DOI: 10.1109/isscc.1979.1155906
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Abstract: IR REFLECTANCE PLETHYSMOGRAPHY has been used f y some time to provide non-invasive measurement of heart rate . This paper will describe a plethysmograph system in which all active analog and digital circuit elements, with the exception of the LED drive and sensor, have been integrated on a single CMOS chip 2.39 x 2.77mm; Figure 1. The IC approach makes possible the construction of the complete instrument within a digital wristwatch. The plethysmograph electronics share a common hybrid substrate with the watch…

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