Our Transit-Time flow probes have been the gold-standard for vascular and tubing-based flow measurement for over 35 years. On the vascular side, Flowprobes in a variety of configurations are suitable to be placed around vessels 0.3mm and larger in diameter which allows researchers to measure anything from a mouse’s carotid to a cow’s aorta. These probes are designed to be implanted in a perivascular fashion, calculating flow without having to disturb blood flow or directly interact with the blood. This allows for the fluid dynamics to be maintained, as well as the patency of the vessel. The technology has been described in previous blogs and webinars; the resulting data is highly resolved and accurate. It is common for this technology to be utilized as a standalone measurement, for example in carotid thrombosis where flow measurement is used to quantify thrombosis progression by looking at changes in blood flow. However, this technology can also be meaningful in various settings where it can work cohesively to deliver new parameters and optimize others. Let’s take a look:
Pressure and flow are two fundamental characteristics in a closed system that includes a pump, such as our cardiovascular system. By conducting vascular flow measurements with our probes and blood pressure with solid-state pressure catheters, researchers can better understand the properties of this system.
For scientists interested in cardiovascular function, a pressure catheter can be placed in the left ventricle of the heart – either via retrograde insertion or through the apex. From pressure data, you can calculate important indices such as dP/dt and maximum/minimum pressure gradients. When partnered with an aortic flow probe, you can also ascertain measurements of cardiac output and stroke volume. When used together, you get a comprehensive picture of load-dependent contractile performance, see the figure on the left below.
Taking a similar approach with our flow probe placed on the aorta, a pressure catheter can be placed in both the arterial and venous branches of the circulatory system. This approach allows you to calculate systemic vascular resistance (SVR), also known as total peripheral resistance, see the figure on the right above. SVR is the calculation of cardiac output (CO), central venous pressure (CVP), and mean arterial pressure (MAP). Understanding this relationship allows you to better understand the global properties of the cardiovascular system as well as the loading conditions on the heart.
The probes are designed to minimize any disturbance of the blood flow under study for the most accurate measurements possible. As they are implanted in a perivascular fashion and don’t directly interact with the blood, the patency of the vessel is maintained and the fluid dynamics are in as natural of a state as possible.
Transonic understands what it takes to collect meaningful data in your lab and strives to present opportunities for synergistic data collection. If we can help answer any questions about this topic or any other, please be sure to check out our webinar series that covers best practices related to data collection with our technologies as well as interesting new surgical approaches and models. We can also be reached here. Cheers!