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Research paper thumbnail of Threshold for Defining Fever Varies with Age Especially in Children and can be Further Improved Using Artificial Intelligence Techniques: A Multi-site Diagnostic Accuracy Study

Book Publisher International (a part of SCIENCEDOMAIN International), Apr 21, 2022

Research paper thumbnail of Clinical Performance of Infrared Consumer-Grade Thermometers

Journal of Nursing Measurement, 2013

Background and Purpose: Technology of ear infrared (IR) thermometers has improved. This study com... more Background and Purpose: Technology of ear infrared (IR) thermometers has improved. This study compared a modern ear thermometer to forehead or temporal artery thermometers. Methods: Temperatures were measured with a heated-tip ear thermometer, a temporal artery thermometer, 3 forehead thermometers, and a thermistor-based reference thermometer in monitor mode. Results: In 171 subjects, mean bias with the forehead thermometers was significantly higher (p , .001) than with the ear thermometer (0.01 °C 6 0.41 °C). In 64 febrile subjects, bias with the ear thermometer was significantly lower than with 3 of the other thermometers. A false-negative reading was less likely with the ear thermometer (8%) versus the others (55%, 56%, 28%, and 47%). Conclusions: Modern ear thermometry provides more precise measurements closer to those of a reference thermometer and is less likely to give false-negative readings than forehead or temporal artery measurements.

Research paper thumbnail of Evaluation of key design parameters for mitigating motion artefact in the mobile reflectance PPG signal to improve estimation of arterial oxygenation

Physiological Measurement, Jul 27, 2018

OBJECTIVE Pulse oximetry, a widely accepted method for non-invasive estimation of arterial oxygen... more OBJECTIVE Pulse oximetry, a widely accepted method for non-invasive estimation of arterial oxygen saturation (SpO2) and pulse rate (PR), is increasingly being adapted for mobile applications. Previous work in mitigating motion artefact, which corrupts the photoplethysmogram (PPG) used in pulse oximetry, has focused on reducing noise using signal processing algorithms or through sensor design that controlled only one variable at a time. In this work, we have investigated the effect of several variables such as sensor weight, relative motion, placement, and contact force against the skin that can impact motion artefact independently or by interacting with each other. APPROACH We have identified a unique combination of these variables that is most optimal in reducing motion artefacts using a full factorial design of experiments methodology and evaluated the effect of these factors on PPG readings with and without motion. MAIN RESULTS Data collected on 10 diverse subjects showed that placement (p = 0.03), contact force (p = 0.004), and sensor-to-skin adhesion or relative motion when combined with force (p < 0.001) had the most significant effect on reducing the motion artefact signal. Sensor weight (p = 0.822) by itself had no significant effect, however when combined with sensor adhesion (p < 0.001) had a significant impact. SIGNIFICANCE This lays the foundation for future development of more robust sensors that can significantly reduce the effect of motion artefacts in reflectance-based pulse oximetry and could have great clinical value due to significant reduction of SpO2 errors and false alarms associated with motion artefact, making wearable pulse oximetry more reliable in mobile applications.

Research paper thumbnail of Optimizing the input feature sets and machine learning algorithms for reliable and accurate estimation of continuous, cuffless blood pressure

Scientific Reports

The advent of mobile devices, wearables and digital healthcare has unleashed a demand for accurat... more The advent of mobile devices, wearables and digital healthcare has unleashed a demand for accurate, reliable, and non-interventional ways to measure continuous blood pressure (BP). Many consumer products claim to measure BP with a cuffless device, but their lack of accuracy and reliability limit clinical adoption. Here, we demonstrate how multimodal feature datasets, comprising: (i) pulse arrival time (PAT); (ii) pulse wave morphology (PWM), and (iii) demographic data, can be combined with optimized Machine Learning (ML) algorithms to estimate Systolic BP (SBP), Diastolic BP (DBP) and Mean Arterial Pressure (MAP) within a 5 mmHg bias of the gold standard Intra-Arterial BP, well within the acceptable limits of the IEC/ANSI 80601-2-30 (2018) standard. Furthermore, DBP’s calculated using 126 datasets collected from 31 hemodynamically compromised patients had a standard deviation within 8 mmHg, while SBP’s and MAP’s exceeded these limits. Using ANOVA and Levene’s test for error means an...

