Comparison of a handheld turbine spirometer to conventional spirometry in children with cystic fibrosis

Home Spirometry for Post-COVID Recovery: A Clinical Validation Study of an Ultrasonic Device

Background/Objectives: Patients recovering from COVID-19 often experience persistent respiratory symptoms, necessitating pulmonary function monitoring. While clinical spirometry is the gold standard, home spirometry offers a remote alternative. This study evaluated the validity of an ultrasonic home-based spirometer for monitoring lung function in post-COVID-19 pneumonia patients over 12 weeks. Methods: This prospective study included 30 post-COVID pneumonia patients who underwent clinical spirometry at weeks 4, 8 and 12. Participants performed weekly home spirometry using the SpiroHome Personal® device. Agreement between home and clinical spirometry was assessed using a Bland-Altman analysis, intraclass correlation coefficients (ICCs), and Pearson correlation coefficients. Pulmonary function changes over time were analyzed using repeated measures ANOVA. Results: Home spirometry showed strong agreement with clinical spirometry for forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1), with ICC values exceeding 0.92. The Bland-Altman analysis demonstrated minimal bias, though limits of agreement exceeded the clinically accepted threshold of ±150 mL. FEV1/FVC ratios showed greater variability. Pulmonary function improved significantly over 12 weeks for both methods (p < 0.002). Patient adherence to home spirometry remained high, with a median of 18.50 sessions [IQR: 15.00-26.00] and an overall compliance rate of 98.33% ± 9.13%. Conclusions: Home spirometry provides reliable pulmonary function measurements, particularly for FVC and FEV1, supporting its role as a remote monitoring tool. Despite minor variability in FEV1/FVC, home spirometry enables frequent assessment of lung function recovery, potentially reducing hospital visits and improving patient management.

Inferring forced expiratory volume in 1 second (FEV1) from mobile ECG signals collected during quiet breathing

Objective.Forced expiratory volume in one second (FEV1) is an important metric for patients to track at home for their self-management of asthma and chronic obstructive pulmonary disease (COPD). Unfortunately, the state-of-the-art for measuring FEV1 at home either depends on the patient's physical effort and motivation, or relies on bulky wearable devices that are impractical for long-term monitoring. This paper explores the feasibility of using a machine learning model to infer FEV1 from 270 seconds of a single-lead electrocardiogram (ECG) signal measured on the fingers with a mobile device.Methods.We evaluated the model's inferred FEV1 values against the ground truth of hospital-grade spirometry tests, which were performed by twenty-five patients with obstructive respiratory disease.Results.The model-inferred FEV1 compared to the spirometry-measured FEV1 with a correlation coefficient ofr = 0.73, a mean absolute percentage error of 23% and a bias of -0.08.Conclusions.These results suggest that the ECG signal contains useful information about FEV1, although a larger, richer dataset might be necessary to train a machine learning model that can extract this information with better accuracy.Significance.The benefit of a mobile ECG-based solution for measuring FEV1 is that it would require minimal effort, thus encouraging patient adherence and promoting successful self-management of asthma and COPD.

Acceptability of Telehealth Post-Pandemic Among Clinicians Across the United States Caring for People With Cystic Fibrosis

BACKGROUND

The COVID-19 pandemic ushered widespread adoption of telehealth (TH) by cystic fibrosis (CF) centers in the USA. TH was initially described as well-accepted by both clinicians and patients. As we move past the unusual circumstances of the pandemic, the sustainability of TH remains untested. This study sought to test the durability of clinician perceptions of TH post-pandemic.

METHODS

This is a cross-sectional, survey study of clinicians at seven US CF centers. We refined a previously disseminated survey initially designed to assess clinician perceptions of TH in 2020. Survey results were analyzed using descriptive statistics and current responses were compared to prior results.

RESULTS

Clinician perceptions surrounding TH remain high but have changed over time with 75% now endorsing satisfaction (90% in 2020, p = 0.02). The most cited barriers were technology limitations (68%) and limited in-person assessments (66%). We found a significant decrease in concern over missing in-person assessments compared to 2020. Benefits of TH included convenience for patients and families (100%) and reduction in missed days of school or work (100%). In total, 83% of current respondents felt TH should remain part of routine CF care. A majority indicated certain patient characteristics increased their preference to conduct at least one TH visit per year.

