During cardiopulmonary resuscitation (CPR), the depth of compression is a critical factor affecting the effectiveness of the rescue and the patient's prognosis. However, it is difficult to master the correct compression depth in manual CPR. If the compression depth is too deep, it may cause rib fractures, while insufficient compression depth may fail to establish effective circulation. Although most existing manual CPR compression depth control devices can indicate the depth but lack direct limiting functions. Against this background, led by a team of faculty and students from the Department of Emergency and Rescue Medicine at Xuzhou Medical University, on the basis of the development of a portable CPR protection device (National Invention Patent of China, patent number: ZL 2021 1 0309001.4), the device's compression depth limiting performance was further expanded, and then a new type of CPR compression depth limiting device suitable for different body types was developed. This device has applied for a National Invention Patent of China (patent application number: ZL 2023 1 0644910.2) and has been granted a National Utility Model Patent of China (patent number: ZL 2023 2 1384853.0). The device consists of a horizontal support beam, a vertical sliding beam, a guide block, a rotating shaft, a rotating arm, a limit slider and a limit pin. The horizontal support beams of the two limit devices are fixed horizontally to the horizontal side beams of the portable CPR protection device by bolts, and the connecting arms at the bottom of the vertical sliding beams are fixedly connected with the pressing mechanism, so that precise control of the pressing depth in CPR operation can be realized according to the patient's body size by the mechanical linkage of the vertical sliding beams and the rotating arms, as well as by the blocking and limiting effect of the rotating arms and the guiding blocks on the limiting sliders. It can prevent the occurrence of complications such as chest wall fractures, and thereby increase the success rate of manual CPR, and its structure is simple, low-cost, and suitable for social popularization.
Cardiopulmonary Resuscitation/instrumentation* ; Humans ; Equipment Design ; Pressure

In this study, a closed-loop controller for chest compression which adjusts chest compression depth according to the coronary perfusion pressure (CPP) was proposed. An effective and personalized chest compression method for automatic mechanical compression devices was provided, and the traditional and uniform chest compression standard neglecting individual difference was improved. This study rebuilds Charles F. Babbs human circulation model with CPP simulation module and proposes a closed-loop controller based on a fuzzy control algorithm. The performance of the fuzzy controller was evaluated and compared to that of a traditional PID controller in computer simulation studies. The simulation results demonstrated that the fuzzy closed-loop controller produced shorter regulation time, fewer oscillations and smaller overshoot than those of the traditional PID controller and outperforms the traditional PID controller in CPP regulation and maintenance.
Algorithms ; Arterial Pressure ; Cardiopulmonary Resuscitation ; instrumentation ; Computer Simulation ; Coronary Vessels ; physiopathology ; Humans ; Models, Theoretical ; Perfusion ; Thorax

The inspiratory impedance threshold device (ITD) was put forward by Lurie in 1995, and was assigned as a class II a recommendation by the International Liaison Committee on Resuscitation (ILCOR) resuscitation guidelines in 2005. The ITD is used to augment negative intrathoracic pressure during recoil of the chest so as to enhance venous return and cardiac output, and to decrease intracranial pressure. In the recent years many researches on the ITD have been1 carried out, but all the researches can not take out a clear evidence to support or refute the use of the ITD. This paper introduces the structure and working principle of the ITD in detail, the research results and the debates about the use of the ITD for the past years.
Cardiopulmonary Resuscitation ; instrumentation ; Electric Impedance ; Humans ; Pressure

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

This paper introduces the development and animal tests of a miniaturized electrical chest compression device. Based on pulse width modulation technology produced by micro control unit, the device can control the frequency and depth of the compression accurately, as well as perform real-time adjustment. Therefore, it can perform continuous and stable chest compression for long time, which may increase the successful rate of cardiopulmonary resuscitation (CPR). Besides, the device can also produce different types of compression waveforms, including trapezoidal and triangular waveforms. Then, the performance and efficacy of the device was assessed with a rat model of asphyxial cardiac arrest (CA).
Animals ; Cardiopulmonary Resuscitation ; instrumentation ; Disease Models, Animal ; Electricity ; Heart Arrest ; therapy ; Heart Rate ; Pressure ; Rats ; Thorax

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

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