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The dynamic responses of two-dimensional granular material subjected to the oblique impact and side impact of a spherical projectile are investigated experimentally and also numerically by using discrete element method. The granular material is modeled by the 329 nylon spheres arranged regularly and two-dimensionally in a rectangular container. The numerical simulations are carried out at the impact velocities less than 10 m/s. The numerical simulations are compared with the results of measurements using high-speed video camera. It is ascertained that the motion of each particle can be well simulated by discrete element method. The dynamic response of the particulate aggregation is elucidated by probing the distribution of velocity vectors of individual particle and normal direction component of contact forces between particles in detail. The effect of wave propagation on the shattering behavior of granular materials is manifested. It is found that the dynamic arching in granular material is formed just under impact point.

Treatment of cervical carotid stenosis with the contralateral internal carotid artery (ICA) occlusion or severe stenosis has not been established because of its specific cerebral circulation. We sought to clarify the clinical features and best surgical treatment of cervical severe carotid stenosis with contralateral ICA occlusion or severe stenosis.We studied 8 patients with bilateral severe ICA stenosis (≥70%) and 5 patients with ICA severe stenosis and contralateral ICA occlusion. To evaluate cerebral circulation, regional cerebral blood flow (rCBF) of the middle cerebral arterial territory and stump pressure of the ICA were measured. rCBF was measured before and after CEA. Rates of association of systemic diseases were analyzed. There was no perioperative complication or new stroke in the follow-up time (2-138 months) in this series. In 3 of the 8 patients, rCBFs were bilaterally decreased below 40 ml/100 g/min. rCBF of severe ICA stenosis with contralateral ICA occlusion or severe stenosis was lower than that of unilateral ICA stenosis. In 6 of 9 patients who underwent CEA, rCBF increased over 15% after operation. Stump pressures of the ICA in the patients with severe ICA stenosis associated with contralateral ICA occlusion or severe stenosis were significantly (p

To clarify the correlation between high-shear flow and hemolysis in blood pumps, detail shear velocity distribution was quantified by an experimental method with a model centrifugal blood pump that has a series data of hemolysis tests and computational fluid dynamic analyses. Particular attention was paid to the shear velocity near the casing surface in the volute where the high shear causes in circumferentially wide region that is considerable to cause high hemolysis. Three pump models were compared concern with the radial gap width between the impeller and casing (the radial volute width) also with the outlet position whereas the impeller geometry was identical. These casing geometries were as follows: model 1-the gap width is standard 3mm and the outlet locates to make a smooth geometrical connection with the volute, model 2-the gap width is small 0.5mm and the outlet locates to make the smooth geometrical connection with the volute, and model 3-the gap width is small 0.5mm and the outlet locates to hardly make the smooth geometrical connection with the volute but be similar radial position with that of model 1. Velocity was quantified with a particle tracking velocimetry that is one of the quantitative flow visualization techniques, and the shear velocity was calculated. Results showed that all large shear velocity existed within the layers of about 0.1mm from the casing surface and that those layers were hardly affected by a vane passage even if the gap width is 0.5mm. They also showed that the maximum shear velocity appeared on the casing surface, and the shear velocities of models 2 and 3 were almost twice as large as that of model 1. This finding is in full corresponding with the results of hemolysis tests which showed that the hemolysis levels of both models 2 and 3 were 1.5 times higher than that of model 1. These results suggest that detailed high-shear evaluation near the casing surface in the volute is one of the most important keys in estimating the hemolysis of a centrifugal blood pump.

