Non-contact physiological monitoring of post-operative patients in the intensive care unit

AbstractProlonged non-contact camera-based monitoring in critically ill patients presents unique challenges, but may facilitate safe recovery. A study was designed to evaluate the feasibility of introducing a non-contact video camera monitoring system into an acute clinical setting. We assessed the accuracy and robustness of the video camera-derived estimates of the vital signs against the electronically-recorded reference values in both day and night environments. We demonstrated non-contact monitoring of heart rate and respiratory rate for extended periods of time in 15 post-operative patients. Across day and night, heart rate was estimated for up to 53.2% (103.0 h) of the total valid camera data with a mean absolute error (MAE) of 2.5 beats/min in comparison to two reference sensors. We obtained respiratory rate estimates for 63.1% (119.8 h) of the total valid camera data with a MAE of 2.4 breaths/min against the reference value computed from the chest impedance pneumogram. Non-contact estimates detected relevant changes in the vital-sign values between routine clinical observations. Pivotal respiratory events in a post-operative patient could be identified from the analysis of video-derived respiratory information. Continuous vital-sign monitoring supported by non-contact video camera estimates could be used to track early signs of physiological deterioration during post-operative care.

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Non-contact physiological monitoring of preterm infants in the Neonatal Intensive Care Unit

npj Digital Medicine ◽

10.1038/s41746-019-0199-5 ◽

2019 ◽

Vol 2 (1) ◽

Cited By ~ 7

Author(s):

Mauricio Villarroel ◽

Sitthichok Chaichulee ◽

João Jorge ◽

Sara Davis ◽

Gabrielle Green ◽

...

Keyword(s):

Intensive Care Unit ◽

Heart Rate ◽

Respiratory Rate ◽

Preterm Infants ◽

Neonatal Intensive Care ◽

Mean Absolute Error ◽

Vital Signs ◽

Absolute Error ◽

Video Camera ◽

The Mean

AbstractThe implementation of video-based non-contact technologies to monitor the vital signs of preterm infants in the hospital presents several challenges, such as the detection of the presence or the absence of a patient in the video frame, robustness to changes in lighting conditions, automated identification of suitable time periods and regions of interest from which vital signs can be estimated. We carried out a clinical study to evaluate the accuracy and the proportion of time that heart rate and respiratory rate can be estimated from preterm infants using only a video camera in a clinical environment, without interfering with regular patient care. A total of 426.6 h of video and reference vital signs were recorded for 90 sessions from 30 preterm infants in the Neonatal Intensive Care Unit (NICU) of the John Radcliffe Hospital in Oxford. Each preterm infant was recorded under regular ambient light during daytime for up to four consecutive days. We developed multi-task deep learning algorithms to automatically segment skin areas and to estimate vital signs only when the infant was present in the field of view of the video camera and no clinical interventions were undertaken. We propose signal quality assessment algorithms for both heart rate and respiratory rate to discriminate between clinically acceptable and noisy signals. The mean absolute error between the reference and camera-derived heart rates was 2.3 beats/min for over 76% of the time for which the reference and camera data were valid. The mean absolute error between the reference and camera-derived respiratory rate was 3.5 breaths/min for over 82% of the time. Accurate estimates of heart rate and respiratory rate could be derived for at least 90% of the time, if gaps of up to 30 seconds with no estimates were allowed.

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Validation of a wearable biosensor device for vital sign monitoring in septic emergency department patients in Rwanda

Digital Health ◽

10.1177/2055207619879349 ◽

2019 ◽

Vol 5 ◽

pp. 205520761987934

Author(s):

Stephanie C Garbern ◽

Gabin Mbanjumucyo ◽

Christian Umuhoza ◽

Vinay K Sharma ◽

James Mackey ◽

...

