[The rotating aeration method (Fuchs system) in the treatment of liquid and communal refuse. 11. Effect of rotating aeration on the agent of swine vesicular disease].
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Animals↗
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[Application of a rotating gamma camera to cardiac imaging. (3) Evaluation of thallium ECT (emission computed tomography) by a 180 degree rotation data collection method].
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Heart↗
[The rotation aeration system (Fuchs System) for the treatment of liquid animal and municipal waste. 4. Hygienic studies with the rotation aeration of municipal sewage].
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Hydrogen-Ion Concentration↗
[The rotating aeration (system fuchs) for treatment of liquid and municipal wastes. 10th report: the effect of the rotating aeration on viruses: from the picorna-, reo-, and adeno-group].
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Adenoviridae↗
[The immediate and long-term utility of rotational atherotomes: extraction atherectomy and rotational ablation atherectomy].
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Atherectomy, Coronary↗
[Shift rotation--politicians equate shift with rotation. Interview by Marit Fonn].
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Health Personnel↗
The rotator cuff functional index.
BACKGROUND: Despite improvements in the clinical assessment of rotator cuff injuries, shortcomings exist in diagnosing rotator cuff tears. PURPOSE: To formulate a clinical rotator cuff functional index for predicting rotator cuff tears based on handheld dynamometer measurements for shoulder strength testing and to assess its ability to diagnose a rotator cuff tear. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Preoperative handheld dynamometer measurements, including supraspinatus, external rotation, internal rotation, adduction, and lift-off force, were compared in 100 patients with full-thickness rotator cuff tears (> 1.0 cm) and 100 patients with no rotator cuff injury (confirmed by arthroscopy). Using multiple logistic regression analysis, the rotator cuff functional index and index for rotator cuff tear size were formulated in which 100 represented excellent rotator cuff function and less than 0 indicated a full-thickness supraspinatus tear. Each patient's index was calculated to determine its clinical value in predicting a rotator cuff tear; the Pearson correlation coefficient was established for the rotator cuff functional index for rotator cuff size. RESULTS: Two handheld dynamometer measurements predicted a rotator cuff tear (P < .001, r = 0.53), with rotator cuff functional index = 1.27 * supraspinatus (N) - 0.72 * adduction (N) - 11.6, but not tear size (r = 0.38). In predicting a rotator cuff tear (rotator cuff functional index < 0 = rotator cuff tear; rotator cuff functional index > 0 = no tear), the rotator cuff functional index had 83% sensitivity, 79% specificity, 80% positive predictive value, 82% negative predictive value, likelihood ratio of 4.0 for a positive test result and 0.2 for a negative test result and an accuracy of 81%. CONCLUSION: The 2 most useful tests for determining a rotator cuff tear with a handheld dynamometer were supraspinatus force and adduction force (as negative control). A functional index based on these measurements was able to rule out a rotator cuff tear and predict the presence but not the size of the tear.
Adult↗
The effect of anterior cruciate ligament graft rotation on knee laxity and graft tension: An in vitro biomechanical analysis.
PURPOSE: The purpose of this study was to determine the effects of rotating a bone-patellar tendon- bone allograft during anterior cruciate ligament reconstruction on anteroposterior (AP) knee laxity and forces developed within the graft. TYPE OF STUDY: In vitro biomechanical study using human cadaveric knees. METHODS: Thirteen fresh-frozen knee specimens received bone-patella tendon-bone allografts that were pretensioned at 30 degrees of flexion to restore AP laxity to that of the intact knee. AP laxity was then measured at 0 degrees, 30 degrees, and 90 degrees of knee flexion with the graft in neutral rotation and in 90 degrees and 180 degrees of internal and external rotation. Five specimens received allografts that were rotated to 90 degrees internally and externally and then tensioned. Two knee specimens were used to measure the effects of graft rotation on graft force at full extension; 1 received 7 separate allografts and the other received 10 allografts. During testing, the potted end of the allograft that was connected to a tibial load cell was rotated. RESULTS: In specimens tensioned and then rotated, AP laxity at 30 degrees of knee flexion decreased an average of 0.9 mm with 90 degrees of graft rotation in either direction. At 180 degrees of external rotation, the mean decrease in laxity of 1.8 mm was significantly greater than that for 180 degrees of internal rotation (P <.05). When significant, all mean laxity reductions at 0 degrees and 90 degrees of flexion were less than those at 30 degrees of flexion. In specimens where the graft was rotated and then tensioned, rotation had no significant effect on laxity. With the exception of 90 degrees of external rotation, rotation of the graft increased graft tension at full extension; 90 degrees of internal rotation increased mean graft force by 11 N (P <.05). Rotating the graft 180 degrees in either direction increased mean graft force at full extension by 25 N (P <.05). CONCLUSIONS: Although minor, rotating the graft had significant effects on knee laxity and graft tension. In general, AP laxity decreased and graft tension increased with increasing rotation of the graft. The direction of rotation did not seem to be important. As a result, clinicians who choose to rotate their patellar tendon grafts can expect that the biomechanical changes in the graft with rotation will have little clinical importance.
