Anesthesia providers' visual attention in simulated anesthesia emergencies using conventional number-based and avatar-based patient monitoring: a prospective, eye-tracking study. (Preprint)

BACKGROUND Inadequate situational awareness accounts for two-thirds of preventable complications in anesthesia. An essential tool for situational awareness in the perioperative setting is the patient monitor. However, the conventional monitor has several weaknesses. Avatar-based patient monitoring may address these shortcomings and promote situation awareness, a prerequisite for good decision making. OBJECTIVE The spatial distribution of visual attention is a fundamental process for achieving adequate situation awareness and thus a potential quantifiable surrogate for situation awareness. Moreover, measuring visual attention with a head-mounted eye-tracker may provide insights into usage and acceptance of the new avatar-based patient monitoring modality. METHODS This prospective eye-tracking study compared anesthesia providers' visual attention on conventional and avatar-based patient monitors during simulated critical anesthesia events. We defined visual attention, measured as fixation count and dwell time, as our primary outcome. We correlated visual attention with the potential confounders: performance in managing simulated critical anesthesia events (task performance), work experience, and profession. We used mixed linear models to analyze the results. RESULTS Fifty-two teams performed 156 simulations. After a manual quality check of the eye-tracking footage, we excluded 57 simulations due to technical problems and quality issues. Participants had a median of 198 (IQR 92.5 – 317.5) fixations on the patient monitor with a median dwell time of 30.2 (IQR 14.9 – 51.3) seconds. We found no significant difference in participants' visual attention when using avatar-based patient monitoring or conventional patient monitoring. However, we found that with each percentage point of better task performance, the number of fixations decreased by about 1.39 (coefficient -1.39; 95%CI: -2.44 to -0.34; P=0.02), and the dwell time diminished by 0.23 seconds (coefficient -0.23; 95%CI: -0.4 to -0.06; P=0.01). CONCLUSIONS Using eye-tracking, we found no significant difference in visual attention when anesthesia providers used avatar-based monitoring or conventional patient monitoring in simulated critical anesthesia events. However, we identified visual attention in conjunction with task performance as a surrogate for situational awareness. CLINICALTRIAL Business Management System for Ethics Committees Number Req-2020-00059

Reliability of heart rate and respiration rate measurements with a wireless accelerometer in postbariatric recovery

Recognition of early signs of deterioration in postoperative course could be improved by continuous monitoring of vital parameters. Wearable sensors could enable this by wireless transmission of vital signs. A novel accelerometer-based device, called Healthdot, has been designed to be worn on the skin to measure the two key vital parameters respiration rate (RespR) and heart rate (HeartR). The goal of this study is to assess the reliability of heart rate and respiration rate measured by the Healthdot in comparison to the gold standard, the bedside patient monitor, during the postoperative period in bariatric patients. Data were collected in a consecutive group of 30 patients who agreed to wear the device after their primary bariatric procedure. Directly after surgery, a Healthdot was attached on the patients’ left lower rib. Vital signs measured by the accelerometer based Healthdot were compared to vital signs collected with the gold standard patient monitor for the period that the patient stayed at the post-anesthesia care unit. Over all patients, a total of 22 hours of vital signs obtained by the Healthdot were recorded simultaneously with the bedside patient monitor data. 87.5% of the data met the pre-defined bias of 5 beats per minute for HeartR and 92.3% of the data met the pre-defined bias of 5 respirations per minute for RespR. The Healthdot can be used to accurately derive heart rate and respiration rate in postbariatric patients. Wireless continuous monitoring of key vital signs has the potential to contribute to earlier recognition of complications in postoperative patients. Future studies should focus on the ability to detect patient deterioration in low-care environments and at home after discharge from the hospital.

