Prospective observational study of 2 wearable strain sensors for measuring the respiratory rate.

The respiratory rate is an important factor for assessing patient status and detecting changes in the severity of illness. Real-time determination of the respiratory rate will enable early responses to changes in the patient condition. Several methods of wearable devices have enabled remote respiratory rate monitoring. However, gaps persist in large-scale validation, patient-specific calibration, standardization and their usefulness in clinical practice has not been fully elucidated. The aim of this study was to evaluate the accuracy of 2 wearable stretch sensors, C-STRECH® which is used in clinical practice and a novel stretchable capacitor in measuring the respiratory rate. The respiratory rate of 20 healthy subjects was measured by a spirometer with the stretch sensor applied to 1 of 5 locations (umbilicus, lateral abdomen, epigastrium, lateral chest, or chest) of their body at rest while they were in a sitting or supine position before or after exercise. The sensors detected the largest amplitudes at the epigastrium and umbilicus compared to other sites of measurement for the sitting and supine positions, respectively. At rest, the respiratory rate of the sensors had an error of 0.06 to 2.39 breaths/minute, whereas after exercise, an error of 1.57 to 3.72 breaths/minute was observed compared to the spirometer. The sensors were able to detect the respiratory rate of healthy volunteers in the sitting and supine positions, but there was a need for improvement in detection after exercise.

Comparison of a portable, pneumotach flow-sensor-based spirometer (Spirofy™) with the vitalograph alpha Touch™ spirometer in evaluating lung function in healthy individuals, asthmatics, and COPD patients-a randomized, crossover study.

BACKGROUND: Spirofy™ is India's first portable, pneumotach flow-sensor-based digital spirometer developed to diagnose asthma and chronic obstructive pulmonary disease (COPD). In this study, we compared the performance of the Spirofy™ device with that of the Vitalograph Alpha Touch™ spirometer in measuring the lung capacities of healthy individuals, asthmatics, and COPD patients. We also assessed the inter-device variability between two Spirofy™ devices. METHODS: In a randomized, three-way crossover, open-label study, we measured the differences in forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC) between the Spirofy™ and Vitalograph Alpha Touch™ spirometers. A proportion of the FEV1/FVC ratio distribution of < 0.7 was used to compare the diagnostic accuracies of the Spirofy™ with Vitalograph™ Alpha Touch™ spirometers. RESULTS: Ninety subjects participated in this study. The mean ± SD FVC values obtained from the Spirofy™ 1, Spirofy™ 2, and Vitalograph Alpha Touch™ devices were 2.60 ± 1.05 L, 2.64 ± 1.04 L, and 2.67 ± 1.04 L, respectively. The mean ± SD FEV1 values obtained from the Spirofy™ 1, Spirofy™ 2, and Vitalograph Alpha Touch™ devices were 1.87 ± 0.92 (L), 1.88 ± 0.92 (L), and 1.93 ± 0.93 (L), respectively. A significant positive correlation was found between the FVC and FEV1 values recorded by Vitalograph Alpha Touch™, Spirofy™ 1, and Spirofy™ 2. As compared to Vitalograph Alpha Touch™, the Spirofy™ device showed good sensitivity (97%), specificity (90%), and overall accuracy (93.3%) at an FEV1/FVC ratio < 0.7. No inter-device variability was observed between the two Spirofy™ devices. CONCLUSION: Spirofy™ is a portable and easy-to-use device and is as accurate as the standard Vitalograph Alpha Touch™ spirometer for the diagnosis of COPD and asthma. TRIAL REGISTRATION: CTRI/2021/09/036492 (Clinical Trials Registry - India).

Comparative analysis of pulmonary ventilation distribution between low-cost and branded incentive spirometers using electrical impedance tomography in healthy adults: Study protocol.

