Residual-based monitoring of human health
Improved human health monitoring is provided in the context of sensor measurements of typical vital signs and other biological parameters, by a system and method using an empirical model of the parameters and disposed to estimate values of the parameters in response to actual measurements. Residuals resulting from the difference between the estimates and actual measurements are analyzed for robust indications of incipient health issues. Residual analysis is both more robust and more sensitive than conventional univariate range checking on vital signs.
1. A computer-automated monitoring system for early detection of incipient health problems in a monitored patient, comprising:
a computer-accessible memory for storing a set of exemplary data observations of multiple vital signs obtained from said monitored patient comprising a personalized model of said patient;
a data feed for receiving new data observations of said multiple vital signs from said monitored patient;
a computer configured by a kernel-based modeling software module to generate an estimate of the value of at least one of said multiple vital signs, as a weighted combination of a subset of said exemplary data observations where said weights are determined from a kernel function comparison of said subset of exemplary data observations and a said received observation;
said computer being further configured by a localization software module to select said subset of exemplary data observations based on at least some of the vital signs in said received observation;
said computer being further configured by a residual analysis software module to compare said estimate to the corresponding measured value of the at least one of said multiple vital signs in said received data observation to generate a residual; and
said computer being further configured by an alerting module having a rules system configurable to provide a test, wherein the test applies rules to said generated residual of each of a plurality of said multiple vital signs in combination to selectively trigger an alert, the alert being triggered based upon results of the test, and present said alert in a web based interface usable by a medical practitioner for monitoring said patient for incipient health problems.
2. A system according to claim 1 , wherein said kernel-based modeling software module implements a similarity-based model.
3. A computer automated monitoring system according to claim 1 , wherein said test of a said generated residual of each of a plurality of said multiple vital signs selected from the set of: said residual exceeds a threshold: said residual exceeds said threshold for a preselected number of data observations in a preselected window: said residual exceeds a running statistic of a time series of said residuals: and a sequential probability ratio test.
4. A computer automated monitoring system according to claim 3 , wherein said multiple vital signs includes heart rate.
5. A computer automated monitoring system according to claim 3 , wherein said multiple vital signs includes respiration rate.
6. A computer automated monitoring system according to claim 3 , wherein said multiple vital signs includes heart rate variability.
7. A computer automated monitoring system according to claim 3 , wherein said multiple vital signs includes a measure of a time lag between a QRS event and a subsequent blood pressure event.
8. A computer automated monitoring system according to claim 3 , wherein said multiple vital signs includes a measure of a time lag between a respiratory activity and resulting oxygenation changes in the blood.
9. A computer automated monitoring system according to claim 3 , wherein said multiple vital signs includes a measure of breathing depth.
10. A computer automated monitoring system according to claim 3 , wherein said multiple vital signs includes a measure of activity.
11. A computer automated monitoring system according to claim 3 , wherein said multiple vital signs includes a measure of the difference in temperature between the ambient air and the skin.
12. A computer automated monitoring system according to claim 3 , wherein said multiple vital signs includes a measure of blood pressure.
13. A computer automated monitoring system according to claim 1 , wherein said computer is further configured by an adaptation module disposed to add a received data observation to said set of exemplary data observations comprising said personalized model upon selection by a clinical user of an option to adapt said model responsive to an alert.