Real-time feedback systems in CPR

The effect of standalone audio-visual feedback devices on the quality of chest compressions during laypersons' cardiopulmonary resuscitation training: a systematic review and meta-analysis

AIMS

Individual studies that investigated the effect of standalone audio-visual feedback (AVF) devices during laypersons' cardiopulmonary resuscitation (CPR) training have yielded conflicting results. This review aimed to evaluate the effect of standalone AVF devices on the quality of chest compressions during laypersons' CPR training.

METHOD AND RESULT

Randomized controlled trials of simulation studies recruiting participants without actual patient CPR experience were included. The intervention evaluated was the quality of chest compressions with standalone AVF devices vs. without AVF devices. Databases, such as PubMed, Cochrane Central, Embase, Cumulative Index to Nursing & Allied Health Literature (CINAHL), Web of Science, and PsycINFO, were searched from January 2010 to January 2022. The risk of bias was assessed using the Cochrane risk of bias tool. A meta-analysis alongside a narrative synthesis was used for examining the effect of standalone AVF devices.Sixteen studies were selected for this systematic review. A meta-analysis revealed an increased compression depth of 2.22 mm [95% CI (Confidence Interval), 0.88-3.55, P = 0.001] when participants performed CPR using the feedback devices. Besides, AVF devices enabled laypersons to deliver compression rates closer to the recommended range of 100-120 per min. No improvement was noted in chest recoil and hand positioning when participants used standalone AVF devices.

CONCLUSION

The quality of the included studies was variable, and different standalone AVF devices were used. Standalone AVF devices were instrumental in guiding laypersons to deliver deeper compressions without compromising the quality of compression rates. However, the devices did not improve the quality of chest recoil and placement of the hands.

REGISTRATION

PROSPERO: CRD42020205754.

Comparison of real-time feedback and debriefing by video recording on basic life support skill in nursing students

BACKGROUND

Cardiopulmonary resuscitation skill have a direct impact on its success rate. Choosing the right method to acquire this skill can lead to effective performance. This investigation was conducted to compare the effect of Real-time feedback and debriefing by video recording on basic life support skill in nursing students.

METHODS

This quasi-experimental study was performed on 67 first year nursing students. First, a theoretical basic life support (BLS) training session was held for the all participants, at the end of session the pre-test was taken. Students were randomly assigned to two groups. A 4-hour practical BLS training session was conducted in the real - time feedback group as well as the debriefing by video recording group, and at the end of the training, a post-test was taken from each group. Each group received a post-test. Data were analyzed using SPSS 25 software.

RESULTS

Results showed a significant difference between mean (SD) of debriefing by video recording group in pre-test and post-test (p < 0.001) and in the real-time feedback group there was a significant difference between mean (SD) in pre-test and post-test (p < 0.001), respectively. In addition, there was no significant difference between the mean score of basic life support skill in real-time feedback and debriefing by video recording.

CONCLUSIONS

Both real-time feedback and debriefing by video recording were effective on basic life support skill.

The impact of cognitive aids on resuscitation performance in in-hospital cardiac arrest scenarios: a systematic review and meta-analysis

Different cognitive aids have been recently developed to support the management of cardiac arrest, however, their effectiveness remains barely investigated. We aimed to assess whether clinicians using any cognitive aids compared to no or alternative cognitive aids for in-hospital cardiac arrest (IHCA) scenarios achieve improved resuscitation performance. PubMed, EMBASE, the Cochrane Library, CINAHL and ClinicalTrials.gov were systematically searched to identify studies comparing the management of adult/paediatric IHCA simulated scenarios by health professionals using different or no cognitive aids. Our primary outcomes were adherence to guideline recommendations (overall team performance) and time to critical resuscitation actions. Random-effects model meta-analyses were performed. Of the 4.830 screened studies, 16 (14 adult, 2 paediatric) met inclusion criteria. Meta-analyses of eight eligible adult studies indicated that the use of electronic/paper-based cognitive aids, in comparison with no aid, was significantly associated with better overall resuscitation performance [standard mean difference (SMD) 1.16; 95% confidence interval (CI) 0.64; 1.69; I² = 79%]. Meta-analyses of the two paediatric studies, showed non-significant improvement of critical actions for resuscitation (adherence to guideline recommended sequence of actions, time to defibrillation, rate of errors in defibrillation, time to start chest compressions), except for significant shorter time to amiodarone administration (SMD - 0.78; 95% CI - 1.39; - 0.18; I² = 0). To conclude, the use of cognitive aids appears to have benefits in improving the management of simulated adult IHCA scenarios, with potential positive impact on clinical practice. Further paediatric studies are necessary to better assess the impact of cognitive aids on the management of IHCA scenarios.

A comparison of the effectiveness of QCPR and conventional CPR training in final-year medical students at a South African university

INTRODUCTION

High-quality cardiopulmonary resuscitation (CPR) saves lives. Training on basic first aid manikins allows students to practice manoeuvres and provides realistic resistance to chest compressions. Conventional CPR has no real-time feedback to observe the quality of CPR. Quality cardiopulmonary resuscitation (QCPR) is technology using wireless sensors embedded in the manikin to measure the effectiveness of core CPR components. This study compared the effectiveness of CPR training of final-year undergraduate medical students using electronic-feedback QCPR adult manikins and conventional adult manikins. The effectiveness of compressions was compared and return on investment was investigated.

METHODS

In an experimental study, 53 students were divided into two groups using simple random sampling. The QCPR group practised CPR on the QCPR manikins. The CPR group practised on conventional CPR manikins. Both groups were allowed to practice for approximately 10 minutes. After the training session, both groups were tested using the QCPR manikin. Only chest compression performance in adult-sized manikins were measured, recorded and compared.

RESULTS

The median flow fraction for the QCPR group was 78.0% (interquartile range (IQR) 63-89%) and for the CPR group 80.0% (IQR 74-85%). The median number of compressions for the QCPR group was 104 (IQR 101-109) and for the CPR group 107 (IQR 79-124). Both groups achieved a 100% compression rate with adequate depth. The maximum total effectiveness of both groups was 99%. No statistically significant difference was seen for the overall percentage of compression effectiveness between the groups.