BACKGROUND: The Incentive Spirometer (IS) increases lung volume and improves gas exchange by visually stimulating patients to take slow, deep breaths. It prevents respiratory complications and treats postoperative atelectasis in patients undergoing abdominal, thoracic, and neurosurgical procedures. Its effectiveness has been validated in studies that support improved lung capacities and volumes in individuals with respiratory complications, postoperative thoracic surgery, upper abdominal surgery, and bariatric surgery. The modified Pachón incentive spirometer (MPIS) is a cost-effective alternative to branded IS. It is crucial to validate whether the MPIS distributes ventilation as effectively as commercial devices do. Ventilation distribution will be measured using electrical impedance tomography. OBJECTIVE: The aim is to compare the distribution of pulmonary ventilation between the MPIS and another commercial IS in healthy adults using electrical impedance tomography. METHODS: A crossover clinical trial is proposed to evaluate the measurement of pulmonary ventilation distribution using EIT in a sample of healthy adults. All participants will use a commercial flow IS and the MPIS, with the order of assignment randomized. This research will use electrical impedance tomography to validate the operation of the MPIS. CONCLUSIONS: This study protocol will compare two incentive spirometers' impact on pulmonary ventilation, potentially endorsing the adoption of a cost-effective device to enhance accessibility for targeted populations. TRIAL REGISTRATION: The study was registered in ClinicalTrials.gov (NTC05532748).

How to Enhance the Diagnosis of Early Stages of Chronic Obstructive Pulmonary Disease (COPD)? The Role of Mobile Spirometry in COPD Screening and Diagnosis-A Systematic Review.

COPD is the third leading cause of death worldwide. Its diagnosis can be made with spirometry, which is underused due to its limited accessibility. Portable spirometry holds promise for enhancing the efficacy of COPD diagnoses. The study aimed to estimate COPD prevalence diagnosed with a portable spirometer in high-risk patients and compare it with COPD prevalence based on data from conventional, on-site spirometry. We also evaluated the strategy of a proactive approach to identify COPD in high-risk individuals. We conducted a systematic review of original studies on COPD targeted screening and diagnosis with portable and conventional spirometers selected from 8496 publications initially found in three databases: Cochrane, PubMed, and Embase. The inclusion criteria were met by 28 studies. COPD prevalence evaluated with the use of portable spirometers reached 20.27% and was lower compared to that estimated with the use of conventional spirometers (24.67%). In 11 included studies, postbronchodilator tests were performed with portable spirometers, which enabled a bedside COPD diagnosis. Portable spirometers can be successfully used in COPD targeted screening and diagnosis and thus enhance the detection of COPD at early stages.

Diagnosis and Severity Assessment of COPD Using a Novel Fast-Response Capnometer and Interpretable Machine Learning.

INTRODUCTION: Spirometry is the gold standard for COPD diagnosis and severity determination, but is technique-dependent, nonspecific, and requires administration by a trained healthcare professional. There is a need for a fast, reliable, and precise alternative diagnostic test. This study's aim was to use interpretable machine learning to diagnose COPD and assess severity using 75-second carbon dioxide (CO2) breath records captured with TidalSense's N-TidalTM capnometer. METHOD: For COPD diagnosis, machine learning algorithms were trained and evaluated on 294 COPD (including GOLD stages 1-4) and 705 non-COPD participants. A logistic regression model was also trained to distinguish GOLD 1 from GOLD 4 COPD with the output probability used as an index of severity. RESULTS: The best diagnostic model achieved an AUROC of 0.890, sensitivity of 0.771, specificity of 0.850 and positive predictive value (PPV) of 0.834. Evaluating performance on all test capnograms that were confidently ruled in or out yielded PPV of 0.930 and NPV of 0.890. The severity determination model yielded an AUROC of 0.980, sensitivity of 0.958, specificity of 0.961 and PPV of 0.958 in distinguishing GOLD 1 from GOLD 4. Output probabilities from the severity determination model produced a correlation of 0.71 with percentage predicted FEV1. CONCLUSION: The N-TidalTM device could be used alongside interpretable machine learning as an accurate, point-of-care diagnostic test for COPD, particularly in primary care as a rapid rule-in or rule-out test. N-TidalTM also could be effective in monitoring disease progression, providing a possible alternative to spirometry for disease monitoring.

