Development and test of a novel inspiratory muscle strength training device

Clinical need:
Aging exerts direct effects on the heart that increases susceptibility of developing cardiovascular (CV) disease. The greatest increase in CV risk with age is contributed by 2 factors: increased systolic arterial blood pressure and vascular dysfunction. Together these factors are responsible for many of the changes observed in the heart with aging and are key in other major clinical disorders, including stroke and chronic kidney disease, and are implicated in cognitive declines with aging and risk of dementia, including Alzheimer’s disease.
Establishing safe and effective evidence-based strategies for lowering blood pressure among older adults with above-normal baseline levels is a high biomedical research priority if we are to extend the healthy lifespan. However, many older do not engage in time-intensive healthy lifestyle practices that would reduce blood pressure due to competing personal time demands, limited access to facilities, prohibitive costs and/or limited access to transport.
Context:
Cardiovascular diseases (CVD) remain the leading cause of mortality and age is by far the strongest risk factor for CVD. Thus, >90% of all deaths from CVD occur in adults 50+ years of age.
150 minutes of moderate intensity exercise/week has well-documented benefits for lowering blood pressure and improving cardiovascular health however, the University of Arizona’s Respiratory Neurophysiology Laboratory (ARNL) has shown that just 5 mins/day of a novel inspiratory muscle strength training (IMST) can deliver significant improvements in respiratory strength, daytime and nighttime BP and vascular function in older adults with above normal BP.
https://pubmed.ncbi.nlm.nih.gov/32730174/
https://pubmed.ncbi.nlm.nih.gov/32730174/
The results achieved with such an abbreviated training regimen paired with the ability to train when seated, stationary standing, at home, at work, or when travelling are considered potential game changers for exercise and the ability to impact CV risk.
IMST comprises just five sets of six inspiratory efforts (i.e., 30 breaths) against a near infinite resistance (75% maximal inspiratory pressure, cmH2O).
ARNL has designed and built a proto-type training device comprising mouthpiece + tube assembly, one-way rebreathing valve and pressure sensor . The proto-type paired with real-time visual display of breathing pressures provided means for assessing maximal inspiratory pressure and served as the training device in preliminary studies in healthy young adults.

The Project:
We propose to develop an integrated device that combines live pressure monitoring capabilities with a graphical user interface realized through an Android app and automated local recording of trials to capture data without the need for user interaction. The development of this prototype has 2 goals:
1. Provide a simple device for the IMST therapy that can be used by an aging population with minimal technical knowledge and effort.
2. A data collection tool that allows us to capture many trials from patients in the cloud for research purposes.

Specifically, we are seeking to create 3D printable hardware that is easy to fabricate in small volumes to serve our clinical trials and requires no special parts with integrated wireless electronics that feature a pressure transducer and a simple Bluetooth Low energy enabled microcontroller with no more than 1 physical button and a USB port for battery recharge (battery lifetime more than 30 trials). The accompanying app will have no more than 2 buttons and a graphical display that signals the user to increase or decrease exhaling pressure. The app will also automatically save the pressure data of participants locally for the purpose of model development that will use the trial data alongside clinical assessments to enable an AI assisted therapy to maximize outcomes for future users.
From a technology perspective the device will be designed with scalability in mind. The physical device shape, while 3D printed for the prototypes, will be designed for injection molding to enable rapid scalability. The electronic hardware will be designed to feature a single board layout and widely available and economical off the shelf components compatible with standard PCB manufacturing to enable rapid scalability. The app will be written to feature easy serviceability and scalable data management that can interface with third party integrator companies to ultimately enable EPIC integration.