AIM:To evaluate safety and feasibility of microcoil embolization of the common hepatic artery under proper or distal balloon inflation in preoperative preparation for en bloc celiac axis resection for pancreatic body ...AIM:To evaluate safety and feasibility of microcoil embolization of the common hepatic artery under proper or distal balloon inflation in preoperative preparation for en bloc celiac axis resection for pancreatic body cancer.METHODS:Fifteen patients(11 males,4 females;median age,67 years) with pancreatic body cancer involving the nerve plexus surrounding the celiac artery underwent microcoil embolization.To alter the total hepatic blood flow from superior mesenteric artery(SMA),microcoil embolization of the common hepatic artery(CHA) was conducted in 2 cases under balloon inflation at the proximal end of the CHA and in 13 cases under distal microballoon inflation at the distal end of the CHA.RESULTS:Of the first two cases of microcoil embolization with proximal balloon inflation,the first was successful,but there was microcoil migration to the proper hepatic artery in the second.The migrated microcoil was withdrawn to the CHA by an inflated microballoon catheter.Microcoil embolization was successful in the other 13 cases with distal microballoon inflation,with no microcoil migration.Compact microcoil embolization under distal microballoon inflation created sufficient resistance against the vascular wall to prevent migration.Distal balloon inflation achieved the requisite 1 cm patency at the CHA end for vascular clamping.All patients underwent en bloc celiac axis resection without arterial reconstruction or liver ischemia.CONCLUSION:To impede microcoil migration to the proper hepatic artery during CHA microcoil embolization,distal microballoon inflation is preferable to proximal balloon inflation.展开更多
Purpose: To determine whether endovascular embolization of pseudoaneurysms complicating pancreatitis with microcoils was associated with better therapeutic outcome. Materials and Method: The prospective clinical study...Purpose: To determine whether endovascular embolization of pseudoaneurysms complicating pancreatitis with microcoils was associated with better therapeutic outcome. Materials and Method: The prospective clinical study was carried out in the Department of Interventional Radiology for a period of 2 years extending from May 2010 upto August 2012 on 16 male patients in the age group of about 30 - 55 years, with each one of them having vascular complications as a sequel to pancreatitis, after obtaining well informed written consent from each one of them. Results: The outcome of the procedure was judged by the following parameters—a) Restoration of the blood pressure of the patient;b) Cessation of the hemetemesis and malena;c) Reduction in abdominal pain and discomfort and d) Overall improvement in the general condition of the patient. Each of the patients had been on follow up for at least 6 months, except 2 of them, with no new complaints in any of them. The procedure related mortality was none. Conclusion: Vascular complications of pancreatitis need immediate and accurate diagnosis and prompt treatment. Micro coil embolisation, is a minimally invasive technique which helps to exclude the pseudoaneurysm from the circulation and thus reduces the scope for massive life threatening internal hemorrhage, and is a better alternative to surgery.展开更多
Splenic artery aneurysms (SAA) are third most common intra-abdominal aneurysm (after aneurysms of the abdominal aorta and iliac arteries). A splenic artery aneurysm larger than 3 cm is even rare. Splenic artery aneury...Splenic artery aneurysms (SAA) are third most common intra-abdominal aneurysm (after aneurysms of the abdominal aorta and iliac arteries). A splenic artery aneurysm larger than 3 cm is even rare. Splenic artery aneurysms are fatal vascular lesions if ruptured. The incidence of rupture is increased in larger aneurysms. Transcatheter arterial embolization is an alternative method of treatment in a patient with splenic arterial aneurysm which has relative lower morbidity and mortality than surgical procedures. Here, we report a case of giant ruptured proximal splenic artery pseudoaneurysm detected by contrast enhanced computed tomography (CECT) & referred to Interventional Radiology for Transcatheter arterial embolisation.展开更多
This paper reports that carbon microcoils are grown through a chemical vapour deposit process, they are then embedded in silicone rubber, and manipulated to parallel with each other along their axes in the resulting c...This paper reports that carbon microcoils are grown through a chemical vapour deposit process, they are then embedded in silicone rubber, and manipulated to parallel with each other along their axes in the resulting composite. The impedance ｜Z｜ as well as phase angle 8 of both the original carbon microcoil sheets and the aligned carbon microcoil/silicone rubber composites are measured. The results illustrate that carbon microcoils in different forms show different alternating current electric properties. The aligned carbon microcoils in the composites show stable parameters for f 〈 104 Hz but a sharp decrease in both ｜Z｜ and θ for frequencies 〉 10^4 Hz, which will also change as the carbon microcoils are extended. But, the original sheets have a pure resistance with their parameters stable throughout the entire alternating current frequency range investigated.展开更多