Keyword(s):

Heart Rate ◽

Respiratory Rate ◽

Vital Sign ◽

Vital Signs ◽

University Teaching ◽

Suspected Sepsis ◽

Middle Income ◽

Radiologic Study ◽

Emergency Department Patients ◽

Biosensor Device

Objective Critical care capabilities needed for the management of septic patients, such as continuous vital sign monitoring, are largely unavailable in most emergency departments (EDs) in low- and middle-income country (LMIC) settings. This study aimed to assess the feasibility and accuracy of using a wireless wearable biosensor device for continuous vital sign monitoring in ED patients with suspected sepsis in an LMIC setting. Methods This was a prospective observational study of pediatric (≥2 mon) and adult patients with suspected sepsis at the Kigali University Teaching Hospital ED. Heart rate, respiratory rate and temperature measurements were continuously recorded using a wearable biosensor device for the duration of the patients’ ED course and compared to intermittent manually collected vital signs. Results A total of 42 patients had sufficient data for analysis. Mean duration of monitoring was 32.8 h per patient. Biosensor measurements were strongly correlated with manual measurements for heart rate (r = 0.87, p < 0.001) and respiratory rate (r = 0.75, p < 0.001), although were less strong for temperature (r = 0.61, p < 0.001). Mean (SD) differences between biosensor and manual measurements were 1.2 (11.4) beats/min, 2.5 (5.5) breaths/min and 1.4 (1.0)°C. Technical or practical feasibility issues occurred in 12 patients (28.6%) although were minor and included biosensor detachment, connectivity problems, removal for a radiologic study or exam, and patient/parent desire to remove the device. Conclusions Wearable biosensor devices can be feasibly implemented and provide accurate continuous heart rate and respiratory rate monitoring in acutely ill pediatric and adult ED patients with sepsis in an LMIC setting.

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Vital Sign Monitoring Using FMCW Radar in Various Sleeping Scenarios

Sensors ◽

10.3390/s20226505 ◽

2020 ◽

Vol 20 (22) ◽

pp. 6505

Author(s):

Emmi Turppa ◽

Juha M. Kortelainen ◽

Oleg Antropov ◽

Tero Kiuru

Keyword(s):

Heart Rate ◽

Remote Monitoring ◽

Vital Sign ◽

Continuous Wave ◽

Real Life ◽

Vital Signs ◽

Absolute Error ◽

Physical Contact ◽

Radar Signal ◽

Fmcw Radar

Remote monitoring of vital signs for studying sleep is a user-friendly alternative to monitoring with sensors attached to the skin. For instance, remote monitoring can allow unconstrained movement during sleep, whereas detectors requiring a physical contact may detach and interrupt the measurement and affect sleep itself. This study evaluates the performance of a cost-effective frequency modulated continuous wave (FMCW) radar in remote monitoring of heart rate and respiration in scenarios resembling a set of normal and abnormal physiological conditions during sleep. We evaluate the vital signs of ten subjects in different lying positions during various tasks. Specifically, we aim for a broad range of both heart and respiration rates to replicate various real-life scenarios and to test the robustness of the selected vital sign extraction methods consisting of fast Fourier transform based cepstral and autocorrelation analyses. As compared to the reference signals obtained using Embla titanium, a certified medical device, we achieved an overall relative mean absolute error of 3.6% (86% correlation) and 9.1% (91% correlation) for the heart rate and respiration rate, respectively. Our results promote radar-based clinical monitoring by showing that the proposed radar technology and signal processing methods accurately capture even such alarming vital signs as minimal respiration. Furthermore, we show that common parameters for heart rate variability can also be accurately extracted from the radar signal, enabling further sleep analyses.

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Feasibility and Accuracy of a Wearable Biosensor Device for Vital Sign Monitoring in Septic Emergency Department Patients in Rwanda

Prehospital and Disaster Medicine ◽

10.1017/s1049023x1900178x ◽

2019 ◽

Vol 34 (s1) ◽

pp. s85-s86

Author(s):

Stephanie Garbern ◽

Gabin Mbanjumucyo ◽

Christian Umuhoza ◽

Vinay Sharma ◽

James Mackey ◽

...