A new tidal breathing measurement device detects bronchial obstruction during methacholine challenge test.

PURPOSE: Bronchial hyperresponsiveness (BHR), a hallmark of bronchial asthma, is typically diagnosed through a methacholine inhalation test followed by spirometry, known as the methacholine challenge test (MCT). While spirometry relies on proper patients' cooperation and precise execution of forced breathing maneuvers, we conducted a comparative analysis with the portable nanomaterial-based sensing device, SenseGuard™, to non-intrusively assess tidal breathing parameters. MATERIALS AND METHODS: In this prospective study, 37 adult participants with suspected asthma underwent sequential spirometry and SenseGuard™ measurements after inhaling increasing methacholine doses. RESULTS: Among the 37 participants, 18 were MCT responders, 17 were non-responders and 2 were excluded due to uninterpretable data. The MCT responders exhibited a significant lung function difference when comparing the change from baseline to maximum response. This was evident through a notable decrease in forced expiratory volume in 1 â€‹s (FEV1) levels in spirometry, as well as in prominent changes in tidal breathing parameters as assessed by SenseGuard™, including the expiratory pause time (Trest) to total breath time (Ttot) ratio, and the expiratory time (Tex) to Ttot ratio. Notably, the ratios Trest/Ttot (∗p â€‹= â€‹0.02), Tex/Ttot (∗p â€‹= â€‹0.002), and inspiratory time (Tin) to Tex (∗p â€‹= â€‹0.04) identified MCT responders distinctly, corresponding to spirometry (∗p â€‹< â€‹0.0001). CONCLUSIONS: This study demonstrates that tidal breathing assessment using SenseGuard™ device reliably detects clinically relevant changes of respiratory parameter during the MCT. It effectively distinguishes between responders and non-responders, with strong agreement to conventional spirometry-measured FEV1. This technology holds promise for monitoring clinical respiratory changes in bronchial asthma patients pending further studies.

Materialized Oppression in Medical Tools and Technologies.

It is well-known that racism is encoded into the social practices and institutions of medicine. Less well-known is that racism is encoded into the material artifacts of medicine. We argue that many medical devices are not merely biased, but materialize oppression. An oppressive device exhibits a harmful bias that reflects and perpetuates unjust power relations. Using pulse oximeters and spirometers as case studies, we show how medical devices can materialize oppression along various axes of social difference, including race, gender, class, and ability. Our account uses political philosophy and cognitive science to give a theoretical basis for understanding materialized oppression, explaining how artifacts encode and carry oppressive ideas from the past to the present and future. Oppressive medical devices present a moral aggregation problem. To remedy this problem, we suggest redundantly layered solutions that are coordinated to disrupt reciprocal causal connections between the attitudes, practices, and artifacts of oppressive systems.

Validity of a portable spirometer in the communities of China.

BACKGROUND: The lack of simple and affordable spirometry has led to the missed and delayed diagnoses of chronic respiratory diseases in communities. The PUS201P is a portable spirometry developed to solve this problem. OBJECTIVE: We aimed to verify the consistency of the PUS201P spirometer with conventional Jaeger spirometer. METHODS: In this cross-sectional study, we randomly recruited 202 subjects aged > 40 years. Testing with the portable spirometry and conventional spirometry were performed on all participants. We compared forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1/FVC measured by the PUS201P device with the conventional spirometer. Pearson correlation coefficient and Interclass Correlation Coefficient (ICC) were assessed to confirm the consistency of the measures from two instruments. Bland-Altman graph was created to assess the agreement of the measures from two devices. RESULTS: 202 participants were included in this study. The ICC on FEV1, FVC, FEV1/FVC measured by the portable spirometer and the conventional spirometer were 0.95 (95% confidence interval [CI]: 0.94-0.96), 0.92 (95% CI: 0.90-0.94], 0.93 (95% CI: 0.91-0.95), respectively. The Bland-Altman plots showed that the mean difference between the measures from two spirometers are always located in the 95% limits of agreement. CONCLUSIONS: Our results support that the measures from the portable spirometer and the conventional spirometer have a good agreement and reproducibility. And the portable spirometer is a reliable tool to screen and diagnose chronic airway diseases in the primary care settings.