Research paper thumbnail of Threshold for Defining Fever Varies with Age Especially in Children and can be Further Improved Using Artificial Intelligence Techniques: A Multi-site Diagnostic Accuracy Study

Emerging Trends in Disease and Health Research Vol. 7

Research paper thumbnail of US20200375513A

PULSE OXIMETER SENSORS WITH REDUCED S, 2020

Pub . No .: US 2020/0375513 A1 ABSTRACT ( 72 ) Inventors : Rajesh S. Kasbekar , Worcester , MA (... more Pub . No .: US 2020/0375513 A1

ABSTRACT
( 72 ) Inventors : Rajesh S. Kasbekar , Worcester , MA
( US ) ; Yitzhak Mendelson , Worcester ,
MA ( US )
( 21 ) Appl . No .: 16 / 362,084
( 22 ) Filed : Jun . 3 , 2019
A reflective PPG sensor , in which motion artifacts have a
reduced effect , is configured to be placed on one of a
forehead , a finger or a wrist of a subject on a location
selected according to a predetermined range of a signal
quality index and has a force per unit area between 0.3
N / cm² and 1.5 N / cm² , and a bonding pressure , for sensor to
skin adhesion , between 10 N / cm² and 20 N / cm² . In one
instance , the reflective PPG sensor of these teachings also
has a weight between 6 g and 12 g .

Research paper thumbnail of US20200375513A

Research paper thumbnail of Clinical Performance of Infrared Consumer-Grade Thermometers

Journal of Nursing Measurement, 2013

Background and Purpose: Technology of ear infrared (IR) thermometers has improved. This study com... more Background and Purpose: Technology of ear infrared (IR) thermometers has improved. This study compared a modern ear thermometer to forehead or temporal artery thermometers. Methods: Temperatures were measured with a heated-tip ear thermometer, a temporal artery thermometer, 3 forehead thermometers, and a thermistor-based reference thermometer in monitor mode. Results: In 171 subjects, mean bias with the forehead thermometers was significantly higher (p , .001) than with the ear thermometer (0.01 °C 6 0.41 °C). In 64 febrile subjects, bias with the ear thermometer was significantly lower than with 3 of the other thermometers. A false-negative reading was less likely with the ear thermometer (8%) versus the others (55%, 56%, 28%, and 47%). Conclusions: Modern ear thermometry provides more precise measurements closer to those of a reference thermometer and is less likely to give false-negative readings than forehead or temporal artery measurements.

Research paper thumbnail of Threshold for defining fever varies with age, especially in children: A multi‐site diagnostic accuracy study

Research paper thumbnail of Evaluation of key design parameters for mitigating motion artefact in the mobile reflectance PPG signal to improve estimation of arterial oxygenation

Physiological Measurement, 2018

Objective: Pulse oximetry, a widely accepted method for non-invasive monitoring of arterial oxyg... more Objective: Pulse oximetry, a widely accepted method for non-invasive monitoring of arterial oxygen saturation (SpO2) and pulse rate (PR), is increasingly being adapted for mobile applications. Previous work in mitigating motion artifact, that corrupts the photoplethysmogram (PPG) used in pulse oximetry, has focused on reducing noise using signal processing algorithms or through sensor design that controlled only one variable at a time. In this work, we have investigated the effect of several variables such as sensor weight, relative motion, placement and contact force against the skin that can impact motion artifact independently or by interacting with each other.
Approach: We have identified a unique combination of these variables that is most optimal in reducing motion artifacts using a full factorial design of experiments methodology and evaluated the effect of these factors on PPG readings with and without motion.
Main Results: Data collected on ten diverse subjects showed that placement (p=0.03), contact force (p=0.004) and sensor-to-skin adhesion or relative motion when combined with force (p<0.001) had the most significant effect on reducing the motion artifact signal. Sensor weight (p=0.822) by itself had no significant effect, however when combined with sensor adhesion (p<0.001) had a significant impact.
Significance: This lays the foundation for future development of more robust sensors that can significantly reduce the effect of motion artifacts in reflectance-based pulse oximetry and could have great clinical value due to significant reduction of SpO2 errors and false alarms associated with motion artifact, making wearable pulse oximetry more reliable in mobile applications.
Keywords: Pulse oximeter; photoplethysmograph; reflectance sensor; motion artifact; design of experiments; full factorial

Research paper thumbnail of Clinical performance of infrared consumer-grade

Background and Purpose: Technology of ear infrared (IR) thermometers has improved. This study com... more Background and Purpose: Technology of ear infrared (IR) thermometers has improved. This study compared a modern ear thermometer to forehead or temporal artery thermometers. Methods: Temperatures were measured with a heated-tip ear thermometer, a temporal artery thermometer, 3 forehead thermometers, and a thermistor-based reference thermometer in monitor mode. Results: In 171 subjects, mean bias with the forehead thermometers was significantly higher (p &amp;amp;amp;amp;lt; .001) than with the ear thermometer (0.01 °C ± 0.41 °C). In 64 febrile subjects, bias with the ear thermometer was significantly lower than with 3 of the other thermometers. A false-negative reading was less likely with the ear thermometer (8%) versus the others (55%, 56%, 28%, and 47%). Conclusions: Modern ear thermometry provides more precise measurements closer to those of a reference thermometer and is less likely to give false-negative readings than forehead or temporal artery measurements.

