This paper proposes a vehicle vibration detection algorithm using an IMU sensor. This algorithm is used to make a driver health care system based on a contact-type bio sensor robust. The driver health care system based on a contact-type bio sensor is highly sensitive to a vehicle's vibration. Though suspension contributes to ride quality reasonably well isolated from road noise, the vehicle's vibration is transferred to the driver. For this reason, contact between the driver and the bio sensor becomes unstable and the driver's biosignals are not measured well. This unreliably measured biosignal data result in faulty health care services. So we need to detect the vehicle's vibration in real time and remove unreliably measured biosignal data at the same time. The proposed vehicle vibration detection algorithm is used to do that and the performance of the algorithm is demonstrated by experiments, in which the bio sensor is mounted in the steering wheel and the IMU sensor is mounted in the car's center console.