Biopsy device having a linear motor

A controller circuit, comprising:

• a first feedback circuit having at least one drive characteristic sensor associated with a linear motor shaft of a linear motor;
• a second feedback circuit having a housing position detector connected to a device housing;
• a processor circuit communicatively coupled to the first feedback circuit and the second feedback circuit;
• and
• non-transitory, processor readable memory circuit communicatively coupled to the processor circuit, the non-transitory, processor readable memory circuit comprising programming instructions thereon that, when executed by the processor circuit, cause the processor circuit to:
• control an axial advancement of a distal end of the linear motor shaft in accordance with a linear motor shaft advancement profile based on first control signals received from the at least one drive characteristic sensor of the first feedback circuit, and
• maintain the distal end of the linear motor shaft at a constant axial position, as offset by a position indicated by the linear motor shaft advancement profile, based on second control signals received from the housing position detector of the second feedback circuit so as to compensate for user movement of the device housing.