Keyword(s):

Emergency Department ◽

Heart Rate ◽

Respiratory Rate ◽

Vital Sign ◽

Vital Signs ◽

Correlation Coefficients ◽

University Teaching ◽

Suspected Sepsis ◽

The Impact ◽

Biosensor Device

Introduction:Low and middle-income countries (LMICs) bear a disproportionately high burden of sepsis, contributing to an estimated 90% of global sepsis-related deaths. Critical care capabilities needed for septic patients, such as continuous vital sign monitoring, are often unavailable in LMICs.Aim:This study aimed to assess the feasibility and accuracy of using a small wireless, wearable biosensor device linked to a smartphone, and a cloud analytics platform for continuous vital sign monitoring in emergency department (ED) patients with suspected sepsis in Rwanda.Methods:This was a prospective observational study of adult and pediatric patients (≥ 2 months) with suspected sepsis presenting to Kigali University Teaching Hospital ED. Biosensor devices were applied to patients’ chest walls and continuously recorded vital signs (including heart rate and respiratory rate) for the duration of their ED course. These vital signs were compared to intermittent, manually-collected vital signs performed by a research nurse every 6-8 hours. Pearson’s correlation coefficients were calculated over the study population to determine the correlation between the vital signs obtained from the biosensor device and those collected manually.Results:42 patients (20 adults, 22 children) were enrolled. Mean duration of monitoring with the biosensor device was 34.4 hours. Biosensor and manual vital signs were strongly correlated for heart rate (r=0.87, p<0.001) and respiratory rate (r=0.74 p<0.001). Feasibility issues occurred in 9/42 (21%) patients, although were minor and included biosensor falling off (4.8%), technical/connectivity problems (7.1%), removal by a physician (2.4%), removal for a procedure (2.4%), and patient/parent desire to remove the device (4.8%).Discussion:Wearable biosensor devices can be feasibly implemented and provide accurate continuous vital sign measurements in critically ill pediatric and adult patients with suspected sepsis in a resource-limited setting. Further prospective studies evaluating the impact of biosensor devices on improving clinical outcomes for septic patients are needed.

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Evaluating the Accuracy of the VitalWellness Device

Iproceedings ◽

10.2196/16250 ◽

2019 ◽

Vol 5 (1) ◽

pp. e16250

Author(s):

Nicole Polanco ◽

Sharon Odametey ◽

Neda Derakhshani ◽

Mark Khachaturian ◽

Connor Devoe ◽

...

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Standard Deviation ◽

Body Temperature ◽

Respiratory Rate ◽

Linear Relationship ◽

Vital Sign ◽

Skin Color ◽

Vital Signs ◽

Mean Difference

Background Wellness devices for health tracking have gained popularity in recent years. Additionally, portable and readily accessible wellness devices have several advantages when compared to traditional medical devices found in clinical environments The VitalWellness device is a portable wellness device that can potentially aide vital sign measuring for those interested in tracking their health. Objective In this diagnostic accuracy study, we evaluated the performance of the VitalWellness device, a wireless, compact, non-invasive device that measures four vital signs (blood pressure (BP), heart rate (HR), respiratory rate (RR), and body temperature using the index finger and forehead. Methods Volunteers age ≥18 years were enrolled to provide blood pressure (BP), heart rate (HR), respiratory rate (RR), and body temperature. We recruited participants with vital signs that fell within and outside of the normal physiological range. A sub-group of eligible participants were asked to undergo an exercise test, aerobic step test and/or a paced breathing test to analyze the VitalWellness device’s performance on vital signs outside of the normal physiological ranges for HR and RR. Vital signs measurements were collected with the VitalWellness device and FDA-approved reference devices. Mean, standard deviation, mean difference, standard deviation of difference, standard error of mean difference, and correlation coefficients were calculated for measurements collected; these measurements were plotted on a scatter plot and a Bland-Altman plot. Sensitivity analyses were performed to evaluate the performance of the VitalWellness device by gender, skin color, finger size, and in the presence of artifacts. Results 265 volunteers enrolled in the study and 2 withdrew before study completion. Majority of the volunteers were female (62%), predominately white (63%), graduated from college or post college (67%), and employed (59%). There was a moderately strong linear relationship between VitalWellness BP and reference BP (r=0.7, P<.05) and VitalWellness RR and reference RR measurements (r=0.7, P<.05). The VitalWellness HR readings were significantly in line with the reference HR readings (r=0.9, P<.05). There was a weaker linear relationship between VitalWellness temperature and reference temperature (r=0.3, P<.05). There were no differences in performance of the VitalWellness device by gender, skin color or in the presence of artifacts. Finger size was associated with differential performance for RR. Conclusions Overall, the VitalWellness device performed well in taking BP, HR, and RR when compared to FDA-approved reference devices and has potential serve as a wellness device. To test adaptability and acceptability, future research may evaluate user’s interactions and experiences with the VitalWellness device at home. In addition, the next phase of the study will evaluate transmitting vital sign information from the VitalWellness device to an online secured database where information can be shared with HCPs within seconds of measurement.

