Mikro-Cath™ - Airway Pressures

High-fidelity catheter for airway and esophageal pressure measurements

The Mikro-Cath™ pressure catheter delivers high-fidelity data for analysis of airway pressures. Clear, accurate signals from the solid-state pressure sensor catheter provide continuous, real-time assessments.

Mikro-Cath™ Airway Pressure Catheter

Understand Airway Pressures for Respiratory Conditions

The Mikro-Cath pressure catheter provides sleep disorder research specialists, pulmonologists and otolaryngologists with the ability to measure high-fidelity airway pressures in patients. The high-fidelity airway and esophageal pressure data supports understanding of respiratory physiology during obstructive sleep apnea and other apneic event studies.¹

Contact a Sales Rep  or call 832-667-7000 to learn more about how the Mikro-Cath Pressure Catheter can advance your research.

The Mikro-Cath pressure catheter is approved for use in the United States, Europe, and Japan for cardiovascular measurements and is approved for use in the United States and Europe for intra-compartmental and airway pressure measurements. 

Millar Mikro-Cath CE Mark

¹Ron Oliven, Guy Cohen, Yaniv Dotan, Mostafa Somri, Alan R. Schwartz, Arie Oliven, "Alteration in upper airway dilator muscle co-activation during sleep: comparison of patients with 4 OSA and healthy subjects.," American Physiological Society Journal, vol. 2017, 28 pages, 2017. doi:10.1152/japplphysiol.01067.2016

Clinicians can obtain more comprehensive and accurate measurements for:

  • Airway pressure studies/measurements
  • Obstructive sleep apnea studies
  • Sleep disorder studies

Airway pressure measurements support obstructive sleep apnea diagnosis through direct and reliable pressure readings in comparison to fluid-filled pressure measurements. 

The human pharyngeal airway is collapsible and tends to obstruct above (OSA) or below 63 (healthy subjects) atmospheric pressure in the absence of active dilator muscle force¹. Intrathoracic pressure (Pes) was measured with a Millar catheter (Millar Inc. Houston, TX), positioned in the esophagus and used to measure the downstream pressure that developed during resistive breathing and during hypopneas and apneas. Analogue-to-digital acquisition of all parameters was performed at 1000 Hz for monitoring and data storage on a digital polygraphic data acquisition system (LabVIEW, National Instruments, Austin TX).


¹Oliven, Ron, et al. “Alteration in Upper Airway Dilator Muscle Co-Activation during Sleep: Comparison of Patients with OSA and Healthy Subjects.” Journal of Applied Physiology, 2017, doi:10.1152/japplphysiol.01067.2016.

Here are some other airway publications:

Chowdhuri, Susmita, et al. "Effect of Age on Long-Term Facilitation and Chemosensitivity during NREM Sleep." Journal of Applied Physiology, vol. 119, no. 10, 2015, pp. 1088–1096., doi:10.1152/japplphysiol.00030.2015. https://www.physiology.org/journal/jappl

Boudewyns, A.n., et al. “Site of Upper Airway Obstruction in Obstructive Apnoea and Influence of Sleep Stage.” European Respiratory Journal, vol. 10, no. 11, Jan. 1997, pp. 2566–2572., doi:10.1183/09031936.97.10112566. http://erj.ersjournals.com/

Oliven, Ron, et al. “Alteration in Upper Airway Dilator Muscle Co-Activation during Sleep: Comparison of Patients with OSA and Healthy Subjects.” Journal of Applied Physiology, 2017, doi:10.1152/japplphysiol.01067.2016. https://www.physiology.org/journal/jappl

Sands, Scott A, et al. "Quantifying the Arousal Threshold Using Polysomnography in Obstructive Sleep Apnea." Sleep, Sept. 2017, doi:10.1093/sleep/zsx183. https://academic.oup.com/sleep/advance-article-abstract/doi/10.1093/sleep/zsx183/4608578

Sankari, Abdulghani, et al. "Characteristics and Consequences of Non-Apneic Respiratory Events During Sleep." Sleep, Sept. 2016, doi:10.1093/sleep/zsw024. https://academic.oup.com/sleep/article-abstract/40/1/zsw024/2661543

El-Chami, Mohamad, et al. "Time of Day Affects the Frequency and Duration of Breathing Events and the Critical Closing Pressure during NREM Sleep in Participants with Sleep Apnea." Journal of Applied Physiology, vol. 119, no. 6, 2015, pp. 617–626., doi:10.1152/japplphysiol.00346.2015. https://www.physiology.org/journal/jappl

Wellman, A., et al. “Test of the Starling Resistor Model in the Human Upper Airway during Sleep.” Journal of Applied Physiology, vol. 117, no. 12, 2014, pp. 1478–1485., doi:10.1152/japplphysiol.00259.2014. https://www.physiology.org/journal/jappl


TIP F SIZE3.5F (1.2 mm)
BODY F SIZE2.3F (0.8 mm)
USE<24 hours
SENSOR SENSITIVITY3.68 µV/V/cmH2O, nominal
ACCURACY+/- 1.4 cmH20 +/- 1% of reading from -68 cmH20 to +68 cmH20

Indications for Use Statement:

The Mikro-Cath Pressure Catheter is a single‐use catheter intended to be used for medical research and diagnostic purposes. The catheter is indicated to measure cardiovascular, intra-compartmental, and airway pressures in the human body. The catheter is used as a minimally invasive device under short-term limited body contact (<24 hours).

The Mikro-Cath may be introduced into the respiratory system through an existing orifice or through an incision.  

Recommended Setup: The catheter connects via cable to the Millar PCU-2000 Patient Control Unit to display pressure waveforms on a monitor while streaming data and measurements to the DAQ or computer.  

Additional contraindications, precautions and warnings are referenced in the Instructions for Use available under the Knowledge Center acute catheter manuals.