Measurement device and method thereof

A method of using a measurement device comprising:

• inserting at least a portion of a measurement device into a patient, the measurement device comprising first and second finger connectors, a string extending between the first and second finger connectors and having an extension portion extending beyond one of the first and second connectors, and an indicator associated with the extension portion;
• positioning the first finger connector at a first target location;
• positioning the second finger connector at a second target location so that the first and second connectors are separated by a separation distance;
• determining the separation distance between the first finger connector and the second finger connector based on an extension length of the extension portion, which extension length can be determined from outside of the patient.