scholarly journals Design and 3D-model of a dynamic bubble trap for cardiopulmonary bypass

Author(s):  
A. P. Kuleshov ◽  
A. S. Buchnev ◽  
A. A. Drobyshev ◽  
G. P. Itkin

The use of extracorporeal circulation systems (cardiopulmonary bypass pumps, ECMO) can lead to brain and coronary artery microembolism, which significantly reduces postoperative rehabilitation and often leads to severe complications. Microembolism occurs when oxygen or air microbubbles (MBs) enter the arterial system of patients. Existing CPB pumps come with built-in bubble trap systems but cannot remove bubbles in the circuit. ECMO devices have arterial filters but cannot reliably filter out <40 μm bubbles in a wide flow range. We have proposed an alternative method that involves the use of an efficient dynamic bubble trap (DBT) for both large and small bubbles. The design includes development of two DBT variants for hemodynamic conditions of adult and pediatric patients. The device is installed in the CPB pump and ECMO outlet lines. It provides sufficient bubble separation from the lines in a blood flow of 3.0–5.0 L/min for adults and 0.5–2.0 L/min for children. The developed computer models have shown that MBs smaller than 10 μm can be filtered. The use of this device will greatly reduce the likelihood of air embolism and provide the opportunity to reconsider the concept of expensive arterial filters.

Author(s):  
Saleh A Othman ◽  

Background: Blood flow to the brain is in parallel with brain metabolism in almost all brain disorders except in brain tumors and therefore regional cerebral blood flow can be used as a marker of metabolic brain activity and hence it is closely linked to neuronal activity, the activity distribution is presumed to reflect neuronal activity levels in different areas of the brain. Purpose: The aim of this work is to demonstrate to pediatrician in general and pediatric neurologist in particular the variations in cerebral perfusion during normal development which should be taken into consideration at the time of interpreting SPECT brain perfusion scan in different pediatric brain disorders. Method: Brain SPECT was performed 10 minutes after an intravenous injection of 11.1 MBq/kg (0.3 mCi/kg), and the minimum dose is 185 MBq (5 mCi) of 99mTc-HMPAO (4). Results: This was a retrospective analysis of SPECT brain perfusion scan of pediatric patients performed between October 2015 and December 2019 at our institution. We selected normal and abnormal studies in pediatric population with age range (5 months - 14 years). Conclusion: Although anatomic cross sectional imaging give details of neurological structural changes, SPECT perfusion mirrors indirectly both metabolic and neuronal activity changes. Therefore, accurate interpretation of SPECT perfusion will consolidate its role as part of the diagnostic protocol and used when the findings of other imaging modalities do not explain the symptoms or fail partially or completely in determining the etiology of brain disorders in pediatric patients.


1988 ◽  
Vol 255 (5) ◽  
pp. H1114-H1129 ◽  
Author(s):  
M. J. Davis

Regulation of blood flow depends on changes in the sum of arterial (Ra) and venous (Rv) resistances, whereas regulation of capillary pressure (Pc) depends on the ratio of Rv to Ra. If the myogenic response of the arterial system (i.e., delta Ra) is the primary mechanism for controlling pressure and flow when perfusion pressure is lowered, then Pc and total flow should be regulated to the same degree under these conditions. This hypothesis was tested by making direct measurements of Pc and flow in skin and skeletal muscle in the wings of unanesthetized bats. The box method was used to reduce perfusion pressure to the wing. Pressures were measured with a servo-null system; flows were computed from measurements of vascular diameters and red cell velocities using intravital microscopy. All branching orders of arterioles dilated significantly during decreases in box pressure (Pb). For 0 less than Pb less than or equal to -30 mmHg, total flow (1st-order arteriolar flow) remained nearly constant, whereas Pc was "regulated" only approximately 60%. These results cannot be explained by changes in arteriolar resistance alone and suggest that changes in Rv may be important. The possible consequences of flow redistribution, capillary recruitment, and micropressure sampling procedures are discussed in relationship to local regulation of capillary pressure and flow.


1994 ◽  
Vol 81 (SUPPLEMENT) ◽  
pp. A693 ◽  
Author(s):  
B. D. Spiess ◽  
R. P. Cocbran ◽  
K. Kunzelman ◽  
C. Vocelka ◽  
L. Soltow ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document