Validation of heart rate extracted from wrist-based photoplethysmography (PPG) in the perioperative setting: a prospective observational study. (Preprint)

BACKGROUND Measurement of heartrate (HR) through an unobtrusive, wrist-worn optical HR monitor (OHRM) in the form of a wristband could enable earlier recognition of patient deterioration and timely intervention. OBJECTIVE The goal of this study is to assess the agreement between HR extracted from an OHRM and the golden standard patient monitor during surgery and in the recovery period. METHODS The agreement in beats per minute (bpm) was evaluated between the gold standard electrocardiogram (ECG) from the patient monitor and the HR extracted from the photoplethysmography (PPG) sensor by the OHRM. RESULTS A total of 271.8 hours of data in 99 patients was recorded simultaneously by the OHRM and patient monitor. Median coverage was 86% (interquartile range: 65% to 95%) and did not differ significantly between surgery and recovery (Wilcoxon paired difference test P .17). Agreement analysis showed the limits of agreement (LoA) of the difference between the OHRM and the ECG HR were within the range ± 5 bpm. The mean bias was -0.14 bpm (LoA between -3.08 and 2.79) and -0.19 % (LoA between -4.79 and 4.39) for the PPG measured HR compared to the ECG measured HR during surgery and -0.11 bpm (LoA between -2.79 and 2.59) and -0.15 % (LoA between -3.92 and 3.64) during recovery. CONCLUSIONS An OHRM can obtain good quality signals for HR in the majority of the patients for most of the time in the perioperative setting. OHRM HR monitoring is within the acceptable range compared to ECG derived heartrate, which implies that an OHRM can be considered clinically acceptable for heart rate monitoring in low acuity hospitalized patients. CLINICALTRIAL This non-randomized trial was not registered in a trial registration.

The use of personal telemedical system for monitoring the condition of patients during rehabilitation in the inpatient facility

An autonomous wearable patient monitor with the function of broadcasting the measured parameters via wireless channels of computer networks to the server (to the cloud), and from there to the central console of the department, remote computers, tablets and doctors’ smartphones was tested. It was used to monitor the vital parameters of the patient’s body during rehabilitation in the inpatient facility. Various load programs have been tested: exercise therapy, kinesiotherapy, mechanotherapy, and verticalization.

Genetic Deep Convolutional Autoencoder Applied for Generative Continuous Arterial Blood Pressure via Photoplethysmography

Hypertension affects a huge number of people around the world. It also has a great contribution to cardiovascular- and renal-related diseases. This study investigates the ability of a deep convolutional autoencoder (DCAE) to generate continuous arterial blood pressure (ABP) by only utilizing photoplethysmography (PPG). A total of 18 patients are utilized. LeNet-5- and U-Net-based DCAEs, respectively abbreviated LDCAE and UDCAE, are compared to the MP60 IntelliVue Patient Monitor, as the gold standard. Moreover, in order to investigate the data generalization, the cross-validation (CV) method is conducted. The results show that the UDCAE provides superior results in producing the systolic blood pressure (SBP) estimation. Meanwhile, the LDCAE gives a slightly better result for the diastolic blood pressure (DBP) prediction. Finally, the genetic algorithm-based optimization deep convolutional autoencoder (GDCAE) is further administered to optimize the ensemble of the CV models. The results reveal that the GDCAE is superior to either the LDCAE or UDCAE. In conclusion, this study exhibits that systolic blood pressure (SBP) and diastolic blood pressure (DBP) can also be accurately achieved by only utilizing a single PPG signal.

Evaluation of a continuous neonatal temperature monitor for low-resource settings: a device feasibility pilot study

ObjectiveEvaluate a novel continuous temperature monitor in a low-resource neonatal ward.DesignWe developed a low-cost continuous neonatal temperature monitor (NTM) for use in low-resource settings. Accuracy of NTM was initially assessed in the laboratory. Clinical evaluation then was performed in a neonatal ward in a central hospital in Malawi; eligible neonates (<1 week of age) were recruited for continuous temperature monitoring with NTM and a Philips Intellivue MP30 Patient Monitor.Interventions and outcome measuresThe temperature probes of NTM and the reference patient monitor were attached to the infant’s abdomen, and core temperature was continuously recorded for up to 3 hours. Axillary temperatures were taken every hour. We compared temperatures measured using NTM, the patient monitor and the axillary thermometer.ResultsLaboratory temperature measurements obtained with NTM were within 0.059°C (range: −0.035°C to 0.195°C) of a reference thermometer. A total of 39 patients were recruited to participate in the clinical evaluation of NTM; data from four patients were excluded due to faulty hardware connections. The mean difference in measured temperatures between the NTM and the Intellivue MP30 was −0.04°C (95% CI −0.52°C to 0.44°C).ConclusionNTM meets ISO 80601-2-56 standards for accuracy and is an appropriate, low-cost continuous temperature monitor for neonatal wards in low-resource settings.Trial registration numbersNCT03965312 and NCT03866122.