Multi-points 3D Stretch-Press-Bending Process for Forming of W-Shaped Mirror-Symmetrical Structural Parts

Song Gao,Yingli Sun,Qihan Li,Tonggui He,Jicai Liang 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.23 No.3

To improve the aerodynamic performance of high-end equipment, the mirror-symmetrically 3D curved aluminum structural parts are increasingly assembled in the manufacturing industry. A new type of multi-points 3D stretch-press-bending (3D SPB) process for forming this kind of component is proposed in this paper. A prototype of this process is developed. The 3D SPB experiments are carried out. This new process realizes the complex bending for multi-directional curvature radius, which increases the material utilization by 6.79% and doubles the production efficiency. Then, the numerical simulation models are established. It has a good prediction result for the 3D springback. The maximum relative error of springback prediction is less than 20%. Besides, the effect of pre-stretching and post-stretching are investigated, which determines the most suitable forming parameters at s pre-stretching and 0.3 s post-stretching. At last, the springback direct compensation method is applied to the precise forming of the target part. Though two times adjustment, the deviation reduces effectively. The precise forming experiment is carried out based on the optimized forming parameters. The maximum total deviation is 1.52 mm, which satisfies the forming requirement. The 3D SPB process achieves the pairwise forming of the W-shaped mirror-symmetric structural parts and improves production efficiency.

家兎에 있어서의 Atropine의 中樞性心搏減少에 關하여

宋熙善 전북대학교 의과학연구소 1980 全北醫大論文集 Vol.4 No.1

The author observed changes in heart rate and blood pressure following injection of atropine and scopolamine into the lateral ventricle or cisterna magna of rabbits under urethane anesthesia. The results were as followings : 1. Intraventricular atropine(30, 100, 300ug) slightly decreased the heart rate, while the same amounts of scopolamine did not. 2. Atropine (30, 100, 300ug) administered into cisterna magna produced marked decrease in heart rate, while the same amounts of scopolamine produced slight decrease. 3. The decrease in heart rate by intracisternal atropine was less prominent in the vagoto-mized or methylatropinized rabbits. 4. After intracisternal injection of regitine intracisternal norepinephrine did not produce decrease in heart rate, while intracisternal atropine produced slight decrease. 5. After simultaneous administrations of intracisternal regitine and intravenous me-thyla tropine, intracisternal atropine did not progduce the decrease in heart rate. 6. The stimulation of the vagal center and central adrenorecepters may be responsible for the bradycardia by central atropine. It is suggested that the bradycardia by atropine in man is not related to that in the present experiments.

제왕절개술을 위한 경막외 마취시 국소마취제 용량과 혈중농도의 비교

송희선,한영진,이준례,송정자 대한마취과학회 1994 Korean Journal of Anesthesiology Vol.27 No.7

Epidural anesthesia for cesarean section requires sensory blockade up to T4 level. 18 to 20 ml of 0.5% bupivacaine, 1.5 to 2.0% lidocaine, or 3.0% chloropmcaine usually produces an adequate sensory blockade to T4 level. However, when we used that amount of local anesthetics, most of the patients often complained of mild to moderate pain or discomfort during delivery of baby, manipulation of peritoneum or the uterus. So we feeled the need of increase in dosage of local anesthetics and we used 26 ml of local anesthetics or local anesthetic-fentanyl mixture. This study was undertaken to measure plasma concentration of lidocaine and observe the possible systemic toxicity of local anesthetics with the total dosage of beyond maximum recom-mended dose. Epidural anesthesia were performed with a 17 gauge Tuohy needle and local anesthetics were injected as follows. Group 1 (n;17): 0.5% bupivacaine 100 mg+2% lidocaine 80 mg+fentanyl 100 ㎍ (50 ㎍/ml) Group 2 (n; 15): 2% lidocaine 520 mg without epinephrine Group 3 (n; ll): 2% lidocaine 480 mg + fentanyl 100 ㎍ All groups were received 26 ml of local anesthetics or local anesthetic-fentanyl mixture. We checked the level of anesthesia, length of spinal column, cardiovascular changes, plasma concen- tration of lidocaine, toxic systemic reactions and patient's complaints. The plasma concentration of lidocaine were measured by immunofluorescence assay at 2, 5, 7, 10, 12 and 15 minutes after injection of local anesthetics. The results were as follows; 1) The peak plasma concentration of lidocaine were measured 12 minutes after administration of local anesthetics in the group 2 and 3. 2) Sensory blockade up to T4 level could be accomplished within 10 minutes after epidural anesthesia in the group l. 3) In the group 2 and 3, onset of action was more rapid. These groups had a tendency to fall in blood pressure than the group 1, but recovered soon with small dose of ephedrine. 4) In one patient, maximum peak plasma concentration of hdocaine was 6.8 ug/ml, but no adversereaction was observed. Above results suggested that 26 ml of local anesthetics in all groups could be used for appropriate anesthesia for cesarean section with minimal camplications and patient's satisfaction.