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2319. Clinical Predictors of Influenza and Hospitalization of Children with Influenza in an Emergent Care Setting

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.1997 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S795-S796

Author(s):

Suchitra Rao ◽

Molly Lamb ◽

Angela Moss ◽

Emad Yanni ◽

Rafik Bekkat-Berkani ◽

...

Keyword(s):

Heart Rate ◽

Oxygen Saturation ◽

Respiratory Rate ◽

Vital Sign ◽

Influenza Infection ◽

Vital Signs ◽

Urgent Care ◽

Peak Heart Rate ◽

Initial Oxygen ◽

Z Scores

Abstract Background Objective measures utilizing early vital sign data show promise in predicting more severe outcomes among adults with influenza, but data are sparse in children. The objectives of this study were to determine the value of vital signs in predicting influenza infection or hospitalization due to influenza infection among children evaluated in an emergency department (ED) or urgent care (UC) setting in Colorado. Methods We evaluated vital signs obtained from a prospective cohort study of children aged 6 months to 8 years of age with influenza like illness evaluated at an ED/UC site in Aurora, CO from 2016–2018, and who underwent influenza testing by PCR. We collected the first set of vital signs, peak heart rate and temperature, and converted heart rate (HR) and respiratory rate (RR) to z-scores by age. HR z scores were further adjusted for temperature. Bivariable analyses for each vital sign as a predictor of influenza-related hospitalization and influenza infection as main outcomes were conducted. Predictors with P < 0.2 were entered into a multivariable logistic regression model to determine odds ratios (OR) and 95% CI; model performance was assessed using the Brier score and discriminative ability with the C statistic. Results Among 1478 children, 411 were positive for influenza, of which 28 were hospitalized. In multivariable analyses, among children with influenza infection, lower initial oxygen saturation (OR 0.87, 95% CI 0.78–0.98, P = 0.026) and higher adjusted respiratory rate (OR 2.09, 95% CI 1.21–3.61, P = 0.0085) were significant predictors of hospitalization (Figure 1). Among children with ILI, higher peak temperature (OR 1.46, 95% CI 1.30–1.63, P < 0.0001), lower adjusted peak heart rate (OR 0.79, 95% CI 0.69–0.90, P = 0.0005), higher initial oxygen saturation (OR 1.07, 95% CI 1.03–1.12 P = 0.002) and lower adjusted respiratory rate (OR 0.74, 95% CI 0.64–0.87, P = 0.0002) were significant predictors for having PCR-confirmed influenza. However, this model had poor calibration and discriminatory ability. Conclusion Higher respiratory rate adjusted for age and lower initial oxygen saturation were significant predictors of hospitalization among young children with PCR-confirmed influenza, but were not reliable discriminators of having influenza infection. Disclosures All authors: No reported disclosures.

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Feasibility of continuous monitoring of vital signs in surgical patients on a general ward: an observational cohort study

BMJ Open ◽

10.1136/bmjopen-2020-042735 ◽

2021 ◽

Vol 11 (2) ◽

pp. e042735

Author(s):

Jobbe P L Leenen ◽

Eline M Dijkman ◽

Joris D van Dijk ◽

Henderik L van Westreenen ◽

Cor Kalkman ◽

...

