Statistical method for assessing autonomic balance
First Claim
Patent Images
1. A method for operating an implantable medical device in order to assess a subject'"'"'s autonomic balance, comprising:
- sensing electrical activity in a ventricle and generating a ventricular sense signal when the sensed electrical activity exceeds a predetermined threshold;
measuring time intervals between each pair of successive ventricular senses, referred to as RR intervals, over a predetermined long-term period, where N is the total number of RR interval measurements during the predetermined long-term period and the measured RR intervals RR1 through RRN are referred to as an RR time series;
computing mean values Mxi through MxL of successive x-second segments of the RR time series, where x is a predetermined number and L is the total number of such x-second segments in the RR time series, and computing a variance of the mean values Mx1 through MxL, referred to as [SDx]2;
computing mean values My1 through MyK of successive y-second segments of the RR time series, where y is a predetermined number greater than x and K is the total number of such y-second segments in the RR time series, and computing a variance of the mean values My1 through MyK, referred to as [SDy]2;
computing a mean value of squared successive differences between the RR intervals in the RR time series, referred to as [rMSSD]2; and
, estimating a ratio of the low frequency content in the RR time series between approximately 1/x Hz and 1/y Hz and higher frequency content in the RR time series, referred to as LF/HF, as;
LF/HF=K([SDx]2−
[SDy]2)/[rMSSD]2 wherein K is a defined constant and LF/HF is reflective of the subject'"'"'s autonomic balance.
1 Assignment
0 Petitions
Accused Products
Abstract
A computationally efficient method for assessing a subject'"'"'s autonomic balance by measurement of heart rate variability is disclosed which is particularly suitable for implementation by an implantable medical device. Statistical surrogates are used to represent frequency components of an RR time series. A ratio of the low frequency component to the high frequency component may then be estimated to assess the subject'"'"'s autonomic balance.
-
Citations
20 Claims
-
1. A method for operating an implantable medical device in order to assess a subject'"'"'s autonomic balance, comprising:
-
sensing electrical activity in a ventricle and generating a ventricular sense signal when the sensed electrical activity exceeds a predetermined threshold;
measuring time intervals between each pair of successive ventricular senses, referred to as RR intervals, over a predetermined long-term period, where N is the total number of RR interval measurements during the predetermined long-term period and the measured RR intervals RR1 through RRN are referred to as an RR time series;
computing mean values Mxi through MxL of successive x-second segments of the RR time series, where x is a predetermined number and L is the total number of such x-second segments in the RR time series, and computing a variance of the mean values Mx1 through MxL, referred to as [SDx]2;
computing mean values My1 through MyK of successive y-second segments of the RR time series, where y is a predetermined number greater than x and K is the total number of such y-second segments in the RR time series, and computing a variance of the mean values My1 through MyK, referred to as [SDy]2;
computing a mean value of squared successive differences between the RR intervals in the RR time series, referred to as [rMSSD]2; and
,estimating a ratio of the low frequency content in the RR time series between approximately 1/x Hz and 1/y Hz and higher frequency content in the RR time series, referred to as LF/HF, as;
LF/HF=K([SDx]2−
[SDy]2)/[rMSSD]2wherein K is a defined constant and LF/HF is reflective of the subject'"'"'s autonomic balance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A cardiac rhythm management device, comprising:
-
a sensing channel for sensing electrical activity in a ventricle;
a controller interfaced to the sensing channel which detects a ventricular sense when the sensed electrical activity exceeds a predetermined threshold;
wherein the controller is programmed with executable instructions for;
measuring time intervals between each pair of successive ventricular senses, referred to as RR intervals, over a predetermined long-term period, where N is the total number of RR interval measurements during the predetermined long-term period and the measured RR intervals RR1 through RRN are referred to as an RR time series;
computing mean values Mx1 through MxL of successive x-second segments of the RR time series, where x is a predetermined number and L is the total number of such x-second segments in the RR time series, and computing a variance of the mean values Mx1 through MxL, referred to as [SDx]2;
computing mean values My1 through MyK of successive y-second segments of the RR time series, where y is a predetermined number greater than x and K is the total number of such y-second segments in the RR time series, and computing a variance of the mean values My1 through MyK, referred to as [SDy]2;
computing a mean value of squared successive differences between the RR intervals in the RR time series, referred to as [rMSSD]2; and
,estimating a ratio of the low frequency content in the RR time series between approximately 1/x Hz and 1/y Hz and higher frequency content in the RR time series, referred to as LF/HF, as;
LF/HF=K([SDx]2−
[SDy]2)/[rMSSD]2wherein K is a defined constant and LF/HF is reflective of the subject'"'"'s autonomic balance. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
-
Specification