Low-Cost Open-Source Device to Measure Maximal Inspiratory and Expiratory Pressures

Abstract

The measurement of maximal inspiratory (MIP) and maximal expiratory (MEP) pressures is a widely used technique to non-invasively evaluate respiratory muscle strength in clinical practice. The commercial devices that perform this test range from whole body plethysmographs to portable spirometers, both expensive and include a wide range of other respiratory tests. Given that a portable, low-cost, and specific option for MIP and MEP measuring device is not currently available in the market. A high-performance and easy-to-build prototype has been developed and the detailed technical information to easily reproduce it is freely released. A novel device is based on an Arduino microcontroller with a digital display, an integrated pressure transducer, and three-dimensional (3D) printed enclosure (total retail cost €80). The validation of the device was performed by comparison with a laboratory reference setting, and results showed accuracy within ±1%. As the device design is available according to the open-source hardware approach, measuring MIP/MEP can greatly facilitate easily available point-of-care devices for the monitoring of patients and, most important, for making this lung function measurement tool affordable to users in low- and middle-income countries.

Nocebo Effects of Clinical Communication and Placebo Effects of Positive Suggestions on Respiratory Muscle Strength

“…For these tests, the device PTS2000 Version 4.0 (Puritan Bennett, Pleasanton, CA, United States) and the software BreathLab PTS were used. An accuracy of 2.5% is reported for spirometry and of 1% for pressure measurements (Graham et al, 2019;Aymerich et al, 2021). The tests took place after information, demonstration, and practicing of the maneuver in a quiet, designated room at the university hospital.…”

Low-cost and open-source neonatal incubator operated by an Arduino microcontroller

“…In this way, the incubator can be replicated and utilized by potential users in LMICs just by following the detailed instructions we provide in this work. The incubator presented herein will add to many other devices [17] , [18] , [19] , [20] , which based on Arduino control, may contribute to improve the healthcare of patients who otherwise could not be adequately treated.…”

Open-Source Hardware May Address the Shortage in Medical Devices for Patients with Low-Income and Chronic Respiratory Diseases in Low-Resource Countries

“…Since measuring MIP and MEP is non-invasive, this technique helps in diagnosing and characterizing the disease and in monitoring the evolution of the patient's disease status and response to therapy. Given that commercial devices for measuring MIP/MEP are expensive, a low-cost, open-source device has been recently proposed [59]. The MIP/MEP measurement technique is straightforward from both conceptual and technical viewpoints.…”

“…A measuring session starts by asking the user to select a MIP or MEP measurement to run; then, data acquisition begins immediately. After 5 s of pressure signal sampling, the device screen shows the corresponding pressure-time curve and the MIP/MEP values are computed according to conventional rules [59]. The device asks the user whether the maneuver should be accepted or rejected and whether a new maneuver should be carried out (Figure 1B).…”

“…The device asks the user whether the maneuver should be accepted or rejected and whether a new maneuver should be carried out (Figure 1B). After repeated maneuvers, the device shows all data from previously accepted tests and informs on whether the quality control criterion to select the final result has been achieved [59]. Figure 1A shows that the device has two independent blocks connected through a 1 m length (3 mm ID) silicone tube.…”