Adult↗
Comparison of the head elevation versus rotation methods in eliciting vestibular evoked myogenic potentials.
OBJECTIVES: Because active and tonic sternocleidomastoid (SCM) muscle contraction is essential for recording the vestibular evoked myogenic potential (VEMP), false-negative VEMPs are sometimes encountered in those who cannot sustain SCM muscle contraction by head elevation. Hence, the goal of this study was to investigate whether the effortless head rotation method can replace the head elevation method in eliciting VEMP responses. DESIGN: Twenty healthy volunteers underwent VEMP testing, using monaural tone burst stimulation. First, the subject was instructed to keep the head elevated in the pitch plane for recording, followed by rotating the head sideways toward one shoulder as head down in the yaw plane for another recording (elevation-rotation sequence). On the next day, VEMP testing was performed in reverse order (rotation-elevation sequence). Twelve patients with cochleo-vestibular disorders were also enrolled in this study and underwent VEMP testing, using the two methods in random order. RESULTS: In the elevation-rotation sequence for subjects without cochleo-vestibular disorders, the response rate for the elevation method (100%) was significantly higher than the response rate for the rotation method (70%). In contrast, no significant difference existed in the response rate between the two methods in the rotation-elevation sequence (85% versus 88%). Comparison of the response rates for the initial elevation (100%) and initial rotation methods (85%) revealed a significantly lower response rate for the initial rotation method. Mean latencies of the onset waveform and peaks p13 and n23 showed significant differences between the two methods when using the elevation-rotation sequence but no differences on the rotation-elevation sequence. Furthermore, the rotation method displayed significantly smaller amplitude than the elevation method when using the elevation-rotation sequence but no significant difference in amplitude between the two methods when applying rotation-elevation sequence. In 12 patients with cochleo-vestibular disorders, the response rates for the elevation method (67%) and rotation method (58%) were significantly reduced compared with the rates for subjects without cochleo-vestibular pathology. However, when either the elevation or the rotation method response was considered, VEMPs were present in 11 (92%) of the 12 patients with cochleo-vestibular disorders. CONCLUSIONS: The head rotation method may serve as an alternative for eliciting VEMPs in those who cannot sustain SCM muscle contraction by head elevation. However, the lower response rate with smaller amplitude prevents the use of the head rotation method as an initial screening test for VEMPs. We therefore recommend that when VEMP responses cannot be elicited by the head elevation method, the head rotation method should be utilized to reduce false-negative results.
Adult↗
Maintaining spatial body alignment on a rotating platform by means of active counter-circling: role of vestibular and podokinesthetic afferents.
We investigated the behaviour of vision-deprived human subjects who try to maintain their horizontal alignment in space on a rotating platform by stepping about their own axis in counter-direction ('podomotor counter-rotation'), and we ask which of two alternative hypotheses best explains this behaviour. (1) The feedback hypothesis assumes that the podomotor counter-rotation is controlled by negative feedback of vestibular signals from the horizontal canals. (2) The reconstruction hypothesis holds that the vestibular cue first is combined with leg proprioceptive afferents signalling the individual's rotation on the platform ('podokinesthetic cue') in a way that reconstructs the platform's motion in space for internal representation; a negative (direction-inverted) copy of this representation then would drive the counter-rotation. Subjects were exposed to three different velocity profiles of platform rotation: VC, constant velocity rotation with sudden onset and offset; VS, sinusoidal rotation; VN, pseudorandom noise sequences. The subjects' response (i.show $132#e., their active self-rotation on the platform) to the onset and offset of VC rotations was reminiscent of a first-order lead system. Specifically, after rotation onset subjects immediately began to step on the platform in opposite direction; initially, the velocity of this response matched that of platform rotation, leading to a fairly good stabilisation of subjects' alignment in space. However, this response declined exponentially; consequently, subjects began to increasingly rotate in space along with the platform, ultimately stepping in place on the platform. After rotation offset, subjects immediately began to step around on the now stationary platform so as to continue their previous rotation in space; this response again declined exponentially until subjects became gradually stable again with respect to space. Within subjects, the time constant (tau) of these responses was similar for onset and offset. Across subjects it exhibited a conspicuous variability, ranging from 7 s to virtually infinity. The responses to VS and VN rotations were closely correlated to what could be predicted for each individual from his tau during VC on the assumption of a first-order lead system. We conclude that the mechanism stabilising body orientation basically is linear (no prediction with sinusoidal rotation, no extrapolation of constant velocity rotation). A comparison of the experimental results with simulations of the feedback hypothesis and of the reconstruction hypothesis suggests that the reconstruction hypothesis is a more likely description of the underlying processing of the vestibular and podokinesthetic cues.