CONCLUSION

Participants achieved acceptable scores on most CPR compression metrics and complied with CPR guidelines in most cases. Efficacy of CPR training on conventional and QCPR manikins was comparable. CPR training in low resource settings can be just as effective on conventional manikins. Immediate feedback technology adds value to the training experience, allowing for individuals to adjust for deviations to set standards.

The burn injury transfer feedback form: A 16 year Australian statewide review of burn inter-hospital transfer

INTRODUCTION

Modern burn care is centralised, and studies show that early, prompt referral to dedicated burn services improve clinical outcomes. We describe the use of a novel clinical instrument, the burn injury Transfer Feedback Form, to support and educate referring clinicians about the early assessment and management of burn injuries. Since 2005, Transfer Feedback Forms have been completed for all burn-injured patients with inter-hospital transfer to a specialised burn unit in the state of New South Wales (NSW), Australia. The aim of this study was to review physiological, procedural, and system or process issues in the care of both adult and paediatric burn-injured patients needing retrieval and transfer in NSW as identified by the Transfer Feedback Form. Secondary objectives were to determine any significant differences in these parameters between metropolitan and regional or remote referring institutions, and if any improvements occurred in these parameters over time.

METHODS

This was a retrospective analysis of all patients who were transferred to a burn unit in NSW between July 2005 and July 2021 using their prospectively completed Transfer Feedback Forms. Patients were divided into metropolitan and non-metropolitan referral sources based on geographic location. Clinical issues or deficiencies identified during each patient transfer were then classified into various groups. To determine if transfer-related clinical concerns had changed with time, two distinct periods before and after 2015, when the NSW Trauma App was introduced, were analysed. We compared trends in frequency of transfer-related concerns before and after App introduction by using interrupted time series analysis.

RESULTS

A total of 3233 patients had Feedback Forms submitted during the 16-year period. We included 929 children (28.7%) and 2304 adults (71.3%). Transfer-related clinical issues were identified in 904 adults (39.0%) and 484 children (52.0%). In both adult and paediatric patients, the most common transfer-related clinical deficiency was in relation to burn size estimation with 525 patients (43.7%) and 207 patients (30.6%), respectively. Between the time periods analysed, the number of issues arising during inter-hospital transfer fell significantly for both adults (from 46.1% to 26.1%; p < 0.05) and children (from 55.3% to 40.7%; p < 0.05). Segmented regression analysis demonstrated a significant break in the rate of transfer-related clinical issues in 2014 (p < 0.05) and 2015 (p < 0.01) for adults. Accurate body surface area estimations also increased significantly by 53% and 50% for adults and children (p < 0.05 for both), respectively, after 2015.

CONCLUSION

Our analysis indicates that the early care of burn-injured patients undergoing inter-hospital transfer is associated with clinical, technical, and logistical challenges. However, introduction of the burn injury Transfer Feedback Form has been associated with improvements in early burn care by referring centres both temporally and geographically. Smartphone-based applications such as the NSW Trauma App have also probably contributed to these findings. Adopting these simple, inexpensive strategies into burn care systems will augment inter-hospital transfer of burn-injured patients, and improve clinical outcomes.

Simulation-Based Training in High-Quality Cardiopulmonary Resuscitation Among Neonatal Intensive Care Unit Providers

INTRODUCTION

American Heart Association guidelines recommend the use of feedback devices for CPR provider resuscitation training. There is paucity of published literature regarding the utility of these devices especially in neonates and infants. We sought to evaluate if simulation-based education and debriefing using a CPR feedback device would improve CPR performance on an infant manikin in a cohort of NICU nurses as evaluated by CPR feedback device.

METHODS

We conducted a prospective, observational simulation study to assess the quality of chest compressions by NICU nurses before and after debriefing using CPR quality data captured by an accelerometer-based device. Chest compression (CC) depth, rate, recoil, CC fraction and nursing confidence level related to performing a high-quality CPR were compared before and after debriefing using paired t-test and Wilcoxon rank sum test.

RESULTS

A total of 62 NICU nurses participated in the study and all of them were Neonatal Resuscitation Program (NRP) certified. There was a significant improvement in CC depth and CC fraction [mean + SD values = 0.79 in + 0.17 (pre-debrief), 0.86 in + 0.21 (post-debrief) (p = 0.034) and 56.8% + 17.7 (pre-debrief), 70.8% + 18.4 (post-debrief) (0.0014), respectively]. There was no difference in CC rate (p = 0.36) and recoil (p = 0.25) between pre and post structured debriefing. The confidence level of nurses in all CPR dynamics (appropriate CC rate, CC depth, team communication, minimizing interruption in CC and coordinating CC with ventilation) was significantly higher after simulation and structured debriefing. All the nurses used 3:1 compression: ventilation ratio of NRP despite the patient being a 4 month old premature baby in the NICU.

CONCLUSIONS

Simulation training and debriefing of NICU nurses using CPR feedback device improved their chest compression quality on an infant mannequin and their confidence level for performing high-quality CPR. NICU providers tend to use NRP protocol of 3:1 compression: ventilation ratio during CPR in the NICU irrespective of age of the infant.

Do automated real-time feedback devices improve CPR quality? A systematic review of literature

AIM

Automated real-time feedback devices have been considered a potential tool to improve the quality of cardiopulmonary resuscitation (CPR). Despite previous studies supporting the usefulness of such devices during training, others have conflicting conclusions regarding its efficacy during real-life CPR. This systematic review aimed to assess the effectiveness of automated real-time feedback devices for improving CPR performance during training, simulation and real-life resuscitation attempts in the adult and paediatric population.

METHODS

Articles published between January 2010 and November 2020 were searched from BVS, Cinahl, Cochrane, PubMed and Web of Science, and reviewed according to a pre-defined set of eligibility criteria which included healthcare providers and randomised controlled trial studies. CPR quality was assessed based on guideline compliance for chest compression rate, chest compression depth and residual leaning.

