Systems and methods to register patient anatomy or to determine and present measurements relative to patient anatomy

A method comprising:

• attaching a first target to an anatomy of a patient, the first target configured to provide positional information in up to six degrees of freedom to an optical sensor configured to provide optical information;
• positioning a registration device to define at least one axis relative to an anatomy of the patient, the registration device attached to a second target in a known positional relationship, the second target configured to provide positional information in up to six degrees of freedom to the optical sensor;
• using a sensor to provide to an intra-operative computing unit:
• measurements for determining a direction of gravity;
• and
• first optical information for the first target and the second target;
• wherein the sensor comprises the optical sensor, and a measuring sensor configured to provide measurements for determining the direction of gravity;
• and
• performing a registration with the intra-operative computing unit to register the anatomy of the patient in the intra-operative computing unit using the measurements for determining a direction of gravity and the first optical information.

A system comprising:

• a first target configured to attach to a pelvis of a patient, the first target configured to provide positional information in up to six degrees of freedom to the optical sensor;
• a second target configured to attach in a known positional relationship to an object, the second target configured to provide positional information in up to six degrees of freedom to the optical sensor, the object comprising a femur, a surgical tool or an implant;
• a handheld registration device configured to define at least one axis of an anatomy of the patient;
• a handheld sensor comprising an optical sensor configured to provide optical information and a measuring sensor configured to provide measurements for determining a direction of gravity;
• and
• an intra-operative computing unit configured to:
• receive, from the handheld sensor, first optical information for the first target and second target, and first measurements for determining the direction of gravity, the first optical information and the first measurements received for a registration step, the first optical information comprising information for the second target attached to the registration device to determine at least one axis relative to the anatomy;
• and
• perform a registration to register the anatomy of the patient in the intra-operative computing unit using the measurements for determining the direction of gravity and the first optical information.

A computer implemented method executed by a processor of an intra-operative computing unit, the method comprising:

• receiving, from a sensor, first optical information for a first target and a second target, and measurements for determining a direction of gravity to perform a registration of an anatomy of a patient, the first optical information comprising information for:
• i) the first target attached to the anatomy of the patient;
• and ii) the second target attached to a registration device to determine at least one axis relative to the anatomy of the patient, and wherein each of the first target and the second target is configured to provide positional information in up to six degrees of freedom to an optical sensor configured to provide optical information, and wherein the sensor comprises the optical sensor, and a measuring sensor, the measuring sensor configured to provide measurements for determining the direction of gravity;
• and
• performing the registration to register the anatomy of the patient in the intra-operative computing unit using the measurements for determining the direction of gravity and the first optical information.