CONCLUSIONS

Despite restoration of full access to in-person care, clinicians caring for pwCF continue to use TH across the surveyed CF centers post-pandemic. Respondents continue to view TH favorably. Further study is needed to understand for which patient and clinical scenarios TH is most appropriate.

Telemedicine and home spirometry in cystic fibrosis: A prospective multicenter study

OBJECTIVES

Telehealth and home spirometry feasibility for children has been established, but their impact on cystic fibrosis (CF) disease progression remains unassessed. We aimed to evaluate the effects of telehealth and home spirometry on CF disease progression and care.

METHODS

Children with CF aged 5-17 years from all Swedish CF centers were provided with home spirometers. A minimum of two in-person visits were replaced with telemedicine visits and participants were instructed to conduct home spirometry before visits. Linear mixed-effects models were used to compare annual CF disease trajectories during the intervention period and prepandemic period (1 January 2019 to 28 February 2020). Participants and caregivers completed study questionnaires.

RESULTS

A total of 59 individuals completed the study over a mean (SD) period of 6.8 (1.4) months, made 3.1 (1.0) physical visits and 2.2 (0.6) telehealth visits per patient year during the study period. The mean difference (95% CI) between the intervention and prepandemic period progression rate for FEV1%, lung clearance index and BMI were -0.4 (-1.3 to 0.5, p = 0.39), 0.11 (-0.07 to 0.28, p = 0.25) and -0.02 (-0.13 to 0.08, p = 0.70), respectively. There were no major shifts in the incidence of airway pathogens, sputum cultures, or antibiotics use between the periods (p > 0.05). The intervention did not increase stress. Almost all participants and caregivers expressed a desire to continue with home spirometry and telemedicine.

CONCLUSION

Combining telehealth and physical visits with access to home spirometry demonstrated comparable effectiveness as exclusively in-person care with enhanced flexibility and personalization of CF care.

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).

Unsupervised home spirometry is not equivalent to supervised clinic spirometry in children and young people with cystic fibrosis: Results from the CLIMB-CF study

BACKGROUND

Handheld spirometry allows monitoring of lung function at home, of particular importance during the COVID-19 pandemic. Pediatric studies are unclear on whether values are interchangeable with traditional, clinic-based spirometry. We aimed to assess differences between contemporaneous, home (unsupervised) and clinic (supervised) spirometry and the variability of the former. The accuracy of the commercially available spirometer used in the study was also tested.

METHODS

Data from participants in the Clinical Monitoring and Biomarkers to stratify severity and predict outcomes in children with cystic fibrosisc (CLIMB-CF) Study aged ≥ 6 years who had paired (±1 day) clinic and home forced expiratory volume in 1 s (FEV1 ) readings were analyzed. Variability during clinical stability over 6-months was assessed. Four devices from Vitalograph were tested using 1 and 3 L calibration syringes.

RESULTS

Sixty-seven participants (median [interquartile range] age 10.7 [7.6-13.9] years) provided home and clinic FEV1 data pairs. The mean (SD) FEV1 % bias was 6.5% [±8.2%]) with wide limits of agreement (-9.6% to +22.7%); 76.2% of participants recorded lower results at home. Coefficient of variation of home FEV1 % during stable periods was 9.9%. Data from the testing of the handheld device used in CLIMB-CF showed a potential underread.

CONCLUSION

In children and adolescents, home spirometry using hand-held equipment cannot be used interchangeably with clinic spirometry. Home spirometry is moderately variable during clinical stability. New handheld devices underread, particularly at lower volumes of potential clinical significance for smaller patients; this suggests that supervision does not account fully for the discrepancy. Opportunities should be taken to obtain dual device measurements in clinic, so that trend data from home can be utilized more accurately.

