Apparatus and method of connection of attachments to a holder

A method of operating a tool assembly, comprising:

• slidably engaging and locking a single cartridge member to a handpiece, wherein the single cartridge member includes a first line, a second line, and a plurality of electrical contacts configured to electrically communicate with at least a corresponding plurality of electrical contacts of the handpiece, wherein the sliding connection of the single cartridge member orients the first line, the second line, the plurality of electrical contacts and the electrical connector for connection to the first instrument assembly;
• connecting a first instrument assembly to the handpiece and making a first connection to the first line and a second connection to the second line;
• delivering electrical energy to the handpiece from at least one of the first line or the second line through at least one electrical contact of the plurality of electrical contacts, wherein slidingly engaging and locking the single cartridge member to the handpiece orients the first line and the second line and orients the plurality of electrical contacts of the single cartridge member in registration with the corresponding plurality of electrical contacts of the handpiece;
• maintaining the single cartridge member connected to the handpiece while removing the first instrument assembly;
• after removing the first instrument assembly, connecting a second instrument assembly to the handpiece while maintaining the single cartridge member connected to the handpiece;
• and
• making a third connection to the first line and a fourth connection to the second line.