International cooperative studies have almost established carotid endarterectomy (CEA) as the surgical treatment for carotid artery stenosis to prevent cerebral infarction. However, the procedure's success depends on ability of a surgeon's technique and perioperative control with complication under 3% for aymptomatic stenosis. There is little experience with CEA in Japan, so reports of long-term follow-up studies are rare. We have performed CEA with a stable team for the past 17 years, and review surgical outcomes and follow-up results.The mean age of 203 CEAs was 64. There were 175 men. We have routinely used a shunt system and intraoperative monitoring under general anesthesia. These patients were followed up for 6.5 years on average, and a change of ADL was evaluated with Glasgow Outcome Scale.Four patients (2.0%) showed neurological deficits such as hemipapresis. The causes were cerebral embolism, wound hemorrhage, cerebral ischaemia by carotid artery hemostasis, and hyperperfusion syndrome. However, all of them were seen in the initial period of more than 10 years before. Mortality was 0%. One hundred and sixty patients were followed up for more than a year. Three patients had re-stenosis and occlusion of the operated internal carotid artery, and 2 of them were operated on again while asymptomatic. Four patients (2.5%) had ischemic attack in the operated side, but all of the lesions were at intracranial sites. Aggravation of ADL was recognized in 28 patients with no carotid lesions. There were 19 deaths, 10 of which were caused by cancers. Twenty-seven patients had ischemic heart diseases, 6 of whom died.CEA is effective for prevention of cerebral infarction, when practiced surgeons perform with intraoperative monitoring. However, general examination and treatment with cardiologists are necessary, because patients often have cardiovascular diseases.

Blood coagulation is one of the primary concerns when using mechanical circulatory support devices such as blood pumps. Noninvasive detection and imaging of thrombus formation is useful not only for the development of more hemocompatible devices but also for the management of blood coagulation to avoid risk of infarction. The objective of this study is to investigate the use of near-infrared light for imaging of thrombus formation in a rotary blood pump. The optical properties of a thrombus at wavelengths ranging from 600 to 750 nm were analyzed using a hyperspectral imaging (HSI) system. A specially designed hydrodynamically levitated centrifugal blood pump with a visible bottom area was used. In vitro antithrombogenic testing was conducted five times with the pump using bovine whole blood in which the activated blood clotting time was adjusted to 200 s prior to the experiment. Two halogen lights were used for the light sources. The forward scattering through the pump and backward scattering on the pump bottom area were imaged using the HSI system. HSI showed an increase in forward scattering at wavelengths ranging from 670 to 750 nm in the location of thrombus formation. The time at which the thrombus began to form in the impeller rotating at 2780 rpm could be detected. The spectral difference between the whole blood and the thrombus was utilized to image thrombus formation. The results indicate the feasibility of dynamically detecting and imaging thrombus formation in a rotary blood pump.

We have developed a hydrodynamically levitated centrifugal pump as a bridge-to-decision device. The purpose of the present study is to determine the optimal bearing gap of a multiarc radial bearing in the developed blood pump for the reduction of hemolysis. We prepared eight pump models having bearing gaps of 20, 30, 40, 80, 90, 100, 180, and 250 μm. The driving conditions were set to a pressure head of 200 mm Hg and a flow rate of 4 L/min. First, the orbital radius of the impeller was measured for the evaluation of the impeller stability. Second, the hemolytic property was evaluated in an in vitro hemolysis test. As a result, the orbital radius was not greater than 15 μm when the bearing gap was between 20 and 100 μm. The relative normalized index of hemolysis (NIH) ratios in comparison with BPX-80 were 37.67 (gap: 20 μm), 0.95 (gap: 30 μm), 0.96 (gap: 40 μm), 0.82 (gap: 80 μm), 0.77 (gap: 90 μm), 0.92 (gap: 100 μm), 2.76 (gap: 180 μm), and 2.78 (gap: 250 μm). The hemolysis tended to increase at bearing gaps of greater than 100 μm due to impeller instability. When the bearing gap decreased from 30 to 20 μm, the relative NIH ratios increased significantly from 0.95 to 37.67 times (P 0.01) due to high shear stress. We confirmed that the optimal bearing gap was determined between 30 and 100 μm in the developed blood pump for the reduction of hemolysis.

