Patent ID: 8257270
Filing Date: 2012-09-04
Classification: A61B

Abstract:
1. A pulse wave measuring apparatus comprising: a pulse wave measuring unit configured to measure pulse wave data; a first detection unit configured to detect first maximum values and first minimum values from the pulse wave data, and store the first maximum values and the first minimum values in a first value storage unit, respectively; a second detection unit configured to detect second maximum values and second minimum values from the pulse wave data sequentially, and to store the second maximum values and the second minimum values in a second value storage unit, wherein the second maximum values are the next largest values in amplitude relative to the first maximum values, the second minimum values are the next smallest values in amplitude relative to the first minimum values; an update unit configured to update the first maximum value stored in the first value storage unit with the second maximum value after elapse of a maximum value update time period after updating the last first maximum value, and to update the first minimum value stored in the first value storage unit with the second minimum value after elapse of a minimum value update time period after updating the last first minimum value; an initialization unit configured to initialize the second value storage unit so that a new second maximum value can be stored in a next cycle of the pulse wave data, in which the last second maximum value is detected, after updating the last first maximum value, and to initialize the second value storage unit so that a new second minimum value can be stored in a next cycle of the pulse wave data, in which the last second minimum value is detected, after updating the last first minimum value; a timing detection unit configured to detect a timing, at which the pulse wave data intersects a threshold value determined by the last first maximum value and the last first minimum value in two continuous cycles; and an interval calculation unit configured to calculate a pulse wave interval using the last timing and the present timing detected by the timing detection unit, wherein detection of the second maximum values by the second detection unit is performed by detecting a present value of the pulse wave data as a new second maximum value when the present value is smaller than the last first maximum value and larger than the last second maximum value, and detection of the second minimum values by the second detection unit is performed by detecting the present value as a new second minimum value when the present value is larger than the last first minimum value and smaller than the last second minimum value.