External defibrillator and methods for operating the external defibrillator
Methods and apparatus are provided for minimizing the inherent time delays within external defibrillators. The methods and apparatuses utilize timing schemes for initiation and completion of charging of an energy storage device of an external defibrillator, measuring one or physical parameters of the patient and conducting a physiology analysis of the patient. The initiation and completion of one or more of these activities are arranged so that the energy storage device is charged to a desired level and available for a defibrillation shock to the patient with minimal delay after activation of the external defibrillator.
1. An external defibrillator that is configured to provide a defibrillation shock through a plurality of electrodes attached to a patient, comprising:
a connection port configured to be coupled to the plurality of electrodes;
an energy storage device coupled to the connection port; and
a controller coupled to the energy storage device, the controller configured to:
measure a physical parameter of the patient at a first time instant (t 1 );
determine a charge for the energy storage device that is at least partially based on the physical parameter at a second time instant (t 2 ) that occurs after the first time instant (t 1 );
complete a physiology analysis of the patient at a sixth time instant (t 6 ) that occurs after the second time instant (t 2 );
determine a rate for charging the energy storage device to substantially achieve the charge after a fifth time instant (t 5 ) and before a seventh time instant (t 7 ), the fifth time instant (t 5 ) occurring after the second time instant (t 2 ) and before the sixth time instant (t 6 ), the seventh time instant (t 7 ) occurring after the sixth time instant(t 6 ); and
begin to charge the energy storage device at the rate at a third time instant (t 3 ) that occurs after the second time instant (t 2 ) and before the fifth time instant (t 5 ).
2. The external defibrillator of claim 1 , in which the controller is further configured to begin the physiology analysis at about a fourth time instant (t 4 ) that occurs before the fifth time instant (t 5 ).
3. The external defibrillator of claim 2 , in which the fourth time instant (t 4 ) occurs after the third time instant (t 3 ).
4. The external defibrillator of claim 2 , in which the fourth time instant (t 4 ) is substantially equal to the third time instant (t 3 ).
5. The external defibrillator of claim 2 , in which the controller is further configured to activate at an initial time instant (t 0 ) that occurs before the first time instant (t 1 ).
6. The external defibrillator of claim 1 , in which the physical parameter is a transthoracic impedance.
7. The external defibrillator of claim 1 , in which the physiology analysis is an ECG analysis.
8. The external defibrillator of claim 1 , in which the fifth time instant (t 5 ) is within about two (2) seconds of the sixth time instant (t 6 ).
9. The external defibrillator of claim 1 , in which the seventh time instant (t 7 ) is within about two (2) seconds of the sixth time instant (t 6 ).