Optical coherence tomography(OCT)allows a direct and precise measurement of laser welding depth by coaxially measuring the keyhole depth and can be used for process monitoring and control.When OCT measurement was take...Optical coherence tomography(OCT)allows a direct and precise measurement of laser welding depth by coaxially measuring the keyhole depth and can be used for process monitoring and control.When OCT measurement was taken during single-beam laser welding,the keyhole instability of aluminum welding resulted in highly scattered OCT data and complicated the welding depth extraction methods.As a combination of an inner core beam and an outer ring beam,a novel adjustable ring mode(ARM)laser for producing a stable keyhole was applied to the OCT measurement.Different ARM laser power arrangements were conducted on aluminum and copper.The results indicated that the ring beam greatly improved the stability of the core beam-induced keyhole,and smooth welding depth can be extracted from the concentrated OCT data.展开更多
A 45-year-old man of Middle Eastern origin, morbid obese, with a body mass index of 39 had an intragastric balloon, filled with 500 mL of saline/methylene blue and intended as definite therapy, inserted some8 wk previ...A 45-year-old man of Middle Eastern origin, morbid obese, with a body mass index of 39 had an intragastric balloon, filled with 500 mL of saline/methylene blue and intended as definite therapy, inserted some8 wk previously. He was admitted to the emergency department with abdominal cramps. An ultrasound of the abdomen was performed in ER which confirmed the balloon to be in place without any abnormality.He was discharged home on symptomatic medication.Patient remains symptomatic therefore he reported back to ER 2 d later. Computed tomography scan was performed this time for further evaluation which revealed a metallic ring present in the small bowel while the intra-gastric balloon was in its proper position.There was no clinical or radiological sign of intestinal obstruction. Patient was hospitalized for observation and conservative management. The following night,patient experienced sudden and severe abdominal pain, therefore an X-ray of the abdomen in erect position was done, which showed free air under the right dome of diaphragm. Patient was transferred to O.R for emergency laparotomy. There were two small perforations identified at the site of the metallic ring entrapment. The ring was removed and the perforations were repaired. Due to increasing prevalence of obesity and advances in modalities for its management,physicians should be aware of treatment options, their benefits, complications and clinical presentation of the known complications. Physicians need to be updated to approach these complications within time, to avoid lifethreatening situations caused by these appliances.展开更多
基金supported by the National Natural Science Foundation of China(No.12002215)the China Postdoctoral Science Foundation(No.2022T150437)the National Key Research and Development Program of China(No.2019YFC1511102)。
文摘Optical coherence tomography(OCT)allows a direct and precise measurement of laser welding depth by coaxially measuring the keyhole depth and can be used for process monitoring and control.When OCT measurement was taken during single-beam laser welding,the keyhole instability of aluminum welding resulted in highly scattered OCT data and complicated the welding depth extraction methods.As a combination of an inner core beam and an outer ring beam,a novel adjustable ring mode(ARM)laser for producing a stable keyhole was applied to the OCT measurement.Different ARM laser power arrangements were conducted on aluminum and copper.The results indicated that the ring beam greatly improved the stability of the core beam-induced keyhole,and smooth welding depth can be extracted from the concentrated OCT data.
文摘A 45-year-old man of Middle Eastern origin, morbid obese, with a body mass index of 39 had an intragastric balloon, filled with 500 mL of saline/methylene blue and intended as definite therapy, inserted some8 wk previously. He was admitted to the emergency department with abdominal cramps. An ultrasound of the abdomen was performed in ER which confirmed the balloon to be in place without any abnormality.He was discharged home on symptomatic medication.Patient remains symptomatic therefore he reported back to ER 2 d later. Computed tomography scan was performed this time for further evaluation which revealed a metallic ring present in the small bowel while the intra-gastric balloon was in its proper position.There was no clinical or radiological sign of intestinal obstruction. Patient was hospitalized for observation and conservative management. The following night,patient experienced sudden and severe abdominal pain, therefore an X-ray of the abdomen in erect position was done, which showed free air under the right dome of diaphragm. Patient was transferred to O.R for emergency laparotomy. There were two small perforations identified at the site of the metallic ring entrapment. The ring was removed and the perforations were repaired. Due to increasing prevalence of obesity and advances in modalities for its management,physicians should be aware of treatment options, their benefits, complications and clinical presentation of the known complications. Physicians need to be updated to approach these complications within time, to avoid lifethreatening situations caused by these appliances.