Adult↗
Motor processes in mental rotation.
Much indirect evidence supports the hypothesis that transformations of mental images are at least in part guided by motor processes, even in the case of images of abstract objects rather than of body parts. For example, rotation may be guided by processes that also prime one to see results of a specific motor action. We directly test the hypothesis by means of a dual-task paradigm in which subjects perform the Cooper-Shepard mental rotation task while executing an unseen motor rotation in a given direction and at a previously-learned speed. Four results support the inference that mental rotation relies on motor processes. First, motor rotation that is compatible with mental rotation results in faster times and fewer errors in the imagery task than when the two rotations are incompatible. Second, the angle through which subjects rotate their mental images, and the angle through which they rotate a joystick handle are correlated, but only if the directions of the two rotations are compatible. Third, motor rotation modifies the classical inverted V-shaped mental rotation response time function, favoring the direction of the motor rotation; indeed, in some cases motor rotation even shifts the location of the minimum of this curve in the direction of the motor rotation. Fourth, the preceding effect is sensitive not only to the direction of the motor rotation, but also to the motor speed. A change in the speed of motor rotation can correspondingly slow down or speed up the mental rotation.
Adult↗
An isokinetic profile of trunk rotation strength in elite tennis players.
PURPOSE: The changes in stroke production in the modern game of tennis have increased the demands on trunk rotation in elite tennis players. Unlike the shoulder, where unilateral strength adaptations have been identified, no study to date has objectively quantified side to side rotational trunk strength in elite tennis players. METHODS: One hundred nine elite tennis players were tested using a Cybex isokinetic torso rotation unit at 60 and 120 degrees x s(-1) to measure left and right rotation while stabilized in a seated position. A repeated-measures ANOVA was used with post hoc dependent t-tests where main effect differences were identified to determine side to side rotational differences. RESULTS: No significant difference in trunk rotation strength was measured in the elite male players. Peak torque to body weight ratios averaged 63.7 and 57.5% for forehand rotation (left rotation in right-handed player) and 64.4 and 59.2% for backhand rotation at 60 and 120 degrees x s(-1), respectively. In females, slightly greater (P < 0.001) backhand rotation strength (right rotation in a right-handed player) was measured at both testing speeds with peak torque to body weight ratios ranging between 47.7 and 45.1% for left rotation and 50.8 and 48.3% for right rotation at 60 and 120 degrees x s(-1), respectively. Left rotation/right rotation ratios ranged from 95 to 98% for males and from 94 to 96% for females. CONCLUSIONS: Elite-level male tennis players have symmetric trunk rotation strength. Elite female tennis players have slightly greater backhand rotation strength (by 4-8%) than forehand rotation. Conditioning programs for elite tennis players should include exercises to facilitate and develop bilateral trunk rotation.
Abdominal Muscles↗
[Study of the liver and the portal venous system with digital rotational angiography].
