This study was designed in two phases: Phase I is designed to confirm that the surgeon is able to perform accurate liver surface registration including standard liver features used as landmarks during a scheduled laparoscopic liver ablation procedure and acquires a level of comfort with the procedure.

The surface of the liver will be manually swabbed with the study tracked laparoscopic probe with landmarks noted during data collection. After registration of the liver is obtained, the registration points obtained during this procedure will be evaluated by the surgeon by moving the tracked laparoscopic probe over the liver surface and evaluating the location of the tracked laparoscopic probe displayed on the guidance system three dimensional (3D) image. The surgeon will accept or reject the registration accuracy.

The hypothesis is that the surgeon will be able to successfully acquire liver surface registrations with a small learning curve for technique and will be able to proceed to Phase II of the study.

Phase II contains the registration process included above but adds the additional process of tracking the ablation probe used to perform tumor ablation by attaching the Pathfinder Multi-Tool adaptor and collecting data showing the location of the ablation probe as tracked and displayed on the Pathfinder three dimensional (3D) image.

The surgeon will use ultrasound (US) guidance to locate tumor location during the laparoscopic procedure. The images collected during this process will be recorded by Pathfinder.

The Pathfinder System used during this study is used for data collection purposes only and is not used during the surgical procedure as an image guided system.

Preoperative computed tomography (CT) scans, obtained as standard of care, will be used to generate the image guided liver system 3D liver surface images used during the study.

During the laparoscopic procedure, the Pathfinder device will be inserted through the standard laparoscopic ports (5mm or 10mm) being used for the staging procedure.

A total study population will include 30 subjects: 10 in Phase I and 20 in Phase II that complete the laparoscopic procedure scheduled.

Inclusion Criteria:

• Scheduled for laparoscopic liver ablation procedure
• Had a preoperative CT image that includes the liver

Exclusion Criteria:

• Severe cirrhosis of the liver
• Kidney failure or dialysis
• Unable to consent

Any subject scheduled for a laparoscopic procedure where liver surface visualization and surface swabbing is feasible with standard port placement.