Remote monitoring in telehealth care delivery across the U.S. cystic fibrosis care network.

BACKGROUND: Cystic fibrosis (CF) programs and people with CF (PwCF) employed various monitoring methods for virtual care during the COVID-19 pandemic. This paper characterizes experiences with remote monitoring across the U.S. CF community. METHODS: The CF Foundation (CFF) sponsored distribution of home spirometers (April 2020 to May 2021), surveys to PwCF and CF programs (July to September 2020), and a second program survey (April to May 2021). We used mixed methods to explore access, use, and perspectives regarding the use of remote monitoring in future care. RESULTS: By October 2020, 13,345 spirometers had been distributed, and 19,271 spirometers by May 2021. Programs (n=286) estimated proportions of PwCF with home devices increased over seven months: spirometers (30% to 70%), scales (50% to 70%), oximeters (5% to 10%) with higher estimates in adult programs for spirometers and oximeters. PwCF (n=378) had access to scales (89%), followed by oximeters (48%) and spirometers (47%), often using scales and oximeters weekly, and spirometers monthly. Over both surveys, some programs had no method to collect respiratory specimens for cultures associated with telehealth visits (47%, n=132; 41%, n=118). Most programs (81%) had a process for phlebotomy associated with a telehealth visit, primarily through off-site labs. Both PwCF and programs felt future care should advance remote monitoring and recommended improvements for access, training, and data collection systems. CONCLUSIONS: PwCF and programs experienced unprecedented access to remote monitoring and raised its importance for future care. Improvements to current systems may leverage these shared experiences to augment future care models.

An initial evaluation of the safety of a disposable oscillating positive expiratory pressure device in patients with chronic obstructive pulmonary disease: a sort-term pilot study.

BACKGROUND: Handheld oscillating positive expiratory pressure (OPEP) devices have been a mainstay of treatment for patients with hypersecretory conditions such as cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) since the 1970s. Current devices are reusable and require regular cleaning and disinfection to prevent harbouring potentially pathogenic organisms. Adherence to cleaning regimens for respiratory devices is often poor and in response to this, a prototype disposable OPEP device-the 'UL-OPEP' (University of Limerick-Oscillating Positive Expiratory Pressure device)-was developed to mitigate the risk of contamination by pathogens. The device was previously evaluated successfully in a group of paediatric CF patients. The aim of the current study was to initially evaluate the safety of the prototype in patients with COPD over a period of 1 month to ensure no adverse events, negative impacts on lung function, exercise tolerance, or quality of life. Data on user experience of the device were also collected during post-study follow-up. METHODS: A sample of 50 volunteer participants were recruited from pulmonary rehabilitation clinics within the local hospital network. The patients were clinically stable, productive, and not current or previous users of OPEP devices. Participants were invited to use a prototype disposable OPEP device daily for a period of 1 month. Pre- and post-study lung function was assessed with standard spirometry, and exercise tolerance with the 6-min-walk-test (6MWT). Quality of life was assessed using the St. George's Respiratory Questionnaire (SGRQ), and user experience of the prototype device evaluated using a post-study questionnaire. RESULTS: 24 Participants completed the study: 9 were female. Overall median age was 67.5 years, range 53-85 years. Lung function, 6-min walk test, and SGRQ scores showed no significant change post-study. User feedback was positive overall. CONCLUSIONS: The results indicate that the UL-OPEP is safe to use in patients with COPD. No adverse events were recorded during the study or in the follow-up period of 2 weeks. The device did not negatively impact patients' lung function, exercise tolerance, or quality of life during short term use (1 month), and usability feedback received was generally positive. Larger, longer duration studies will be required to evaluate efficacy. Registration The study was approved as a Clinical Investigation by the Irish Health Products Regulatory Authority (CRN-2209025-CI0085).

Precision and accuracy of FEV1 measurements from the Vitalograph copd-6 mini-spirometer in a healthy Ugandan population.

