Systems, devices and methods for enhancing operative accuracy using inertial measurement units

A surgical navigation method comprising:

• moving one or more surgical instruments having an instrument array and an inertial measurement unit (IMU) while the instrument array is rotated or angled relative to a camera less than a threshold amount where the instrument array is within a line or sight of the camera and determining movement of the instrument array using the camera is possible, but determining movement of the instrument array using the camera is likely to induce error;
• using a processor to continuously determine location and positioning of the one or more surgical instruments from image data received from the camera showing the instrument array of the one or more surgical instruments;
• moving the one or more surgical instruments such that the instrument array moves from being rotated or angled relative to the camera less than the threshold amount to being rotated or angled relative to the camera more than the threshold amount;
• using the processor to continuously determine location and positioning of the one or more surgical instruments from IMU data received from the IMU of the one or more surgical instruments while the instrument array of the one or more surgical instruments is rotated or angled relative to the camera more than the threshold amount;
• and
• continuously displaying on a display coupled to the processor the location and positioning of the one or more surgical instruments throughout movement thereof wherein the instrument array of the one or more surgical instruments is, at a first time, rotated or angled relative to the camera less than the threshold amount and, at a second time, rotated or angled relative to the camera more than the threshold amount.