This paper presents an efficient hierarchical occlusion test algorithm to support the global illumination solution such as Ray Tracing and Radiosity. This method, which is based on a cone volume intersection examinati...This paper presents an efficient hierarchical occlusion test algorithm to support the global illumination solution such as Ray Tracing and Radiosity. This method, which is based on a cone volume intersection examination, can rapidly remove the irrelevant parts in a scene and find the vertices which fall into the shadow area of a given object. It is an effective alternative to the conventional shadow feeler method.展开更多
AIM: To reveal angiographic findings to predict the re-sult of balloon test occlusion(BTO).METHODS: The cerebral angiograms of 42 consecu-tive patients who underwent cerebral angiography in-cluding both the Matas and ...AIM: To reveal angiographic findings to predict the re-sult of balloon test occlusion(BTO).METHODS: The cerebral angiograms of 42 consecu-tive patients who underwent cerebral angiography in-cluding both the Matas and Allcock maneuvers and BTO were retrospectively analyzed. Visualization of the an-terior cerebral artery(ACA) and the middle cerebral ar-tery(MCA) by the cross flow on the tested side during the Matas or Allcock maneuver was graded on a 5-point scale. Circle of Willis(COW) anatomy with respect to the presence/absence of a collateral path to reach the tested internal carotid artery(ICA) was classified intofour categories. A univariate logistic analysis was used to analyze the associations between each angiographic finding and the BTO result. Sensitivity, specificity, accu-racy, positive predictive value, and negative predictive value for each finding were calculated. RESULTS: Five patients(12%) were BTO-positive and the remaining 37 patients(88%) were BTO-negative. Visualizations of the ACA and MCA as well as the COW anatomy were significantly associated with the BTO re-sult(P = 0.0051 for ACA, P = 0.0002 for MCA, and P < 0.0001 for COW anatomy). In particular, good MCA vi-sualization and the presence of an anterior connection(collateral path to the tested ICA from the contralateral ICA via the anterior communicating artery) in the COW were highly predictive for negative BTO(negative pre-dictive value = 100% for both).展开更多
Reliability of medical devices such as infusion pumps is extremely important because these devices are being used in patients who are in critical condition. Occlusion pressure, as an important parameter of infusion pu...Reliability of medical devices such as infusion pumps is extremely important because these devices are being used in patients who are in critical condition. Occlusion pressure, as an important parameter of infusion pumps, should be detected when an occlusion occurred. How-ever, infusion pumps’ occlusion pressure could not be tested and the performance of these pumps is not known to us. In order to test the occlusion pressure of infusion pump, a testing system has been put forward according to standards of IEC 60601-2-24:1998/ GB 9706.27- 2005. The system is comprised of sensor, acquisition card, three-way tap and so on;this system is controlled by a PC. At the same time, sampling rate could be changed if necessary and test time could be recorded. And then the characteristics of this system were studied, such as linear, effects of pump rates and different pumps. The system remained linear in a given environment. The higher is the pump rate, the faster is the time to reach occlusion condi-tion. The testing system has been proved to be effective in testing the occlusion pressure of infusion pumps and the accuracy error of pressure is content the demand of ±1% of range.展开更多
The frequency of neurologic complications of cerebral angiography is 0.3%-2.3%, and the frequency of the persistent neurologic deficits that remain over 7-10 days is 0.4%-0.5%. On the other hand, all neurologic compli...The frequency of neurologic complications of cerebral angiography is 0.3%-2.3%, and the frequency of the persistent neurologic deficits that remain over 7-10 days is 0.4%-0.5%. On the other hand, all neurologic complications of balloon test occlusion (BTO) have been reported in 0%-8.3% and especially in 1.6%-1.7% of symptomatic neurologic complications. There are a few reports concerning a seizure related to cerebral angiography and BTO. We report a case of prolonged seizures and left hemiparesis during and after BTO of the right internal carotid artery. The patient showed repeated focal seizures and prolonged left hemiparesis lasting for approximately 2 months. Computed tomography and magnetic resonance imaging demonstrated no abnormal findings. Suspected mechanisms of seizure were a cerebral blood flow change induced by BTO and neurotoxicity of accumulated contrast medium. A combination of prolonged focal seizures and subsequent hemiparesis is a rare complication of BTO, which should be taken into consideration during BTO.展开更多