OBJECTIVE: Evaluate the accuracy and precision of the copd-6 mini-spirometer for FEV1 in a rural Ugandan population. METHODS: In a cross-sectional study, 171 smallholder farmers performed spirometry with copd-6, and a diagnostic-quality spirometer. RESULTS AND DISCUSSION: The copd-6 underestimated FEV1 at low flows and overestimated FEV1 at high flows. Across all participants, the device slightly overestimated FEV1 by 0.04 [0.02; 0.06] L. Calibration data showed similar patterns. CONCLUSION: The copd-6 could be considered as an affordable tool for research on lung function impairment in resource-constrained settings. However, further validation in a study population with obstructive lung disease is needed.

Computational tools for inversion and uncertainty estimation in respirometry.

In many physiological systems, real-time endogeneous and exogenous signals in living organisms provide critical information and interpretations of physiological functions; however, these signals or variables of interest are not directly accessible and must be estimated from noisy, measured signals. In this paper, we study an inverse problem of recovering gas exchange signals of animals placed in a flow-through respirometry chamber from measured gas concentrations. For large-scale experiments (e.g., long scans with high sampling rate) that have many uncertainties (e.g., noise in the observations or an unknown impulse response function), this is a computationally challenging inverse problem. We first describe various computational tools that can be used for respirometry reconstruction and uncertainty quantification when the impulse response function is known. Then, we address the more challenging problem where the impulse response function is not known or only partially known. We describe nonlinear optimization methods for reconstruction, where both the unknown model parameters and the unknown signal are reconstructed simultaneously. Numerical experiments show the benefits and potential impacts of these methods in respirometry.

Current limits for flowmeter resistance in metabolic carts can negatively affect exercise performance.

PURPOSE: To investigate whether a metabolic cart using a flowmeter in the upper range of accepted resistance to airflow (<1.5 cmH2 O∙L-1 ∙s-1 for flows up to 14 L∙s-1 , American Thoracic Society) negatively impacts exercise performance in healthy individuals. METHODS: 16 recreationally active males (age 25 ± 1 years, height 180 ± 6 cm, weight 73.5 ± 5.8 kg, all mean ± SD) performed two incremental tests on a bicycle ergometer on each of two visits, using a metabolic cart with a flowmeter of either low (Oxycon Pro) or high (Innocor) airflow resistance. Mouth pressures, gas exchange, blood lactate concentration [La- ], perception of breathlessness, respiratory, and leg exertion were assessed throughout the tests. RESULTS: Tests performed with the Innocor were significantly shorter (15.3 ± 3.2 vs. 15.8 ± 3.3 min, p < 0.0001) and showed higher maximal flow resistance (1.3 ± 0.2 vs. 0.3 ± 0.0 cmH2 O∙L-1 ∙s-1 , p < 0.0001). At end-exercise, peak oxygen consumption (-200 ± 220 ml.min-1 , p < 0.0001), minute ventilation (-19.9 ± 10.5 L.min-1 , p < 0.0001), breathing frequency (-5.4 ± 5.2 breaths.min-1 , p < 0.0001), heart rate (-2.1 ± 3.6 bpm, p = 0.002) and [La- ] (-0.7 ± 1.0 mmol.L-1 , p < 0.0001), but not tidal volume (-0.1 ± 0.2 L, p = 0.172) were lower with the Innocor, while the perception of breathlessness was higher (+3.8 ± 5.1 points, p < 0.0001). CONCLUSIONS: Airflow resistance in the upper range of current guidelines can significantly affect exercise performance and respiratory pattern in young, healthy males during incremental exercise. The present results indicate the need to revisit guidelines for devices used in ergospirometry.

Effects of three pulmonary ventilation regimes in patients undergoing coronary artery bypass graft surgery: a randomized clinical trial.