Research paper thumbnail of Threshold for Defining Fever Varies with Age Especially in Children and can be Further Improved Using Artificial Intelligence Techniques: A Multi-site Diagnostic Accuracy Study

Book Publisher International (a part of SCIENCEDOMAIN International), Apr 21, 2022

Research paper thumbnail of Clinical Performance of Infrared Consumer-Grade Thermometers

Journal of Nursing Measurement, 2013

Background and Purpose: Technology of ear infrared (IR) thermometers has improved. This study com... more Background and Purpose: Technology of ear infrared (IR) thermometers has improved. This study compared a modern ear thermometer to forehead or temporal artery thermometers. Methods: Temperatures were measured with a heated-tip ear thermometer, a temporal artery thermometer, 3 forehead thermometers, and a thermistor-based reference thermometer in monitor mode. Results: In 171 subjects, mean bias with the forehead thermometers was significantly higher (p , .001) than with the ear thermometer (0.01 °C 6 0.41 °C). In 64 febrile subjects, bias with the ear thermometer was significantly lower than with 3 of the other thermometers. A false-negative reading was less likely with the ear thermometer (8%) versus the others (55%, 56%, 28%, and 47%). Conclusions: Modern ear thermometry provides more precise measurements closer to those of a reference thermometer and is less likely to give false-negative readings than forehead or temporal artery measurements.

Research paper thumbnail of Evaluation of key design parameters for mitigating motion artefact in the mobile reflectance PPG signal to improve estimation of arterial oxygenation

Physiological Measurement, Jul 27, 2018

OBJECTIVE Pulse oximetry, a widely accepted method for non-invasive estimation of arterial oxygen... more OBJECTIVE Pulse oximetry, a widely accepted method for non-invasive estimation of arterial oxygen saturation (SpO2) and pulse rate (PR), is increasingly being adapted for mobile applications. Previous work in mitigating motion artefact, which corrupts the photoplethysmogram (PPG) used in pulse oximetry, has focused on reducing noise using signal processing algorithms or through sensor design that controlled only one variable at a time. In this work, we have investigated the effect of several variables such as sensor weight, relative motion, placement, and contact force against the skin that can impact motion artefact independently or by interacting with each other. APPROACH We have identified a unique combination of these variables that is most optimal in reducing motion artefacts using a full factorial design of experiments methodology and evaluated the effect of these factors on PPG readings with and without motion. MAIN RESULTS Data collected on 10 diverse subjects showed that placement (p = 0.03), contact force (p = 0.004), and sensor-to-skin adhesion or relative motion when combined with force (p < 0.001) had the most significant effect on reducing the motion artefact signal. Sensor weight (p = 0.822) by itself had no significant effect, however when combined with sensor adhesion (p < 0.001) had a significant impact. SIGNIFICANCE This lays the foundation for future development of more robust sensors that can significantly reduce the effect of motion artefacts in reflectance-based pulse oximetry and could have great clinical value due to significant reduction of SpO2 errors and false alarms associated with motion artefact, making wearable pulse oximetry more reliable in mobile applications.

Research paper thumbnail of Optimizing the input feature sets and machine learning algorithms for reliable and accurate estimation of continuous, cuffless blood pressure

Scientific Reports

The advent of mobile devices, wearables and digital healthcare has unleashed a demand for accurat... more The advent of mobile devices, wearables and digital healthcare has unleashed a demand for accurate, reliable, and non-interventional ways to measure continuous blood pressure (BP). Many consumer products claim to measure BP with a cuffless device, but their lack of accuracy and reliability limit clinical adoption. Here, we demonstrate how multimodal feature datasets, comprising: (i) pulse arrival time (PAT); (ii) pulse wave morphology (PWM), and (iii) demographic data, can be combined with optimized Machine Learning (ML) algorithms to estimate Systolic BP (SBP), Diastolic BP (DBP) and Mean Arterial Pressure (MAP) within a 5 mmHg bias of the gold standard Intra-Arterial BP, well within the acceptable limits of the IEC/ANSI 80601-2-30 (2018) standard. Furthermore, DBP’s calculated using 126 datasets collected from 31 hemodynamically compromised patients had a standard deviation within 8 mmHg, while SBP’s and MAP’s exceeded these limits. Using ANOVA and Levene’s test for error means an...

