PRIORITY

The present application claims priority to United Kingdom application No. 1902526.1, filed Feb. 25, 2019, the contents of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a defibrillator providing cardio pulmonary resuscitation (CPR) feedback to a person during the performance of CPR on a subject.

2. Background

Various circumstances may arise when a defibrillator instructs a person to carry out CPR on a subject. CPR involves the compression of the subject's chest to cause the heart to pump blood around their circulatory system, primarily to provide oxygenated blood to the subject's heart and brain. If the compression of the chest is too shallow, then the heart will not pump sufficient oxygenated blood and the heart and brain tissue will start to die. For effective CPR, guidelines recommend a specific target depth of compression of the subject's chest. Typically, however, most people do not achieve this target depth. Defibrillators which provide feedback based on comparison of CPR performance of the person with a guideline-set target depth can discourage the person if they do not reach the target.

SUMMARY

It is an object of the present invention to provide a defibrillator which assesses CPR carried out by a person on a subject and provides CPR feedback to the person based on the person's CPR performance.

According to the disclosure there is provided a defibrillator which assesses cardio pulmonary resuscitation (CPR) carried out by a person on a subject and provides CPR feedback to the person, including:

a biosignal measurement system configured to measure biosignals of the subject, determine when CPR is required and produce a CPR start signal and determine and when CPR is to be ceased and produce a CPR stop signal,

a CPR measurement system configured to measure compression signals during CPR chest compressions by the person, and

a CPR assessment system connected to the biosignal measurement system to receive the CPR start signal and the CPR stop signal, connected to the CPR measurement system to receive compression signals. The CPR assessment system can be configured to perform the steps or operations including one or more of (in any order):

(i) receiving the CPR start signal and produce a first feedback signal, (ii) receiving compression signals measured during a first plurality of chest compressions by the person, (iii) using the compression signals to establish a first CPR performance measurement of the person, (iv) setting a CPR performance baseline of the person equal to the first CPR performance measurement of the person, (v) receiving compression signals measured during a further plurality of chest compressions by the person, (vi) using the compression signals to establish a further CPR performance measurement of the person, and (vii) comparing the further CPR performance measurement of the person with the CPR performance baseline of the person. A step (viii) can include, when the further CPR performance measurement of the person is greater than the CPR performance baseline of the person, producing a second feedback signal and set the CPR performance baseline of the person equal to the further CPR performance measurement of the person and going to step (x). Further steps can include (ix) when the further CPR performance measurement of the person is less than the CPR performance baseline of the person, producing a third feedback signal and go to step (x), (x) when the CPR stop signal is not received, returning to step (v), and (xi) when the CPR stop signal is received, producing a fourth feedback signal. The system can further include a feedback unit connected to the CPR assessment system and configured to receive the feedback signals and issue CPR feedback to the person.

