A study of rotation in a prosthetic heart valve under spiral flow conditions using a high speed video camera

The Jyros valve, the leaflets of which can be rotated in an orifice ring by spiral flow, was also shown to have the unique characteristic of less energy loss than that of other types of valves. This study was carried out to further examine precise hydrodynamic characteristics of the valve. The Jyros valve was placed at the aortic position of a spiral vortex pump (SV pump) fixed in a mock circuit. Pressure gradient at the valve was measured with pressure transducers. Another experiment was conducted under the same conditions, in which we fixed its leaflets in place so that they could not rotate within the ring (fixed Jyros). In addition, the movement of the valve was analyzed with a high speed video camera. The results from these experiments were as follows: (1) The valve leaflet rotation occurs at the late systolic phase, when the valve begins closing, and (2) during this phase, pressure gradient at the valve was lower by 3 mmHg compared to the fixed valve under usual drive conditions. Based on the above results, the valve rotation is shown to reduce flow resistance under the rotational flow condition.