A study on estimating blood pressure during body postural change based on pulse transit time

We are interested in healthcare for a bed ridden patient. Although a bed ridden patient in the hospital can be led to a circulatory disorder or a serious secondary disease, it is still difficult to give an adequate healthcare service for the patient due to side effects. Thus, we focus on the method of measuring the continuous and non-invasive bio signal in order to provide important insight into the patient´s overall physical condition. In this paper, we estimate the blood pressure during the change of body posture based on the pulse transit time. Accordingly, we newly propose the measurement system and the equation for estimating the blood pressure, and then prove the effectiveness through the experiment of changing the body posture. Through all of results, we found that it is possible to estimate the blood pressure during the change (45 and 75 deg) of body posture with the continuous (5 min) and non-invasive method by monitoring the condition of patient.