Measurement of chest wall motion using a motion capture system with the one-pitch phase analysis method

Spirometry is a standard method for assessing lung function. However, its use is challenging in some patients, and it has limitations such as risk of infection and inability to assess regional chest wall motion. A three-dimensional motion capture system using the one-pitch phase analysis (MCO) method can facilitate high precision measurement of moving objects in real-time in a non-contacting manner. In this study, the MCO method was applied to examine thoraco-abdominal (TA) wall motion for assessing pulmonary function. We recruited 48 male participants, and all underwent spirometry and chest wall motion measurement with the MCO method. A significant positive correlation was observed between the vital capacity (Spearman’s ρ = 0.68, p < 0.0001), forced vital capacity (Spearman’s ρ = 0.62, p < 0.0001), and tidal volume (Spearman’s ρ = 0.61, p < 0.0001) of spirometry and the counterpart parameters of MCO method. Moreover, the MCO method could detect regional rib cage and abdomen compartment contributions and could assess TA asynchrony, indicating almost complete synchronous movement (phase angle for each compartment: − 5.05° to 3.86°). These findings suggest that this technique could examine chest wall motion, and may be effective in analyzing chest wall volume changes and pulmonary function.

Efficacy of Chest Compressions Performed on Patients in Dental Chairs Versus on the Floor

This study aimed to investigate the characteristics of chest compressions performed in dental chairs (DCs) with 2 different structural support designs and on the floor. This randomized prospective study was conducted to compare the effectiveness of chest compressions (rate and depth) using a feedback device and a manikin reporting system. The mean anterior chest wall motion measurements captured using the feedback device were significantly increased in the DCs than on the floor, whereas the percentage of net chest compression depths ≥5 cm as measured using the manikin reporting system were significantly decreased in the DCs than on the floor. These findings suggest that cardiopulmonary resuscitation performed in a DC without the use of a supporting stool or stiff backboard is not likely to be effective even if a DC design that incorporates a supportive steel column is utilized.

A Study to Compare the Immediate Effects of Inverse Ratio Breathing and Diaphragmatic Breathing on Pulmonary Functions and Thoracic Expansion in Patients with Chronic Obstructive Pulmonary Disease

Background: COPD leads to airway obstruction, hyperinflation, mechanical disadvantage of respiratory muscles which places accessory muscles in shortened position, leading to increase resistance to chest wall expansion, this causes decrease in pulmonary function. Breathing exercises assist by decreasing dyspnea. Diaphragmatic breathing aims to improve chest wall motion and distribution of ventilation. In Inverse ratio breathing, the ra­tio of I:E becomes 2:1. This study aims to compare the immediate effects of diaphragmatic and inverse ratio breathing in patients with COPD. Method: Study was conducted on 60 patients having COPD. Subjects were randomly selected to perform diaphragmatic or inverse ratio breathing first on day 1, and other technique on day 2. Diaphragmatic breathing was performed for total duration of 5 minutes within 10 minute interval at 6-8 breathes/minute. Washout period of one day was given. Next day, subject was asked to perform inverse ratio breathing using visual video feedback (inspiration for 4 seconds and expiration for 2 seconds) for 10 minutes. Outcome measures: Pulmonary functions (FVC, FEV1, FEV1/FVC, MVV) and thoracic expansion at 2nd, 4th, 6th intercostal space Results: Result showed significant improvement for FVC, FEV1 and MVV, but FEV1/FVC shows no significant difference after diaphragmatic breathing. There was no significant difference for pulmonary functions after inverse ratio breathing. Results showed no significant difference for thoracic expansion after either of two breathing techniques. Conclusion: Diaphragmatic breathing showed significant improvement in pulmonary functions, however no improvement was observed in thoracic expansion. Inverse ratio breathing showed no improvement in pulmonary functions or thoracic expansion. Key words: COPD, diaphragmatic breathing, inverse ratio breathing, pulmonary functions, thoracic expansion

Modelling of Chest Wall Motion for Cardiorespiratory Activity for Radar-Based NCVS Systems

Chest wall motion can provide information on critical vital signs, including respiration and heartbeat. Mathematical modelling of chest wall motion can reduce an extensive requirement of human testing in the development of many biomedical applications. In this paper, we propose a mathematical model that simulates a chest wall motion due to cardiorespiratory activity. Chest wall motion due to respiration is simulated based on the optimal chemical–mechanical respiratory control-based mechanics. The theory of relaxation oscillation system is applied to model the motion due to cardiac activity. The proposed mathematical chest wall model can be utilized in designing and optimizing different design parameters for radar-based non-contact vital sign (NCVS) systems.