The vascular occlusion test (VOT) is an experiment that simulates the process of distal ischemia-reperfusion of tissue based on the monitoring of tissue oxygen saturation (StO2) to obtain VOT parameters related to StO...The vascular occlusion test (VOT) is an experiment that simulates the process of distal ischemia-reperfusion of tissue based on the monitoring of tissue oxygen saturation (StO2) to obtain VOT parameters related to StO2 changes to evaluate microcirculation function of the measured muscle tissue. VOT has the advantages of real-time, noninvasive and continuous, and is widely used to evaluate the functional status of peripheral microcirculation and the relationship between microcirculation changes and prognosis of patients. In clinical work, doctors mainly focus on hemodynamics of patients, while microcirculation function is often neglected due to the lack of real-time monitoring methods, which may lead to severe poor prognosis of patients, especially patients with critical illness. This paper focuses on the clinical application of vascular occlusion test based on tissue oxygen saturation monitoring.展开更多
The authors are reporting on a study drawn from unpublished dissertation done by the corresponding author when he completed his neurosurgical training in Paris, France in 2004, few years before the advent of flow dive...The authors are reporting on a study drawn from unpublished dissertation done by the corresponding author when he completed his neurosurgical training in Paris, France in 2004, few years before the advent of flow diverters. The study was a retrospective review of giant intracranial aneurysms treated by superficial temporal artery to middle cerebral artery bypass combined with endovascular occlusion of the parent artery. From 1990 to 2003, 29 consecutive cases of giant cerebral aneurysms, not suitable to selective treatment were managed in that way. Twenty-one medical records had enough data to allow objective evaluation. Sixteen female and five male patients bearing 21 giant aneurysms were involved. Their mean age was 46 years. The aneurysm was revealed by mass effect in 13 cases and subarachnoid hemorrhage in one case. On admission 19 patients presented with unruptured aneurysms and two have sustained a subarachnoid hemorrhage. The balloon occlusion test before the bypass operation was not tolerated in 18 patients. The treatment was completed in 19 patients and 17 of them had parent artery occlusion with latex detachable balloons. The only death of the series occurred before the endovascular treatment. The mean follow-up period was 30 months. After completion of the treatment, 16 (84%) patients had no symptom. Aneurysm recanalization or rupture was not observed after the parent artery occlusion. With the combination of superficial temporal artery to middle cerebral artery bypass + endovascular parent artery occlusion, 90% of giant intracranial aneurysms untreatable selectively were permanently excluded with a good outcome in 95%.展开更多
In order to investigate the force characteristics of the occlusal pile, this paper takes the underground garage support project of Nanchang Bayi Square as the research background and studies the bending moment of the ...In order to investigate the force characteristics of the occlusal pile, this paper takes the underground garage support project of Nanchang Bayi Square as the research background and studies the bending moment of the occlusal pile after the excavation process of the foundation pit through the model test. The test results show that the bending moment of the pile increases and then decreases with the increase of soil depth under horizontal load, and the bending moment reaches the maximum near the excavation surface of the foundation pit;the test results can provide a reference for the design of occluded pile body in practical engineering.展开更多
为了更好地应对多目标跟踪联合检测算法面对的场景遮挡问题,通过结合注意力机制,提出基于Transformer的运动预测和数据关联(Transformer-based motion prediction and data association,TrMPDA)联合检测跟踪方法。首先,考虑到置信度检...为了更好地应对多目标跟踪联合检测算法面对的场景遮挡问题,通过结合注意力机制,提出基于Transformer的运动预测和数据关联(Transformer-based motion prediction and data association,TrMPDA)联合检测跟踪方法。首先,考虑到置信度检测框的质量以及深度特征的视觉表示能力对遮挡场景下跟踪效果的影响,重新设计TrMPDA骨干网络中的ResNet卷积模块,利用相邻像素和长距离像素间丰富的上下文关系指导动态注意矩阵的学习,增强深度特征的视觉表示能力,并通过边界框的宽和高估计边界框位置,提高置信度检测框的质量。其次,在本文方法中保留所有的检测框,根据阈值大小划分高置信度检测框和低置信度检测框,分别执行数据关联匹配,以此来平衡由于遮挡导致的检测框低置信度。实验结果表明本文提出的TrMPDA方法与典型的Sort、JDE、Fairmot等多目标跟踪算法相比具有更好的跟踪效果,能够应对多目标跟踪中目标遮挡的问题。展开更多
文摘This paper presents an efficient hierarchical occlusion test algorithm to support the global illumination solution such as Ray Tracing and Radiosity. This method, which is based on a cone volume intersection examination, can rapidly remove the irrelevant parts in a scene and find the vertices which fall into the shadow area of a given object. It is an effective alternative to the conventional shadow feeler method.
