| Summary: |
Blood rheology is highly dependent on plasma viscosity, haematocrit and mechanical properties of red blood cells. Nevertheless, the application of external forces as magnetic fields to blood flow can significantly affects its rheological behaviour. Recent studies showed that applying a magnetic pulse to a small sample of blood could reduce its viscosity; on the other hand the addition of magnetic particles to blood and the application of a magnetic field would instead increase its viscosity. These facts could be useful in some clinical applications, to abort haemorrhages or to remove blood clots. Many doctors have reported very recently [1] seeing an alarming number of COVID-19 patients with blood clots in the blood that can cause serious problems, such as heart attack and stroke, according to news reports. The application of magnetic fields to blood flow could reduce the blood viscosity, hence avoiding blood clots. Until data no scientific in estigations have been developed further in this area and several questions are still open: how can the rheology of blood be related with the intensity of the magnetic fields? How the blood microstructure evolves during the application of the external fields and how their intrinsic characteristics are altered? How the magnetic field influences the elasticity of blood? In order to answer these questions, this proposal has an ambitious objective: a full rheological characterization of whole human blood applying magnetic fields under shear and uniaxial extensional flows. The application of these fields in the extensional rheometer goes beyond the limitations of the traditional rheology and has only been performed in the host institution (FEUP) with carbonyl iron particles in glycerine and cornstarch suspensions in olive oil, respectively. The BIGGEST IDEA of this project is to provide to the scientific community with a pioneering guideline able to predict the viscoelasticity of blood under the application of magnetic fields in  |
Summary
Blood rheology is highly dependent on plasma viscosity, haematocrit and mechanical properties of red blood cells. Nevertheless, the application of external forces as magnetic fields to blood flow can significantly affects its rheological behaviour. Recent studies showed that applying a magnetic pulse to a small sample of blood could reduce its viscosity; on the other hand the addition of magnetic particles to blood and the application of a magnetic field would instead increase its viscosity. These facts could be useful in some clinical applications, to abort haemorrhages or to remove blood clots. Many doctors have reported very recently [1] seeing an alarming number of COVID-19 patients with blood clots in the blood that can cause serious problems, such as heart attack and stroke, according to news reports. The application of magnetic fields to blood flow could reduce the blood viscosity, hence avoiding blood clots. Until data no scientific in estigations have been developed further in this area and several questions are still open: how can the rheology of blood be related with the intensity of the magnetic fields? How the blood microstructure evolves during the application of the external fields and how their intrinsic characteristics are altered? How the magnetic field influences the elasticity of blood? In order to answer these questions, this proposal has an ambitious objective: a full rheological characterization of whole human blood applying magnetic fields under shear and uniaxial extensional flows. The application of these fields in the extensional rheometer goes beyond the limitations of the traditional rheology and has only been performed in the host institution (FEUP) with carbonyl iron particles in glycerine and cornstarch suspensions in olive oil, respectively. The BIGGEST IDEA of this project is to provide to the scientific community with a pioneering guideline able to predict the viscoelasticity of blood under the application of magnetic fields in shear and/or uniaxial extensional flows. The MAIN QUESTIONS to be solved are the relation of the blood rheology with the intensity and direction of the magnetic field, and also the evolution of the blood microstructure under the application of these external forces and how is reflected in its intrinsic characteristics. This NOVEL CONCEPT in the blood flow characterization will contribute to the state of the art in the field of hemorheology for biomedical applications with a direct IMPACT in the TECHNOLOGY opening a NEW DOOR in the development of patient treatment therapies where the application of magnetic pulses are crucial as in the case of novel cancer therapeutic methods or to prevent heart attacks, for instance.
The NOVELTY of this work lays in the fact that up to date there are NO WORKS with a full rheological characterization of blood under shear and extensional flows with the application of a magnetic field. The ground-breaking idea for providing such a tool to predict the viscoelastic properties of whole blood by means of rheology represents a high risk-high gain research proposal as the promising results could change the scientific horizon in advanced treatment therapies and therefore it can be considered an OPEN-ENDED proposal as new challenging ideas would be open. Understanding the rheological properties and flow dynamics of whole human blood is of great importance for the early detection, diagnosis and therapy of circulatory disorders as well as for the development of cardiovascular devices and prosthesis, such as blood pumps, heart valves or stents. Some diseases, such as cardiovascular disorders, myocardial infarction, arterial hypertension, diabetes mellitus, cholesterol and triglyceride levels and sickle cell anaemia could be monitored by a routine screening of hemorheological measurements. The flow of blood in physiological conditions typically involves large deformations, large deformation rates and periodic forcing with large amplitude and therefore characterization of blood under large amplitude oscillatory shear flow (LAOS) is of great importance, also under conditions of extensional flow.
Nevertheless, it is common the use of external magnetic fields in the diagnosis and in the treatment of many diseases. The use of variable magnetic fields in medicine covers areas as orthopaedics, rheumatology, internal medicine, neurology or dentistry. A novel and fully rheological characterization of whole blood under the action of external fields in shear and extensional flows is, therefore fundamental to provide deeper insight into new treatment therapies. The aim is to provide for the very first time a complete understanding of the microstructural changes of whole human blood as magnetic fields are applied. As a consequence, the viscoelasticity will undergo a clear dependence of the external forces apart for the well-know dependence of RBC concentration or temperature. |