surgery
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• 제36권10호
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• pp.748-753
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• 2003

배경: 폐결절은 경우에 따른 특히 경피침생검이 기술적으로 어렵거나 검사 후 병리세포검사로 확진이 되지 않는 경우에 대부분에서 흉강경을 이용한 조직검사를 요한다. 그러나 결절의 크기나 작거나 폐실질 깊숙이 위치한 경우에는 술 전 또는 술 중에 결절의 위치를 파악하기 위한 여러 가지 방법 등이 이용된다. 따라서 저자들은 폐결절을 경피침생검 시 방사선 비투과성 백금조각(이하 결절표시기)을 생검 전 또는 생검 후에 결절 내 또는 결절주위에 위치하여 병리조직검사에서 확진이 어려운 경우에 흉강경수술 시 재차 술 전 폐결절표시 과정을 피하는 방법을 고안하여 전향적으로 평가하였다. 대상 및 방법: 흉부 CT검사하여 경피침생검과정에 생검침을 결절내부 또는 결절인접부위에 위치한 경우에 결절 표시기를 생검침내부에 위치한 후 스타일렛을 이용하여 결절표시를 서서히 밀어 넣어 결절 내 혹은 인접부위에 위치한 것을 CT검사에서 확인한 다음 결절의 생검검사를 한다. 결과: 1999년 5월부터 2000년 5월 사이에 26명의 환자에서 28 결절을 대상으로 1예를 제외하고 모두에서 결절표시기를 결절 내 혹은 주위에 위치하였다. 이중 7건은 생검을 하지 않고 흉강경수술을 위하여 결절표시기를 위치하였고, 21건의 흉강경수술 중 18예(85%)에서 결절의 위치파악을 파악하거나 결절절제시 충분한 여유를 확보하기 위하여 수술 중 이동용 방사선 투시기를 이용하였다. 결론: 흉강경수술이 예상되는 폐결절에 대한 저자들의 방침이 흉부 CT검사하 폐결절 위치 표시과정을 생략함으로써 의료비, 시간을 절감할 수 있는 효과적인 방법으로 생각한다.

• 한국정밀공학회지
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• 제31권4호
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• pp.359-364
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• 2014

This paper describes the development of needle type probe that measures temperature and injects medicine for both diagnosis and treatment of musculoskeletal pain syndrome (MPS). The size of trigger points is from several micrometers to millimeter. Therefore, it is required to develop a medical device that is capable of not only finding the trigger points by temperature measurement, but also injecting medicine at the exact location for treatment. To challenge these difficulties, thermocouple was fabricated on the surface of a needle using metal deposition process. Special type of stainless-constantan thermocouple was achieved from the stainless body of a needle itself and deposited constantan metal film. In particular, parylene coating enables to limit the temperature sensitive area to the end of the needle tip. Fabricated needle type probe produces $3.25mV/^{\circ}C$ of thermoelectric sensitivity and compared its performance with commercial T-type thermocouple in animal muscle sample.

• 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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.476-480
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• 2003

Polyethylene used as insulating material of power cable is nonpolar and low dielectric loss polymer. But it has defects of tree generation and accumulation of space charge by an applied voltage resulting in the decreased life and performance. To solve these problems, mixed films with LLDPE and EVA that is similar to LLDPE at physical properties in case of low VA contents were made and tested due to the blend ratios of 80:20, 70:30, 60:40 and 50:50[wt%] respectively. We investigated AC electrical treeing characteristics to acquire the best mixture ratio and effect of the tip radius of needle electrode to develop excellent treeproof materials. The degree of crystallity calculated with XRD pattern is higher for pure LLDPE, 50:50 and 70:30. For DSC analysis, it is confirmed that the melting points of mixed specimens are lower than that of pure LLDPE and higher than pure EVA's. The shape of tree propagation showed that pure EVA was electrical tree shape of the branch type, pure LLDPE and blended specimens was able to confirm tree shape of the bush type. As the tip radius go up in the blend ratio 70:30 specimen, the tree inception voltage rise. Probably the reason is the relaxation of electric field in the specimen with bigger tip ratio. As the 6 specimens were applied AC 5[KV],7.5[KV],10[KV] respectively, tree growth length is far shorter in the specimen with blend ratio 70:30, 50:50 than in pure EVA and pure LLDPE specimen. Conclusively, it is confirmed that specimens of which blend ratio are 70:30 and 50:50 are good in electrical tree retardant characteristics, especially, 70:30 has lower dielectric loss than 50:50 and its mixture ratio is the best.

• 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.

• The Korean Journal of Pain
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• 제14권2호
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• pp.199-206
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• 2001

Background: The lumbar sympathetic ganglia are variable in both position and numbers. The aim of this study was to detect the appropriate lumbar vertebral level where the lumbar sympathetic ganglia primarily aggregate. Methods: Forty patients comprising of hyperhidrosis (26 cases), complex regional pain syndrome (10 cases), peripheral artery occlusion disease (3 cases) and postherpetic neuralgia (1 case) underwent lumbar sympathetic block. We randomly selected one of two (L2 or L3) levels and the L4 level. The position of the needle tip and distribution of dye was verified by injection of a mixture of radio-opaque dye (1.5 ml) and 4% lidocaine (1.5 ml) and subsequently confirmed by L-spine anteroposterior and a lateral view X-ray. We considered the response positive when the skin temperature increased more than $1^{\circ}C$ in 5 min. Results: In general, the positive response ratio was greater when the needle tip located at the L2 or L4 level vice L3 and when the drug was distributed on the lower half of the L4 body and in the L4/5 intervertebral disc space. In a right side block, the positive response ratio was greater when the drug was distributed on the lower half of the L4 body and in the L4/5 intervertebral disc space, although in a left side block there was no significant difference seen between the levels. The complications of the neurolytic block were alcohol neuritis (7.5%) and hypoesthesia (5%) on the L1 or L2 dermatome. Conclusions: The best effect with least chance of complication may be induced by spreading the drug on the lower half of the L4 body and/or into the L4/5 intervertebral disc space by placing the needle tip on the L4 body.

• 대한족부족관절학회지
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• 제22권4호
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• pp.151-155
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• 2018

Purpose: Toe ulcers have been implicated as a causative factor in diabetic foot amputation. The aim of this study was to evaluate the outcomes of percutaneous needle flexor tenotomies of diabetic claw toes with ulcers or pending ulcers. Materials and Methods: The authors undertook a retrospective chart review between January 2014 and June 2016 to identify those patients who underwent a percutaneous needle flexor tenotomy for diabetic claw toe deformities. We evaluated 54 toes in 42 patients. Twenty-four patients were female and the mean age at the time of operation was 57 years. The mean follow-up time was 11 months. Thirty-four patients (46 toes) had tip toe ulcers or pending ulcers and 8 patients (8 toes) had dorsal pending ulcers. All patients had palpable pulses and good capillary refill. Results: Forty-three of 46 tip toe ulcers (93.5%) healed without significant complications and 8 dorsal ulcers showed no specific changes within 5 weeks. There were no recurrent ulcers at final follow-up. Four patients developed transfer lesion of the adjacent toe and needed subsequent tenotomy. Conclusion: Percutaneous needle tenotomy in an outpatient clinic was an effective and safe method for treating toe ulcers in neuropathic patients to offload the tip of the toe so that ulcer healing could occur.