Characterizing the biomechanical differences between novice and expert point-of-care ultrasound practitioners using a low-cost gyroscope and accelerometer integrated sensor: A pilot study.

Introduction: Point-of-care ultrasound (POCUS) has become an important diagnostic tool in acute care medicine; however, little is known about the biomechanical differences between novice and expert practitioners. Methods: A low-cost ($50 CAD) gyroscope and accelerometer integrated sensor was assembled and affixed to an ultrasound probe. Seventeen participants, nine novices and eight experts, were recruited to perform three abdominal and four cardiac scans on a standardized patient. Participant demographics, time per scan, average acceleration, average angular velocity, decay in acceleration and angular velocity over time, and frequency of probe movements were analyzed. Video capture with blinded video review was scored. Results: On video review, experts had higher image optimization and acquisition scores for both abdominal and cardiac scans. Experts had shorter scan times for abdominal (7 s vs. 26 s, p = 0.003) and cardiac (11 s vs. 26 s, p < 0.001) scans. There was no difference in average acceleration (g) between novices and experts performing abdominal (1.02 vs. 1.01, p = 0.50) and cardiac (1.01 vs. 1.01, p = 0.45) scans. Experts had lower angular velocity (°/s) for abdominal scans (10.00 vs. 18.73, p < 0.001) and cardiac scans (15.61 vs. 20.33, p = 0.02) There was a greater decay in acceleration over time for experts performing cardiac scans compared to novices (-0.194 vs. -0.050, p = 0.03) but not for abdominal scans or when measuring angular velocity. The frequency of movements (Hz) was higher for novices compared to experts for abdominal (16.68 vs. 13.79, p < 0.001) and cardiac (17.60 vs. 13.63, p = 0.002) scans. Discussion: This study supports the feasibility of a low-cost gyroscope and accelerometer integrated sensor to quantify the biomechanics of POCUS. It may also support the concept of "window shopping" as a method by which experts obtain abdominal and cardiac views, where sliding is used to find an acoustic window, then smaller rocking and tilting probe movements are used to refine the image.

Elevated levels of transforming growth factor-beta(1) in serum of patients with stable bronchiectasis.

Bronchiectasis is a chronic inflammatory and infective airway disease characterized by irreversible dilatation of the bronchi and persistent purulent sputum. Transforming growth factor-beta(1) (TGF-beta(1)) has been found to be increased in the lungs or bronchoalveolar lavage fluid of patients with inflammatory lung diseases. However, little is known on the serum TGF-beta(1) levels in patients with bronchiectasis. We aimed to determine the serum TGF-beta(1) concentrations in 95 patients with stable bronchiectasis (63 women; mean+/-sd age, 58.9+/-14.1 years) and 68 control subjects (23 women; 48.9+/-12.8 years) by ELISA, and to correlate with clinical parameters. The serum TGF-beta(1) levels were significantly higher in bronchiectatic patients compared with control subjects (median [range], 1812.5 pg/ml [1226.4-4114.5 pg/ml] vs. 1342.4 pg/ml [940.3-2371.7 pg/ml]; P<0.001). There was, however, no correlation between serum TGF-beta(1) levels with FEV(1) (% predicted), FVC (% predicted), 24h sputum volume, the number of bronchiectatic lung lobes or total white blood cell count (P>0.05). Our findings support previous indications that TGF-beta(1) may contribute to bronchiectatic airway inflammation. Further studies on the potential mechanisms and pathogenesis implications of this elevation should also be pursued in future.

Clinical value of ciliary assessment in bronchiectasis.

Although ciliary dysfunction and numerous ultrastructural defects have been described, and these could be etiologically important in the development of bronchiectasis, their correlation with relevant clinical parameters have not been systematically evaluated. We have prospectively evaluated the prevalence and clinical significance of ciliary beat frequency and ultrastructural defects of nasal respiratory mucosa obtained from 152 stable patients with idiopathic bronchiectasis (100F, 57.7 +/- 15.2 yrs) and 127 control subjects (58F, 56.0 +/- 24.2 yrs). Bronchiectasis patients had significantly slower ciliary beat frequency (p < 0.05), and a greater percent of patients had central and peripheral microtubular defects (OR 14.4, 95% CI 5.6-36.8), namely, extra peripheral microtubules, "9 + 1", "8 + 2", and compound cilia (p < 0.05), but not microtubular disarrangement, extra matrix or ciliary tail abnormalities (p > 0.05), than controls. Bronchiectasis patients also had a greater proportion of cilia with any ultrastructural microtubular defects, compound cilia, and ciliary tails than controls (p < 0.05). Ciliary beat frequency did not correlate with clinically relevant parameters (p > 0.05). However, the percent of cilia with central, but not peripheral, microtubular defects correlated with 24 h sputum volume (r = 0.40, p = 0.001, and r = -0.04, p = 0.70, respectively) and FEV1 (r = -0.24, p = 0.01, and r = 0.00, p = 0.99 respectively). Our results strongly suggest a pathogenic role for central microtubular defects in the development of idiopathic bronchiectasis.