Polyamide 11 (PA11) is one of bioplastics (plant-derived plastics or recyclable-resource-based plastics). It is produced from renewable castor seeds. The castor seeds are inedible. This point is important due to the future food insecurity. In order to increase Young’s modulus, in the present study, silica nanoparticles were added to PA11. The effects of the addition of silica nanoparticles and the surface treatment of nano silica particles on the stress-strain curves of PA11-based polymer composites at high strain rates were examined. After dynamic tensile tests, the fracture surfaces of the specimens were observed.

Cerebral regional oxygen saturation (rSO2) can be measured immediately and noninvasively just after arrival at the hospital and may be useful for evaluating the futility of resuscitation for a patient with out-of-hospital cardiopulmonary arrest (OHCA). We examined the best practices involving cerebral rSO₂ as an indicator of the futility of resuscitation.This study was a single-center, prospective, observational analysis of a cohort of consecutive adult OHCA patients who were transported to the University of Tokyo Hospital from October 1, 2012, to September 30, 2013, and whose cerebral rSO₂ values were measured.During the study period, 69 adult OHCA patients were enrolled. Of the 54 patients with initial lower cerebral rSO₂ values of 26% or less, 47 patients failed to achieve return of spontaneous circulation (ROSC) in the receiver operating characteristic curve analysis (optimal cutoff, 26%; sensitivity, 88.7%; specificity, 56.3%; positive predictive value, 87.0%; negative predictive value, 60.0%; area under the curve [AUC], 0.714; P = .0033). The AUC for the initial lower cerebral rSO₂ value was greater than that for blood pH (AUC, 0.620; P = .1687) or lactate values (AUC, 0.627; P = .1081) measured upon arrival at the hospital as well as that for initial higher (AUC, 0.650; P = .1788) or average (AUC, 0.677; P = .0235) cerebral rSO₂ values. The adjusted odds ratio of the initial lower cerebral rSO₂ values of 26% or less for ROSC was 0.11 (95% confidence interval, 0.01-0.63; P = .0129).Initial lower cerebral rSO₂ just after arrival at the hospital, as a static indicator, is associated with non-ROSC. However, an initially lower cerebral rSO₂ alone does not yield a diagnosis performance sufficient for evaluating the futility of resuscitation.

To investigate deposition of platelets in centrifugal blood pumps, flow visualization analysis for a model centrifugal pump was conducted and the results were compared with those of a numerical analysis and an animal experiment. The region behind the impeller was investigated, and it was found that washout holes induced stagnation relative to the impeller along a belt at 52% radius for a rotational speed of 3130 rpm and a flow rate of 51/min. This result was in good agreement with the finding of computational fluid dynamic analysis which predicted stagnation at 54%. The visualization result was also compared to that of an experiment conducted on a dog at a rotational speed of 2600 rpm and a flow rate of 0.51/min. The flow visualization results, predicting stagnation at 68% radius, had a certain correlation with the animal experiment, which revealed platelet deposition at 55% radius.

For understanding the mechanical behavior of nano-scale metallic contact, the first principle simulations are conducted for atomic chain and bulk single crystal of aluminum under tension. The elastic constants calculated for the bulk coincides well with the experimental data reported. The distance between the adjacent atoms in the chain under no load is 0.247 nm, which is much smaller than the distance between the nearest atoms in the bulk (0.283 nm) . The chain breaks at the maximum load of 1.1 nN and at the strain of about 0.2. The chain shows higher strength and lower elongation in comparison with the bulk.

Background The aim of this study was to assess morphological changes in the endarterectomized carotid region using B-mode ultrasonography (USG). METHODS USG examinations were performed on 54 Japanese patients who underwent carotid endarterectomy (CEA). The endarterectomized regions were periodically investigated and the intima-media thickness (IMT) was measured. RESULTS Postoperative USGs revealed an evident step formation (type I: 20.4%), a gentle slope (type II: 42.6%), or complete smoothness (type III: 37.0%) at the junction of the endarterectomized carotid region and the common carotid artery (CCA). The IMT of the CCA progressively increased from type I to type III. Patients were followed up for an average of 2.7 years. The new intima-media complex (IMC) was confirmed in all cases after 9 months; it was visualized as an isoechoic layer (7%) or a mixture of iso- and hypoechoic layers (93%). Changes in the IMT during the follow-up period were classified into three groups: no change (group I: 23.1%), decrease (group II: 15.4%), and increase (group III: 61.5%). CONCLUSIONS USG is useful to clarify the complicated healing processes of the endarterectomized carotid artery.

