A driver comprising: a drive shaft configured to be coupled to an intraosseousdevice；a motor coupled to a power source and further coupled to the drive shaft by amulti- gear drivesystem, where the motor is coupled in fixed relation to at least one gear ofthe multi-gear drivesystem； and a trigger coupled to the motor and configured to activate themotor to move thedrive shaft； where the multi-gear drive system is configured to causeoscillating rotation ofthe drive shaft.
