Smart Servo for a Mechanical CPR System
The invention relates to an apparatus and a method for automated Cardio Pulmonary Resuscitation. The apparatus comprises a chest compression actuator, an actuator driver that supplies time-varying drive signals to the chest compression actuator in dependence of operating parameters of the actuator driver, a physiological parameter sensor supplying measured values of a physiological parameter related to the function of the chest compression actuator, and an adaptive control for the operating parameters of the actuator driver. The operating parameters determining a dynamic behavior of a system comprising the chest compression actuator and a chest of a patient.
1 . Automated cardio pulmonary resuscitation apparatus, comprising a chest compression actuator for exerting a force on a chest of a patient based on a drive signal,
an actuator driver for supplying time-varying drive signals to the chest compression actuator in dependence of operating parameters of the actuator driver, the operating parameters determining a dynamic behavior of a system comprising the chest compression actuator and the chest,
a physiological parameter sensor for measuring a chest compression waveform resulting from the exerted force on the chest by the chest compression actuator, and
an adaptive control for iteratively determining the drive signal for the chest compression actuator based upon a comparison of the measured chest compression waveform with a desired waveform for chest compression.
2 . (canceled)
3 . Automated cardio pulmonary resuscitation apparatus according to claim 1 , wherein operating parameters of the actuator driver subject to the adaptive control comprise at least one among a gain of the controller and the desired value.
4 . (canceled)
5 . Automated cardio pulmonary resuscitation apparatus according to claim 1 , wherein the comparison is a difference between the measured chest comparison waveform and the desired waveform and differentiates the difference with respect to time.
6 . Automated cardio pulmonary resuscitation apparatus according to claim 5 , wherein the iteration is defined by an iterative learning law as follows:
u
k
+
1
(
t
)
=
u
k
(
t
)
+
γ
·
t
e
k
(
t
)
,
where u k (t) is a control signal for the chest compression actuator during a current time interval,
u k+1 (t) is a control signal for the chest compression actuator during a subsequent time interval,
γ is an iterative learning gain,
e k (t) is the difference between the desired value and the measured value, and d/dt is the derivative with respect to time.
7 . Method for automated cardio pulmonary resuscitation, comprising:
a) setting operating parameters that determine a dynamic behavior of a system comprising a chest of a patient and a chest compression actuator of an automated cardio pulmonary resuscitation apparatus to safe initial values, the method further comprising iteratively performing
b) performing at least one chest compression by the cardio pulmonary resuscitation apparatus based on the set operating parameters,
c) collecting a chest compression waveform resulting from the chest compression,
d) evaluating the chest compression waveform with respect to compliance with a desired waveform for chest compression,
e) modifying the operating parameters according to an adaptive control scheme using the evaluation.
8 . (canceled)
9 . (canceled)
10 . Method according to claim 7 , wherein evaluating is defined by an iterative learning law as follows:
u
k
+
1
=
u
k
+
γ
·
t
e
k
,
where u k is a control signal for the chest compression actuator during a current time interval,
u k+1 is a control signal for the chest compression actuator during a subsequent time interval,
γ is an iterative learning gain,
e k is the difference between the desired value and the measured value, and d/dt is the derivative with respect to time.
11 . (canceled)
12 . (canceled)