The effect of a cutout on the pump pressure-flow characteristics and the impeller stability was quantified using computational fluid dynamics analysis in order to provide good hemocompatibility of the monopivot extracorporeal circulation pump. As a result, the following findings were clarified. The pump pressure is lower in the cutout model than in the no-cutout model. The impeller stability with respect to the buoyancy of the impeller is better in the cutout model than in the no-cutout model. The impeller stability with respect to the impeller tilt is better in the cutout model than in the no-cutout model. Therefore, the cutout model, in which the geometry corresponds to the commercialized pump, was likely to be better than the no-cutout model because the stability that has the possibility to decrease the gap instantaneously to increase hemolysis despite the impeller rotational speed slightly.

A centrifugal blood pump for artificial heart has to have low hemolysis and no thrombus formation. For finding and removing the fluid dynamic causes of the above mentioned phenomena, flow visualization was utilized, as flow visualization can identify the high shear and stagnation locations which relate to hemolysis and thrombus formation respectively. In the present paper, general fluid dynamic characteristics of centrifugal blood pumps will be extracted, through analyzing four typical centrifugal pumps with flow visualization technique. Finding shear in the volute and diffuser regions, confirming vortex formation at washout holes, and quantitative analysis of the flow in the inlet regions are the shown examples. The obtained results correspond well to hemolysis tests, which proves that flow visualization is a useful tool in developing and analyzing blood pumps for artificial hearts.

Using temperature profiles obtained by the GPS/MET (GPS Meteorology) experiment from April 1995 to February 1997, we have extracted mesoscale temperature perturbations with vertical wavelengths ranging from 2 to 10 km and background Brunt-Vaisala frequency squared, N2. For each occultation event, we can evaluate a potential energy Ep which is assumed to be caused by atmospheric gravity waves. The monthly mean values of Ep at 15–20 km around Japan showed an annual variation with an enhancement in winter, which is consistent with the climatological behavior of the kinetic energy of gravity waves observed with the MU (middle and upper atmosphere) radar (34.9°N, 136.0°E) from 1985 to 1989. We have then derived the global distribution of Ep at 20–30 km during Northern Hemisphere winter (from November to February). Our analysis shows that the largest Ep values are generally centered around the equator between 25°N and 25°S with considerable longitude variations. Longitudinal variations of Ep at 20–30 km in a latitude range of 30°–60°N are also analyzed, resulting in larger Ep values over the continents than over the Pacific Ocean. Using GPS/MET data without antispoofing, latitudinal variations of Ep are determined in 15–45 km. Although large Ep values are concentrated near the equator at 20–30 km, Ep tends to become larger at midlatitudes at 30–40 km and higher-altitude regions. At midlatitudes, Ep is found to be larger in winter months in both hemispheres. Height variations of Ep indicate a decrease at 25–30 km and a monotonic increase above 30 km.

In this paper, an acoustic lens is designed and built in order to determine wave velocities from measured critical angles of waves, using the complex V(z) curve method. The properties of the new lens are evaluated by the transfer function of the lens and the time-domain response of the transducer. The performance of the new lens is examined using specimens of fused quartz and glass. These results are compared with those of a lens using the conventional V(z) method. It is shown that the critical angles of the waves can be determined clearly and simultaneously using the new lens.

