Measurement of tissue thickness using ultrasound and force measurements

An apparatus, comprising:

• a catheter having a distal segment configured for insertion into contact with a wall of a cavity in a body of a subject, the cavity having an inner surface and an outer surface;
• a contact force sensor and an ultrasound transducer disposed in the distal segment;
• an ultrasound generator operatively connected to the catheter and configured for actuating the transducer to simultaneously generate ultrasound reflection data associated with various tissue interfaces, including from the wall of the cavity, the reflection data representative of times-of-flight from the various tissue interfaces during a time;
• an actuator operatively connected to the catheter and configured for reciprocating the catheter against the wall of the cavity a plurality of times during the time while the transducer is active;
• electrical circuitry linked to the contact force sensor and operative for measuring a contact force between the catheter and the wall of the cavity;
• and
• a processor linked to the electrical circuitry and the transducer, the processor configured for (i) receiving the reflection data during the given time, (ii) comparing the reflection data with contact force data measured by the contact force sensor during the time, (iii) identifying a set of the reflection data having a highest correlation with the contact force data during the time, and (iv) determining a tissue thickness for the tissue interface associated with the identified set of the reflection data according to times-of-flight therebetween.