1. Field of the Invention
The present invention relates to an automatic blood pressure measuring apparatus which can accurately measure a blood pressure of a female subject even at the time of childbirth.
2. Related Art Statement
There is known an automatic blood pressure (BP) measuring apparatus which monitors BP values of a living subject by periodically changing an air pressure of an inflatable cuff applied to a body portion of the subject at a predetermined measurement period and detecting a pressure pulse wave produced in the cuff during the change of air pressure of the cuff. It is known that the BP values measured using the inflatable cuff are reliable.
Meanwhile, it is medically important to monitor BP values of a female subject at the time of childbirth. However, in the case where the above-mentioned BP measuring apparatus is used to monitor, using the cuff, BP values of a female subject who heavily moves her body each time she feels a labor pain (i.e., uterine contraction), the BP measuring apparatus may not accurately measure the BP values of the subject because of her heavy physical motion.
It is therefore an object of the present invention to provide an automatic blood pressure measuring apparatus which can measure an accurate blood pressure of a female subject, even during childbirth.
The above object has been achieved by the present invention. According to a first feature of the present invention, there is provided an apparatus for automatically measuring a blood pressure of a female subject, comprising a blood-pressure measuring device which includes an inflatable cuff adapted to apply a pressing force to a body portion of the subject and automatically measures, by changing the pressing force of the cuff, a blood pressure of the female subject at a predetermined measurement period; a labor-pain-signal detecting device which detects, from the female subject, a labor-pain signal which changes in relation to a labor pain of the subject; and a first blood-pressure-measurement starting means for operating the blood-pressure measuring device to start a blood-pressure measurement, when the predetermined measurement period has elapsed and when the labor-pain signal detected by the labor-pain-signal detecting device falls within a reference range.
In the present automatic BP measuring apparatus, the first BP-measurement starting means operates the BP measuring device to start a BP measurement, only when the labor-pain signal detected by the labor-pain-signal detecting device falls within a reference range. If the labor-pain signal falls within the reference range, then the female subject is not feeling a labor pain and accordingly she is not moving her body. Since the present apparatus starts a BP measurement when the female subject is not moving her body, it can accurately measure one or more BP values of the subject.
According to a second feature of the present invention, the blood-pressure measuring apparatus further comprises a labor-pain-period-relating-information determining means for determining, based on the labor-pain signal detected by the labor-pain-signal detecting device, labor-pain-period-relating information relating to a labor-pain period at which the female subject periodically feels a labor pain; and a measurement-period shortening means for shortening the predetermined measurement period, when the determined labor-pain-period-relating information indicates that the labor-pain period of the subject has shortened.
During childbirth, it is medically needed to detect more quickly any abnormal tendency of the female subject when the labor-pain-period-relating information indicates that the labor-pain period of the subject has shortened. To this end, the present automatic BP measuring apparatus employs the measurement-period shortening means which shortens, when the labor-pain-period-relating information indicates that the labor-pain period of the subject has shortened, the predetermined measurement period, so that the BP measuring device measures a BP value of the subject at the shortened measurement period. Thus, the present apparatus can more quickly detect the abnormal tendency of BP values of the female subject.
According to a third feature of the present invention, the blood-pressure measuring apparatus further comprises an abnormality judging means for judging, when the labor-pain signal detected by the labor-pain-signal detecting device does not fall within the reference range when the blood-pressure measuring device is performing a first blood-pressure measurement, that the first blood-pressure measurement is abnormal; and a second blood-pressure-measurement starting means for operating the blood-pressure measuring device to start a second blood-pressure measurement when the labor-pain signal detected by the labor-pain-signal detecting device has changed to fall within the reference range again after the abnormality judging means has judged that the first blood-pressure measurement is abnormal.
When the female subject feels a labor pain during a BP measurement of the BP measuring device, the BP measuring device may not accurately measure one or more BP values of the subject. However, the present automatic BP measuring apparatus employs the abnormality judging means which judges, if the labor-pain signal does not fall within the reference range when the BP measuring device is performing a first BP measurement, that the first BP measurement is abnormal, and the second BP-measurement starting means which operates the BP measuring device to start a second BP measurement when the labor-pain signal has changed to fall within the reference range again after the abnormality judging means has judged that the first BP measurement is abnormal. Thus, the present apparatus can accurately measure one or more BP values of the female subject.