To realize the measurement of the chest compression depth during the administration of manual cardiopulmonary resuscitation, two 3-axis digital accelerometers were applied for chest compression acceleration and environment acceleration acquisition, with one placed in the chest compression sensor pad, and the other placed in the back sensor pad. Then double integration was made for the acceleration-to-depth conversion with both of the accelerations after preprocessing. The method further included integration reset mechanism based on compression force, with the force point of a pre-determined threshold and the maximum force point as the starting point and the ending point of the integration, respectively. Moreover, a software compensation algorithm was implemented to further increase the accuracy of the depth estimation and reliability of the acceleration. The final performance of the compression depth estimation is within +/- 0.6 cm with 95% confidence of a total of 283 compressions. Accurate and real-time estimation of chest compression depth greatly facilitates the control of compression depth for the lifesaver during manual cardiopulmonary resuscitation.
Acceleration ; Cardiopulmonary Resuscitation ; instrumentation ; methods ; Heart Arrest ; therapy ; Heart Massage ; methods ; standards ; Humans ; Pressure ; Thorax

No study has examined the effectiveness of backboards and air deflation for achieving adequate chest compression (CC) depth on air mattresses with the typical configurations seen in intensive care units. To determine this efficacy, we measured mattress compression depth (MCD, mm) on these surfaces using dual accelerometers. Eight cardiopulmonary resuscitation providers performed CCs on manikins lying on 4 different surfaces using a visual feedback system. The surfaces were as follows: A, a bed frame; B, a deflated air mattress placed on top of a foam mattress laid on a bed frame; C, a typical air mattress configuration with an inflated air mattress placed on a foam mattress laid on a bed frame; and D, C with a backboard. Deflation of the air mattress decreased MCD significantly (B; 14.74 +/- 1.36 vs C; 30.16 +/- 3.96, P < 0.001). The use of a backboard also decreased MCD (C; 30.16 +/- 3.96 vs D; 25.46 +/- 2.89, P = 0.002). However, deflation of the air mattress decreased MCD more than use of a backboard (B; 14.74 +/- 1.36 vs D; 25.46 +/- 2.89, P = 0.002). The use of a both a backboard and a deflated air mattress in this configuration reduces MCD and thus helps achieve accurate CC depth during cardiopulmonary resuscitation.
Beds ; Cardiopulmonary Resuscitation/*instrumentation/methods ; *Compressive Strength ; Equipment Design ; Heart Massage/*instrumentation/methods ; Humans ; Intensive Care Units ; Manikins ; Prospective Studies

INTRODUCTIONThe aim of the study is to investigate the effect of using Automated External Defibrillator (AED) audiovisual feedback on the quality of cardiopulmonary resuscitation (CPR) in a manikin training setting.

MATERIALS AND METHODSFive cycles of 30 chest compressions were performed on a manikin without CPR prompts. After an interval of at least 5 minutes, the participants performed another 5 cycles with the use of real time audiovisual feedback via the ZOLL E-Series defibrillator. Performance data were obtained and analysed.

RESULTSA total of 209 dialysis centre staff participated in the study. Using a feedback system resulted in a statistically significant improvement from 39.57% to 46.94% (P=0.009) of the participants being within the target compression depth of 4 cm to 5 cm and a reduction in those below target from 16.45% to 11.05% (P=0.004). The use of feedback also produced a significant improvement in achieving the target for rate of chest compression (90 to 110 compressions per minute) from 41.27% to 53.49%; (P<0.001). The mean depth of chest compressions was 4.85 cm (SD=0.79) without audiovisual feedback and 4.91 (SD=0.69) with feedback. For rate of chest compressions, it was 104.89 (SD=13.74) vs 101.65 (SD=10.21) respectively. The mean depth of chest compression was less in males than in females (4.61 cm vs 4.93 cm, P=0.011), and this trend was reversed with the use of feedback.

CONCLUSIONIn conclusion, the use of feedback devices helps to improve the quality of CPR during training. However more studies involving cardiac arrest patients requiring CPR need to be done to determine if these devices improve survival.

Adult ; Audiovisual Aids ; Cardiopulmonary Resuscitation ; instrumentation ; methods ; Defibrillators ; Feedback ; Female ; Humans ; Male ; Manikins ; Middle Aged ; Pressure ; Prospective Studies ; Thorax ; Young Adult

INTRODUCTIONAccording to the findings of some studies, instability due to inertia during changes in speed may negatively impact the quality of chest compressions performed during cardiopulmonary resuscitation (CPR) in a moving environment. This study thus aimed to introduce a simple device that maintains the balance of a person performing CPR in a moving environment, such as an ambulance. We also sought to evaluate the effectiveness of this device in the improvement of the quality of chest compressions.

METHODSThe experiment comprised a total of 40 simulated cardiopulmonary arrest scenes (20 in the experimental group and 20 in the control), in which CPR was conducted by eight paramedics. Each simulation involved two paramedics randomly selected from the eight. The ambulance took the same route from the simulated site to the hospital, and continuous CPR was performed on a manikin in the ambulance with or without the aid of our proposed novel device.

RESULTSThe average number of chest compressions per simulation in the experimental and control groups was 1330.75 and 1266.60, respectively (p = 0.095). The percentage of chest compressions with adequate depth achieved in the experimental and control groups was 72% ± 4% and 50% ± 3%, respectively (p < 0.0001).

CONCLUSIONBy maintaining the balance of the CPR performer, our proposed novel device can offset the negative impact that instability (due to a moving environment) has on chest compressions. The device may also lead to an increase in the percentage of chest compressions that achieve adequate depth.

Adult ; Allied Health Personnel ; Ambulances ; Cardiopulmonary Resuscitation ; instrumentation ; methods ; Emergency Medical Services ; methods ; Equipment Design ; Equipment Safety ; Female ; Humans ; Male ; Manikins ; Movement ; Out-of-Hospital Cardiac Arrest ; mortality ; therapy ; Physical Exertion ; physiology ; Reference Values ; Risk Assessment ; Sensitivity and Specificity ; Survival Rate ; Treatment Outcome