RESULTS

The selection strategy led to 19 eligible studies, 16 in training/simulation and three in real-life CPR. Feedback devices during training and/or simulation resulted in improved acquisition of skills and enhanced performance in 15 studies. One study resulted in no significant improvement. During real resuscitation attempts, three studies demonstrated significant improvement with the use of feedback devices in comparison with standard CPR (without feedback device).

CONCLUSION

The use of automated real-time feedback devices enhances skill acquisition and CPR performance during training of healthcare professionals. Further research is needed to better understand the role of feedback devices in clinical setting.

Effect of real-time and post-event feedback in out-of-hospital cardiac arrest attended by EMS - A systematic review and meta-analysis

OBJECTIVES

A systematic review to determine if cardiopulmonary resuscitation (CPR) guided by either real-time or post-event feedback could improve CPR quality or patient outcome compared to unguided CPR in out-of-hospital cardiac arrest (OHCA).

METHODS

Four databases were searched; PubMed, Embase, CINAHL, and Cochrane Library in August 2020 for post 2010 literature on OHCA in adults. Critical outcomes were chest compression depth, rate and fraction. Important outcomes were any return of spontaneous circulation, survival to hospital and survival to discharge.

RESULTS

A total of 9464 studies were identified with 61 eligibility for full text screening. A total of eight studies was included in the meta-analysis. Five studies investigated real-time feedback and three investigated post-event feedback. Meta-analysis revealed that real-time feedback statistically improves compression depth and rate while post-event feedback improved depth and fraction. Feedback did not statistically improve patient outcome but an improvement in absolute numbers revealed a clinical effect of feedback. Heterogenity varied from "might not be important" to "considerable".

CONCLUSION

To significantly improve CPR quality real-time and post-event feedback should be combined. Neither real-time nor post event feedback could statistically be associated with patient outcome however, a clinical effect was detected. The conclusions reached were based on few studies of low to very low quality.

PROSPERO REGISTRATION

CRD42019133881.

Rapid degradation of psychomotor memory causes poor quality chest compressions in frequent cardiopulmonary resuscitation providers and feedback devices can only help to a limited degree: A crossover simulation study

Studies report a decline in the psychomotor memory of cardiopulmonary resuscitation (CPR) providers within months of training, but they are prone to subject bias. We hypothesized that this degradation is faster and more prevalent in real world practice. The aims of our study were to 1. assess the quality of chest compressions (CC) delivered routinely by CPR-certified clinicians who are not primed by study conditions, and 2. investigate if psychomotor memory degrades if feedback devices are removed. Forty anaesthetists and intensivists participated in a voluntary, half-day, randomized crossover study using case-based simulation. Participants were paired and randomly assigned into 2 groups; each receiving automated feedback either in the first or second cycle of CPR. Two cycles of CC and defibrillation (ACLS protocol) were administered on a manikin. CC parameters including overall quality were measured by a feedback device. The median proportion of good quality CC was poor at baseline but improved with feedback; 38.2% (IQR 27.7, 58.7) to 57.7% (IQR 38.0, 68.7), P < .05. The median proportion of good quality CC fell after feedback withdrawal; 50.5% (IQR 24.5, 67.7) to 25.6% (9, 37.6), P < .05. No carryover effect was observed. Treatment effect and period effect were detected. Baseline quality of CC amongst frequent CPR providers is poor, and can be improved partly by feedback devices. As psychomotor memory of good quality CCs degrades rapidly after removal of feedback, a multimodal approach is required for CPR skill retention. Future research on the optimal frequency of CPR training, including the use of feedback devices in clinical practice should be explored.

Development of Smart-Ring-Based Chest Compression Depth Feedback Device for High Quality Chest Compressions: A Proof-of-Concept Study

Recently, a smart-device-based chest compression depth (CCD) feedback system that helps ensure that chest compressions have adequate depth during cardiopulmonary resuscitation (CPR) was developed. However, no CCD feedback device has been developed for infants, and many feedback systems are inconvenient to use. In this paper, we report the development of a smart-ring-based CCD feedback device for CPR based on an inertial measurement unit, and propose a high-quality chest compression depth estimation algorithm that considers the orientation of the device. The performance of the proposed feedback system was evaluated by comparing it with a linear variable differential transformer in three CPR situations. The experimental results showed compression depth errors of 2.0 ± 1.1, 2.2 ± 0.9, and 1.4 ± 1.1 mm in the three situations. In addition, we conducted a pilot test with an adult/infant mannequin. The results of the experiments show that the proposed smart-ring-based CCD feedback system is applicable to various chest compression methods based on real CPR situations.

Improving the quality of training paramedics by means of cadavers - a pilot study

BACKGROUND

Paramedics are authorised to perform emergency procedures, including trauma assessment according to global standards. The aim of the study was to answer the question whether the use of cadavers in teaching practical competencies to medical rescue students, in the field of trauma assessment, is necessary as a supplement to learning in simulated conditions with the use of mannequins.

METHODS

Research included several stages. The first stage was conduction of classes for 27 students in the field of rapid trauma assessment, in accordance with the guidelines of the International Trauma Life Support. In the second stage, a plan of a test in which students had to perform an analogous procedure of rapid trauma assessment, but with the use of cadavers, human unfixed specimens, was prepared. The Delphi method was used to develop and approve checklists, as well as a scale to assess the global correctness of identification of head, torso and limb injuries by medical rescue students.

RESULTS

The identification rate was 76.54% in the head area, 67.90% in the torso area, while in the limb area it equalled 44.45%. A significant difference in scores, compared to the examination performed on a mannequin, was observed (Wilcoxon = 4.541; p = 0.000). The most difficult to make a correct diagnosis were injuries related to a fracture of the proximal end of the femur and a dislocated wrist (only 18.52% of correct answers). The students highly rated the usefulness of the examination, by awarding it an average of 4.76 points (SD ± 0.56) on the Likert scale (0-5).

CONCLUSIONS

The study shows that the use of cadavers to teach practical competencies in the field of trauma assessment to medical rescue students can be an effective supplement to simulated learning. Students could feel the difference between the human body and the mannequin. More research is needed to assess whether realistic simulation translates into objective endpoints, such as the effectiveness of diagnosis in the examination of trauma patients. However, it should be remembered that the introduction of this teaching method is expensive and requires adequate base, as well as the compliance with a number of formal requirements.