Keyword(s):

Heart Rate ◽

Cohort Study ◽

Respiratory Rate ◽

Vital Sign ◽

Continuous Monitoring ◽

Vital Signs ◽

Observational Cohort Study ◽

General Ward ◽

Surgical Patients ◽

Observational Cohort

ObjectiveTo determine feasibility, in terms of acceptability and system fidelity, of continuous vital signs monitoring in abdominal surgery patients on a general ward.DesignObservational cohort study.SettingTertiary teaching hospital.ParticipantsPostoperative abdominal surgical patients (n=30) and nurses (n=23).InterventionsPatients were continuously monitored with the SensiumVitals wearable device until discharge in addition to usual care, which is intermittent Modified Early Warning Score measurements. Heart rate, respiratory rate and axillary temperature were monitored every 2 min. Values and trends were visualised and alerts sent to the nurses.OutcomesSystem fidelity was measured by analysis of the monitoring data. Acceptability by patients and nurses was assessed using questionnaires.ResultsThirty patients were monitored for a median duration of 81 hours (IQR 47–143) per patient, resulting in 115 217 measurements per parameter. In total, 19% (n=21 311) of heart rate, 51% (n=59 184) of respiratory rate and 9% of temperature measurements showed artefacts (n=10 269). The system algorithm sent 972 alerts (median alert rate of 4.5 per patient per day), of which 90.3% (n=878) were system alerts and 9.7% (n=94) were vital sign alerts. 35% (n=33) of vital sign alerts were true positives. 93% (n=25) of patients rated the patch as comfortable, 67% (n=18) felt safer and 89% (n=24) would like to wear it next time in the hospital. Nurses were neutral about usefulness, with a median score of 3.5 (IQR 3.1–4) on a 7-point Likert scale, ease of use 3.7 (IQR 3.2–4.8) and satisfaction 3.7 (IQR 3.2–4.8), but agreed on ease of learning at 5.0 (IQR 4.0–5.8). Neutral scores were mostly related to the perceived limited fidelity of the system.ConclusionsContinuous monitoring of vital signs with a wearable device was well accepted by patients. Nurses’ ratings were highly variable, resulting in on average neutral attitude towards remote monitoring. Our results suggest it is feasible to monitor vital signs continuously on general wards, although acceptability of the device among nurses needs further improvement.

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Prospective Validation of Smartphone-based Heart Rate and Respiratory Rate Measurement Algorithms

10.21203/rs.3.rs-620411/v1 ◽

2021 ◽

Author(s):

Sean Bae ◽

Silviu Borac ◽

Yunus Emre ◽

Jonathan Wang ◽

Jiang Wu ◽

...

Keyword(s):

Heart Rate ◽

Respiratory Rate ◽

Vital Signs ◽

Absolute Error ◽

Medical Settings ◽

Post Exercise ◽

Specialized Equipment ◽

The Mean ◽

Respiratory Conditions ◽

Absolute Percent Error

Abstract Measuring vital signs plays a key role in both patient care and wellness, but can be challenging outside of medical settings due to the lack of specialized equipment. In this study, we prospectively evaluated smartphone camera-based techniques for measuring heart rate (HR) and respiratory rate (RR) for consumer wellness use. HR was measured by placing the finger over the rear-facing camera, while RR was measured via a video of the participants sitting still in front of the front-facing camera. In the HR study of 95 participants (with a protocol that included both measurements at rest and post exercise), the mean absolute percent error (MAPE) ± standard deviation of the measurement was 1.6% ± 4.3%, which was significantly lower than the pre-specified goal of 5%. No significant differences in the MAPE were present across colorimeter-measured skin-tone subgroups: 1.8% ± 4.5% for very light to intermediate, 1.3% ± 3.3% for tan and brown, and 1.8% ± 4.9% for dark. In the RR study of 50 participants, the mean absolute error (MAE) was 0.78 ± 0.61 breaths/min, which was significantly lower than the pre-specified goal of 3 breath/min. The MAE was low in both healthy participants (0.70 ± 0.67 breaths/min), and participants with chronic respiratory conditions (0.80 ± 0.60 breaths/min). These results validate the accuracy of our smartphone camera-based techniques to measure HR and RR across a range of pre-defined subgroups.

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Prospective validation of smartphone-based heart rate and respiratory rate measurement algorithms

10.1101/2021.03.08.21252408 ◽

2021 ◽

Author(s):

Sean Bae ◽

Silviu Borac ◽

Yunus Emre ◽

Jonathan Wang ◽

Jiang Wu ◽

...