With the rapid development of microelectronics and flexible electronics technology,self-powered sensors have significant application prospects in human-machine interface systems and Internet of Things.However,piezoele...With the rapid development of microelectronics and flexible electronics technology,self-powered sensors have significant application prospects in human-machine interface systems and Internet of Things.However,piezoelectric-and triboelectricbased sensors have low current output and are easily affected,while electromagnetic-based sensors are difficult to miniaturize.This work proposes a high-density stacked microcoil integrated microminiaturized electromagnetic vibration energy harvester(EVEH).The double-layer high-density microcoil is fabricated on both sides of the flexible polyimide substrate interconnected via the central through-hole.Owing to reduced single coil line width,line spacing,and stacked structure,the number of turns can be substantially enhanced.Moreover,the relative position of the coils and magnet has a considerable influence on the performances;due to the huge change rate in magnetic flux when the coil is placed in the radial direction of the magnet than in the axial direction,the open-circuit voltage in the radial direction is 10 times greater.The microcoil can maintain good performance at high,low temperatures and under bending conditions.When the distance between the ends of the coil changes from 2 to 20 mm in 2 mm steps,the bending angle of the coil changes from 45°to 270°in 45°steps;furthermore,when the coil is exposed to-40and 60℃conditions,the coil resistance is maintained at approximately 447Ω.The peak open-circuit voltage of three-piece microcoils reaches 0.41 V at 4 Hz under 2g,and the output voltage and current increase with an increasing number of stacked layers.These excellent properties indicate that EVEH can be used for self-powered acceleration sensing.The sensitivity is measured to be 0.016 V/(m/s^(2))with a correlation coefficient of 0.979 over the acceleration range of 1–18 m/s^(2).Thus,the developed microminiaturized EVEH has enormous potential for self-powered sensing applications in confined spaces and harsh environments.展开更多
Objective: To evaluate the long-term effect of endovascular occlusion with microcoils on traumatic pseudoaneurysms (TPAs) in the common carotid artery in rabbits.Methods: TPAs in the right common carotid artery were s...Objective: To evaluate the long-term effect of endovascular occlusion with microcoils on traumatic pseudoaneurysms (TPAs) in the common carotid artery in rabbits.Methods: TPAs in the right common carotid artery were surgically made in 16 rabbits. At 3-4 weeks after operation, the survived 12 models were randomly divided into a control group (n=3) with no treatment and an experimental group (n=9), in which TPAs were intraluminally embolized with microcoils and corresponding therapy was given. Three months after embolization, the TPAs were examined with digital subtraction angiography and pathology. Results: The 3 rabbits in the control group all died of rupture of TPA. Among the 9 TPAs occluded with microcoils, 4 were completely occluded, 4 were partially occluded, and 1 was excluded due to the microcoils migrating into the parent artery. Three months after embolization, the 4 TPAs which were completely occluded remained obliterated as determined by digital subtraction angiographic findings. The parent artery remained unobstructed and the structure of the TPAs were replaced by a mass of scar tissues. The 4 TPAs which were partially occluded remained unruptured and the microcoils were compressed.Conclusions: The lumen in TPA can be completely occluded by microcoils and the parent artery is unblocked. Partial occlusion of the lumen can also prevent the rupture of TPA.展开更多
This paper introduces a new technology to fabricate a micro electromagnetic actuator with high energy density without an enclosed magnetic circuit. This technology includes fabricating multi-turns planar micro coils a...This paper introduces a new technology to fabricate a micro electromagnetic actuator with high energy density without an enclosed magnetic circuit. This technology includes fabricating multi-turns planar micro coils and fabricating the thick magnetic （NiFe） core on the silicon wafer. The multi-turns planar micro coils are fabricated by the electroplating method from the surface along the line and by dynamically controlling the current density of the copper electrolytes. In order to fabricate thick NiFe plating,the adhesion properties between the NiFe plating and the silicon substrates are improved by changing the surface roughness of the silicon substrates and increasing the thickness of the seed layer. Furthermore,the micro electromagnetic actuator is tested and the energy density of the actuator is evaluated by force testing. The experiments show that the microactuator is efficient in producing high magnetic energy density and high magnetic force.展开更多