후두마스크 삽입 및 기관내삽관이 안압에 미치는 영향

송희선,이상귀,김재양 대한마취과학회 1994 Korean Journal of Anesthesiology Vol.27 No.7

Many studies have been performed in order to evaluate intraocular pressure changes during induction and maintenance of anesthesia in ocular surgery. Use of the laryngeal mask airway permits the maintenance of a clear airway without laryngoscopy. To evaluate the effect of laryngeal mask airway placement with/withaut laryngoscopy on intraocular pressure, sixty patients were randomly allocated to one of three groups; a tracheal intubation group with laryngoscopy (TI, n=20); a laryngeal mask airway placement group with laryngoscopy (LMA-L, n=20); a laryngeal mask airway placement group with blind technique (LMA, n=20). The authors compared the intraocular pressure and hemodynamic responses to the laryngeal mask airway insertion with (LMA-L group) and without (LMA group) laryngoscope to those of tracheal intubation (TI group) in 60 patients during a standardized anesthetic pratice. Baseline measurements of intrao- cular pressure, heart rate, and arterial blood pressures were recorded and repeated at one minute after insertion of the airway device in each group. Insertion of the laryngeal mask airway required significantly more time (LMA-L group, 15.5 sec; LMA group, 14.3 sec) in comparison with that for the tracheal intubation (9.1 sec). The laryngeal mask airway placement did not increase intraocular pressure, or arterial blood pressures except for heart rate above baseline values. However, tracheal intubation was associated with significant increases of intraocular pressure, heart rate, and arterial blood pressure at one minute compared to the baseline values. The mean intraocular pressures at one minute after airway instrumentation in TI group were significantly different from those of LMA or LMA-L group. The authors suggest that a laryngeal mask airway may be a good alternative to tracheal intubation in intraocular surgery if a laryngeal mask airway is not contraindicated.

Epinephrine 과 Clonidine 에 의한 T-Cain 척수마취의 연장 효과

송희선,한영진,이상귀,최현규,신감진 대한마취과학회 1991 Korean Journal of Anesthesiology Vol.24 No.3

Vasoconstrictors such as epinephrine or phenylephrine have been used as an adjunct to local anesthetics to prolong the duration of spinal anesthesia. Recently, clonidine, an areceptor agonist, has been proved to have analgesic effect and to prolong epidural and spinal anesthesia. We used 0.3mg of epinephrine, 75 μg and 150 μg of clonidine in spinal anesthesia with 12 mg of T-Cain respectively and compared hemodynamic and analgesic effects of each drug. Heart rate and blood pressure were checked before, during and after anesthesia. Sensory level was checked by pin-prick method and motor blockade was measured by Bromages scale. The results were as follows. 1) Heart rate changed little in the epinephrine group and decreased significantly in all other groups. 2) Systolic blood pressure decreased significantly in all groups except the epinephrine group. Both 75 μg and 150 μg of clonidine caused a significant fall in diastolic pressure. 3) The onset time for sensory and motor blockade varied little among all gro 4) Sensory blockade was significantly higher in the 150 μg of clonidine group than the control group. Time to achieve the maximum level of sensory blockade was significantly faster in control group than 150 μg of clonidine group. 5) The duration of sensory and motor blockade was significantly prolonged in epinephrine and clonidine group than control group. The results indicate that clonidine, when used as an adjunct to T-Cain spinal anesthesia, is as effective as epinephrine in prolongation of motor and sensory blockade.

