Blood pressure is one of the most common diagnostic parameter. Usually this parameter is measured through indirectly, by the non-invasive measuring method, instead of the direct, invasive method. This is done by inflating and deflating a cuff around the upper arm. Besides the classical method based on noticing the Korotkoff sounds, the oscillometric method is widely spread. While measuring the blood pressure with the auscultation method, a trained medical specialist needed, the oscillometric measurement technique can be automatized. In several applications, like the intensive care monitoring devices, the automated operation is essential. In these applications, special attention must be taken for safety. This is required by several medical standards. My aim is to design a device which satisfies these requirements. After learning the theoretical basics, I developed signal processing algorithms. In the second part of my thesis, beyond implementing the algorithms to a microcontroller based environmental, I also developed the cuff controlling mechanisms.