A flow visualization study of a centrifugal blood pump was conducted to find the shear and velocity profiles in the back gap between the impeller and the casing. For a wide range of Reynolds numbers and specific speeds, it was found that high shear exists only in the boundary layers of the moving and stationary walls. The velocity profile was essentially laminar. It was also found that the total thickness of the high shear regions is 0.3-0.6mm for conditions of artificial heart and the thickness is determined only by Reynolds number. Hence, it can be concluded that reducing the impeller velocity is the only way to reduce wall shear stress and that increasing the gap width is not effective.

The functional characteristics of a thin film/coating depend critically upon its interface characteristics and adhesion to the substrate. However, reliable assessment of interface characteristics has remained a complex problem. Interface integrity is one such characteristic that is of critical importance to thin film characterization, failure analysis and process development efforts. This paper presents the scanning acoustic microscope (SAM) as an effective tool for the characterization of thin film/substrate interface integrity as well as nondestructive subsurface imaging. The potential offered by the SAM as an important tool to be used in conjunction with indentation/fracture mechanics based studies of thin film adhesion is also presented. The application of innovative SAM based imaging techniques for the assessment of film integrity and damage in representative titanium nitride and polycrystalline diamond thin films is presented.

With a 250% scaled-up pump model, high speed video camera, and argon ion laser light sheet, flow patterns related to hemolysis were visualized and analyzed with 4 frame particle tracking software. Different flow patterns and shear distributions were clarified by flow visualization for pumps modified to have different hemolysis levels. A combination of in vitro hemolysis tests, flow visualization, and CFD analysis suggested a close relationship between hemolysis and high shear caused by small impeller/casing gaps. Because arbitrary cross sections can be illuminated by laser light sheet, flow visualization is a useful tool in finding locations related to hemolysis in the design process of rotary blood pumps.

To establish quantitative, efficient design theories for centrifugal blood pumps, computational fluid dynamics (CFD) analyses were compared to the results of flow visualization tests and hemolysis tests, mainly on the Nikkiso centrifugal blood pump. The results turned out to coincide in the velocity vector plots. CFD analysis revealed that the smaller the gap is, the greater the shear stress becomes. This tendency becomes even greater with a radial gap change. Hemolysis study also indicated that the smaller the gap is, the greater the hemolysis. CFD analysis in comparison with hemolysis tests could be a useful index for developing blood pumps in the future.

Background and Purpose —The efficacy of superficial temporal artery–middle cerebral artery (STA-MCA) anastomosis in adult moyamoya disease was evaluated by clinicopathophysiological studies. Methods —Fifteen patients with cerebral ischemic attacks (ischemia group) and 15 patients with intracranial hemorrhages (hemorrhage group) were investigated. Clinicoangiographic features and regional cerebral blood flow (rCBF) of the MCA territory were preoperatively and postoperatively investigated, and cortical arterial pressure (CAP) and anastomotic blood flow (AF) were intraoperatively measured. Results —In the ischemia group, the preoperative rCBF of 38.4 mL/100 g per minute was significantly increased to 42.1 mL/100 g per minute with a diminution of angiographic moyamoya vessels in 67% of patients after surgery. The mean CAP and AF were 25.6 mm Hg and 34.7 mL/min, respectively. Proximal and distal cerebral vascular resistance (PCVR=[Mean Systemic Arterial Blood Pressure−Mean CAP]/rCBF and DCVR=[Mean CAP/rCBF]) were 1.78 and 0.68, respectively. One patient died perioperatively as a result of intracerebral hemorrhage. During follow-up (mean, 67 months), 12 of 14 patients recovered without neurological deficits, 1 was moderately disabled because of the initial insult, and another patient experienced an intracerebral hemorrhage but recovered fully. In the hemorrhage group, the preoperative rCBF of 38.0 mL/100 g per minute was significantly increased to 42.7 mL/100 g per minute with a diminution of moyamoya vessels in 60% after surgery. The mean CAP and AF were 29.1 mm Hg and 24.1 mL/min, respectively. PCVR and DCVR were 1.72 and 0.77, respectively. One patient became hemiparetic because of perioperative intracerebral hemorrhage. During follow-up (mean, 94 months), 3 patients had fatal intracranial hemorrhages, 10 had good recoveries, and 2 had moderate disabilities. Conclusions —This study revealed a high PCVR and a very low DCVR in both the ischemia and hemorrhage groups of patients. STA-MCA anastomosis partially normalized cerebral circulation and decreased moyamoya vessels but did not completely prevent rebleeding.

