This study designed a portable and easily accessible lung vibration device that is simple to use and can operate with both a battery system and a charging system for greater convenience. It helps enhance the effectiveness of mucus drainage, prevents complications, and reduces both the duration and cost of hospital treatment.

Lung vibration device uses a motor as the power source to generate vibrations and has a shape similar to an iron. It is connected by an electrical cord in this section and can operate using either a battery system or a charging system. It features a vertically aligned handle perpendicular to the main body for a firm grip. The base of the device has a sponge head to absorb shock from the vibration during use, which is removable. The on/off switch is located at the end of the handle. This device uses 220-volt alternating current. The unit weighs approximately 1.1 kilograms and is made of strong and durable plastic.

Inclusion Criteria:

• Male or female
• Aged 18-59 years
• Inpatients at Burapha University Hospital, Mueang District, Chonburi Province, with pulmonary secretion retention
• Referred by their attending physician for enhanced secretion clearance through physical therapy methods

Exclusion Criteria:

• Having inflamed wounds on the chest or back
• Having unstable vital signs, defined as: resting heart rate <60 or >100 beats per minute; blood pressure <90/60 or >120/80 mmHg; respiratory rate <12 or >20 breaths per minute; oxygen saturation <95%; and body temperature >37°C
• Having a bleeding tendency, defined as a platelet count <20,000 per cubic millimeter
• Taking medications that increase bleeding risk within 7 days prior to participation, including: Anticoagulants (such as Warfarin, Dabigatran, Rivaroxaban, Apixaban, Edoxaban), Antiplatelet agents (such as Aspirin, Clopidogrel, Dipyridamole, Prasugrel, Ticagrelor)
• Having an International Normalized Ratio (INR) >1.1 for those not on anticoagulants, and >3.0 for those on anticoagulants
• Having subcutaneous emphysema
• Experiencing severe hemoptysis (coughing up blood)
• Having chest wall pain
• Having acute spinal cord injury, rib fractures, or conditions associated with high fracture risk
• Having skin grafts or burn wounds
• Being admitted to intensive care units (ICU, RICU, or CICU)
• Having untreated pneumothorax
• Having an acute inflammatory process of the respiratory system
• Having inflammatory or infectious conditions such as tuberculosis, lung abscess, or COVID-19
• Having respiratory diseases that are contraindications or precautions for lung vibration, including COPD, uncomplicated pneumonia, asthma, lung cancer, or metastatic cancer

There is no plan to make individual participant data (IPD) available to other researchers.

Masking will not be employed in this crossover study, as both participants and investigators will be aware of the intervention administered in each period.