Problem Statement

1
Aerosolized Drug Delivery Using Continuous
Positive Airway Pressure Device
Joe Decker Patrick Kurkiewicz Annie
Loevinger Steve Welch
Problem Statement
Budget
Client Dr. Mihai Teodorescu, MD 1 Advisor
John Webster, PhD2 1 Department of Geriatrics,
Gerontology and Sleep Medicine School of
Medicine and Public Health and Center for Sleep
Medicine and Sleep Research - University of
Wisconsin Madison 2Department of Biomedical
Engineering University of Wisconsin Madison
A method is needed for automated delivery of
respiratory anti-inflammatory drugs, like
albuterol, to patients as they use continuous
positive airway pressure (CPAP) device.
Background

• Sleep Apnea
• Occurs when the trachea of the subject closes
  during sleep, repeatedly waking the subject and
  causing chronic sleep deprivation
• Affects over 12 million Americans
• Continuous Positive Airway Pressure (CPAP)
  devices
• Includes a pressure source, a circuit, and tubing
  to a mask worn by a patient
• Provides positive pressure to assist in patient
  breathing.
• Used for sleep apnea or in ambulatory situations
  for patients with asthma.

Final Design

• Function
• Detects breathing cycle from microphone attached
  to CPAP machine and amplifies/filters signal.
• Uses LabJack U3 to process breathing cycle and
  determines when to turn switch on.
• Switch activates ultrasonic nebulizer, which
  delivers drug to patient.

Future Work
Nebulizer Column
Breathing Cycle Waveform

• RD work will continue in January, 2010.
• Change design of Albuterol reservoir so that the
  following problems are solved
• Heating of Albuterol Solution
• Inadequate mixing of nebulized drug with CPAP
  flow
• Acquire data pertaining to nebulized drug that
  makes it to the CPAP mask
• Automate nebulization and create user interface
  with adjustable dosage settings based on this
  information.
• Conduct Stage I trials in Dr. Teodorescus
  sleep research lab.

Inhale
Exhale
Piezoelectric Plate
Image from Webster, J.G. 2009. Medical
Instrumentation. Hoboken, NJ John Wiley Sons,
Inc.

• Nebulizer devices
• Aerosolizes liquid medication into a mist of many
  small liquid droplets (1 10 ?m)
• Often used with albuterol sulfate, a
  bronchodilator.

• Ultrasonic Nebulizer (above right)
• Uses high-frequency piezoelectric crystal to
  aerosolize drug for patient delivery
• Program
• Detects breathing rate waveform (left) from
  microphone amplifier/filter circuit
• Averages past 3 breathing cycles to estimate next
  cycle
• Can program when to turn on/off ultrasonic
  nebulizer based on estimated breathing rate

Threshold

• Ultrasonic Nebulizer
• Uses ultrasonic waves
• Efficiency 86/-5

• Jet Nebulizer
• Uses pressurized air
• Efficiency 39/-3

patient
References
Testing
Image from www.mece.ualberta.ca/arla/tutorial.htm
American Sleep Apnea Association (ASAA).
www.sleepapnea.org Dhand, R. 2004. Basic
Techniques for Aerosol Delivery During Mechanical
Ventilation. Respiratory Care. Vol. 49, No. 6
June 2004. Estes, M. C., Fiore, J.,
Mechlenburg, D. M., Ressler, H., and Kepler, J.
2005. Method and Apparatus for Providing
Positive Airway Pressure to a Patient. US
Patent, 6,932,084. Assigned to RIC Investments,
Inc. Franca, E.E.T., Dornelas de Andrade, A.
F., Cabral, G., Filho, P. A., Silva, K.C., Filho,
V. C. G., Marinho, P. E. M., Lemos, A., and
Parreria, V.F. 2006. Nebulization associated
with bi-level noninvasive ventilation Analysis
of pulmonary radioaerosol deposition.
Respiratory Medicine. Is. (2006) 100,
721-728. Gessler T Schmehl T Hoeper M M
Rose F Ghofrani H A Olschewski H Grimminger F
Seeger W. 2001. Ultrasonic versus jet
nebulization of iloprost in severe pulmonary
hypertension. The European respiratory journal
official journal of the European Society for
Clinical Respiratory Physiology 200117(1)14-9.
Hess, D. R. 2007. The Mask for Noninvasive
Ventilation Principles of Design and Effects on
Aerosol Delivery. J. Aerosol Med. Vol. 20,
Supplement 1. LabJack U3. 2009. U3 Specs.
Onine www.labjack.com/u3/specs Sanders, M.
H. and Zdrojkowski, R. J. 1992. Method and
Apparatus for Maintaining Airway Patency to Treat
Sleep Apnea and Other Disorders. US Patent,
5,148,802. Webster, J.G. 2009. Medical
Instrumentation. Hoboken, NJ John Wiley Sons,
Inc.
Image from www.sonozap.com/nebulizer.htm
Design Specifications

• Left Spectrophotographic curve for albuterol at
  269 nm.
• Right Observed albuterol concentration of the
  bulk solution during nebulization and theoretical
  albuterol concentration if no albuterol were
  nebulized.
• Data indicates that observed albuterol
  concentration was lower than theoretical
  concentration if no albuterol were nebulized

• The drug delivery device should
• Deliver nebulized medication within the CPAP
  circuit.
• Be compatible with any CPAP device currently on
  the market.
• Be capable of daily use, for at least 8 hours at
  a time.
• Deliver up to three 3 mL doses of medication
  during usage.
• Allow the user to sleep comfortably and safely
  during use.
• Include a user-programmable feature to specify
  dosage and delivery timing.

Acknowledgements
Dr. Mihai TeodorescuDepartment of Geriatrics,
Gerontology and Sleep Medicine Dr. John
WebsterDepartment of Biomedical Engineering Jim
Maynard Department of Chemistry
CPAP Nebulized
Albuterol Sulfate