Inclusion Criteria:

• Ages 12-50 years. [NOTE: Only the Johns Hopkins site will enroll subjects under 18.]
• Clinical history consistent with asthma (GINA 4 definitions) for at least six months
• Current symptoms and features of partly-controlled or uncontrolled asthma, according to GINA classification of asthma control

• A stable (1 month) treatment regimen consisting of:

  • as needed short-acting bronchodilators alone,
  • as needed short-acting bronchodilators in combination with low- or medium-dose inhaled corticosteroids (<= 1000 mcg per day beclomethasone or equivalent,
  • any combination of long acting beta-agonist bronchodilator and low- or medium-dose inhaled corticosteroid (as defined above),as needed short-acting bronchodilators in combination with montelukast or other leukotriene modifier
• Willingness to comply with the study protocol and ability to perform the study procedures.
• Willingness to attend the study site according to the specified treatment schedule

Inclusion Criteria Assessed at Visit 1:

• Pre-bronchodilator FEV1 between 60% predicted and the lower limit of normal.
• Pre-bronchodilator FEV1/FVC less than the lower limit of normal.
• Reversibility of FEV1 of at least 200 ml, 15-20 minutes after 4 puffs of albuterol HFA pressurized metered-dose inhaler pMDI.

Inclusion Criteria Assessed at Visit 2:

• Reversibility of FEV1 of at least 200ml, 15-30 minutes after 4 puffs of albuterol HFA pMDI if not confirmed at Visit 1 plus
• Using short-acting bronchodilator therapy on two or more occasions in each of the two weeks preceding Visit 2 plus (Ventolin HFA counter decrease of at least 8 puffs)

• Partly controlled or uncontrolled of asthma as indicated by one to three, but not four of the following in each of the two weeks preceding Visit 2:

  • Daytime symptoms more than twice per week
  • Any limitation of activity
  • Any nocturnal symptoms or awakening
  • PEF<80% of predicted on any day

Exclusion Criteria:

• Pulmonary disease other than asthma, such as smoking-related COPD, clinically significant bronchiectasis, lung resection, and interstitial lung disease.
• Other significant systemic illness which might, in the opinion of the investigator alter the risk or outcome of the study (e.g. cardiovascular arrhythmias or conduction abnormalities, hyperthyroidism, uncontrolled hypertension, cancer)
• Tobacco smoking greater than 10 pack-year of cumulative exposure or current smoking within 10 years.
• Respiratory tract infection within 6 weeks of the study.
• Seasonal allergies causing symptoms within the past 4 weeks. Perennial or out of season allergic rhinitis is acceptable. Nasal corticosteroids and long-acting antihistamines are acceptable.
• Any investigational drug or treatment within 30 days.
• Use of cromolyn, nedocromil, theophylline, tiotropium, or oral albuterol within 1 week prior to Visit 1 of the study.
• Current use of omalizumab or within the last 8 weeks.
• Subjects on anti-depressant (mono-amine oxidase inhibitors or tricyclic antidepressants) treatment within 8 weeks.
• Non-potassium sparing diuretics unless in fixed combination with potassium sparing diuretics within one week.
• Digoxin, within one week, unless levels have been monitored previously while taking albuterol or LABAs.
• Presence of an implanted cardiac pacemaker or neurostimulator. A removable transcutaneous nerve stimulator, not used during the treatment sessions is acceptable.
• Non-selective beta agonists. (acceptable choices include: bisproprolol, betaxolol, atenolol, acebutolol and metoprolol)
• Subjects who are pregnant or breast feeding.
• Persons employed by or related to those employed by the investigative site (e.g. Pulmonary Division).
• Prior Fenzian treatment for any indication
• Hypersensitivity or intolerance of albuterol HFA pMDI (Ventolin) or its components. Note: if the subject is using ipratropium bromide for rescue short-acting bronchodilator, they must specifically not have been placed on that treatment due to intolerance of albuterol/salbutamol.
• Inability to withhold, before and during each visit (except the initial consent visit), xanthine-containing foods (coffee, tea, cola, chocolate, etc.) and alcohol for 6 hours, and short-acting bronchodilators for 8 hours.
• Unwillingness to stop use of non-study supplied albuterol (nebulized, CFC or HFA), other short-acting beta agonists (e.g. epinephrine, levalbuterol, metaproterenol, pirbuterol, terbutaline) and ipratropium during the study (after consent through visit 4).
• Inability to coordinate the timing for doses of long-acting beta agonists (withhold period at least 12 hours prior to visit) with Visits 1, 2, 3 or 4