Ultrasonic intracavity probe for 3D imaging

An ultrasonic intracavity probe for scanning a volumetric region from within the body comprising:

• a handle section to be held during use of the probe;
• and
• a shaft section having a distal end which is to be inserted into a body cavity during use of the probe;
• a pivotally mounted convex array transducer enclosed by a rigidly dimensioned compartment of a transducer mount assembly at the distal end of the shaft section and facing a direction in front of the probe, wherein a space behind the convex array transducer in the rigidly dimensioned compartment of the transducer mount assembly is at least partially filled with a backing material;
• a motor located in the handle section;
• a drive shaft coupled to the motor and further coupled to the array transducer via two mating gears having perpendicular input and output axes, wherein the drive shaft is configured to move the convex array transducer during scanning to sweep an image plane through a volumetric region extending in front of the probe, and wherein the motor rotates the drive shaft so as to sweep the image plane;
• and
• a liquid bath constrained to the shaft section to the exclusion of the handle section and located in the compartment of the transducer mount assembly at the distal end of the shaft section, wherein a majority of the liquid bath is located within the transducer mount assembly and a remaining portion of the bath is contained within a volume compensation balloon extending along the shaft section proximal of the transducer mount assembly, wherein the backing material displaces a volume in the transducer mount assembly that would otherwise be occupied by the liquid bath,
• wherein at least a volume of the liquid bath is selected such that the center of gravity of the probe is located in the handle section.