1. Delivery of Inhaled Drugs through CPAP
Team Members:
Sara Karle
Michele Lorenz
Emily Maslonkowski
Client: Dr. Mihai Teodorescu
Advisor: Prof. Mitch Tyler

2. Background Client treats patients with both sleep apnea + asthma
Continuous positive airway pressure (CPAP)
Delivery of long-acting inhaled medication
Clinical research setting

3. Intended Prototype Functions
Initialize automatically at desired time
Mechanical agitation
Synchronize actuation + inhalation
Peak detection algorithm
Oral drug delivery
Automatic shutdown

4. Algorithm Specifics Acquisition begins Find peak 1, store t1
Retrieve t1, t2, calculate
Δtpeaks tL
Δtpeaks tD
Use known lag time tL
Calculate delay tD
Algorithm waits for t = tD after the next peak, produces output to power actuation cam

5. Project Tasks * Completed Fall ’07: Projected Spring ’08:
Mechanical agitator/actuator for pMDI
Breathing detection parameter = T°
Differential amplifier circuit
Peak detection algorithm
Projected Spring ’08:
Integration: mechanical + electrical communication
Algorithm:
Timing
Memory (data storage)
“Filter” abnormalities
Calculations
Outputs A B
If B > A: do not store peak
briefly delay acquisition/storage of peaks *

6. Prototype Testing Problem: Various breathing patterns
Test: Validation of system function
3 different subjects
Actuation timed with subject inhalation (visual)
Results:
Timing correct = algorithm valid
Timing off = rework algorithm

7. Prototype Testing Problem: Breathing abnormalities
Test: Validation of system function
Single subject, voluntary abnormalities
Sighing, holding breath, coughing
Actuation timed with subject inhalation (visual)
Results:
Timing correct = algorithm valid
Timing off = rework algorithm

8. Prototype Testing Problem: Canister tilt effect on output dose
Test: Life-of-inhaler evaluation
Control pMDI
45° pMDI
90° pMDI
Spectrophotometric analysis of released dose
5 actuations per tested sample
Reveals importance of inhaler orientation
Orientation dictates patient/inhaler position
If orientation constrained, may require multiple doses per use

9. Future Work Placement of inhaler w.r.t. patient
Use of bite plate/OPAP (oral CPAP)
Miniaturization of mechanical device
Stepper motor
Microcontroller
Additional functions:
Counter (remaining doses)
Adjust to different canister sizes

10. Questions?