Research paper thumbnail of Threshold for Defining Fever Varies with Age Especially in Children and can be Further Improved Using Artificial Intelligence Techniques: A Multi-site Diagnostic Accuracy Study

Emerging Trends in Disease and Health Research Vol. 7

Research paper thumbnail of US20200375513A

PULSE OXIMETER SENSORS WITH REDUCED S, 2020

Pub . No .: US 2020/0375513 A1 ABSTRACT ( 72 ) Inventors : Rajesh S. Kasbekar , Worcester , MA (... more Pub . No .: US 2020/0375513 A1

ABSTRACT
( 72 ) Inventors : Rajesh S. Kasbekar , Worcester , MA
( US ) ; Yitzhak Mendelson , Worcester ,
MA ( US )
( 21 ) Appl . No .: 16 / 362,084
( 22 ) Filed : Jun . 3 , 2019
A reflective PPG sensor , in which motion artifacts have a
reduced effect , is configured to be placed on one of a
forehead , a finger or a wrist of a subject on a location
selected according to a predetermined range of a signal
quality index and has a force per unit area between 0.3
N / cm² and 1.5 N / cm² , and a bonding pressure , for sensor to
skin adhesion , between 10 N / cm² and 20 N / cm² . In one
instance , the reflective PPG sensor of these teachings also
has a weight between 6 g and 12 g .

Research paper thumbnail of US20200375513A

Research paper thumbnail of Clinical Performance of Infrared Consumer-Grade Thermometers

Journal of Nursing Measurement, 2013

Background and Purpose: Technology of ear infrared (IR) thermometers has improved. This study com... more Background and Purpose: Technology of ear infrared (IR) thermometers has improved. This study compared a modern ear thermometer to forehead or temporal artery thermometers. Methods: Temperatures were measured with a heated-tip ear thermometer, a temporal artery thermometer, 3 forehead thermometers, and a thermistor-based reference thermometer in monitor mode. Results: In 171 subjects, mean bias with the forehead thermometers was significantly higher (p , .001) than with the ear thermometer (0.01 °C 6 0.41 °C). In 64 febrile subjects, bias with the ear thermometer was significantly lower than with 3 of the other thermometers. A false-negative reading was less likely with the ear thermometer (8%) versus the others (55%, 56%, 28%, and 47%). Conclusions: Modern ear thermometry provides more precise measurements closer to those of a reference thermometer and is less likely to give false-negative readings than forehead or temporal artery measurements.

Research paper thumbnail of Threshold for defining fever varies with age, especially in children: A multi‐site diagnostic accuracy study

Research paper thumbnail of Evaluation of key design parameters for mitigating motion artefact in the mobile reflectance PPG signal to improve estimation of arterial oxygenation

Physiological Measurement, 2018

Objective: Pulse oximetry, a widely accepted method for non-invasive monitoring of arterial oxyg... more Objective: Pulse oximetry, a widely accepted method for non-invasive monitoring of arterial oxygen saturation (SpO2) and pulse rate (PR), is increasingly being adapted for mobile applications. Previous work in mitigating motion artifact, that corrupts the photoplethysmogram (PPG) used in pulse oximetry, has focused on reducing noise using signal processing algorithms or through sensor design that controlled only one variable at a time. In this work, we have investigated the effect of several variables such as sensor weight, relative motion, placement and contact force against the skin that can impact motion artifact independently or by interacting with each other.
Approach: We have identified a unique combination of these variables that is most optimal in reducing motion artifacts using a full factorial design of experiments methodology and evaluated the effect of these factors on PPG readings with and without motion.
Main Results: Data collected on ten diverse subjects showed that placement (p=0.03), contact force (p=0.004) and sensor-to-skin adhesion or relative motion when combined with force (p<0.001) had the most significant effect on reducing the motion artifact signal. Sensor weight (p=0.822) by itself had no significant effect, however when combined with sensor adhesion (p<0.001) had a significant impact.
Significance: This lays the foundation for future development of more robust sensors that can significantly reduce the effect of motion artifacts in reflectance-based pulse oximetry and could have great clinical value due to significant reduction of SpO2 errors and false alarms associated with motion artifact, making wearable pulse oximetry more reliable in mobile applications.
Keywords: Pulse oximeter; photoplethysmograph; reflectance sensor; motion artifact; design of experiments; full factorial

Research paper thumbnail of Clinical performance of infrared consumer-grade

Background and Purpose: Technology of ear infrared (IR) thermometers has improved. This study com... more Background and Purpose: Technology of ear infrared (IR) thermometers has improved. This study compared a modern ear thermometer to forehead or temporal artery thermometers. Methods: Temperatures were measured with a heated-tip ear thermometer, a temporal artery thermometer, 3 forehead thermometers, and a thermistor-based reference thermometer in monitor mode. Results: In 171 subjects, mean bias with the forehead thermometers was significantly higher (p &amp;amp;amp;amp;lt; .001) than with the ear thermometer (0.01 °C ± 0.41 °C). In 64 febrile subjects, bias with the ear thermometer was significantly lower than with 3 of the other thermometers. A false-negative reading was less likely with the ear thermometer (8%) versus the others (55%, 56%, 28%, and 47%). Conclusions: Modern ear thermometry provides more precise measurements closer to those of a reference thermometer and is less likely to give false-negative readings than forehead or temporal artery measurements.