Ring cutter for safely transecting a ring trapped on an appendage

Abstract

A ring cutter for transecting a ring trapped on an appendage. The ring cutter includes a body, a motor housed in the body, a blade drivingly connected to the motor, a guard coupled to the body, a guard actuator drivingly connected to the guard and controlling a movement of the guard, a current sensor positioned to sense electrical current associated with the motor, and a processor communicatively coupled to the current sensor and the guard actuator. The blade has a rotation axis and a peripheral cutting edge. The guard is insertable between the ring and the appendage to position the ring between the guard and the blade. The processor is configured to: i) receive, from the current sensor, an electrical current reading associated with the motor, and ii) transmit, to the guard actuator, one or more commands to control the movement of the guard based on the electrical current reading.

1 . A ring cutter for safely transecting a ring trapped on an appendage, the ring cutter comprising:
 a body;   a blade motor housed in the body;   a circular blade drivingly connected to the blade motor, the blade having a blade rotation axis and a peripheral cutting edge;   a guard coupled to the body and insertable between the ring and the appendage to position the ring between the guard and the blade;   a guard actuator drivingly connected to the guard and controlling a movement of the guard;   a current sensor positioned to sense electrical current associated with the blade motor; and   one or more processors communicatively coupled to the current sensor and the guard actuator, wherein the one or more processors are configured to collectively:
 receive, from the current sensor, an electrical current reading associated with the blade motor; and 
 transmit, to the guard actuator, one or more commands to control the movement of the guard based at least on the electrical current reading. 
   
     
     
         2 . The ring cutter of  claim 1 , wherein said controlling the movement of the guard comprises controlling a movement speed of the guard toward the peripheral cutting edge, and the one or more processors are further configured to collectively:
 in response to determining that the electrical current reading is below a predetermined lower threshold value, direct the guard actuator to increase the movement speed of the guard toward the peripheral cutting edge.   
     
     
         3 . The ring cutter of  claim 2 , wherein the one or more processors are further configured to collectively:
 in response to determining that the electrical current reading exceeds a predetermined upper threshold value, direct the guard actuator to decrease the movement speed of the guard toward the peripheral cutting edge.   
     
     
         4 . The ring cutter of  claim 1 , wherein the guard has a guard proximal end pivotably connected to the body at a guard pivot axis, and a guard distal end spaced apart from the guard proximal end, the guard distal end being insertable between the ring and the appendage to position the ring between the guard and the blade. 
     
     
         5 . The ring cutter of  claim 4 , wherein the blade motor has a motor rotation axis that extends longitudinally, and the guard pivot axis extends laterally. 
     
     
         6 . The ring cutter of  claim 4 , wherein said controlling the movement of the guard comprises controlling a pivoting of the guard about the guard pivot axis. 
     
     
         7 . The ring cutter of  claim 6 , wherein the guard is pivotable about the guard pivot axis in:
 a guard closing direction, which moves the guard distal end toward the peripheral cutting edge, and   a guard opening direction, which moves the guard distal end away from the peripheral cutting edge.   
     
     
         8 . The ring cutter of  claim 7 , wherein the one or more processors are further configured to collectively:
 in response to determining that the electrical current reading is below a predetermined lower threshold value, direct the guard actuator to pivot the guard about the guard pivot axis in the guard closing direction.   
     
     
         9 . The ring cutter of  claim 6 , wherein the guard is pivotable about the guard pivot axis between at least:
 a cutting start position, and   a cutting finished position, in which the guard distal end is closer to the peripheral cutting edge than in the cutting start position.   
     
     
         10 . The ring cutter of  claim 9 , wherein the one or more processors are further configured to collectively:
 in response to determining that the electrical current reading is below a predetermined lower threshold value, direct the guard actuator to pivot the guard about the guard pivot axis toward the cutting finished position.   
     
     
         11 . The ring cutter of  claim 9 , wherein the guard is inhibited from pivoting toward the peripheral cutting edge when in the cutting finished position. 
     
     
         12 . The ring cutter of  claim 9 , wherein the guard is pivotable about the guard pivot axis to a guard insertion position, in which the guard distal end is spaced farther apart from the peripheral cutting edge than in the cutting start position. 
     
     
         13 . The ring cutter of  claim 12 , further comprising a user-operable guard adjustment input communicatively coupled to at least one of the processors, and the one or more processors are further configured to collectively:
 direct the guard actuator to pivot the guard about the guard pivot axis between the guard insertion position and the cutting start position in response to user interaction with the guard adjustment input.   
     
     
         14 . The ring cutter of  claim 9 , wherein the one or more processors are configured to collectively:
 perform said receiving and transmitting when the guard is between the cutting start position and the cutting finished position.   
     
     
         15 . The ring cutter of  claim 4 , wherein the guard includes a guard distal segment that has the guard distal end, the guard distal segment including a ring abutment ledge and a curved ring lever extending distally from the ring abutment ledge, the curved ring lever being insertable between the ring and the appendage to position the ring against the ring abutment ledge. 
     
     
         16 - 20 . (canceled) 
     
     
         21 . The ring cutter of  claim 1 , further comprising an energy storage member electrically coupled to the blade motor to power the blade motor. 
     
     
         22 . The ring cutter of  claim 1 , further comprising a pistol grip handle provided at a rear end of the ring cutter. 
     
     
         23 . The ring cutter of  claim 22 , wherein the pistol grip handle has an upper end that is mounted to the body. 
     
     
         24 . The ring cutter of  claim 23 , wherein, when the ring cutter is oriented with an upper end of the ring cutter positioned above a lower end of the ring cutter, the body has a body upper surface and a body lower surface, and the upper end of the pistol grip handle is mounted to the body lower surface. 
     
     
         25 . The ring cutter of  claim 22 , further comprising a resting base provided at a lower end of the pistol grip handle, the resting base extending outboard of the lower end of the pistol grip handle, the resting base being engageable with a ring cutter support surface.