AbstractsBiology & Animal Science

Blood flow and its regulation, as well as hemodynamics in general, are important for the health of tissues and hence the measurement of these quantities has many applications in research and clinical environments. Various optical techniques are attractive for the measurement of blood flow since they are often non- or minimally-invasive, continuous and are relatively inexpensive. During my PhD I have contributed to the monitoring of blood flow in experimental animal models with the construction of a multimodal device, based on laser speckle flowmetry and optical intrinsic signals, capable of measuring superficial microvascular cerebral blood flow, blood oxygenation and blood volume for translational research. This device was applied in animal models of ischemic stroke and is flexible to be modified and used for other purposes. In doing so, I have developed new experimental methods and image processing protocols that allowed us to perform longitudinal studies where the animal can be removed from the device several times. Furthermore, this device has been used as a tool in a multi-disciplinary study to understand the role of the Mannose-binding lectin protein in reperfusion injury after an ischemic stroke in animal models. This then led to the main contribution of this work which is the development of the speckle contrast optical spectroscopy and tomography, a new non-invasive, optical technique for deep blood flow measurement that paves the way for deeper and three dimensional imaging of blood flow. This new method was first developed from a theoretical perspective. Then it was validated in tissue simulating phantoms and demonstrated to be feasible in measurements on the human arm muscle. Overall, these contributions will allow the development of cost-effective, non-invasive tomographic methods for the measurement of blood flow even in humans.; El flujo sanguíneo y su regulación, así como la hemodinámica en general, son parámetros importantes para determinar el estado de salud de los tejidos; por esto, su medición tiene numerosas aplicaciones en los ámbitos clínico y de investigación. Varias técnicas ópticas resultan atractivas para la medición del flujo sanguíneo dado su carácter no invasivo o mínimamente invasivo, continuo y relativamente económico. Durante mi trabajo doctoral he contribuido a la monitorización del flujo sanguíneo, en modelos de experimentación animal, con la construcción de un dispositivo multimodo, basado en la flujometría de speckle láser (laser speckle flowmetry, LSF) y las señales ópticas intrínsicas (optical intrinsic signals, OIS), capaz de medir flujo sanguíneo de la microvasculatura superficial en el cerebro, oxigenación sanguínea y volumen sanguíneo en investigación traslacional. Este dispositivo fue aplicado en modelos animales de infarto cerebral; sin embargo, es flexible y puede ser modificado y utilizado para otros propósitos. Así pues, he desarrollado nuevos métodos experimentales y protocolos de procesamiento de imágenes que nos permitieron llevar a cabo estudios longitudinales,…