文摘AIM:To evaluate safety and feasibility of microcoil embolization of the common hepatic artery under proper or distal balloon inflation in preoperative preparation for en bloc celiac axis resection for pancreatic body cancer.METHODS:Fifteen patients(11 males,4 females;median age,67 years) with pancreatic body cancer involving the nerve plexus surrounding the celiac artery underwent microcoil embolization.To alter the total hepatic blood flow from superior mesenteric artery(SMA),microcoil embolization of the common hepatic artery(CHA) was conducted in 2 cases under balloon inflation at the proximal end of the CHA and in 13 cases under distal microballoon inflation at the distal end of the CHA.RESULTS:Of the first two cases of microcoil embolization with proximal balloon inflation,the first was successful,but there was microcoil migration to the proper hepatic artery in the second.The migrated microcoil was withdrawn to the CHA by an inflated microballoon catheter.Microcoil embolization was successful in the other 13 cases with distal microballoon inflation,with no microcoil migration.Compact microcoil embolization under distal microballoon inflation created sufficient resistance against the vascular wall to prevent migration.Distal balloon inflation achieved the requisite 1 cm patency at the CHA end for vascular clamping.All patients underwent en bloc celiac axis resection without arterial reconstruction or liver ischemia.CONCLUSION:To impede microcoil migration to the proper hepatic artery during CHA microcoil embolization,distal microballoon inflation is preferable to proximal balloon inflation.
文摘Purpose: To determine whether endovascular embolization of pseudoaneurysms complicating pancreatitis with microcoils was associated with better therapeutic outcome. Materials and Method: The prospective clinical study was carried out in the Department of Interventional Radiology for a period of 2 years extending from May 2010 upto August 2012 on 16 male patients in the age group of about 30 - 55 years, with each one of them having vascular complications as a sequel to pancreatitis, after obtaining well informed written consent from each one of them. Results: The outcome of the procedure was judged by the following parameters—a) Restoration of the blood pressure of the patient;b) Cessation of the hemetemesis and malena;c) Reduction in abdominal pain and discomfort and d) Overall improvement in the general condition of the patient. Each of the patients had been on follow up for at least 6 months, except 2 of them, with no new complaints in any of them. The procedure related mortality was none. Conclusion: Vascular complications of pancreatitis need immediate and accurate diagnosis and prompt treatment. Micro coil embolisation, is a minimally invasive technique which helps to exclude the pseudoaneurysm from the circulation and thus reduces the scope for massive life threatening internal hemorrhage, and is a better alternative to surgery.
文摘Splenic artery aneurysms (SAA) are third most common intra-abdominal aneurysm (after aneurysms of the abdominal aorta and iliac arteries). A splenic artery aneurysm larger than 3 cm is even rare. Splenic artery aneurysms are fatal vascular lesions if ruptured. The incidence of rupture is increased in larger aneurysms. Transcatheter arterial embolization is an alternative method of treatment in a patient with splenic arterial aneurysm which has relative lower morbidity and mortality than surgical procedures. Here, we report a case of giant ruptured proximal splenic artery pseudoaneurysm detected by contrast enhanced computed tomography (CECT) & referred to Interventional Radiology for Transcatheter arterial embolisation.
基金Project supported by the Natural Science Foundation of Jiangsu Province of China (Grant No. BK2008129)
文摘This paper reports that carbon microcoils are grown through a chemical vapour deposit process, they are then embedded in silicone rubber, and manipulated to parallel with each other along their axes in the resulting composite. The impedance ｜Z｜ as well as phase angle 8 of both the original carbon microcoil sheets and the aligned carbon microcoil/silicone rubber composites are measured. The results illustrate that carbon microcoils in different forms show different alternating current electric properties. The aligned carbon microcoils in the composites show stable parameters for f 〈 104 Hz but a sharp decrease in both ｜Z｜ and θ for frequencies 〉 10^4 Hz, which will also change as the carbon microcoils are extended. But, the original sheets have a pure resistance with their parameters stable throughout the entire alternating current frequency range investigated.