Mobile App Support for Cardiopulmonary Resuscitation: Development and Usability Study

Background

The user requirements for in-hospital cardiopulmonary resuscitation (CPR) support apps are understudied. To study usability, functionality, and design based on user requirements, we applied a mixed methods research design using interviews, observations, and a Kano questionnaire to survey perspectives of both physicians and nurses.

Objective

This study aims to identify what an in-hospital CPR support app should include to meet the requirements and expectations of health care professionals by evaluating the CprPrototype app.

Methods

We used a mixed methods research design. The qualitative methods consisted of semistructured interviews and observations from an advanced life support (ALS) course; both provided input to the subsequent questionnaire development. The quantitative method is a questionnaire based on the Kano model classifying user requirements as must-be, one-dimensional (attributes causing satisfaction when present and dissatisfaction when absent), attractive, indifferent, and reverse (attributes causing dissatisfaction when present and satisfaction when absent). The questionnaire was supplemented with comment fields. All respondents were physicians and nurses providing ALS at hospitals in the Central Denmark Region.

Results

A total of 83 physicians and nurses responded to the questionnaire, 15 physicians and nurses were observed during ALS training, and 5 physicians were interviewed. On the basis of the Kano questionnaire, 53% (9/17) of requirements were classified as indifferent, 29% (5/17) as attractive, and 18% (3/17) as one-dimensional. The comments revealed 7 different categories of user requirements with noticeable differences between those of physicians and nurses: technological challenges, keep track of time, documentation and history, disturbing element, improvement areas: functions, improvement areas: design, and better guidance.

Conclusions

The study provides recommendations to developers on the user requirements that need to be addressed when developing CPR support apps. Three features (one-dimensional attributes) must be incorporated in an in-hospital CPR support app: reminder of rhythm check, reminder of resuscitation drugs, and differentiate between adults and children. In addition, 5 features (attractive attributes) would result in higher user satisfaction: all functions on one side, access to the patient journal in the app, automatic time recording when cardiac arrest is called, sound to guide the chest compression rate (metronome), and send CPR history to the DANARREST(Danish in-hospital cardiac arrest registry) database.

Monitoring chest compression rate in automated external defibrillators using the autocorrelation of the transthoracic impedance

Aim

High-quality chest compressions is challenging for bystanders and first responders to out-of-hospital cardiac arrest (OHCA). Long compression pauses and compression rates higher than recommended are common and detrimental to survival. Our aim was to design a simple and low computational cost algorithm for feedback on compression rate using the transthoracic impedance (TI) acquired by automated external defibrillators (AEDs).

Methods

ECG and TI signals from AED recordings of 242 OHCA patients treated by basic life support (BLS) ambulances were retrospectively analyzed. Beginning and end of chest compression series and each individual compression were annotated. The algorithm computed a biased estimate of the autocorrelation of the TI signal in consecutive non-overlapping 2-s analysis windows to detect the presence of chest compressions and estimate compression rate.

Results

A total of 237 episodes were included in the study, with a median (IQR) duration of 10 (6–16) min. The algorithm performed with a global sensitivity in the detection of chest compressions of 98.7%, positive predictive value of 98.7%, specificity of 97.1%, and negative predictive value of 97.1% (validation subset including 207 episodes). The unsigned error in the estimation of compression rate was 1.7 (1.3–2.9) compressions per minute.

Conclusion

Our algorithm is accurate and robust for real-time guidance on chest compression rate using AEDs. The algorithm is simple and easy to implement with minimal software modifications. Deployment of AEDs with this capability could potentially contribute to enhancing the quality of chest compressions in the first minutes from collapse.

Effects of real-time feedback on cardiopulmonary resuscitation quality on outcomes in adult patients with cardiac arrest: A systematic review and meta-analysis

AIM

To investigate the relationship between the implementation of real-time audiovisual cardiopulmonary resuscitation (CPR) feedback devices with cardiac arrest patient outcomes, such as return of spontaneous circulation (ROSC), short-term survival, and neurological outcome.

METHODS

We systematically searched PubMed, Embase, and the Cochrane CENTRAL from inception date until April 30, 2020, for eligible randomized and nonrandomized studies. Pooled odds ratio (OR) for each binary outcome was calculated using R system. The primary patient outcome was ROSC. The secondary outcomes were short-term survival and favorable neurological outcomes (cerebral performance category scores: 1 or 2).

RESULTS

We identified 11 studies (8 nonrandomized and 3 randomized studies) including 4851 patients. Seven studies documented patients with out-of-hospital cardiac arrest and four studies documented patients with in-hospital cardiac arrest. The pooled results did not confirm the effectiveness of CPR feedback device, possibly because of the high heterogeneity in ROSC (OR: 1.42, 95% CI: 1.03-1.94, I²: 80%, tau²: 0.1875, heterogeneity test p <  0.01) and survival-to-discharge (OR: 1.27, 95% CI: 0.74-2.18, I²: 86%, tau²: 0.4048, heterogeneity test p <  0.01). The subgroup analysis results revealed that heterogeneity was due to the types of devices used. Patient outcomes were more favorable in studies investigating portable devices than in studies investigating automated external defibrillator (AED)-associated devices.

CONCLUSIONS

Whether real-time CPR feedback devices can improve patient outcomes (ROSC and short-term survival) depend on the type of device used. Portable devices led to better outcomes than did AED-associated devices. Future studies comparing different types of devices are required to reach robust conclusion.

PROTOCOL REGISTRATION

Prospero registration ID CRD42020155388.