Comparison of Pneumotachometer and Portable Digital Turbine Spirometry for Field-Based Assessment: An Air Quality, Environment, and Respiratory Outcomes in Bronchopulmonary Dysplasia Study

Introduction: Data on the use of remote spirometry are limited in the pediatric population. We sought to assess the feasibility and accuracy of a digital turbine spirometer, Medical International Research (MIR) Spirobank Smart (MIR, New Berlin, WI, USA), compared with a pneumotachography spirometer, Pneumotrac (Vitalograph Inc., Lenexa, KS, USA), in field-based clinical research. Methods: This is a cross-sectional study of a subgroup of school-aged participants enrolled in the Air quality, Environment, and Respiratory Outcomes in Bronchopulmonary Dysplasia (BPD) study, who performed same-day paired coached baseline spirometry measurements from the Pneumotrac and MIR devices. Proportion of successful tests was estimated for each device and compared using McNemar's test. Correlation between devices forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) was analyzed by Lin's concordance correlation, and Bland-Altman plots were generated. Results: Twenty-one participants with history of BPD completed home spirometry maneuvers on both devices. The mean age of participants was 8.7 years. The mean FEV1 and FVC measurement was 81% predicted and 90.4% predicted, respectively. The proportion of acceptable tests appeared higher using Pneumotrac (81%) than when using MIR (67%), although without evidence of discordance (P = 0.317). Among subjects with successful tests on both devices, Lin's concordance correlation demonstrated moderate agreement (FEV1 r = 0.955, 95% confidence interval [CI]: 0.87-0.98; FVC r = 0.971, CI: 0.91-0.99). The mean difference in FEV1 between Pneumotrac and MIR was 0.079 L (95% limits of agreement were -0.141 to 0.298 L) and FVC was 0.075 L (95% limits of agreement were -0.171 to 0.322 L). These were relatively small and without evidence of systematic or volume-dependent bias. Conclusions: Utilizing turbine spirometers may be a promising and feasible way to perform pulmonary function testing for field research in children.

Home Spirometry in Children with Cystic Fibrosis

We report the implementation of a pediatric home spirometry program at our institution. A respiratory therapist provided either a virtual or an in-person initiation visit that included a coached spirometry session. Families were instructed to perform daily uncoached spirometry sessions for 5 days. The program's quality assurance component was deemed not to be human research by the local IRB. In total, 52 subjects completed an initiation visit (34 with at least 3 additional uncoached spirometry sessions). The clinic spirometry and coached (same-day) sessions and uncoached (same-week) sessions were completed by 12 and 17 subjects, respectively. The median (99% CI) coefficients of variation for FEV₁% of the uncoached maneuvers were 3.5% (2.9-5.9%). The median (IQR) FEV₁% and FEV₁ (mL) absolute differences between coached and uncoached home spirometry were -2% (-4 and +3%) and -25 mL (-93 and +93 mL), respectively. The median (IQR) absolute differences in FEV₁% and FEV₁ (mL) between coached or uncoached home spirometry and clinic spirometry were -6% (-10 and -2%) and -155 mL (-275 and -88 mL), and -4% (-10 and +5%), and -110 mL (-280 and +9 mL), respectively. Differences in absolute FEV₁ (L) and FEV₁% were found among different modalities of spirometry performed by people with cystic fibrosis. Understanding the variability of uncoached home spirometry and the differences among coached and uncoached home spirometry, hospital and coached home spirometry, and hospital and uncoached home spirometry for any given individual is crucial to effectively utilize this tool in clinical care.

Real-world feasibility of short-term, unsupervised home spirometry in CF

OBJECTIVES

The objective of this study was to study the performance of two available home spirometers used by people with Cystic Fibrosis (PwCF) over a short-term period and to assess user experience.

STUDY DESIGN

This was a prospective observational study. Participants age 6 years and older were recruited to participate if they could complete acceptable spirometry in the clinic setting.

METHODS

Participants used either the NuvoAir Air Next or the ZEPHYRx MIR Spirobank Smart spirometer. They underwent a one-time virtual training session, then completed 2 weeks of daily spirometry followed by 2 months of weekly spirometry. Participants responded to surveys and completed a debrief interview to understand user experience. Statistical analyses examined feasibility, reliability, and accuracy of each spirometer in an unsupervised, real-world setting.

RESULTS

We report high adherence (80% [95% CI 61%-92%]) to our study protocol in all session attempts, but lower rates of adherence after discarding sessions performed with inadequate technique (47% [95% CI 28%-66%] to 63% [95% CI 44%-80%]). We found high reliability of each device by analyzing day-to-day variability and good concordance to recent in-clinic testing (NuvoAir r = 0.91 [0.82-0.93]; ZEPHYRx r = 0.70 [0.45-0.84]). Patient experience in this cohort was favorable with most reporting ease of use and reassurance knowing lung function was being tracked over time.