The aim was to compare the effect of diaphragmatic breathing exercise (DBE), flow- (FIS) and volume-oriented incentive spirometry (VIS) on pulmonary function- (PFT), functional capacity-6-Minute Walk Test (6 MWT) and Functional Difficulties Questionnaire (FDQ) in subjects undergoing Coronary Artery Bypass Graft surgery (CABG). The purpose of incorporating pulmonary ventilator regimes is to improve ventilation and avoid post-operative pulmonary complications. CABG patients (n = 72) were allocated to FIS, VIS and DBE groups (n = 24 each) by block randomization. Preoperative and postoperative values for PFT were taken until day 7 for all three groups. On 7th postoperative day, 6 MWT and FDQ was analyzed using ANOVA and post-hoc analysis. PFT values were found to be decreased on postoperative day 1(Forced Vital Capacity (FVC) = FIS group-65%, VIS group-47%, DBE group-68%) compared to preoperative day (p < 0.001). PFT values for all 3 groups recovered until postoperative day 7 (FVC = FIS group-67%, VIS group-95%, DBE group-59%) but was found to reach the baseline in VIS group (p < 0.001). When compared between 3 groups, statistically significant improvement was observed in VIS group (p < 0.001) in 6 MWT and FDQ assessment. In conclusion, VIS was proven to be more beneficial in improving the pulmonary function (FVC), functional capacity and FDQ when compared to FIS and DBE.

Home self-monitoring in patients with asthma using a mobile spirometry system.

BACKGROUND: Self-management is an appealing strategy for prevention of asthma exacerbations. This study aimed to evaluate the feasibility and safety of a portable spirometer for unsupervised home spirometry measurements among patients with asthma. METHODS: A multi-center, prospective, single-arm, open study recruited 86 patients with controlled or partly controlled asthma (41 women, 38.6 ± 10.4 y/o and 45 men, 36.2 ± 12.1 y/o). After a training session, patients performed daily spirometry at home with the AioCare® mobile spirometry system. Each spirometry examination was recorded and evaluated according to the ATS/ERS acceptability and repeatability criteria. The primary endpoint was defined as three or more acceptable examinations in any given seven-day period (+/- 1 day) during any of the three weeks of the study. The system allowed for online review of measurements by physicians/nurses to provide feedback to patients. RESULTS: Of 78 patients with complete data, 67 (86%) achieved the primary endpoint. Seventy-five (96%) participants used the device correctly once or more, and 10 (13%) patients succeeded every single day over the three-week follow-up. The rate of acceptable spirometry examinations differed between the sites (p = 0.013). Retraining was required in 20 of 62 (32%) eligible patients, and successful in 8 individuals (40%). Satisfaction with the AioCare® system was high, 90% of respondents perceived it as useful and user-friendly. CONCLUSIONS: Self-monitoring of asthma with a connected mobile spirometer is feasible, safe and satisfactory for patients with asthma. It remains to be established whether unsupervised home spirometry measurements may improve early diagnosis and outcomes of self-management in cases of exacerbation or loss of asthma control.

Highlights BoxThis study aimed to evaluate the ability of patients with asthma to perform high-quality daily spirometry examinations at home with using the AioCare^® mobile spirometry system. The study showed that unsupervised home spirometry is safe and feasible in patients with asthma. Most patients used the device on most days of the study, and nearly 90% of all patients achieved the primary endpoint. There were no device-related adverse events.

Validation of an app-based portable spirometer in adolescents with asthma.