文摘AIM: To reveal angiographic findings to predict the re-sult of balloon test occlusion(BTO).METHODS: The cerebral angiograms of 42 consecu-tive patients who underwent cerebral angiography in-cluding both the Matas and Allcock maneuvers and BTO were retrospectively analyzed. Visualization of the an-terior cerebral artery(ACA) and the middle cerebral ar-tery(MCA) by the cross flow on the tested side during the Matas or Allcock maneuver was graded on a 5-point scale. Circle of Willis(COW) anatomy with respect to the presence/absence of a collateral path to reach the tested internal carotid artery(ICA) was classified intofour categories. A univariate logistic analysis was used to analyze the associations between each angiographic finding and the BTO result. Sensitivity, specificity, accu-racy, positive predictive value, and negative predictive value for each finding were calculated. RESULTS: Five patients(12%) were BTO-positive and the remaining 37 patients(88%) were BTO-negative. Visualizations of the ACA and MCA as well as the COW anatomy were significantly associated with the BTO re-sult(P = 0.0051 for ACA, P = 0.0002 for MCA, and P < 0.0001 for COW anatomy). In particular, good MCA vi-sualization and the presence of an anterior connection(collateral path to the tested ICA from the contralateral ICA via the anterior communicating artery) in the COW were highly predictive for negative BTO(negative pre-dictive value = 100% for both).
文摘Reliability of medical devices such as infusion pumps is extremely important because these devices are being used in patients who are in critical condition. Occlusion pressure, as an important parameter of infusion pumps, should be detected when an occlusion occurred. How-ever, infusion pumps’ occlusion pressure could not be tested and the performance of these pumps is not known to us. In order to test the occlusion pressure of infusion pump, a testing system has been put forward according to standards of IEC 60601-2-24:1998/ GB 9706.27- 2005. The system is comprised of sensor, acquisition card, three-way tap and so on;this system is controlled by a PC. At the same time, sampling rate could be changed if necessary and test time could be recorded. And then the characteristics of this system were studied, such as linear, effects of pump rates and different pumps. The system remained linear in a given environment. The higher is the pump rate, the faster is the time to reach occlusion condi-tion. The testing system has been proved to be effective in testing the occlusion pressure of infusion pumps and the accuracy error of pressure is content the demand of ±1% of range.
文摘The frequency of neurologic complications of cerebral angiography is 0.3%-2.3%, and the frequency of the persistent neurologic deficits that remain over 7-10 days is 0.4%-0.5%. On the other hand, all neurologic complications of balloon test occlusion (BTO) have been reported in 0%-8.3% and especially in 1.6%-1.7% of symptomatic neurologic complications. There are a few reports concerning a seizure related to cerebral angiography and BTO. We report a case of prolonged seizures and left hemiparesis during and after BTO of the right internal carotid artery. The patient showed repeated focal seizures and prolonged left hemiparesis lasting for approximately 2 months. Computed tomography and magnetic resonance imaging demonstrated no abnormal findings. Suspected mechanisms of seizure were a cerebral blood flow change induced by BTO and neurotoxicity of accumulated contrast medium. A combination of prolonged focal seizures and subsequent hemiparesis is a rare complication of BTO, which should be taken into consideration during BTO.