TCD findings used for evaluating vasospasm (VSP) due to ruptured aneurysm are controversial. To clarify these TCD findings, intra-arterial DSA (IA-DSA) was applied to study morphological changes and to measure cerebral circulation time (CCT) . Forty-six patients with ruptured aneurysms treated by neck clipping at the acute stage were investigated. Clinical grade and CT findings were estimated using the Hunt and Hess classification and Fisher's classification, respectively. Mean flow velocity (MFV) in the M1 segment was measured by TCD. IA-DSA was performed on the day 7-13 day. Angiographic VSP was categorized by Fisher's classification. CCT was defined by the time difference between the two peak optical density curves recorded by IA-DSA at the carotid artery (C3-4) and the ascending vein. Mean CCT was 3.7 sec in patients without VSP and 4.3 sec in those with slight to moderate VSP, which were significantly different from mean CCT, 6.2 sec, in patients with severe VSP. MFV in patients with no, slight to moderate, and severe VSP was 82, 104 and 124 cm/sec, respectively, none of the differences being significant. Additionally, patients with diffuse VSP extending from the M2 to peripheral sites showed increased CCT values and an unchanged MFV value. These findings suggest that use of the MFV at the M1 segement for estimating the severity of diffuse peripheral VSP is problematic.

A flow visualization study of a centrifugal blood pump was conducted to find velocity profiles in the gap between the impeller and the housing. Investigating a wide range of Reynolds numbers and specific speeds, it was found that high shear is found only in the boundary layers of the moving and stationary walls and that the total thickness of the boundary layers is 0. 3-0. 6mm depending the Reynolds number.

Activation studies of cerebral circulation are important for evaluation of cerebrovascular reactivity (CVR) . In this study, CVR was investigated in 52 healthy subjects, 25 patients with chronic severe hypertension and 16 patients with hyperlipidemia. All the patients had normal findings of neurological studies, brain CT and neck vessel echo-Doppler. The CVR was assessed by TCD recording of blood flow velocity in the middle cerebral artery (MCAFV) under resting conditions and at 5, 10, 15 and 20 min after i.v. injection of 1g Acz. Additionally, we performed an Acz-activated 133Xe-CT study in 8 healthy patients (16 hemispheres) who had mild carotid stenosis on MR-angiography. The regional cerebral blood flow (rCBF) in the MCA territory was measured and the CVR was also analyzed. MCAFV and CVR determined by TCD study showed a non-significant tendency to be reduced in the group aged over 60 yr. The MCAFV under resting conditions was nearly the same in the normal controls and in the patients with hypertension, but the CVR was decreased in patients even without stroke. The normal value of CVR seemed to be 40-50% in this study. When planning surgical treatment for asymptomatic patients (e.g.; those with occlusive cerebrovascular disease and unruptured cerebral aneurysm) with decreased CVR, they should be treated carefully using prophylaxis for ischemic complications.

