Method and system for aligning a prosthesis during surgery

A system to guide surgery comprising:

• a first sensor unit comprising an optical sensor to couple to an object in a known or measurable orientation such that a relative position of the first sensor unit with respect to the object is known when attached, the optical sensor configured to receive light and determine a direction of the light;
• a second sensor unit to couple to a first bone of a patient, the second sensor unit comprising markers configured to emit and/or reflect light to provide a signal representing a six degrees of freedom position to the first sensor unit and, in response to the signal, the first sensor unit generating and communicating sensor information with which to determine a relative position in six degrees of freedom of the object with respect to the first bone;
• at least one human interface sensor to receive user input for an operation of the system;
• a processor;
• and a non-transitory computer readable storage device storing instructions, which when executed by the processor, cause the system to:
• perform operations to guide the surgery wherein at least some operations are responsive to user input received and wherein the operations comprise displaying information in accordance with the relative position in six degrees of freedom of the object and the first bone as determined according to the sensor information and the relative position of the first sensor and the object.

A method to guide surgery comprising:

• receiving, at a processor, sensor information from a first sensor unit comprising an optical sensor attached to an object in a known or measurable orientation such that the relative position of the first sensor unit with respect to the object is known, the optical sensor receiving light and determining a direction of the light;
• receiving, at the processor, a relative position of a second sensor unit with respect to a first bone of a patient, and wherein the second sensor unit comprises markers to one of emit, reflect, and both emit and reflect light to provide a signal to the first sensor unit representing a six degrees of freedom position of the second sensor unit and, in response to the signal, the first sensor unit generating and communicating the sensor information with which to determine the relative position in six degrees of freedom of the object with respect to the first bone;
• receiving, at the processor, user input from at least one human interface sensor;
• and
• performing operations to guide the surgery wherein at least some operations are responsive to the user input received and wherein the operations comprise displaying information in accordance with the relative position in six degrees of freedom of the object and the first bone as determined according to the sensor information and the relative position of the first sensor and the object.

A system to guide surgery comprising:

• a first sensor unit comprising an optical sensor to couple to an object in a known or measurable orientation such that a relative position of the first sensor unit with respect to the object is known when attached and wherein the optical sensor operates to receive light and determine a direction of the light;
• a second sensor unit to couple to a first bone of a patient, the second sensor unit to operate to emit and/or reflect light to provide a signal representing a six degrees of freedom position to the first sensor unit and, in response to the signal, the first sensor unit generating and communicating sensor information with which to determine a relative position in six degrees of freedom of the object and the first bone;
• a processor;
• and a non-transitory computer readable storage device storing instructions, which when executed by the processor, cause the system to:
• perform operations to guide the surgery, the operations comprising displaying information in accordance with the relative position in six degrees of freedom of the object with respect to the first bone as determined according to the sensor information and the relative position of the first sensor with respect to the object;
• wherein:
• the at least one human interface sensor communicates the user input wirelessly for receiving by the processor;
• the object comprises a surgical tool or a second bone of the patient;
• and
• the second sensor unit comprises at least four markers arranged such that only fewer than all of the markers lie in a same plane.