Patent ID: 7535135

Claim:
A handheld medical device including a brushless electric motor comprising: a rotor magnet; a coil apparatus for electromagnetically driving the rotor magnet; a rotor shaft for transmitting a rotary movement, said rotor shaft being firmly connected to said rotor magnet and running through a rotation axis of the rotor magnet; at least one electromagnetic transducer element for detection of the magnetic field of the rotor magnet; and at least one bearing disposed on said rotor shaft only on a first side of said rotor magnet outside the axial extent of said rotor magnet and no bearings disposed on a second side of said rotor magnet, wherein when more than one bearing is disposed on said rotor shaft, the bearings are disposed immediately adjacent to each other; wherein said at least one electromagnetic transducer element is disposed on a second side of the rotor magnet opposite to the first side of the rotor magnet where the at least one bearing is disposed, is located outside the axial extent of the rotor magnet with respect to the rotation axis, is arranged essentially within the maximum radial extent of the rotor magnet, and is attached directly or indirectly to the coil apparatus, being encapsulated with the coil apparatus to form a component; and wherein said electric motor is an internal motor in which the coil apparatus is disposed essentially radially outwardly of said rotor magnet.