High sensitivity Doppler radar system for detecting respiration and heart rate using improved isolation technique

Heart rate measurement using a continuous wave Doppler radar sensor (CW-DRS) has been applied to cases where non-contact detection is required, such as the monitoring of vital signs in home healthcare. However, as a CW-DRS measures the speed of movement of the chest surface, which comprises cardiac and respiratory signals by body motion, extracting cardiac information from the superimposed signal is difficult. Therefore, it is challenging to extract cardiac information from superimposed signals. Herein, we propose a novel method based on a matched filter to solve this problem. The method comprises two processes: adaptive generation of a template via singular value decomposition of a trajectory matrix formed from the measurement signals, and reconstruction by convolution of the generated template and measurement signals. The method is validated using a dataset obtained in two different experiments, i.e., experiments involving supine and seated subject postures. Absolute errors in heart rate and standard deviation of heartbeat interval with references were calculated as 1.93±1.76bpm and 57.0±28.1s for the lying posture, and 9.72±7.86bpm and 81.3±24.3s for the sitting posture.

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Use Of Linear-Polarization Doppler Radar System to Detect Falls: Results From a Simulated Living Environment

Proceedings of the Human Factors and Ergonomics Society Annual Meeting ◽

10.1177/1071181320641003 ◽

2020 ◽

Vol 64 (1) ◽

pp. 11-12

Author(s):

Sunwook Kim ◽

Maury A. Nussbaum ◽

Fleming Lure

Keyword(s):

Linear Polarization ◽

Doppler Radar ◽

Radar System ◽

Living Environment

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Signal-adapted wavelets for Doppler radar system

7th International Conference on Control, Automation, Robotics and Vision, 2002. ICARCV 2002. ◽

10.1109/icarcv.2002.1234783 ◽

2004 ◽

Author(s):

Soon-Huat Ong

Keyword(s):

Doppler Radar ◽

Radar System

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Circulating levels of growth hormone in postural orthostatic tachycardia syndrome

Scientific Reports ◽

10.1038/s41598-021-87983-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Madeleine Johansson ◽

Fabrizio Ricci ◽

Janin Schulte ◽

Margaretha Persson ◽

Olle Melander ◽

...

Keyword(s):

Heart Rate ◽

Growth Hormone ◽

Orthostatic Intolerance ◽

High Sensitivity ◽

Symptom Assessment ◽

Postural Orthostatic Tachycardia Syndrome ◽

Daily Life Activities ◽

Median Plasma ◽

Symptom Assessment Scale ◽

Plasma Gh

AbstractPostural orthostatic tachycardia syndrome (POTS) is a cardiovascular autonomic disorder with poorly understood etiology and underlying pathophysiology. Since cardiovascular morbidity has been linked to growth hormone (GH), we studied GH levels in patients with POTS. We conducted an age-sex-matched case–control study in patients with POTS (age 31 ± 9 years; n = 42) and healthy controls (32 ± 9 years; n = 46). Plasma GH levels were measured using high-sensitivity chemiluminescence sandwich immunoassay. The burden of orthostatic intolerance symptoms was assessed by the Orthostatic Hypotension Questionnaire (OHQ), consisting of a symptom assessment scale (OHSA) and a daily activity scale (OHDAS). POTS patients had significantly higher composite OHQ score than controls, more symptoms and less activity. Supine heart rate and diastolic blood pressure (BP), but not systolic BP, were significantly higher in POTS. Median plasma GH levels were significantly lower in POTS (0.53 ng/mL) than controls (2.33 ng/mL, p = 0.04). GH levels were inversely related to OHDAS in POTS and supine systolic BP in POTS and controls, but not heart rate neither group. POTS is associated with lower GH levels. Impairment of daily life activities is inversely related with GH in POTS. A higher supine diastolic BP is inversely associated with GH levels in POTS and healthy individuals.

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