1. A method for calculating a variability value that is indicative of AF using a sequence of RR intervals, comprising the steps of:
obtaining a signal sequence comprising a plurality of RR intervals wherein said signal sequence is obtained by monitoring the time intervals between successive heart beats of a patient’s heart by measuring at least one of electrical activity; acoustic activity; trans-thoracic impedance; blood pressure; blood velocity; blood oxygenation; heart movement andor deformation;
converting each RR interval in said sequence into an instantaneous heart rate value;
sorting said instantaneous heart rate values into ascending order;
calculating the difference between each successive heart rate;
discarding the two largest differences generated in the previous step; and
calculating a variability value by adding the retained differences.
2. The method of claim 1, further comprising the steps of segmenting said RR interval sequence into a plurality of segments and generating a variability value for each said segment.
3. The method of claim 2, further comprising the step of filtering said generated variability value for at least one segment using previous or successive segment variability values.
4. The method of claim 3 wherein said filtering is implemented by a 7-sample median filter.
5. The method of claim 2, further comprising the steps of comparing at least one said variability value to at least one threshold.
6. The method of claim 5 wherein said step of comparing at least one said variability value to at least one threshold comprises comparing at least one said variability value to an AF detection threshold or an AF startend threshold.
7. The method of claim 6, wherein after said step of comparing at least one said variability value to at least one threshold, a corresponding segment is flagged as \u2018probably containing AF\u2019 when said detection threshold is exceeded and an AF event is detected when a pre-determined number of consecutive segments are flagged as \u2018probably containing AF\u2019 and a corresponding segment is flagged as \u2018AF extension permitted\u2019 when said startend threshold is exceeded.
8. The method of claim 7, wherein once an AF event has been detected, previous andor following segments are tested for the AF extension permitted flag and, if found, the detected AF event is extended to include said segment(s).
9. The method of claim 1 wherein RR intervals shorter than 180 milliseconds or longer than 2 seconds are discarded from the variability calculation.
10. The method of claim 1, further comprising the step of reducing said variability value if said sequence contains no heart rate interval greater than a heart rate threshold.
11. The method of claim 10 wherein said heart rate threshold is 60 beats per minute.
12. The method of claim 10 wherein said reduction is implemented by halving said variability value.
13. The method of claim 1, further comprising the step of limiting said variability value if said sequence is identified as containing a heart rate trend.
14. The method of claim 13 wherein said heart rate trend is identified by, for each instantaneous heart rate of an RR interval, if the heart rate is significantly greater or less than the previous interval heart rate, defining the start of a trend.
15. The method of claim 14 wherein a trend is determined to persist until an RR interval with a significant heart-rate change in an opposite direction is detected.
16. The method of claim 15 wherein, once a new trend is determined on a RR interval, all intervals in a previous trend are flagged as being of the previous trend type.
17. The method of claim 16 wherein each RR interval in a trend is flagged as being a member of a long heart rate if a consecutive number of RR interval trend flags exceeds a long heart rate threshold.
18. The method of claim 17 wherein each RR interval in a trend is flagged as being a member of a short heart rate if a consecutive number of RR interval trend flags exceeds a lower short heart rate threshold.
19. The method of claim 18 wherein each RR interval in a trend is flagged as being not trended if no threshold conditions apply.
20. The method of claim 19 where, for a plurality of RR intervals, trend flags are tested to establish whether said plurality is dominated by heart trend behavior.
21. (canceled)
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The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A vehicle control device comprising:
a first memory for storing a road condition data, which includes a map data, a curve radius of a road and a road inclination angle of the road;
a position detector for detecting a position of a vehicle;
a first controller for detecting unusual behavior of the vehicle and for controlling the vehicle in response to the unusual behavior;
a driving condition detector for detecting a driving condition of the vehicle;
an information acquiring element for acquiring weather information;
a second memory for storing a driving data;
a data acquiring element for acquiring the driving condition as a compensation data, for acquiring the road condition data at a point where the first controller controls the vehicle in response to the unusual behavior, and for acquiring the weather information;
a memory controller for operating the second memory to store the point as an attention spot in the second memory, the point where the first controller controls the vehicle in response to the unusual behavior;
a first optimum mode determining element for determining an optimum vehicle control mode based on the compensation data at the attention spot, the road condition data and the weather information; and
a second controller for controlling the vehicle in such a manner that the driving condition of the vehicle coincides with the optimum vehicle control mode when the vehicle runs through the attention spot or before the vehicle runs through the attention spot.
2. The device according to claim 1, wherein
the second controller controls the vehicle in such a manner that the driving condition of the vehicle coincides with the optimum vehicle control mode when the vehicle runs through a spot similar to the attention spot or before the vehicle runs through the spot similar to the attention spot.
3. The device according to claim 1, further comprising:
a notification element; and
a notification element controller for controlling the notification element to notify a position of the attention spot in the map data when the vehicle runs through the attention spot or before the vehicle runs through the attention spot, wherein
the position of the attention spot is stored in the second memory.
4. The device according to claim 1, further comprising:
a notification element;
a driving characteristics determining element for determining driving characteristics of a driver of the vehicle at the attention spot based on the driving condition, the road condition data and the weather information; and
a notification element controller for controlling the notification element to notify the driving characteristics.
5. The device according to claim 1, further comprising:
a notification element;
a second optimum mode determining element for determining an optimum vehicle control information for the driver based on the optimum vehicle control mode and a vehicle speed, wherein the vehicle speed is detected by the driving condition detector when the vehicle runs through the attention spot or before the vehicle runs through the attention spot; and
a notification element controller for controlling the notification element to notify the optimum vehicle control information.
6. The device according to claim 1, further comprising:
a notification element;
a tire wearing detector for determining a wearing degree of a tire in the vehicle; and
a notification element controller for controlling the notification element to notify the wearing degree of the tire.
7. A vehicle control device comprising:
a first memory for storing a road condition data, which includes a map data, a curve radius of a road and a road inclination angle of the road;
a position detector for detecting a position of a vehicle;
a first controller for detecting unusual behavior of the vehicle and for controlling the vehicle in response to the unusual behavior;
a driving condition detector for detecting a driving condition of the vehicle;
an information acquiring element for acquiring weather information;
a second memory for storing a driving data;
a data acquiring element for acquiring the driving condition as a compensation data, for acquiring the road condition data at a point where the first controller controls the vehicle in response to the unusual behavior, and for acquiring the weather information;
a memory controller for operating the second memory to store the point as an attention spot in the second memory, the point where the first controller controls the vehicle in response to the unusual behavior; and
a notification element for notifying the point of the attention spot in the map data.
8. A method for controlling a vehicle comprising:
storing a road condition data in a first memory, wherein the road condition data includes a map data, a curve radius of a road and a road inclination angle of the road;
detecting a position of the vehicle;
detecting unusual behavior of the vehicle and controlling the vehicle in response to the unusual behavior;
detecting a driving condition of the vehicle;
acquiring weather information;
storing a driving data in a second memory;
acquiring the driving condition as a compensation data, the road condition data at a point where the vehicle is controlled in response to the unusual behavior, and the weather information;
operating the second memory to store the point as an attention spot in the second memory, the point where the vehicle is controlled in response to the unusual behavior;
determining an optimum vehicle control mode based on the compensation data at the attention spot, the road condition data and the weather information; and
controlling the vehicle in such a manner that the driving condition of the vehicle coincides with the optimum vehicle control mode when the vehicle runs through the attention spot or before the vehicle runs through the attention spot.