Study on the Improvement of Electrical Facility System of Automated External Defibrillators by Real-Time Measurement of Thoracic Impedance

Sudden Cardiac Arrest (SCA) is a serious emergency disease that has increased steadily every year. To this end, an Automated External Defibrillator (AED) is placed in a public place so that even non-professional medical personnel can respond to SCA. However, the thoracic impedance of patients changes due to CardioPulmonary Resuscitation (CPR) and artificial respiration during first aid treatment. In addition, changes in chest statues due to gender, age, and accidents cause changes in thoracic impedance in real time. The change in thoracic impedance caused by this has a negative effect on the intended electrical energy of the automatic heart shocker to the emergency patient. To prove this, we divided it into adult and pediatric modes and experimented with the energy error of the AED according to the same impedance change. When the first peak current was up to 56.4 (A) and at least 8.4 (A) in the adult mode, the first peak current was up to 32.2 (A) and at least 4.8 (A), respectively, when the impedance changed, the error of the current figure occurred. In this paper, the inverse relationship between thoracic impedance and electric shock energy according to the state of the cardiac arrest patient is demonstrated through the results of the experiment, and the need for an electric facility system that can revise for changes in thoracic impedance of the cardiac arrest patient by reflecting them on electric shock energy in real time is presented.

Estimation of Arterial Blood Pressure Based on Artificial Intelligence Using Single Earlobe Photoplethysmography during Cardiopulmonary Resuscitation

This study investigates the feasibility of estimation of blood pressure (BP) using a single earlobe photoplethysmography (Ear PPG) during cardiopulmonary resuscitation (CPR). We have designed a system that carries out Ear PPG for estimation of BP. In particular, the BP signals are estimated according to a long short-term memory (LSTM) model using an Ear PPG. To investigate the proposed method, two statistical analyses were conducted for comparison between BP measured by the micromanometer-based gold standard method (BP_MEAS) and the Ear PPG-based proposed method (BP_EST) for swine cardiac model. First, Pearson's correlation analysis showed high positive correlations (r = 0.92, p < 0.01) between BP_MEAS and BP_EST. Second, the paired-samples t-test on the BP parameters (systolic and diastolic blood pressure) of the two methods indicated no significant differences (p > 0.05). Therefore, the proposed method has the potential for estimation of BP for CPR biofeedback based on LSTM using a single Ear PPG.

Feasibility of an augmented reality cardiopulmonary resuscitation training system for health care providers

AIM OF THE STUDY

Augmented reality (AR) has the potential to offer a novel approach to CPR training that supplements conventional training methods with gamification and a more interactive learning experience. This is done through computer-generated imagery superimposed on users' view of the real environment to simulate interactive training scenarios. We sought to test the feasibility of an AR CPR training system (CPReality) for health care providers (HCPs).

METHODS

In this feasibility trial, a CPR training manikin was integrated with a commercial AR device (Microsoft HoloLens) to provide participants with real-time audio-visual feedback via a holographic overlay of blood flow to vital organs dependent on CC quality. In this system, higher quality CC visually improved virtual blood circulation. HCPs performed a 2-minute cycle of hands-only CPR using only the AR system, and CC parameters were recorded. Descriptive data on participants' demographics, CC quality, and satisfaction with the training environment were reported using quantitative and qualitative analysis.

RESULTS

Between 10/2018-11/2018, we enrolled a convenience sample of 51 HCPs. The median age of participants was 31 years (IQR 27-41), 71% (36/51) were female, and 67% (34/51) were registered nurses. CC rates (mean 126 ± 12.9 cpm), depths (median 53 mm, IQR 46-58), and percent with complete recoil (median 80%, IQR 12-100) were consistent with guideline recommendations for good quality CPR. Participants were predominantly satisfied with the system, with 82% perceiving the experience as realistic, 98% recognizing the visualizations as helpful for training, and 94% willing to use the application in future CPR training.

CONCLUSIONS

As AR is increasingly applied in the healthcare setting, integration in CPR training offers a novel and promising educational approach. In this convenience sample of trained HCPs, high quality CC delivery was feasible using the AR CPR training system which was received favorably by most participants.

Real-time compression feedback for patients with in-hospital cardiac arrest: a multi-center randomized controlled clinical trial

Objective

To determine if real-time compression feedback using a non-automated hand-held device improves patient outcomes from in-hospital cardiac arrest (IHCA).

Methods

We conducted a prospective, randomized, controlled, parallel study (no crossover) of patients with IHCA in the mixed medical–surgical intensive care units (ICUs) of eight academic hospitals. Patients received either standard manual chest compressions or compressions performed with real-time feedback using the Cardio First Angel™ (CFA) device. The primary outcome was sustained return of spontaneous circulation (ROSC), and secondary outcomes were survival to ICU and hospital discharge.

Results

One thousand four hundred fifty-four subjects were randomized; 900 were included. Sustained ROSC was significantly improved in the CFA group (66.7% vs. 42.4%, P < 0.001), as was survival to ICU discharge (59.8% vs. 33.6%) and survival to hospital discharge (54% vs. 28.4%, P < 0.001). Outcomes were not affected by intra-group comparisons based on intubation status. ROSC, survival to ICU, and hospital discharge were noted to be improved in inter-group comparisons of non-intubated patients, but not intubated ones.

Conclusion

Use of the CFA compression feedback device improved event survival and survival to ICU and hospital discharge.

Trial registration

The study was registered with Clinicaltrials.gov (NCT02845011), registered retrospectively on July 21, 2016.

The effectiveness of traditional Basic Life Support training and alternative technology-enhanced methods in high schools

Background:

Implementation of resuscitation training in school programs is a promising approach to improve rates of cardiopulmonary resuscitation use by trained bystanders. Unfortunately, theoretical cardiopulmonary resuscitation instruction alone is not sufficiently effective in developing practical skills.

Objectives:

This study aimed to investigate the effectiveness of traditional Basic Life Support training and alternative instructional methods to achieve learning objectives of Basic Life Support education.

Methods:

This quasi-experimental study was conducted in a secondary school in Ankara, Turkey. Eighty-three voluntary students were randomly allocated to theoretical (Group A), video-based (Group B), and mobile-assisted video-based instructions (Group C). All groups were led by the course teacher. Assessments were conducted in training and again 1 week later. Assessments were based on Basic Life Support knowledge and confidence performance scores.

