The Four D’s – Conditions Explained

Dysphagia (difficulty swallowing)
Dystussia (disordered cough)
Dysphonia (weakened speaking voice)
Dyspnea (shortness of breath)

These are clinically known by those involved in respiratory health as the ‘Four Ds.’ One or more of these health conditions are typically present in most people that are utilizing an Aspire Respiratory product. The most common of the Aspire devices used is the EMST150 which provides effective respiratory muscle strength training backed up by evidence-based clinical validation by specific patient need(s). The EMST150 has been clinically determined to effectively in addressing these needs as follows…

For Difficulty Swallowing (Dysphagia): EMST150 training improves swallowing function by improving hyoid and laryngeal excursions and improved laryngeal vestibule closure.

For A Disordered Cough (Dystussia): EMST150 training improves respiratory function by increasing maximum expiratory pressure and improving cough airflow measures.

For A Weakened Speaking Voice (Dysphonia): EMST150 training improves voice quality by improving subglottal pressure.

For Shortness of Breath (Dyspnea): EMST150 training decreases breathlessness, the paralyzing feeling of running out of breath, improving the ability to do exercise-based tasks with longer endurance.

health care researchers working laboratory


The EMST150 training system was originally tested on a group of high school band students, both boys, and girls, nearly 20 years ago. The objective was to see if young people playing musical instruments that required strong expiratory power could increase their exhaled air pressure by power training with the EMST150. All the students that received training with the EMST150 experienced increased exhaled strength.

From this simple beginning, the EMST150 research team went on to apply training to a diverse range of people and found the EMST150 trainer increased exhaled air pressure, or strength, in all who participated in the training. Our experience, working hand in hand with doctors and clinicians around the globe, verifies EMST150’s nearly immediate and straightforward results and its ability to maintain its positive benefits with continued use. Simply put, the EMST150 is the only device of its kind that has been rigorously tested, is accurately calibrated, with countless reports of verifiable patient outcomes.

The Devices

The EMST150

Aspire Respiratory Products Expiratory Muscle Strength Trainer

The EMST150 is the most scientifically tested, clinically proven, handheld expiratory muscle strength trainer available! Designed by a well-respected team of researchers, the one-of-a-kind EMST150 device now has nearly two decades worth of evidence-based outcomes. The EMST150 research team and scientists worldwide know that the simple use of the EMST150 over a short period of time results in an unquestionable improvement in breathing force while improving the strength of cough, swallow, and voice. In trial after trial, the EMST150 training system has shown significant improvements in the strength of healthy individuals and individuals diagnosed with neurological/neurogenic diseases such as Parkinson’s disease, stroke, head and neck cancer, multiple sclerosis, ALS, and spinal cord injury, as well as snoring and sleep apnea (OSA). The latest studies also show promising results in other disease types, including Pompe and Huntington’s chorea.

How it Works

The EMST150’s exceptional design uses a unique, calibrated pressure relief valve that creates an isometric load to the muscles used for coughing, swallowing and breathing out. This is similar to the experience that occurs when you lift weights to strengthen muscles in other parts of your body. It uses the same principle as the weight machines in the gym. The EMST150™ is quite simply your hand-held “weight machine.”

The EMST150™ can be carried with you anywhere and used anytime to improve and maintain your muscle strength even after completing your initial training! It is calibrated so you can measure your progress over time as you progress to higher levels of ability, again, just like lifting weights. The calibration on the EMST150 is adjustable from 0-150cm of H20 (water pressure), allowing for a safe and full range of use as the breathing, swallow cough, and voice strength increases during your training program. This calibration feature allows you to measure your progress over time accurately. The EMST150 device is so lightweight and compact it can travel anywhere with you, in your gym bag, handbag or briefcase, or exercise in the comfort of home.

EMST75 Lite

The EMST75 Lite

Expiratory Muscle Strength Training for those with more severe respiratory weakness. People suffering from respiratory weakening ailments and with limited respiratory strength may need to utilize the new EMST75 Lite, which provides a lower breath strength threshold. The EMST75 Lite allows patients with higher levels of respiratory weakness to begin improving their expiratory pressure before graduating to the EMST150. You should check with a healthcare professional, whether this device is appropriate for your condition.

The IA150 Inspiratory Adapter

Inspiratory Muscle Strength Training with the IA150 Adapter

Studies show that people can achieve added benefits from training both the inspiratory and expiratory muscles with the EMST150. Inspiratory muscle strength training has been proven to strengthen the inspiratory muscles, the muscles that you use to breathe in, thereby improving lung function and overall respiratory strength. Additionally, inspiratory muscle strength training has been proven to enhance physical performance and increase physical endurance.

Inspiratory training with the EMST150 is achieved by simply attaching the available IA150 Adapter to the device, making the one device capable of providing both expiratory and inspiratory muscle strength training.

If you have a health challenge or condition, check with a healthcare professional, whether IMST is appropriate for you.

Training & Usage Videos

EMST150 Instructional Video Pro

IA150 Instructional Video


How to Train Inspiratory Muscles  using the !A150 Adapter

Elite Global Partners

Aspire Respiratory Products works with numerous distributors and Elite Global Partners to bring the EMST150 to consumers around the world, including…