Eric W. STARR,James A. SCULL,Eric AYERS,Bernie F. HETE,Donald S. WILCZEK,Mark H. SANDERS
申请号：
US13718423
公开号：
US20140276120A1
申请日:
2012.12.18
申请国别(地区):
US
年份:
2014
代理人:
摘要：
A method and apparatus for monitoring changes in the intra-thoracic pressure of a patient due to the patients respiratory activity or volumetric changes in the extra-thoracic arterial circulatory system due to cardiac function based on the changes in pressure in the patients extra-thoracic arterial circulatory system as measured by a plethysmography sensor, such as an photoplethysmograph. A frequency spectrum is generated for the plethysmograph signal and the frequencies of interest is isolated from the frequency spectrum by setting appropriate cutoff frequencies for the frequency spectrum. This isolated frequency is used to filter the plethysmograph signal to provide a signal indicative of the patients respiratory activity or cardiac function.
