A novel flow and pressure catheter for complete interventional cardiology physiology management

Ischemia with No Obstructive Coronary Artery (INOCA) in angina patients increases the risk of major cardiac events, with a 1.5x increased mortality rate. There is a link between COVID-19 infection and impairment in the myocardial micro-vasculation which may cause an increase of INOCA patients. Fractional Flow Reserve (FFR), is the standard of care in cardiology but its diagnostic function is only related to Obstructive Coronary Artery disease (or epicardial) and it is ineffective with INOCA. The lack of effective and accurate tools for timely evaluation of coronary impairments creates a clinical unmet need. The PhysioCath catheter was developed within the Eurostars project “FP-Catheter, E!113577” aims to resolve this need a provide an effective tool to interventional cardiologists. The main project outcome is a catheter prototype equipped with a blood flow velocity sensor based on a thermo-convection principle, and a fiber optic pressure sensor (based on Fabry-Perot principle). While the use of Fabry-Perot type of sensor is already standard in the industry, the use of a thermo-convection sensor represents a progress with respect the state of the art. The sensor creates an overheat of 7°C above the physiological blood's temperature (considered as being within the safety limits), and it exchanges thermal power with the blood stream. The power is then measured and converted to velocity by means of a calibration curve. The project encompassed interviews with 14 clinical experts, the summary of the interviews indicated that the preferred form of the device is an over the wire microcatheter, with rapid exchange. Within the project then, it was developed a 3Fr microcatheter, with a rapid exchange section of 24cm. Both pressure sensor and flow velocity sensor were integrated in this embodiment. Finally, the PhysioCath prototype was evaluated in a bench test study. The test setup was composed by an anatomical silicone phantom of the aortic root and the coronaries (Elastrat, Geneva, Switzerland), perfused with a peristaltic pump (Harvard Apparatus, Holliston MA, US). The measurements performed by the flow velocity sensor were compared against and external doppler flow velocity sensor. While the pressure measurement was assessed for stability and presence of drift. The data processing revealed and extreme accuracy in the measurement of flow based indexes like CFR (±6% variability), accuracy of the blood flow velocity measurement (±10%), and extreme stability in the measurement of both pressure and flow velocity. In the second part of the project (that is currently ongoing), it will be studied the performance of the device within an animal setting. In conclusion, the PhysioCath device is a microcatheter integrating bot pressure measurement and blood flow velocity measurement. Its performance is of very high accuracy and stability, that represent a main step ahead with respect the current state of the art, based mainly on thermodilution. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Eureka-Eurostars Test bench Microcatheter prototype

Plug Regime Flow Velocity Measurement Problem Based on Correlability Notion and Twin Plane Electrical Capacitance Tomography: Use Case

In this paper, the authors present the flow velocity measurement based on twin plane sensor electrical capacitance tomography and the cross-correlation method. It is shown that such a technique has a significant restriction for its use, particularly for the plug regime of a flow. The major issue is with the irregular regime of the flow when portions of propagated material appear in different time moments. Thus, the requirement of correlability of analyzed input signal patterns should be met. Therefore, the checking of the correlability should be considered by such a technique. The article presents a study of the efficiency of the original algorithm of automatic extraction of the suitable signal patterns which has been recently proposed, to calculate flow velocity. The obtained results allow for choosing in practice the required parameters of the algorithm to correct the extraction of signal patterns in a proper and accurate way. Various examples of the application of the discussed algorithm were presented, along with the analysis of the influence of the parameters used on the quality of plugs identification and determination of material flow.

Research of velocity field in vessel’s wake current from «side by side» mooring

В настоящей работе приведены результаты исследования полей скоростей, возникающие при обтекании потоком жидкости судов в счале в зависимости от формы корпуса судов, расстояния между ними и относительного смещения корпусов судов лабораторными, натурными и численными методами. Лабораторные эксперименты выполнялись с применением ADV-датчика. Натурные эксперименты проводились на акватории р. Волга с двумя танкерами. Для численного моделирования использовался программный комплекс FineMarineTM. Выполненное сопоставление результатов измерений скорости потока различными методами, показало достаточную сходимость результатов. Получено, что для моделей судов с упрощенными обводами характер спутного потока жидкости существенно зависит от расстояния между моделями. Показано, что увеличение расстояния между судами может приводить к значительному увеличению скорости спутного течения в раннем следе за счаленными корпусами, но при относительном продольном смещении судов такой картины не наблюдается. This work presents the results of the study of velocity fields that occur when a stream of fluid flows along “side by side” vessels’ mooring, depending on the hull forms, the distance between them and the relative displacement of the hull by laboratory, full-sized and numerical methods. Laboratory experiments were performed using an ADV-sensor. Field experiments were conducted with two tankers in the water area of ​​the river Volga. The FineMarineTM software package was used for numerical simulation. A correlation of the results of the flow velocity measurement by various methods showed sufficient convergence of the results. It was found that the cocurrent stream of fluid pattern for models of vessels with simplistic hull form depends heavily on the distance between the models. It is shown that an increase in the distance between the vessels can lead to a significant increase in the fluid velocity of the concurrent stream in the early wake of the hulls of vessels’ mooring, but this picture is not observed with a relative longitudinal displacement of the vessels.