Intra-operative heart size measuring tool
A heart size measuring tool includes a tubular body, a flexible measuring cord having length indicia, a measuring cord support mechanism movable between retracted and extended states with respect to the body, and an actuating mechanism to move the measuring cord support mechanism. When in the retracted state the measuring cord support mechanism is positioned within the tubular body with the measuring cord in a collapsed position. When the measuring cord support mechanism is in the extended state the measuring cord extends around a portion of a heart to be measured. A scale on the body can be used in connection with the indicia on the measurement cord to provide a reading of the heart size.
1. A heart measurement tool comprising:
a tubular body;
a suction cup disposed at a distal end of the tubular body;
a plurality a elongate support members having respective distal end portions;
a flexible measuring cord supported by a distal end portion of at least one of the elongate support members;
an actuating mechanism slidably positionable to move the distal end portions of the plurality of elongate support members proximally and distally of the suction cup;
a scale disposed on a proximal portion of the heart measurement tool; and
a cord tension control mechanism that establishes a maximum tension of the flexible measuring cord.
2. The heart measurement tool of claim 1 , wherein the cord tension control mechanism comprises a spring.
3. The heart measurement tool of claim 1 , wherein the cord tension control mechanism comprises a spring-loaded spool that is biased to wind up slack portions of the flexible measuring cord.
4. The heart measurement tool of claim 1 , wherein the scale is located on a portion of the tubular body outside of the patient when the flexible measuring cord is in the measuring position.
5. The heart measurement tool of claim 1 , wherein the plurality of elongate support members comprises at least three elongate support members.
6. The heart measurement tool of claim 1 , wherein the actuating mechanism is attached to the proximal ends of each of the elongate support members.
7. The heart measurement tool of claim 1 , wherein the tubular body defines a lumen that extends from the suction cup through all of the tubular body.
8. The heart measurement tool of claim 1 , wherein the plurality of elongate support members comprises at least three elongate support members, and wherein the flexible measuring cord is supported by the distal end portion of each of the at least three elongate support members.
9. The heart measurement tool of claim 1 , wherein the distal end portion of each of the elongate support members includes a guide through which the flexible measuring cord extends.
10. The heart measurement tool of claim 1 , wherein the heart measurement tool is reconfigurable between a first configuration in which the plurality of elongate support members extend distally beyond the suction cup and a second configuration in which the plurality of elongate support members are retracted proximally of the suction cup.
11. The heart measurement tool of claim 10 , wherein the while the heart measurement tool is configured in the first configuration, the plurality of elongate support members extend radially outward from the tubular body.
12. The heart measurement tool of claim 10 , wherein the while the heart measurement tool is configured in the first configuration, the actuating mechanism is closer to the suction cup than while the heart measurement, tool is configured in the second configuration.