CONCLUSIONS

This real-world study showed good performance of two different available home spirometers used by children and adults with CF. While overall adherence was high, suboptimal technique reduced the total interpretable data, possibly limiting feasibility. Future work should focus on developing sustainable training and coaching programs to support the success of home spirometry in a CF chronic care model.

Telehealth application of an ultrasonic home spirometer

OBJECTIVE

To investigate the validity and home use of a personal ultrasonic spirometer.

METHODS

Supervised spirometry was performed using laboratory equipment and a personal ultrasonic spirometer. In addition, the ability of children to perform acceptable spirometry during supervised telehealth appointments at home was assessed.

RESULTS

59 children completed spirometry on both devices. There was high between-device intraclass correlation coefficient (ICC) for forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC): ICC 0.991 (95% CI 0.985 to 0.995) and 0.989 (95% CI 0.981 to 0.993), respectively. Bland-Altman analysis revealed mean bias and limits of agreement of -0.01 (-0.22 to 0.24) L for FEV₁ and -0.02 (-0.30 to 0.33) L for FVC. 125 of 140 (89%) supervised telehealth spirometry sessions were acceptable.

CONCLUSION

There was excellent reliability in between-device measurements; however, the limits of agreement were wide. Therefore, caution is needed if the device is used interchangeably with laboratory equipment. High success rates of telehealth spirometry sessions indicate the device is suitable for this application.

Telemedicine and cystic fibrosis: Do we still need face-to-face clinics?

There has been growing interest in telemedicine for cystic fibrosis over recent years based largely on convenience for patients and/or increasing the frequency of surveillance and early detection which, it is assumed, could improve treatment outcomes. During 2020, the covid-19 pandemic catalysed the pace of development of this field, as CF patients were presumed to be at high risk of infection. Most clinics adapted to digital platforms with provision of lung function monitoring and sample collection systems. Here, we present the views of multidisciplinary team members at a large paediatric CF centre on what has worked well and what requires further optimisation in the future. In response to the question posed, 'Do we still need face to face clinics?' our answer is 'Yes, but not every time, and not for everyone'.

Initiating home spirometry for children during the COVID-19 pandemic - A practical guide

The COVID-19 pandemic has led to a rapid escalation in use of home monitoring and video consultations in children with a variety of chronic respiratory conditions. Our department set up a home spirometry service from scratch once it became evident that we needed to keep patients away from hospital clinics whenever possible. We faced a number of challenges but now have around 400 children using home spirometers. There are a number of portable spirometers available, some with online platforms. The technology, particularly the software/apps interface, has been improved by the companies in response to issues that have arisen. We believe the use of home monitoring is here to stay.

Clinical Validation of the Spirohome Clinic Ultrasonic Spirometer in Child and Adolescent Patients

Background

Spirometers are critical devices that reveal the respiratory dynamics caused by respiratory problems and their severity and facilitate their diagnosis and follow-up. Hand-held spirometers have emerged relatively recently and offer several advantages over conventional desktop systems. There remains, however, a need for reassurance of high-quality spirometry testing with next-generation portable spirometers that connect over Bluetooth^® to smart device applications. In this study, we examine the accuracy and repeatability of lung function measurements of a novel hand-held ultrasonic spirometer, the Spirohome Clinic and compare its clinical performance to a reference device, the EasyOne Air.

Methods

Benchtop validation of the spirometers was conducted using a lung simulator device according to ATS/ERS guidelines and the ISO 26782 standard waveforms. Subsequently, 48 volunteers (pediatric patients between 6 and 11 years of age and adolescent patients between 12 and 18 years of age) performed spirometry with both the Spirohome Clinic and the EasyOne Air spirometer during their clinic visits. Spirometric data including repeated FEV₁, FVC, FEV₆, FEF_25-75, and PEF measurements were collected.

Results

Both the Spirohome Clinic and the EasyOne Air successfully passed requirements for accuracy stated in relevant guidelines and standards for spirometry. The only statistically significant (p<0.05) difference was for FVC measurement accuracy. Clinical comparisons revealed strong correlation between spirometers in the measurement of key pulmonary function parameters including FEV₁ and FVC with a Pearson's correlation coefficient of 0.99. Bland–Altman plots showed good agreement between mean differences of FEV₁ and FVC with the majority measurements remaining between the limits of 95% agreement for both the entire patient cohort and also in age and gender subsets.