基金Sichuan provincial health department(2018SHD1-10)
文摘The vascular occlusion test (VOT) is an experiment that simulates the process of distal ischemia-reperfusion of tissue based on the monitoring of tissue oxygen saturation (StO2) to obtain VOT parameters related to StO2 changes to evaluate microcirculation function of the measured muscle tissue. VOT has the advantages of real-time, noninvasive and continuous, and is widely used to evaluate the functional status of peripheral microcirculation and the relationship between microcirculation changes and prognosis of patients. In clinical work, doctors mainly focus on hemodynamics of patients, while microcirculation function is often neglected due to the lack of real-time monitoring methods, which may lead to severe poor prognosis of patients, especially patients with critical illness. This paper focuses on the clinical application of vascular occlusion test based on tissue oxygen saturation monitoring.
文摘The authors are reporting on a study drawn from unpublished dissertation done by the corresponding author when he completed his neurosurgical training in Paris, France in 2004, few years before the advent of flow diverters. The study was a retrospective review of giant intracranial aneurysms treated by superficial temporal artery to middle cerebral artery bypass combined with endovascular occlusion of the parent artery. From 1990 to 2003, 29 consecutive cases of giant cerebral aneurysms, not suitable to selective treatment were managed in that way. Twenty-one medical records had enough data to allow objective evaluation. Sixteen female and five male patients bearing 21 giant aneurysms were involved. Their mean age was 46 years. The aneurysm was revealed by mass effect in 13 cases and subarachnoid hemorrhage in one case. On admission 19 patients presented with unruptured aneurysms and two have sustained a subarachnoid hemorrhage. The balloon occlusion test before the bypass operation was not tolerated in 18 patients. The treatment was completed in 19 patients and 17 of them had parent artery occlusion with latex detachable balloons. The only death of the series occurred before the endovascular treatment. The mean follow-up period was 30 months. After completion of the treatment, 16 (84%) patients had no symptom. Aneurysm recanalization or rupture was not observed after the parent artery occlusion. With the combination of superficial temporal artery to middle cerebral artery bypass + endovascular parent artery occlusion, 90% of giant intracranial aneurysms untreatable selectively were permanently excluded with a good outcome in 95%.
文摘In order to investigate the force characteristics of the occlusal pile, this paper takes the underground garage support project of Nanchang Bayi Square as the research background and studies the bending moment of the occlusal pile after the excavation process of the foundation pit through the model test. The test results show that the bending moment of the pile increases and then decreases with the increase of soil depth under horizontal load, and the bending moment reaches the maximum near the excavation surface of the foundation pit;the test results can provide a reference for the design of occluded pile body in practical engineering.
文摘为了更好地应对多目标跟踪联合检测算法面对的场景遮挡问题,通过结合注意力机制,提出基于Transformer的运动预测和数据关联(Transformer-based motion prediction and data association,TrMPDA)联合检测跟踪方法。首先,考虑到置信度检测框的质量以及深度特征的视觉表示能力对遮挡场景下跟踪效果的影响,重新设计TrMPDA骨干网络中的ResNet卷积模块,利用相邻像素和长距离像素间丰富的上下文关系指导动态注意矩阵的学习,增强深度特征的视觉表示能力,并通过边界框的宽和高估计边界框位置,提高置信度检测框的质量。其次,在本文方法中保留所有的检测框,根据阈值大小划分高置信度检测框和低置信度检测框,分别执行数据关联匹配,以此来平衡由于遮挡导致的检测框低置信度。实验结果表明本文提出的TrMPDA方法与典型的Sort、JDE、Fairmot等多目标跟踪算法相比具有更好的跟踪效果,能够应对多目标跟踪中目标遮挡的问题。