OBJECTIVES: Objective measurements of asthma impairment could aid teens in recognition of changes in asthma status over time. Ready access to a conventional spirometer is not realistic outside of the clinical setting. In this proof-of-concept study, we compared the performance of the VitalFlo mobile spirometer to the nSpire KoKo® sx1000 spirometer for accuracy in measuring Forced Expiratory Volume in one second (FEV1) and Forced Vital Capacity (FVC) in adolescents with asthma. METHODS: Two hundred forty pulmonary function measurements were collected from 48 adolescents with persistent asthma from the University of North Carolina's pediatric allergy and pulmonology subspecialty clinics. Participants performed spirometry with the nSpireKoKo® sx1000 spirometer and the VitalFlo spirometer during their clinic visits. 119 simulated FVC maneuvers were conducted on both devices to standardize measurements. Pearson correlations, Bland-Altman procedure, and two-sample comparison tests were performed to assess the relationship between the two spirometers. RESULTS: VitalFlo measurements were significantly highly correlated with nSpireKoKo® spirometer values for FEV1, (r2=0.721, [95% CI, 0.749 ± 0.120], P < 0.001) and moderately for FVC (r2= 0.617, [95% CI, 0.640 ± 0.130], P < 0.001) measurements. There were no statistically significant differences of the mean FEV1 (M = 0.00764, SD = 0.364, t(59)=0.16, P = 0.87) and FVC measurements (M = 0.00261, SD = 0.565, t(59)=0.036, P = 0.97.) between the VitalFlo and nSpireKoKo® systems. Both devices demonstrated significantly high correlation when comparing the automated FVC (r2 = 0.997, [95% CI, 1.00 ± 0.00974], P < 0.001) measurements. Bland-Altman plots did not demonstrate significant bias between devices for both FEV1 (0.00764 L) and FVC (0.00261 L) measurements. CONCLUSIONS: Lung function measurements from the VitalFlo mobile spirometer were comparable to a commercially-available spirometer commonly used in clinical settings. This validated app-based spirometer for home use has the potential to improve asthma self-management.

Remote FEV1 Monitoring in Asthma Patients: A Pilot Study.

Forced expiratory volume in one second (FEV1 ) is a critical parameter for the assessment of lung function for both clinical care and research in patients with asthma. While asthma is defined by variable airflow obstruction, FEV1 is typically assessed during clinic visits. Mobile spirometry (mSpirometry) allows more frequent measurements of FEV1 , resulting in a more continuous assessment of lung function over time and its variability. Twelve patients with moderate asthma were recruited in a single-center study and were instructed to perform pulmonary function tests at home twice daily for 28 days and weekly in the clinic. Daily and mean subject compliances were summarized. The agreement between clinic and mobile FEV1 was assessed using correlation and Bland-Altman analyses. The test-retest reliability for clinic and mSpirometry was assessed by interclass correlation coefficient (ICC). Simulation was conducted to explore if mSpirometry could improve statistical power over clinic counterparts. The mean subject compliance with mSpirometry was 70% for twice-daily and 85% for at least once-daily. The mSpirometry FEV1 were highly correlated and agreed with clinic ones from the same morning (r = 0.993) and the same afternoon (r = 0.988) with smaller mean difference for the afternoon (0.0019 L) than morning (0.0126 L) measurements. The test-retest reliability of mobile (ICC = 0.932) and clinic (ICC = 0.942) spirometry were comparable. Our simulation analysis indicated greater power using dense mSpirometry than sparse clinic measurements. Overall, we have demonstrated good compliance for repeated at-home mSpirometry, high agreement and comparable test-retest reliability with clinic counterparts, greater statistical power, suggesting a potential for use in asthma clinical research.

Impacts of Respiratory Muscle Training on Respiratory Functions, Maximal Exercise Capacity, Functional Performance, and Quality of Life in School-Aged Children with Postoperative Congenital Diaphragmatic Hernia.

OBJECTIVES: Congenital diaphragmatic hernia (CDH) is a birth defect affecting the respiratory functions, functional performance, and quality of life (QOL) in school-aged children. Rarely have studies been conducted to evaluate the impacts of respiratory muscle training on school-aged children with postoperative CDH. The current study was designed to evaluate the impacts of respiratory muscle training on respiratory function, maximal exercise capacity, functional performance, and QOL in these children. METHODS: This study is a randomized control study. 40 children with CDH (age: 9-11 years) were assigned randomly into two groups. The first group conducted an incentive spirometer exercise combined with inspiratory muscle training (study group, n = 20), whereas the second group conducted only incentive spirometer exercise (control group, n = 20), thrice weekly for twelve consecutive weeks. Respiratory functions, maximal exercise capacity, functional performance, and pediatric quality of life inventory (PedsQL) were assessed before and after the treatment program. Results. Regarding the posttreatment analysis, the study group showed significant improvements in all outcome measures (FVC%, p < 0.001; FEV1%, p = 0.002; VO2max, p = 0.008; VE/VCO2 slope, p = 0.002; 6-MWT, p < 0.001; and PedsQL, p < 0.001), whereas the control group did not show significant changes (p > 0.05). CONCLUSION: Respiratory muscle training may improve respiratory functions, maximal exercise capacities, functional performance, and QOL in children with postoperative CDH. Clinical commendations have to be considered to include respiratory muscle training in pulmonary rehabilitation programs in children with a history of CDH.

