Abstract: A wearable apparatus capable of altering a physiological parameter such as the heart rate of a user to provide a relaxing or stimulating effect on the user is provided. The apparatus comprises a device capable of engaging the patient's skin to provide a rhythmic tactile stimulus to the user that can alter the user's heart rate and an arrangement for securing the device to the user such that the device can apply the stimulus to the user. The apparatus may be part of a system enabling the device to be controlled remotely. The apparatus may also be configured to provide additional tactile stimuli.