1. COPD patient who is on Tiotropium Respimart and other inhalers continued.
2. Those fullfill inclusion criteria will be randomized into two group.
3. To do Baseline CAT score and SGRQ questionnaires with Lung function test.
4. Assess inhaler technique with and without aerochamber.
5. Teach proper inhaler technique by templates and demonstrate to patients.
6. Group A given aerochamber and Group B without aerochamber enroll in the study for total 18 week .
7. First phase for 8 week after that 2 week of washout periode (without aerochamber both arm).
8. Then Group A without aerochamber and Group B with aerochamber continue with all inhalers for 8 week.
9. Followed up at 8th , 11th and 18th week to assess inhaler techniques ,Lung function test and do CAT score, and SGRQ questionnaire.
10. Analysis data