전신 마취시 아산화질소 투여 중단후 중이 내압의 변동

송희선,이상귀,윤용주,홍기환,최현규,신감진,권삼현 대한마취과학회 1991 Korean Journal of Anesthesiology Vol.24 No.6

N₂O can diffuse in and/or out the middle ear cavities and it may alter the middle ear pres-sure. This study was performed to investigate the effect of N₂O discontinuation on the changes in middle ear pressure during general endotracheal anesthesia. We measured middle ear pres-sures and end-tidal NO concentrations at preanesthesia, immediately after N₂O discontinuation and then at every five minutes for 60 minutes under either halothane or enflurane an- esthesia in two groups(group 1=50% administration of N₂O in O₂; group 2=60% administration of N₂O in O₂). The middle ear pressures after N₂O discontinuation decreased slowly but they did not returned to the preanesthetic value in both groups. The end-tidal N₂O concentrations decreased rapidly until five minutes and then they decresed slowly to the zero leve1 until 30 minutes after N₂O discontinuation in both groups. The expected time of the middle ear pres-sure of preanesthesia value was 89.4 minutes in group 1 and 80.9 minutes in group 2 respectively. The middle ear pressure do not return to the level of preanesthesia at 60 minutes after N₂O discontinuation while the end-tidal N₂O concentration decrease to the zero level via 30 minutes after its discontinuation. Thus it is recommended that N₂O administration should be discontinued at least 30 minutes before an application of tympanic membrane patch on the ear drum and N₂O is carefully administered in patients with middle ear and/or upper airway disesses.

제종 α- Adrenoceptor Antagonist 의 Norepinephrine 및 Phenylephrine 승압효과에 미치는 영향

송희선 대한마취과학회 1983 Korean Journal of Anesthesiology Vol.16 No.1

1) The effects of various a-adrenoceptor antagonists on the pressor responses to norepinephrine and phenylephrine were examined in anesthetized rabbits in an attempt to determine whether a_1-and a_2-adrenoceptors are located on vascular smooth muscle. 2) Yohimbine and piperoxan caused a much greater reduction in the pressor responses (rise of 30-50 mmHg) to norepinephrine than to phenylephrine, where as labetalol, thymoxamine, phentolamine and prazosin showed a much greater selectivity in reducing the pressor responses to phnylephrine than to norepinephrine. 3) The pressor action of small dose of norepinephrine (rise of 10-20 mmHg) was not significantly inhibited by the doses of labetalol, thymoxamine and prazosin which caused marked reduction of the above phenylephrine pressor responses, but yohimbine, piperoxan and phenotolamine weakened the action significantly. 4) The results suggest that there are two types, a_1 and a_2, of postsynaptic a-adrenoceptors in the vasculature of rabbits. It seems that phenylephrine produces pressor responses by acting on a_1-type adrenoreceptors; small doses of norepinephrine by acting on a_1-type ; large doses of norepinephrine by acting on both types.

수술중 Bupivacaine 으로 늑간신경차단후 갑자기 발생한 저혈압

송희선,이상귀,송정자,구자홍 대한마취과학회 1994 Korean Journal of Anesthesiology Vol.27 No.5

Postoperative pain may be associated with shallow breathing, inability to cough, and reduction in spirometric values which lead to restrictive pattern of ventilation with hypoxemia and/or hypercarbia. Therefore, postoperative pain should be managed with appropriate methods. The authors have usually performed intraoperative intercostal nerve block with 0.25% bupivacaine hydrochloride to alleviate postoperative thoracotomy pain. A 21 years old male patient developed sudden hypotension and severe bradycardia 1 minute following the intraoperative 4th, 5th, 6th intercostal nerve block with a total of 10 ml of 0.25% bupivacaine hydrochloride, who was treated by ephedrine with success. The authors discuss the possible causes of sudden hypotension and severe bradycardia in detail.