Preoperative training education with incentive spirometry may reduce postoperative pulmonary complications.

OBJECTIVE: To assess whether preoperative incentive spirometer training would influence the development of postoperative pulmonary complications after lung resection. METHODS: Sixty-two lung resection patients were prospectively investigated; 17 were given an incentive spirometer preoperatively and 45 did not have an incentive spirometer preoperatively. Postoperatively, both arms exercised with an incentive spirometer. The number of repetitions per day, balls raised per repetition, correct technique of exercising, and postoperative pulmonary complications were compared between the 2 groups. Univariate binary logistic regression analysis of potential predictors of postoperative pulmonary complications led to multivariate analysis of independent predictors. Receiver operating characteristic analysis established the cutoff points of predictors. RESULTS: The group with no preoperative incentive spirometer developed more postoperative pulmonary complications than the preoperative incentive spirometer group (24.4% vs. 5.9%, respectively, p = 0.045). The preoperative incentive spirometer arm achieved more repetitions per day, balls per repetition, and correct incentive spirometer technique (p = 0.002, p < 0.001, p = 0.034, respectively). Balls raised per repetition and repetitions per day postoperatively were identified as independent predictors of postoperative pulmonary complications (p = 0.032 and p = 0.021, respectively). Less than 5 repetitions per day (sensitivity 93%, specificity 77%, p < 0.001) and less than 2 balls per repetition (sensitivity 93%, specificity 77%, p < 0.001) were predictive of postoperative pulmonary complications. CONCLUSION: Preoperative incentive spirometer exposure ensured better compliance with postoperative treatment and a more accurate technique (balls raised per repetition, repetitions per day). These variables correlated with a lower postoperative pulmonary complication rate.

Impact of breath-hold level on positional error aligned by stent/Lipiodol in Hepatobiliary radiotherapy with breath-hold respiratory control.

BACKGROUND: Respiratory motion management with breath hold for patients with hepatobiliary cancers remain a challenge in the precise positioning for radiotherapy. We compared different image-guided alignment markers for estimating positional errors, and investigated the factors associated with positional errors under breath-hold control. METHODS: Spirometric motion management system (SDX) for breath holds was used in 44 patients with hepatobiliary tumor. Among them, 28 patients had a stent or embolized materials (lipiodol) as alignment markers. Cone-beam computed tomography (CBCT) and kV-orthogonal images were compared for accuracy between different alignment references. Breath-hold level (BHL) was practiced, and BHL variation (ΔBHL) was defined as the standard deviation in differences between actual BHLs and baseline BHL. Mean BHL, ΔBHL, and body-related factors were analyzed for the association with positional errors. RESULTS: Using the reference CBCT, the correlations of positional errors were significantly higher in those with stent/lipiodol than when the vertebral bone was used for alignment in three dimensions. Patients with mean BHL > 1.4 L were significantly taller (167.6 cm vs. 161.6 cm, p = 0.03) and heavier (67.1 kg vs. 57.4 kg, p = 0.02), and had different positional error in the craniocaudal direction (- 0.26 cm [caudally] vs. + 0.09 cm [cranially], p = 0.01) than those with mean BHL < 1.4 L. Positional errors were similar for patients with ΔBHL< 0.03 L and > 0.03 L. CONCLUSION: Under rigorous breath-hold respiratory control, BHL correlated with body weight and height. With more accurate alignment reference by stent/lipiodol, actual BHL but not breath-hold variation was associated with craniocaudal positional errors.