PURPOSE: Digital subtraction angiography is of common clinical use for the evaluation of vascular disease. The rotation of the X-ray tube around the patient's body during contrast medium injection was first proposed in the early seventies in the neuroradiologic field; only recently it has been applied to the evaluation of vascular structures and abdominal parenchymatous organs. We investigated the potential clinical value of digital rotational subtraction angiography in the evaluation of the hepatic arteries and of the portal venous system. MATERIALS AND METHODS: Digital rotational subtraction angiography was performed in 46 patients (34 males and 12 females), mean age 59.3 years (range: 43-72). All the patients underwent digital rotational subtraction angiography after ultrasonographic, CT and/or MRI imaging for evaluation of hepatocellular carcinoma (31 patients) prior to trans-arterial chemoembolization, hepatic metastases from gastrointestinal cancer (9 patients) and pre-surgical study in portal hypertension (6 patients). Digital rotational subtraction angiography was performed using the following technical parameters: a maximum frame rate of 10 views per second, a 1024 x 1024 matrix, a rotation time of 5 seconds, a rotational arch of 90 degrees with a speed of 30 degrees/second. Digital rotational subtraction angiography of the liver was carried out after positioning of a Cobra angiographic catheter in the proper hepatic artery or in the left or right hepatic artery, and subsequent injection of 20-30 ml on contrast medium at a flow rate of 4-7 ml/sec. Conversely, in the portal study the catheter was placed in the splenic or superior mesenteric artery and contrast was administered at 10 ml/sec for an amount of 40-60 ml. Conventional, non-rotational angiography was always obtained with the same catheter and less contrast medium (15-25 at 4-7 ml/sec in the hepatic study, 25-40 ml at 5-7 ml/sec in the portal study). We have evaluated the diagnostic quality (rated as equal, superior or inferior) and the presence of image noise of digital rotational subtraction angiography when compared to digital non-rotational subtraction angiography. We also evaluated the tolerability and the mean time to perform the examination. RESULTS: Compared to non-rotational digital subtraction angiography, the diagnostic quality of digital rotational subtraction angiography was superior in 26 cases, equal in 20 and never inferior: these results are particularly evident in cine-mode. Diagnostic efficacy was similar in the arterial phase and generally better in the venous phase. Image noise was always perceptible, mostly in lateral and oblique views and is related to the patient's size. Noise especially hindered evaluation of the portal venous phase. Digital rotational subtraction angiography was well tolerated by all patients, although its most significative drawback was the prolonged apnea time required (about 8 seconds per single rotation) which can sometimes be difficult for elderly patients. Examination duration is about 5 to 10 minutes. Contrast medium doses required never exceeded 20-60 ml. DISCUSSION: Current evaluation of an hepatic lesion requires injections and multiple views to fully delineate arterial anatomy. This requires the radiologist to create a mental 3-D rendering based upon a 2-D view, obtained on the basis of the radiologist's experience. Rotational angiography, when reviewed in cine-loop, allows a better 3-D rendering than conventional angiography, increasing the advantages of the multiple views obtained from a single angiographic run and allowing an exact imaging of the course and direction of the hepatic arterial branching, making selective catheterization during trans-arterial chemoembolization or other interventional procedures easier. Magnification further improves the evaluation of a mass and of the arterial tree. In hepatic surgery, the most important problem is the precise knowledge of the segment involved and the position of the lesion inside the segment, since a mass in the middle of the segment requires a segmentectomy while a mass near the borders is treated by a larger resection. Digital rotational subtraction angiography improves the visibility of vascular anatomy, allows a better knowledge of hepatic artery branches and improves the angiographic investigation of the liver, permitting a correct spatial assessment. CONCLUSION: Digital rotational subtraction angiography is a useful tool for the evaluation of the liver as well as for transarterial chemoembolization or other interventional procedures. Images are obtained during a single contrast injection, with a better 3-D rendering of the hepatic artery and the portal venous system: no other method provides as complete a visualization of liver vascular anatomy after a single injection of contrast medium in one examination series. (ABSTRACT TRUNCATED)
Adult↗
Moving objects in a rotating environment: rapid prediction of Coriolis and centrifugal force perturbations.