기관튜브의 종류가 굴곡성 후두경을 이용한 경구 기관내삽관의 용이도에 미치는 영향

송희선,이상귀,이준례,김윤희 대한마취과학회 1997 Korean Journal of Anesthesiology Vol.32 No.2

Background : The spiral-wound tracheal tubes have the different flexibility, materials, and shape of bevel according to the manufacturers. Theses different tube characteristics may affect the ease of orotracheal intubation. So this study was designed to investigate the ease of fiberoptic orotracheal intubation with two different types of spiral-wound tracheal tube. Methods : Seventy-one adult female patients who undergo fiberoptic intubation were randomly divided into two groups. Fiberoptic orotracheal intubation with silicone made spiral-wound tracheal tubes(M group) or silicone-rubber made spiral-wound tracheal tubes(R group) was performed. In the first attempt, the tracheal tube was advanced into the trachea over the pediatric fiberoptic laryngoscope which was orotracheally placed with the bevel of the tracheal tube oriented anteriorly at 12 o'clock direction. If the insertion was hindered the tracheal tube was withdrawn about 4∼5cm backward and rotated 60o to the left(10 o'clock direction) and readvanced If the second attempt was unsuccessful the tracheal tube was rotated 60o to the right(2 o'clock direction) and readvanced. If the third attempt was unsuccessful it was considered that the fiberoptic intubation was failed. Results : Success rate of the first attempt was 23.7%(9/38) in group M and 72.7%(24/33)in group R(P$lt;0.05). Failure rate was 23.7%(9/38) in group M and 3.0%(1/33) in group R(P$lt;0.05). Conclusions : It should be considered that the ease of fiberoptic intubation is different according to different types of spiral-wound tracheal tube in the attempt of fiberoptic orotracheal intubation. (Korean J Anesthesiol 1997; 32: 214∼218)

고농도 Isoflurane 흡에 의한 심혈관계 반응의 연령에 따른 차이

송희선,이준례,고성훈,이민승 대한마취과학회 2000 Korean Journal of Anesthesiology Vol.38 No.2

Background : The inhalation of a high concentration of isoflurane transiently increases heart rate (HR) and blood pressure. The current study examined the effects of age on isofluraneinduced circulatory responses. Methods : One hundred-ten patients were randonlly allocated into one of four groups according to age: under 10 years (Group 1),20-40 years (Group 2),41-60 years (Group 3), and over 65 years (Group 4). In each group, the inspired concentration of isoflurane via mask was increased to 5.0 vol % abruptly The target was to produce an end-tidal concentration of isoflurane (ET,isof) of 2.6 vol% which was maintained until the end of the study by adjusting the vaporizer setting when necessary. HR, mean arterial Pressure (MAP), ETisof, and end-tidal concentration of carbon dioxide were measured at baseline and every 30 seconds for 5 minutes after inhalation of isoflurane and for 2 minutes after intubation. Results : HR and MAP significantly increased after inhalation of isoflurane in all four groups compared With the baseline. The time from administration of isoflurane to the maximal HR was less than that for MAP. However. there were no significant differences among the groups for Etisof at the maximal HR and MAP. In Groups 1 and 4, the times for maximal HR were shorter than in Groups 2 and 3. In aged patients (Group 4), the isoflurane-induced HR increase was less than in the other three groups. There were no significant differences among the groups in increases of MAP. Conclusions: The high concentration of isoflurane transiently increases HR and MAP during inhaled anesthesia induction. In aged patients, the increase in HR is less than in younger-aged patients. (Korean J Anesthesiol 2000: 38: 272 ∼219)