An Unobtrusive Wearable Device for Ambulatory Monitoring of Pulse Transit Time to Estimate Central Blood Pressure

Austad, Hanne Opsahl; Vedum, Jon; Røed, Morten Hamremoen; Dalgard, Steffen Harald; Brødreskift, Tomas; Liverud, Anders Erik; Strisland, Frode; Seeberg, Trine M.

doi:10.5220/0005701401790186

Cited by 3 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Studies have shown that low temperature in combination with vibration exposure influences the finger blood flow 23 ) and also increases the risk for pathologies 17 ) . In earlier work we have shown that the sensor and location used in this study may also be used as an indicator of exposure to vibration 24 ) .…”

Section: Discussionmentioning

confidence: 91%

Towards a wearable sensor system for continuous occupational cold stress assessment

et al. 2018

Self Cite

View full text Add to dashboard Cite

This study investigated the usefulness of continuous sensor data for improving occupational cold stress assessment. Eleven volunteer male subjects completed a 90–120-min protocol in cold environments, consisting of rest, moderate and hard work. Biomedical data were measured using a smart jacket with integrated temperature, humidity and activity sensors, in addition to a custom-made sensor belt worn around the chest. Other relevant sensor data were measured using commercially available sensors. The study aimed to improve decision support for workers in cold climates, by taking advantage of the information provided by data from the rapidly growing market of wearable sensors. Important findings were that the subjective thermal sensation did not correspond to the measured absolute skin temperature and that large differences were observed in both metabolic energy production and skin temperatures under identical exposure conditions. Temperature, humidity, activity and heart rate were found to be relevant parameters for cold stress assessment, and the locations of the sensors in the prototype jacket were adequate. The study reveals the need for cold stress assessment and indicates that a generalised approached is not sufficient to assess the stress on an individual level.

show abstract

Section: Discussionmentioning

confidence: 91%

Towards a wearable sensor system for continuous occupational cold stress assessment

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…With the present sampling rate, it was difficult to find the exact time for the maxima of the ICG curve; this could easily be shifted 1-3 samples. A time offset of 8 ms corresponds to about 10 mmHg offset in BP [17]. However, the result is still valid for longer time estimates by averaging over several PTT samples.…”

Section: Clinical Application and Recommendation For Further Workmentioning

confidence: 94%

“…2A) and during cycling (Fig. 2B) [17] for more information. In the current work the sampling time of the raw data (ECG, ICG, PPG) was 4 ms, data was collected and logged with Bluetooth disabled, and filter settings were held constant.…”

Section: A Description Of Isenseu-bp+mentioning

confidence: 99%

“…Thus, the error caused by this method for ICG-B point detection will influence the possibility to detect small changes in blood pressure, and the beat-to-beat variation. For changes in the range evaluated during activity in this study (>20 mmHg and averaged over 10 heart cycles) the error of the ICG-B point detection were judged acceptable [17].…”

Section: B Calculation Of Pulse Transit Timementioning

confidence: 99%

“…To our knowledge, IsenseU-BP+ is the first device aiming to measure BP changes with all components and processing integrated within a single, small unit strapped around the chest, thereby making it truly unobtrusive in daily life. In tests performed on healthy volunteers with normal range BMI using handgrip movement to change blood pressure, it has been verified that IsenseU-BP+ can be used to monitor blood pressure changes [17]. The hypothesis behind the present work was that IsenseU-BP+ can be used to measure PTT in a patient population with both genders and varying age, body shapes and body mass index (BMI).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A Novel Method for Continuous, Noninvasive, Cuff-Less Measurement of Blood Pressure: Evaluation in Patients With Nonalcoholic Fatty Liver Disease

Seeberg

Orr

Opsahl

et al. 2017

IEEE Trans. Biomed. Eng.

Self Cite

View full text Add to dashboard Cite

Abstract-Objective: One promising approach for a continuous, non-invasive, cuff-less ambulatory BP monitor is to measure the pulse wave velocity or the inversely proportional pulse transit time (PTT), based on electrical and optical physiological measurements in the chest area. A device termed IsenseU-BP+ has been developed for measuring continuous BP, as well as other physiological data. The objective of this paper is to present results from the first clinical evaluation with a wide range of patients. The study was set up to verify whether IsenseU-BP+ can be used to measure raw signals with sufficient quality to derive PTT. Methods: The test protocol, run 23 times on 18 different patients with non-alcoholic fatty liver disease, includes both supine measurement at rest as well as measurements during indoor cycling. Changes in PTT were compared with the BP changes measured using validated reference sensors. Results: IsenseU-BP+ measured signals with good quality during rest on 17 of 18 patients despite the high diversity in age, body shape and BMI. Evaluation during cycling was difficult due to a lack of good reference measurements. Conclusion: IsenseU-BP+ measures PTT with high quality during supine rest and exercise and could therefore be suitable for deriving non-invasive continuous BP, although evaluation during exercise was limited due to inaccurate reference BP measurements. Significance: Continuous, non-invasive measurement of BP would be highly beneficial in a number of clinical settings. Systems currently considered gold-standard for the investigation of hypertension carry considerable limitations which could be overcome by the method proposed here.Index Terms-cuff-less blood pressure, pulse transit time, pulse wave velocity, unobtrusive sensing, hypertension

show abstract

Blood pressure altering method affects correlation with pulse arrival time

Heimark

Rindal

Seeberg

et al. 2021

Blood Pressure Monitoring

Self Cite

View full text Add to dashboard Cite

Objective Pulse arrival time (PAT) is a potential main feature in cuff-less blood pressure (BP) monitoring. However, the precise relationship between BP parameters and PAT under varying conditions lacks a complete understanding. We hypothesize that simple test protocols fail to demonstrate the complex relationship between PAT and both SBP and DBP. Therefore, this study aimed to investigate the correlation between PAT and BP during two exercise modalities with differing BP responses using an unobtrusive wearable device. Methods Seventy-five subjects, of which 43.7% had a prior diagnosis of hypertension, participated in an isometric and dynamic exercise test also including seated periods of rest prior to, in between and after. PAT was measured using a prototype wearable chest belt with a one-channel electrocardiogram and a photo-plethysmography sensor. Reference BP was measured auscultatory. Results Mean individual correlation between PAT and SBP was −0.82 ± 0.14 in the full protocol, −0.79 ± 0.27 during isometric exercise and −0.77 ± 0.19 during dynamic exercise. Corresponding correlation between PAT and DBP was 0.25 ± 0.35, −0.74 ± 0.23 and 0.39 ± 0.41. Conclusion The results confirm PAT as a potential main feature to track changes in SBP. The relationship between DBP and PAT varied between exercise modalities, with the sign of the correlation changing from negative to positive between type of exercise modality. Thus, we hypothesize that simple test protocols fail to demonstrate the complex relationship between PAT and BP with emphasis on DBP.

show abstract

An Unobtrusive Wearable Device for Ambulatory Monitoring of Pulse Transit Time to Estimate Central Blood Pressure

Cited by 3 publications

References 0 publications

Towards a wearable sensor system for continuous occupational cold stress assessment

Towards a wearable sensor system for continuous occupational cold stress assessment

A Novel Method for Continuous, Noninvasive, Cuff-Less Measurement of Blood Pressure: Evaluation in Patients With Nonalcoholic Fatty Liver Disease

Blood pressure altering method affects correlation with pulse arrival time

Contact Info

Product

Resources

About