Conclusion

The present study demonstrated that the Spirohome Clinic spirometer conforms to ATS/ERS performance requirements and validates the clinical comparability of its measurement accuracy and repeatability to the EasyOne Air. These findings support the indicated use of the Spirohome Clinic for high-quality lung function testing in clinical settings.

Cystic fibrosis year in review 2020: Section 2 pulmonary disease, infections, and inflammation

The outlook for those with cystic fibrosis (CF) has never been brighter with ever increasing life expectancy and the approval of the highly effective CFTR modulators, such as elexacaftor/tezacaftor/ivacaftor. With that being said, the progressive pulmonary decline and importance of lung health, infection, and inflammation in CF remains. This review is the second part in a three-part CF Year in Review 2020. Part one focused on the literature related to CFTR modulators while part three will feature the multisystem effects related to CF. This review focuses on articles from Pediatric Pulmonology, including articles from other journals that are of particular interest to clinicians. Herein, we highlight studies published during 2020 related to CF pulmonary disease, infection, treatment, and diagnostics.

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.

Clinical validation of digital biomarkers for pediatric patients with asthma and cystic fibrosis - Potential for clinical trials and clinical care

BACKGROUND

Digital biomarkers are a promising novel method to capture clinical data in a home-setting. However, clinical validation prior to implementation is of vital importance. The aim of this study was to clinically validate physical activity, heart rate, sleep and FEV1 as digital biomarkers measured by a smartwatch and portable spirometer in children with asthma and cystic fibrosis (CF).

METHODS

This was a prospective cohort study including 60 children with asthma and 30 children with CF (age 6-16). Participants wore a smartwatch, performed daily spirometry at home and completed a daily symptom questionnaire for 28-days. Physical activity, heart rate, sleep and FEV1 were considered candidate digital endpoints. Data from 128 healthy children was used for comparison. Reported outcomes were compliance, difference between patients and controls, correlation with disease-activity and potential to detect clinical events. Analysis was performed with linear mixed effect models.

RESULTS

Median compliance was 88%. On average, patients exhibited lower physical activity and FEV1 compared to healthy children, whereas the heart rate of children with asthma was higher compared to healthy children. Days with a higher symptom score were associated with lower physical activity for children with uncontrolled asthma and CF. Furthermore, FEV1 was lower and (nocturnal) heart rate was higher for both patient groups on days with more symptoms. Candidate biomarkers and showed a distinct pattern before- and after a pulmonary exacerbation.

CONCLUSION

Portable spirometer- and smartwatch-derived digital biomarkers show promise as candidate endpoints for use in clinical trials or clinical care in pediatric lung disease.

Technical validity and usability of a novel smartphone-connected spirometry device for pediatric patients with asthma and cystic fibrosis

BACKGROUND

Diagnosis and follow-up of respiratory diseases traditionally rely on pulmonary function tests (PFTs), which are currently performed in hospitals and require trained personnel. Smartphone-connected spirometers, like the Air Next spirometer, have been developed to aid in the home monitoring of patients with pulmonary disease. The aim of this study was to investigate the technical validity and usability of the Air Next spirometer in pediatric patients.

METHODS

Device variability was tested with a calibrated syringe. About 90 subjects, aged 6 to 16, were included in a prospective cohort study. Fifty-eight subjects performed conventional spirometry and subsequent Air Next spirometry. The bias and the limits of agreement between the measurements were calculated. Furthermore, subjects used the device for 28 days at home and completed a subject-satisfaction questionnaire at the end of the study period.

RESULTS

Interdevice variability was 2.8% and intradevice variability was 0.9%. The average difference between the Air Next and conventional spirometry was 40 mL for forced expiratory volume in 1 second (FEV1) and 3 mL for forced vital capacity (FVC). The limits of agreement were -270 mL and +352 mL for FEV1 and -403 mL and +397 mL for FVC. About 45% of FEV1 measurements and 41% of FVC measurements at home were acceptable and reproducible according to American Thoracic Society/European Respiratory Society criteria. Parents scored difficulty, usefulness, and reliability of the device 1.9, 3.5, and 3.8 out of 5, respectively.

CONCLUSION

The Air Next device shows validity for the measurement of FEV1 and FVC in a pediatric patient population.