Results:

Statistically significant difference was found for the groups’ Confidence Scale scores (F(2, 73) = 3.513, p = 0.035, ηp2 = 0.088); Group C (6.76 ± 1.70) scored higher than Group A. The groups’ Basic Life Support checklist scores were statistically significant (F(2, 73) = 28.050, p = 0.000, ηp2 = 0.435); Group C (32.32 ± 3.84) scored higher than the other groups. Statistically significant difference was found for the groups’ measurable Basic Life Support scores (F(2, 73) = 13.527, p = 0.000, ηp2 = 0.270); and Group C (23.76 ± 3.98) scored higher than the other groups.

Conclusion:

Our findings showed that all instruction methods led to increased Basic Life Support knowledge scores. The mobile-assisted program significantly increased knowledge scores. Same-group high-quality cardiopulmonary resuscitation parameters were more positive than the other instruction groups except for hand position. Group C students expressed higher confidence in their ability to act in an emergency when witnessing a victim collapse.

Monitoring chest compression quality during cardiopulmonary resuscitation: Proof-of-concept of a single accelerometer-based feedback algorithm

BACKGROUND

The use of real-time feedback systems to guide rescuers during cardiopulmonary resuscitation (CPR) significantly contributes to improve adherence to published resuscitation guidelines. Recently, we designed a novel method for computing depth and rate of chest compressions relying solely on the spectral analysis of chest acceleration. That method was extensively tested in a simulated manikin scenario. The purpose of this study is to report the results of this method as tested in human out-of-hospital cardiac arrest (OHCA) cases.

MATERIALS AND METHODS

The algorithm was evaluated retrospectively with seventy five OHCA episodes recorded by monitor-defibrillators equipped with a CPR feedback device. The acceleration signal and the compression signal computed by the CPR feedback device were stored in each episode. The algorithm was continuously applied to the acceleration signals. The depth and rate values estimated every 2-s from the acceleration data were compared to the reference values obtained from the compression signal. The performance of the algorithm was assesed in terms of the sensitivity and positive predictive value (PPV) for detecting compressions and in terms of its accuracy through the analysis of measurement error.

RESULTS

The algorithm reported a global sensitivity and PPV of 99.98% and 99.79%, respectively. The median (P75) unsigned error in depth and rate was 0.9 (1.7) mm and 1.0 (1.7) cpm, respectively. In 95% of the analyzed 2-s windows the error was below 3.5 mm and 3.1 cpm, respectively.

CONCLUSIONS

The CPR feedback algorithm proved to be reliable and accurate when tested retrospectively with human OHCA episodes. A new CPR feedback device based on this algorithm could be helpful in the resuscitation field.

Performance of cardiopulmonary resuscitation feedback systems in a long-distance train with distributed traction

BACKGROUND

Out-of-hospital cardiac arrest is common in public locations, including public transportation sites. Feedback devices are increasingly being used to improve chest-compression quality. However, their performance during public transportation has not been studied yet.

OBJECTIVE

To test two CPR feedback devices representative of the current technologies (accelerometer and electromag- netic-field) in a long-distance train.

METHODS

Volunteers applied compressions on a manikin during the train route using both feedback devices. Depth and rate measurements computed by the devices were compared to the gold-standard values.

RESULTS

Sixty-four 4-min records were acquired. The accelerometer-based device provided visual help in all experiments. Median absolute errors in depth and rate were 2.4 mm and 1.3 compressions per minute (cpm) during conventional speed, and 2.5 mm and 1.2 cpm during high speed. The electromagnetic-field-based device never provided CPR feedback; alert messages were shown instead. However, measurements were stored in its internal memory. Absolute errors for depth and rate were 2.6 mm and 0.7 cpm during conventional speed, and 2.6 mm and 0.7 cpm during high speed.

CONCLUSIONS

Both devices were accurate despite the accelerations and the electromagnetic interferences induced by the train. However, the electromagnetic-field-based device would require modifications to avoid excessive alerts impeding feedback.

A Feasibility Study for Measuring Accurate Chest Compression Depth and Rate on Soft Surfaces Using Two Accelerometers and Spectral Analysis

Background. Cardiopulmonary resuscitation (CPR) feedback devices are being increasingly used. However, current accelerometer-based devices overestimate chest displacement when CPR is performed on soft surfaces, which may lead to insufficient compression depth. Aim. To assess the performance of a new algorithm for measuring compression depth and rate based on two accelerometers in a simulated resuscitation scenario. Materials and Methods. Compressions were provided to a manikin on two mattresses, foam and sprung, with and without a backboard. One accelerometer was placed on the chest and the second at the manikin's back. Chest displacement and mattress displacement were calculated from the spectral analysis of the corresponding acceleration every 2 seconds and subtracted to compute the actual sternal-spinal displacement. Compression rate was obtained from the chest acceleration. Results. Median unsigned error in depth was 2.1 mm (4.4%). Error was 2.4 mm in the foam and 1.7 mm in the sprung mattress (p < 0.001). Error was 3.1/2.0 mm and 1.8/1.6 mm with/without backboard for foam and sprung, respectively (p < 0.001). Median error in rate was 0.9 cpm (1.0%), with no significant differences between test conditions. Conclusion. The system provided accurate feedback on chest compression depth and rate on soft surfaces. Our solution compensated mattress displacement, avoiding overestimation of compression depth when CPR is performed on soft surfaces.

Effect of the Cardio First Angel™ device on CPR indices: a randomized controlled clinical trial

Background

A number of cardiopulmonary resuscitation (CPR) adjunct devices have been developed to improve the consistency and quality of manual chest compressions. We investigated whether a CPR feedback device would improve CPR quality and consistency, as well as patient survival.

Methods

We conducted a randomized controlled study of patients undergoing CPR for cardiac arrest in the mixed medical-surgical intensive care units of four academic teaching hospitals. Patients were randomized to receive either standard manual CPR or CPR using the Cardio First Angel™ CPR feedback device. Recorded variables included guideline adherence, CPR quality, return of spontaneous circulation (ROSC) rates, and CPR-associated morbidity.