Grip force adaptation to Coriolis and centrifugal force perturbations was tested in healthy subjects. Eight subjects were seated in a rotating chamber in a rotating axis position. They each grasped an instrumented object resting on the thumb, which was stabilized by the other fingers from above. Subjects performed horizontal point-to-point movements with the grasped object away and towards the trunk. These movements were directed in a nonparallel fashion towards the axis of rotation prior (40 pre-rotational movements), during (80 per-rotational movements) and following (40 post-rotational movements) clockwise body rotation. During pre- and post-rotational movements two load force peaks of similar magnitude occurred during the acceleratory and deceleratory phases of the movements. Accordingly, a Coriolis force, which was orthogonal and proportional to the linear velocity of the moving arm, as well as a centrifugal force proportional to the system's squared angular velocity and movement amplitude developed during per-rotational movements. The load perturbations altered the load force profile in a characteristic way. The first 10 per-rotational movement sequence revealed that there was a less precise coupling between grip and load force magnitudes and a reduced temporo-spatial co-ordination between grip and load force profiles. With increasing number of per-rotational movements, there was significant improvement in the temporo-spatial co-ordination and in the coupling in force magnitude between grip and load force profiles, indicating an ongoing adaptation process. The coupling between grip and load forces proved to be similarly precise for the last 10 per-rotational movements and for pre-rotational movements, suggesting complete adaptation. Significant effects were observed for the first post rotational movements following adaptation to the per-rotational load characteristics both for the temporal co-ordination between grip and load forces and for the coupling in force magnitudes. However, the last 10 post-rotational movements proved to be similarly precise with comparison to pre-rotational performance in terms of grip force regulation with movement-induced loads. The results are discussed within the context of the CNS ability to use internal models when planning and processing anticipatory grip force adjustments during manipulative tasks.
Acoustic Stimulation↗
Subcortical rotation in Xenopus eggs: an early step in embryonic axis specification.
The amphibian egg undergoes a rotation of its subcortical cytoplasm relative to its surface during the first cell cycle. Nile blue spots applied to the egg periphery move with the subcortical cytoplasm and make rotation directly observable (J.-P. Vincent, G.F. Oster, and J. C. Gerhart (1986). Dev. Biol. 113, 484). We have previously shown that the direction of rotation accurately predicts the orientation of the embryonic axis developed by the egg. This suggests an important role for subcortical rotation in axis specification. In this report, we provide two kinds of experimental evidence for the essential role of rotation, and against a role for other concurrent cytoplasmic movements such as the convergence of subcortical cytoplasm toward the sperm entry point in the animal hemisphere. First, dispermic eggs develop only one embryonic axis, which is oriented accurately in line with the direction of the single rotation movement and not with the two convergence foci that form in the animal hemisphere. Rotation probably modifies the vegetal, not animal, hemisphere since axial development is normal in dispermic eggs despite highly altered animal subcortical movement. Second, we show that the amount of rotation correlates with the extent of dorsal development. UV irradiation of the vegetal hemisphere, or cold shock of the egg, inhibits rotation effectively. When there is no rotation, there is no dorsal development. On average within the egg population, increasing amounts of rotation correlate with the increasingly anterior limit of the dorsal structures of the embryonic body axis. However, individual partially inhibited eggs vary greatly in the amount of axis formed following a given amount of movement. Furthermore, the egg normally rotates more than is necessary for the development of a complete axis. These findings suggest that rotation, although essential, does not directly pattern the antero-posterior dimension of the body axis, but triggers a response system which varies from egg to egg in its sensitivity to rotation. This system is artificially sensitized by exposure of the egg to D2O shortly before rotation. We show that D2O-treated eggs produce extensive axes despite very limited rotation, often developing into hyperdorsal embryos. However, like normal eggs, they depend on rotation and cannot form dorsal structures if it is eliminated.
Animals↗
Rotational kinematics of the human vestibuloocular reflex. I. Gain matrices.
1. This series of three papers aims to describe the three-dimensional, kinematic input-output relations of the rotational vestibuloocular reflex (VOR) in humans, and to identify the functional advantages of these relations. In this first paper the response to sinusoidal rotation in darkness at 0.3 Hz, maximum speed 37.5%/s, was quantified by the use of the three-dimensional analogue of VOR gain: a 3 x 3 matrix where each element describes the dependence of one component (torsional, vertical, or horizontal) of eye velocity on one component of head velocity. 2. The three matrix elements indicating collinear gains (i.e., dependence of torsional eye velocity on torsional head velocity, vertical on vertical, and horizontal on horizontal) were smaller than the -1's required for optimal retinal image stabilization. Of these three the torsional gain was weakest: -0.37 for rotation about an earth-vertical axis, versus -0.73 and -0.64 for vertical and horizontal gains. Matrix elements indicating cross talk were mostly negligible. There was a tendency to leftward eye rotation in response to clockwise head motion, but this was not statistically significant. 3. VOR responses were compared for rotation about earth-vertical and earth-horizontal axes. The varying otolith input due to the rotation of the gravity vector relative to the head during earth-horizontal axis rotation made no difference to the collinear gains. 4. There were no consistent phase leads or lags except for a torsional phase lead of up to 10 degrees, usually more marked for clock-wise head rotation versus counterclockwise, and for oblique axis rotations versus purely torsional. 5. Torsional gain was magnified, averaging -0.52, when the torsional component of head rotation was only a small part of a predominantly vertical or horizontal rotation, i.e., when the axis of head rotation was near the frontal plane. Because most natural head rotations occur about such axes, the torsional VOR is probably somewhat stronger than the response to pure torsion would suggest. 6. The speed of eye rotation in response to a given stimulus varied widely among subjects, but the direction of rotation was much more uniform. For head rotations about oblique axes out of the frontal plane, there was a systematic misalignment of eye and head axes, with eye axes tilted toward the frontal plane. These findings can be explained on the basis of a strategy where the VOR balances the muscular effort of rotating the eyes against the cost of retinal slip.
