Physiological sensor history backfill system and method

1. A method of sensor history backfill for a local base device operable to wirelessly communicate with a physiological sensor connected to a patient, the method comprising:

obtaining physiological readings for the patient at a predetermined interval;

storing the physiological readings at the physiological sensor as sensor physiological readings;

transmitting the physiological readings from the physiological sensor to the local base device;

storing the physiological readings at the local base device as historic physiological readings;

obtaining a current physiological reading for the patient;

transmitting the current physiological reading from the physiological sensor to the local base device in a current reading message;

detecting at the local base device a record gap in the historic physiological readings between the current physiological reading and the historic physiological readings;

identifying missing physiological readings in the record gap;

transmitting a request for the missing physiological readings from the local base device to the physiological sensor when the current reading message does not include the sensor physiological readings to fill the record gap;

selecting sensor physiological readings for the missing physiological readings;

transmitting the selected sensor physiological readings from the physiological sensor to the local base device; and

filling the record gap in the historic physiological readings with the selected sensor physiological readings from the physiological sensor.

2. The method of claim 1 wherein the local base device is an insulin pump and the physiological sensor is a glucose sensor.

3. The method of claim 1 wherein the local base device includes a local base device clock and the physiological sensor includes a physiological sensor clock, the method further comprising synchronizing the local base device clock and the physiological sensor clock before transmitting the current physiological reading from the physiological sensor to the local base device in the current reading message.

4. The method of claim 1 wherein the filling further comprises repeatedly transferring a predetermined packet number of sensor physiological readings from the physiological sensor to the local base device to provide the sensor physiological readings required to filling the record gap.

5. The method of claim 1 wherein the filling further comprises:

detecting a Time Change marker that occurred during the record gap, the Time Change marker being stored at the local base device; and

adjusting a user clock associated with the historic physiological readings in the record gap on and after a time of the Time Change marker by a time change value associated with the Time Change marker.

6. The method of claim 1 wherein the filling further comprises:

detecting a Sensor Off marker that occurred during the record gap, the Sensor Off marker being stored at the local base device; and

assigning a Sensor Off value to the historic physiological readings in the record gap on and after a time of the Sensor Off marker.

7. The method of claim 1 wherein the filling further comprises:

detecting a Sensor On marker that occurred during the record gap, the Sensor On marker being stored at the local base device; and

filling the record gap in the historic physiological readings in the record gap after a time of the Sensor On marker with sensor physiological readings from the physiological sensor.

8. The method of claim 1 wherein the filling further comprises:

detecting an End of Day marker that occurred during the record gap, the End of Day marker being stored at the local base device; and

associating the End of Day marker with the historic physiological readings in the record gap at a time of the End of Day marker.

9. The method of claim 1 wherein the filling further comprises:

assigning a Gap Fill value to the historic physiological readings in the record gap before a fillable start time defined as time of the current physiological reading less a maximum physiological sensor storage time.

10. The method of claim 1 , further comprising:

detecting an error during sensor history backfill; and

aborting the filling in response to detecting the error.

11. A method of sensor history backfill for a local base device operable to wirelessly communicate with a physiological sensor connected to a patient, the method comprising:

obtaining physiological readings for the patient at a predetermined interval, each of the physiological readings being associated with a physiological reading time;

storing a predetermined storage number of the physiological readings at the physiological sensor with the associated physiological reading time, the predetermined storage number being greater than or equal to one and greater than a predetermined packet number;

measuring a current physiological reading for the patient at a current measurement time;

transmitting from the physiological sensor to the local base device a current message including the current physiological reading, the current measurement time, and the predetermined packet number of the physiological readings immediately before the current physiological reading, the predetermined packet number being greater than or equal to zero;

retrieving a last stored physiological reading time from the local base device memory;

calculating a time gap between the current measurement time and the last stored physiological reading time;

setting a backfill start time equal to the last stored physiological reading time when the time gap is greater than a packet duration defined as the predetermined interval multiplied by the predetermined packet number;

requesting the physiological sensor to transmit to the local base device the predetermined packet number of the physiological readings immediately after the backfill start time;

storing the predetermined packet number of the physiological readings immediately after the backfill start time in the local base device;

adding the packet duration to the backfill start time; and

repeating the requesting, the storing, and the adding when a backfill end time defined as the backfill start time less the packet duration is less than the current measurement time.

12. The method of claim 11 wherein the local base device is an insulin pump and the physiological sensor is a glucose sensor.

13. The method of claim 11 wherein the local base device includes a local base device clock and the physiological sensor includes a physiological sensor clock, the method further comprising synchronizing the local base device clock and the physiological sensor clock before transmitting the current physiological reading from the physiological sensor to the local base device in the current reading message.

14. The method of claim 11 , further comprising:

detecting a Time Change marker that occurred during the time gap, the Time Change marker being stored at the local base device; and

adjusting a user clock associated with physiological readings stored at the local base device on and after a time of the Time Change marker by a time change value associated with the Time Change marker.

15. The method of claim 11 , further comprising:

detecting a Sensor Off marker that occurred during the time gap, the Sensor Off marker being stored at the local base device; and

assigning a Sensor Off value to physiological readings stored at the local base device on and after a time of the Sensor Off marker.

16. The method of claim 11 , further comprising:

detecting a Sensor On marker that occurred during the time gap, the Sensor On marker being stored at the local base device; and

filling the time gap after a time of the Sensor On marker with sensor physiological readings from the physiological sensor.

17. The method of claim 11 , further comprising:

detecting an End of Day marker that occurred during the time gap, the End of Day marker being stored at the local base device; and

associating the End of Day marker with physiological readings stored at the local base device at a time of the End of Day marker.

18. The method of claim 11 , further comprising:

assigning a Gap Fill value to physiological readings stored at the local base device before a fillable start time defined as time of the current physiological reading less a maximum physiological sensor storage time.

19. The method of claim 11 , further comprising:

detecting an error during sensor history backfill; and

aborting the filling in response to detecting the error.