Results

A total of 229 subjects were randomized; 149 were excluded; and 80 were included. Patient demographics were similar. Adherence to published CPR guidelines and CPR quality was significantly improved in the intervention group (p < 0.0001), as were ROSC rates (72 % vs. 35 %; p = 0.001). A significant decrease was observed in rib fractures (57 % vs. 85 %; p = 0.02), but not sternum fractures (5 % vs. 17 %; p = 0.15).

Conclusions

Use of the Cardio First Angel™ CPR feedback device improved adherence to published CPR guidelines and CPR quality, and it was associated with increased rates of ROSC. A decrease in rib but not sternum fractures was observed with device use. Further independent prospective validation is warranted to determine if these results are reproducible in other acute care settings.

Trial registration

ClinicalTrials.gov identifier: NCT02394977. Registered on 5 Mar 2015.

Smartwatches as chest compression feedback devices: A feasibility study

BACKGROUND

Recently, there have been attempts to use smartphones and smartwatches as the feedback devices to improve the quality of chest compressions. In this study, we compared chest compression depth feedback accuracy between a smartphone and a smartwatch in a hands-only cardiopulmonary resuscitation scenario, using a manikin with a displacement sensor system.

METHODS

Ten basic life support providers participated in this study. Guided by the chest compression depths displayed on the monitor of a laptop, which received data from the manikin, each participant performed 2min of chest compressions for each target depth (35mm and 55mm) on a manikin while gripping a smartphone and wearing a smartwatch. Participants had a rest of 1h between the instances, and the first target depth was set at random. Each chest compression depth data value from the smartphone and smartwatch and a corresponding reference value from the manikin with the displacement system were recorded. To compare the accuracy between the smartphone and smartwatch, the errors, expressed as the absolute of the differences between the reference and each device, were calculated.

RESULTS

At both target depths, the error of the smartwatch were significantly smaller than that of the smartphone (the errors of the smartphone vs. smartwatch at 35mm: 3.4 (1.3) vs. 2.1 (0.8) mm; p=0.008; at 55mm: 5.3 (2.8) vs. 2.3 (0.9) mm; p=0.023).

CONCLUSION

The smartwatch-based chest compression depth feedback was more accurate than smartphone-based feedback.

Feedback on the Rate and Depth of Chest Compressions during Cardiopulmonary Resuscitation Using Only Accelerometers

Background

Quality of cardiopulmonary resuscitation (CPR) is key to increase survival from cardiac arrest. Providing chest compressions with adequate rate and depth is difficult even for well-trained rescuers. The use of real-time feedback devices is intended to contribute to enhance chest compression quality. These devices are typically based on the double integration of the acceleration to obtain the chest displacement during compressions. The integration process is inherently unstable and leads to important errors unless boundary conditions are applied for each compression cycle. Commercial solutions use additional reference signals to establish these conditions, requiring additional sensors. Our aim was to study the accuracy of three methods based solely on the acceleration signal to provide feedback on the compression rate and depth.

Materials and Methods

We simulated a CPR scenario with several volunteers grouped in couples providing chest compressions on a resuscitation manikin. Different target rates (80, 100, 120, and 140 compressions per minute) and a target depth of at least 50 mm were indicated. The manikin was equipped with a displacement sensor. The accelerometer was placed between the rescuer’s hands and the manikin’s chest. We designed three alternatives to direct integration based on different principles (linear filtering, analysis of velocity, and spectral analysis of acceleration). We evaluated their accuracy by comparing the estimated depth and rate with the values obtained from the reference displacement sensor.

Results

The median (IQR) percent error was 5.9% (2.8–10.3), 6.3% (2.9–11.3), and 2.5% (1.2–4.4) for depth and 1.7% (0.0–2.3), 0.0% (0.0–2.0), and 0.9% (0.4–1.6) for rate, respectively. Depth accuracy depended on the target rate (p < 0.001) and on the rescuer couple (p < 0.001) within each method.

Conclusions

Accurate feedback on chest compression depth and rate during CPR is possible using exclusively the chest acceleration signal. The algorithm based on spectral analysis showed the best performance. Despite these encouraging results, further research should be conducted to asses the performance of these algorithms with clinical data.

A simple accurate chest-compression depth gauge using magnetic coils during cardiopulmonary resuscitation

This paper describes a new method for calculating chest compression depth and a simple chest-compression gauge for validating the accuracy of the method. The chest-compression gauge has two plates incorporating two magnetic coils, a spring, and an accelerometer. The coils are located at both ends of the spring, and the accelerometer is set on the bottom plate. Waveforms obtained using the magnetic coils (hereafter, "magnetic waveforms"), which are proportional to compression-force waveforms and the acceleration waveforms were measured at the same time. The weight factor expressing the relationship between the second derivatives of the magnetic waveforms and the measured acceleration waveforms was calculated. An estimated-compression-displacement (depth) waveform was obtained by multiplying the weight factor and the magnetic waveforms. Displacements of two large springs (with similar spring constants) within a thorax and displacements of a cardiopulmonary resuscitation training manikin were measured using the gauge to validate the accuracy of the calculated waveform. A laser-displacement detection system was used to compare the real displacement waveform and the estimated waveform. Intraclass correlation coefficients (ICCs) between the real displacement using the laser system and the estimated displacement waveforms were calculated. The estimated displacement error of the compression depth was within 2 mm (<1 standard deviation). All ICCs (two springs and a manikin) were above 0.85 (0.99 in the case of one of the springs). The developed simple chest-compression gauge, based on a new calculation method, provides an accurate compression depth (estimation error < 2 mm).

