Surgical Drilling System For Determining Bone Breakthrough

A surgical drilling system configured for bone drilling and configured to determine a characteristic of a drilling medium from a characteristic of fluid flow, said surgical drilling system comprising:

• a drill chuck configured to be rotated by a motor;
• a surgical drill bit configured to be coupled to the drill chuck, the surgical drill bit comprising:
• a shank portion extending distally along a drill bit axis from a proximal end, the shank portion configured to be coupled to and rotated by the drill chuck, and the shank portion having a proximal surface defining a proximal opening, and
• a drilling portion for drilling through bone, the drilling portion extending distally along the drill bit axis from the shank portion to a distal end, the drilling portion having a distal cutting region comprising:
• a rake surface for cutting into a bone while drilling,
• a clearance surface for directing bone chips away from the bone during drilling, and
• a flank surface disposed between the rake surface and the clearance surface, the flank surface defining a distal opening, and the flank surface configured to abut the bone such that the distal opening is occluded by the bone while the rake surface is cutting into the bone,
• wherein the shank and drilling portions collectively define an inner channel in fluid communication with the proximal and distal openings, and wherein the distal opening is configured to be occluded by the bone during drilling to establish fluid pressure within the inner channel;
• a pump configured to transfer fluid from a fluid source into the inner channel of the surgical drill bit through the proximal opening of the surgical drill bit;
• a sensor disposed in fluid communication with the inner channel and configured to generate a signal responsive to a characteristic of the fluid being transferred to the inner channel of the surgical drill bit;
• and
• a controller configured to receive the signal from the sensor and determine a characteristic of the drilling medium at the distal opening of the surgical drill bit based on the signal.