基金supported in part by the National Key Research and Development Program of China(Grant No.2019YFE0120300)the National Natural Science Foundation of China(Grant Nos.52175554,62171414,52205608)+1 种基金the Fundamental Research Program of Shanxi Province(Grant No.202103021223201)the Young Top Talent Project of Hebei Provincial Department of Education(Grant No.BJK2023116)。
文摘With the rapid development of microelectronics and flexible electronics technology,self-powered sensors have significant application prospects in human-machine interface systems and Internet of Things.However,piezoelectric-and triboelectricbased sensors have low current output and are easily affected,while electromagnetic-based sensors are difficult to miniaturize.This work proposes a high-density stacked microcoil integrated microminiaturized electromagnetic vibration energy harvester(EVEH).The double-layer high-density microcoil is fabricated on both sides of the flexible polyimide substrate interconnected via the central through-hole.Owing to reduced single coil line width,line spacing,and stacked structure,the number of turns can be substantially enhanced.Moreover,the relative position of the coils and magnet has a considerable influence on the performances;due to the huge change rate in magnetic flux when the coil is placed in the radial direction of the magnet than in the axial direction,the open-circuit voltage in the radial direction is 10 times greater.The microcoil can maintain good performance at high,low temperatures and under bending conditions.When the distance between the ends of the coil changes from 2 to 20 mm in 2 mm steps,the bending angle of the coil changes from 45°to 270°in 45°steps;furthermore,when the coil is exposed to-40and 60℃conditions,the coil resistance is maintained at approximately 447Ω.The peak open-circuit voltage of three-piece microcoils reaches 0.41 V at 4 Hz under 2g,and the output voltage and current increase with an increasing number of stacked layers.These excellent properties indicate that EVEH can be used for self-powered acceleration sensing.The sensitivity is measured to be 0.016 V/(m/s^(2))with a correlation coefficient of 0.979 over the acceleration range of 1–18 m/s^(2).Thus,the developed microminiaturized EVEH has enormous potential for self-powered sensing applications in confined spaces and harsh environments.
文摘Objective: To evaluate the long-term effect of endovascular occlusion with microcoils on traumatic pseudoaneurysms (TPAs) in the common carotid artery in rabbits.Methods: TPAs in the right common carotid artery were surgically made in 16 rabbits. At 3-4 weeks after operation, the survived 12 models were randomly divided into a control group (n=3) with no treatment and an experimental group (n=9), in which TPAs were intraluminally embolized with microcoils and corresponding therapy was given. Three months after embolization, the TPAs were examined with digital subtraction angiography and pathology. Results: The 3 rabbits in the control group all died of rupture of TPA. Among the 9 TPAs occluded with microcoils, 4 were completely occluded, 4 were partially occluded, and 1 was excluded due to the microcoils migrating into the parent artery. Three months after embolization, the 4 TPAs which were completely occluded remained obliterated as determined by digital subtraction angiographic findings. The parent artery remained unobstructed and the structure of the TPAs were replaced by a mass of scar tissues. The 4 TPAs which were partially occluded remained unruptured and the microcoils were compressed.Conclusions: The lumen in TPA can be completely occluded by microcoils and the parent artery is unblocked. Partial occlusion of the lumen can also prevent the rupture of TPA.
文摘This paper introduces a new technology to fabricate a micro electromagnetic actuator with high energy density without an enclosed magnetic circuit. This technology includes fabricating multi-turns planar micro coils and fabricating the thick magnetic （NiFe） core on the silicon wafer. The multi-turns planar micro coils are fabricated by the electroplating method from the surface along the line and by dynamically controlling the current density of the copper electrolytes. In order to fabricate thick NiFe plating,the adhesion properties between the NiFe plating and the silicon substrates are improved by changing the surface roughness of the silicon substrates and increasing the thickness of the seed layer. Furthermore,the micro electromagnetic actuator is tested and the energy density of the actuator is evaluated by force testing. The experiments show that the microactuator is efficient in producing high magnetic energy density and high magnetic force.