Effectiveness of chest compression feedback during cardiopulmonary resuscitation in lateral tilted and semirecumbent positions: a randomised controlled simulation study

Feedback devices have been shown to improve the quality of chest compression during cardiopulmonary resuscitation for patients in the supine position, but no studies have reported the effects of feedback devices on chest compression when the chest is tilted. Basic life support-trained providers were randomly assigned to administer chest compressions to a manikin in the supine, 30° left lateral tilt and 30° semirecumbent positions, with or without the aid of a feedback device incorporated into a smartphone. Thirty-six participants were studied. The feedback device did not affect the quality of chest compressions in the supine position, but improved aspects of performance in the tilted positions. In the lateral tilted position, the median (IQR [range]) chest compression rate was 99 (99-100 [96-117]) compressions.min(-1) with and 115 (95-128 [77-164]) compressions.min(-1) without feedback (p = 0.05), and the proportion of compressions of correct depth was 55 (0-96 [0-100])% with and 1 (0-30 [0-100])% without feedback (p = 0.03). In the semirecumbent position, the proportion of compressions of correct depth was 21 (0-87 [0-100])% with and 1 (0-26 [0-100])% without feedback (p = 0.05). Female participants applied chest compressions at a more accurate rate using the feedback device in the lateral tilted position but were unable to increase the chest compression depth, whereas male participants were able to increase the force of chest compression using the feedback device in the lateral tilted and semirecumbent positions. We conclude that a feedback device improves the application of chest compressions during simulated cardiopulmonary resuscitation when the chest is tilted.

A new chest compression depth feedback algorithm for high-quality CPR based on smartphone

BACKGROUND

Although many smartphone application (app) programs provide education and guidance for basic life support, they do not commonly provide feedback on the chest compression depth (CCD) and rate. The validation of its accuracy has not been reported to date. This study was a feasibility assessment of use of the smartphone as a CCD feedback device. In this study, we proposed the concept of a new real-time CCD estimation algorithm using a smartphone and evaluated the accuracy of the algorithm.

MATERIALS AND METHODS

Using the double integration of the acceleration signal, which was obtained from the accelerometer in the smartphone, we estimated the CCD in real time. Based on its periodicity, we removed the bias error from the accelerometer. To evaluate this instrument's accuracy, we used a potentiometer as the reference depth measurement. The evaluation experiments included three levels of CCD (insufficient, adequate, and excessive) and four types of grasping orientations with various compression directions. We used the difference between the reference measurement and the estimated depth as the error. The error was calculated for each compression.

RESULTS

When chest compressions were performed with adequate depth for the patient who was lying on a flat floor, the mean (standard deviation) of the errors was 1.43 (1.00) mm. When the patient was lying on an oblique floor, the mean (standard deviation) of the errors was 3.13 (1.88) mm.

CONCLUSIONS

The error of the CCD estimation was tolerable for the algorithm to be used in the smartphone-based CCD feedback app to compress more than 51 mm, which is the 2010 American Heart Association guideline.

A new method for feedback on the quality of chest compressions during cardiopulmonary resuscitation

Quality of cardiopulmonary resuscitation (CPR) improves through the use of CPR feedback devices. Most feedback devices integrate the acceleration twice to estimate compression depth. However, they use additional sensors or processing techniques to compensate for large displacement drifts caused by integration. This study introduces an accelerometer-based method that avoids integration by using spectral techniques on short duration acceleration intervals. We used a manikin placed on a hard surface, a sternal triaxial accelerometer, and a photoelectric distance sensor (gold standard). Twenty volunteers provided 60 s of continuous compressions to test various rates (80–140 min⁻¹), depths (3–5 cm), and accelerometer misalignment conditions. A total of 320 records with 35312 compressions were analysed. The global root-mean-square errors in rate and depth were below 1.5 min⁻¹ and 2 mm for analysis intervals between 2 and 5 s. For 3 s analysis intervals the 95% levels of agreement between the method and the gold standard were within −1.64–1.67 min⁻¹ and −1.69–1.72 mm, respectively. Accurate feedback on chest compression rate and depth is feasible applying spectral techniques to the acceleration. The method avoids additional techniques to compensate for the integration displacement drift, improving accuracy, and simplifying current accelerometer-based devices.

Effective CPR Procedure With Real Time Evaluation and Feedback Using Smartphones

Timely cardio pulmonary resuscitation (CPR) can mean the difference between life and death. A trained person may not be available at emergency sites to give CPR. Normally, a 9-1-1 operator gives verbal instructions over the phone to a person giving CPR. In this paper, we discuss the use of smartphones to assist in administering CPR more efficiently and accurately. The two important CPR parameters are the frequency and depth of compressions. In this paper, we used smartphones to calculate these factors and to give real-time guidance to improve CPR. In addition, we used an application to measure oxygen saturation in blood. If blood oxygen saturation falls below an acceptable threshold, the person giving CPR can be asked to do mouth-to-mouth breathing. The 9-1-1 operator receives this information real time and can further guide the person giving CPR. Our experiments show accuracy >90% for compression frequency, depth, and oxygen saturation.

Comparing three CPR feedback devices and standard BLS in a single rescuer scenario: a randomised simulation study

BACKGROUND

Efficiently performed basic life support (BLS) after cardiac arrest is proven to be effective. However, cardiopulmonary resuscitation (CPR) is strenuous and rescuers' performance declines rapidly over time. Audio-visual feedback devices reporting CPR quality may prevent this decline. We aimed to investigate the effect of various CPR feedback devices on CPR quality.

METHODS

In this open, prospective, randomised, controlled trial we compared three CPR feedback devices (PocketCPR, CPRmeter, iPhone app PocketCPR) with standard BLS without feedback in a simulated scenario. 240 trained medical students performed single rescuer BLS on a manikin for 8min. Effective compression (compressions with correct depth, pressure point and sufficient decompression) as well as compression rate, flow time fraction and ventilation parameters were compared between the four groups.

RESULTS

Study participants using the PocketCPR performed 17±19% effective compressions compared to 32±28% with CPRmeter, 25±27% with the iPhone app PocketCPR, and 35±30% applying standard BLS (PocketCPR vs. CPRmeter p=0.007, PocketCPR vs. standard BLS p=0.001, others: ns). PocketCPR and CPRmeter prevented a decline in effective compression over time, but overall performance in the PocketCPR group was considerably inferior to standard BLS. Compression depth and rate were within the range recommended in the guidelines in all groups.

CONCLUSION

While we found differences between the investigated CPR feedback devices, overall BLS quality was suboptimal in all groups. Surprisingly, effective compression was not improved by any CPR feedback device compared to standard BLS. All feedback devices caused substantial delay in starting CPR, which may worsen outcome.