04037151 is referenced by 19 patents and cites 5 patents.

The present invention relates to an apparatus for measuring, by cross-correlation, the period and frequency of a substantially periodic signal having random components, such as fetal heart beat signals and other biological signals.

Title
Apparatus for measuring the period and frequency of a signal
Application Number
5/662058
Publication Number
4037151
Application Date
February 27, 1976
Publication Date
July 19, 1977
Inventor
Yasuhito Takeuchi
Kunitachi
JA
Agent
Robert S Hulse
Stephen P Fox
Assignee
Hewlett Packard Company
CA, US
IPC
G01R 23/02
View Original Source