剖検や経食道心エコー図検査 (TEE) で大動脈における動脈硬化病変と虚血性脳血管障害との関連性が指摘されて以来, TEEが大動脈における動脈硬化病変の評価に利用されている.しかし, TEEは侵襲的検査法であり, 全ての患者で探触子が挿入できるわけではない.さらに, 上行大動脈の遠位側は気管の走行によりTEEによる評価が困難である.そこで, 筆者らは右鎖骨上窩からBモード法で大動脈における動脈硬化の評価を試み, その所見をTEEと比較した.右鎖骨上窩からのBモード検査には7.5MHzの周波数を有するlinear型の探触子を, TEEには5-7MHzの可変周波数を有するmultiplane探触子を用いた.お互いの検査所見を知らない異なる検者が20症例で二つの検査を行い, 上行大動脈と大動脈弓部をそれぞれ近位部と遠位部に分けて, 各部位における単純動脈硬化病変 (4mm未満) と複合動脈硬化病変 (4mmを越える) の有無を調べた.近位上行大動脈ではTEEで8個の単純動脈硬化病変を検出したが, 右鎖骨上窩からのBモード検査ではいずれも検出できなかった.遠位上行大動脈では1つの複合動脈硬化病変が両検査でみられ, 右鎖骨上窩からのBモード検査は単純と複合動脈硬化病変をさらに1ずつ検出した.近位大動脈弓部では両検査で6つの複合動脈硬化病変と5つの単純動脈硬化病変がみられ, さらにTEEはもう1つの複合動脈硬化病変を検出した.遠位大動脈弓部ではTEEが2ずつの単純と複合動脈硬化病変を見いだし, 右鎖骨上窩からのBモード検査が3つの複合動脈硬化病変を見いだした.以上の結果から, TEEは近位上行大動脈の評価に, 右鎖骨上窩からのBモード検査は遠位上行大動脈の評価に優れており, 右鎖骨上窩からのBモード検査は上行大動脈と大動脈弓部の評価におけるTEEの所見を補う検査法といえるであろうと結論している.

The purpose of this study is to examine the relationship between the flow condition and hemolysis level by integrating hemolysis test, flow visualization and computational fluid dynamics(CFD)to establish design criteria for the good hemocompatible centrifugal pump. Axial and radial gaps between the impeller tip and casing wall of Nikkiso centrifugal blood pump were modified independently and flow condition and hemolytic property of these pumps were examined. Examined gaps were 1.5, 1.0, and 0.5 mm for axial gap and 3.0, 2.0, 1.0, and 0.5 mm for radial gap, respectively. The pumps with the axial gap of 0.5 mm and the radial gap of 0.5 mm showed higher hemolysis level than the other pumps showed. Maximum shear stress in the pump, estimated by CFD, were increased by decreasing the radial gap from 3.0 to 0.5 mm. Regional flow pattern change at the tongue region by decreasing radial gap was observed by flow visualization. Gaps between impeller tip and casing wall are dominant factors to determine hemolytic property of the centrifugal pump. Relationship between regional flow pattern and blood trauma should be investigated in the future.

邦人の頸部頸動脈狭窄病変に対するシャントシステムをルーチンに用いた血栓内膜剥離術(CEA : carotid endarterectomy)155例,170側の臨床結果を報告する.TIA,RIND,MCS及び無症候性病変症例が各々51,23,45,51例であった.病変の狭窄度と広がりは,各々平均74%,1.2cmであった.術中SEP検査などから約20%に頸動脈遮断による重篤な脳虚血が推察された.手術成績は,mortalityゼロ,morbidity4例であった.長期追跡調査では無症候性の再狭窄,閉塞を3例に認めた.脳虚血発作は,4例に認められたが,CEA部に起因する再発作はみられなかった.死亡例は12例で,原因疾患は7例が癌,2例が心疾患であった.以上より著者らのCEAは,邦人の頸部頸動脈狭窄病変に対する安全かつ有効な手術法であることが示唆された.

A 62-year-old male complaining of unilateral visual disturbance and pain in the involved eye had a small mass at the right orbital apex which was identified as an Aspergillus granuloma by transcranial biopsy. One month later, the patient became comatose because of fatal subarachnoid hemorrhage due to a newly developed aneurysm. Autopsy showed a ruptured aneurysm on the right internal carotid-posterior communicating artery. Histological examination demonstrated prominent Aspergillus invasion of the arterial wall. Aspergillus infection must be taken into consideration in patients with orbital apex syndrome, which may lead to serious cerebrovascular consequences. If sino-orbital lesions are detected by neuroimaging techniques, biopsy using an extradural approach should be performed to obtain a definitive diagnosis.