Patent ID: 8727999
Filing Date: 2014-05-20
Classification: A61B,A63B

Abstract:
1. A pulse measurement device, comprising: a sensing unit to sense a photoplethysmography (PPG) signal and to directly sense an acceleration signal obtained from a user; a pressure control unit to control pressure applied to the sensing unit; a light amount control unit to control an amount of incident light on the sensing unit; and a signal determination unit to determine an optimum pressure range by analyzing the PPG signal varying with a change of the pressure applied to the sensing unit by the pressure control unit and to determine an exercise level of an activity of the user by using the acceleration signal, wherein the optimal pressure range corresponds to a range of maximum peak values of the PPG signal which have a value greater than a preset percentage of a maximum value among the maximum peak values of the PPG signal, wherein the optimal pressure range is a range of pressure values from a minimum pressure value to a maximum pressure value, in which external pressure is applied in accordance with the user's exercise level, the minimum pressure value corresponds to a first maximum peak value of the PPG signal having a value corresponding to the preset percentage of the maximum value among the maximum peak values, and the maximum pressure value corresponds to a second maximum peak value of the PPG signal having a value corresponding to the preset percentage of the maximum value among the maximum peak values, and when the exercise level is determined by the signal determination unit as corresponding to a relatively high level of activity, the pressure control unit controls the pressure applied to the sensing unit to exceed the optimum pressure range and the light amount control unit controls the amount of incident light on the sensing unit to be increased to compensate for any decrease in the PPG signal due to the pressure control unit controlling the pressure to exceed the optimum pressure range.