Acceleration↗
Axial rotation component of thoracic scoliosis.
The axial rotation (rotation about a vertical axis) of the vertebrae, of the ribs, and of the back surface are components of the deformity recognized clinically as the "rib hump" in thoracic scoliosis. Relationships of these rotations to the lateral deviation and lateral curvature of the spine were studied in 40 patients with idiopathic scoliosis. Stereoradiographs of the spine and rib cage were used to measure three components of axial rotation: rotation of the vertebrae, of the rib cage, and of the plane of maximum curvature of the spine. Stereotopographs of the back surface were digitized to measure the axial rotation of the back surface. In individual patients, there were high correlations of all components of axial rotation at each spinal level with the corresponding vertebral lateral deviation from the spinal axis. By regression analyses of the maximum values of each rotation in each curve, the rotation of the apex vertebra was found to be generally of lesser magnitude than the rotation of the plane of maximum curvature of the spine and in an opposite sense in kyphotic curves. The rib cage rotation was generally of lesser magnitude than the vertebra rotation, and the back surface rotation was less than both of these skeletal rotations. Vertebra rotation correlated most closely with lateral deviation of the spine. Simple segmental coupling of axial rotation and lateral bending could not be responsible for this axial rotation.
Humans↗
Changes in aortic rotational flow during cardiopulmonary bypass studied by transesophageal echocardiography and magnetic resonance velocity imaging: a potential mechanism for atheroembolism during cardiopulmonary bypass.
The human aorta is a curved conduit with a complex three-dimensional geometry. The curvature influences axial velocity distribution and introduces transverse velocity components. Rotational flow in the aorta can be demonstrated during normal pulsatile flow using transesophageal echocardiography. Cardiopulmonary bypass may affect the pattern of rotational flow in the aorta and thus influence the generation of atheroemboli. We investigated rotational flow in the descending aorta using color flow mapping and pulse-wave Doppler on transesophageal echocardiography before and during cardiopulmonary bypass. We correlated our findings with magnetic resonance velocity imaging in a model of a human aortic arch connected to a cardiopulmonary bypass circuit. Before cardiopulmonary bypass, rotational flow in the descending aorta was seen in 37 of 40 patients (93%). In the majority of these patients, rotational flow was in the clockwise direction during systole, looking in the direction of flow (30 of 37 patients, 81%, P < 0.01 vs counterclockwise rotation). During cardiopulmonary bypass, there were almost equal numbers of patients with clockwise (18 patients) and counterclockwise rotation (19 patients). Forty-seven percent of patients with clockwise rotation before cardiopulmonary bypass developed reversal in the direction of rotation to counterclockwise during cardiopulmonary bypass. Twenty-nine percent of patients with counterclockwise rotation developed reversal of the direction of rotation during cardiopulmonary bypass. The transverse velocity component increased during cardiopulmonary bypass regardless of the direction of rotation. We also demonstrated clockwise rotation in the descending aorta of a human aortic arch model connected to a cardiopulmonary bypass circuit using magnetic resonance velocity mapping. Before cardiopulmonary bypass, rotation was predominantly clockwise, while during cardiopulmonary bypass, there was no preferred direction of rotation. The geometry of the aorta, which is fairly constant in all patients, imposes handedness to aortic flow before cardiopulmonary bypass. However, during cardiopulmonary bypass, other extrinsic factors such as aortic cannula orientation may influence the direction of rotation. The change in direction of rotational flow and increase in its transverse velocity component during cardiopulmonary bypass may have implications for atheroembolism and arterial branch perfusion during extended periods of non-pulsatile flow.
Aorta↗