Afterload device for a beating heart during examination thereof

Inventors

Steen, Stig • Paskevicius, Audrius • King, Benjamin

Assignees

XVIVO Perfusion AB

Abstract

An examination device for a heart. An afterload device connected to the aorta provides a counter-pressure by an annular space delimited between a rigid cylinder and an elastic tube inserted in the rigid cylinder. The annular space comprises a compressible medium, such as air, nitrogen gas or carbon dioxide and is connected to a reservoir providing a predetermined pressure corresponding to a diastolic pressure. The reservoir is connected to the annular space via a restriction and a back-flow valve. During diastole, the annular space is inflated by the reservoir and provides a diastolic counter pressure for providing coronary flow. During systole, the ejected fluid from the heart ventricle displaces the medium inside the annular space through the restriction to the reservoir, thereby removing energy from the fluid. The compressible medium forms a compliance. Also, there is a preload device comprising a vertical collapsible tube for preload of the atrium.

Core Innovation

The invention relates to an ex-vivo heart examination system and an afterload device for a beating heart during examination thereof. The system provides a fluid flow to a left or right atrium of the beating heart, while the afterload device is connected to a left or right ventricle of the beating heart. The afterload device includes an inertia device comprising a tube enclosing a volume of a fluid providing an inertia, and the inertia device is arranged for connection to the left or right ventricle.

The afterload device further includes a compliance device arranged after the inertia device. The compliance device comprises a rigid body and a membrane tube arranged inside the rigid body for forming an annular space between the rigid body and the membrane tube defining a first medium volume, with the membrane tube in contact with the fluid at the inner side and the rigid body enclosing the first medium volume formed between the outer side of the membrane tube and the rigid body.

A first restriction device is arranged adjacent the compliance device to provide fluid resistance to flow of the fluid. The first restriction device comprises a central plug and annular slits that are covered by the membrane tube at start of systole to provide a first resistance, and the annular slits are uncovered during systole to provide a second resistance during a single heart beat. A second restriction device provides a medium flow resistance from a first medium volume to a second medium volume, connected between the first medium volume and the second medium volume.

In addition, the invention provides a circulation system that includes a preload device configured to be used with the afterload device during examination of the beating heart. The preload device comprises a flexible and collapsible cylindrical tube arranged vertically, to be filled with fluid at a desired flow rate, and connected to a left or right atrium of the beating heart to create a fluid column at a bottom of the cylindrical tube while another portion above the fluid column is collapsed, and atmospheric pressure is generated above the fluid column to provide a predetermined load pressure to fill the left or right atrium.

Claims Coverage

The document includes two independent claims: an afterload device claim and a circulation system claim. Across these claims, there are six inventive features centered on a tube-based inertia device, an annular compliance device, time-varying flow resistance, a second restriction device between medium volumes, and a preload device that generates a predetermined atrial load pressure.

Across the independent claims, the afterload portion is defined by a tube-based inertia device followed by an annular compliance device with a membrane tube inside a rigid body, and by a first restriction device whose annular slits transition from a covered state at start of systole to an uncovered state during systole to provide different resistances within a single heart beat, plus a second restriction device connecting a first and a second medium volume to provide medium flow resistance. The circulation system claim adds a preload device using a vertically arranged flexible collapsible cylindrical tube to generate atmospheric pressure above a fluid column to provide a predetermined load pressure to the atrium.

Stated Advantages

Documented Applications

No documented applications found