Keyword(s):

Heart Rate ◽

Respiratory Rate ◽

Vital Signs ◽

Absolute Error ◽

Medical Settings ◽

Post Exercise ◽

Specialized Equipment ◽

The Mean ◽

Respiratory Conditions ◽

Absolute Percent Error

AbstractMeasuring vital signs plays a key role in both patient care and wellness, but can be challenging outside of medical settings due to the lack of specialized equipment. In this study, we prospectively evaluated smartphone camera-based techniques for measuring heart rate (HR) and respiratory rate (RR) for consumer wellness use. HR was measured by placing the finger over the rear-facing camera, while RR was measured via a video of the participants sitting still in front of the front-facing camera. In the HR study of 95 participants (with a protocol that included both measurements at rest and post exercise), the mean absolute percent error (MAPE) ± standard deviation of the measurement was 1.6% ± 4.3%, which was significantly lower than the pre-specified goal of 5%. No significant differences in the MAPE were present across colorimeter-measured skin-tone subgroups: 1.8% ± 4.5% for very light to intermediate, 1.3% ± 3.3% for tan and brown, and 1.8% ± 4.9% for dark. In the RR study of 50 participants, the mean absolute error (MAE) was 0.78 ± 0.61 breaths/min, which was significantly lower than the pre-specified goal of 3 breath/min. The MAE was low in both healthy participants (0.70 ± 0.67 breaths/min), and participants with chronic respiratory conditions (0.80 ± 0.60 breaths/min). Our results validate that smartphone camera-based techniques can accurately measure HR and RR across a range of pre-defined subgroups.

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Improving the prioritization of children at the emergency department: Updating the Manchester Triage System using vital signs

PLoS ONE ◽

10.1371/journal.pone.0246324 ◽

2021 ◽

Vol 16 (2) ◽

pp. e0246324

Author(s):

Joany M. Zachariasse ◽

Ian K. Maconochie ◽

Ruud G. Nijman ◽

Susanne Greber-Platzer ◽

Frank J. Smit ◽

...

Keyword(s):

Emergency Department ◽

Heart Rate ◽

Respiratory Rate ◽

Vital Sign ◽

Vital Signs ◽

Electronic Health Record Data ◽

Triage System ◽

Capillary Refill ◽

Manchester Triage System ◽

High Urgency

Background Vital signs are used in emergency care settings in the first assessment of children to identify those that need immediate attention. We aimed to develop and validate vital sign based Manchester Triage System (MTS) discriminators to improve triage of children at the emergency department. Methods and findings The TrIAGE project is a prospective observational study based on electronic health record data from five European EDs (Netherlands (n = 2), United Kingdom, Austria, and Portugal). In the current study, we included 117,438 consecutive children <16 years presenting to the ED during the study period (2012–2015). We derived new discriminators based on heart rate, respiratory rate, and/or capillary refill time for specific subgroups of MTS flowcharts. Moreover, we determined the optimal cut-off value for each vital sign. The main outcome measure was a previously developed 3-category reference standard (high, intermediate, low urgency) for the required urgency of care, based on mortality at the ED, immediate lifesaving interventions, disposition and resource use. We determined six new discriminators for children <1 year and ≥1 year: “Very abnormal respiratory rate”, “Abnormal heart rate”, and “Abnormal respiratory rate”, with optimal cut-offs, and specific subgroups of flowcharts. Application of the modified MTS reclassified 744 patients (2.5%). Sensitivity increased from 0.66 (95%CI 0.60–0.72) to 0.71 (0.66–0.75) for high urgency patients and from 0.67 (0.54–0.76) to 0.70 (0.58–0.80) for high and intermediate urgency patients. Specificity decreased from 0.90 (0.86–0.93) to 0.89 (0.85–0.92) for high and 0.66 (0.52–0.78) to 0.63 (0.50–0.75) for high and intermediate urgency patients. These differences were statistically significant. Overall performance improved (R2 0.199 versus 0.204). Conclusions Six new discriminators based on vital signs lead to a small but relevant increase in performance and should be implemented in the MTS.

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