Our sense of smell and the sensation of breathing plays an important role in our daily lives. The sudden absence of these sensations really highlight our dependency on these sensory inputs when it comes to our quality of life. Nasal obstruction, loss of smell, and nasal sinus disease are a few examples of how our olfactory sensations can be diminished. Since the main physiological function of the nasal cavity is the passage of airflow during inhalation and exhalation, airflow is a key factor when it comes to sensation of smell and the sensation of breathing. Therefore, it is important to understand how the airflow in the nasal cavity is affected in various different situations and how that plays into our olfactory sensations. This allows us to understand the nature of different nasal sinus conditions and can help to optimize treatments and suggest appropriate surgical options to alleviate these conditions. 

Our research aims to use computational fluid dynamics (CFD) and other numerical simulation techniques to quantitatively evaluate and understand the nasal airflow in the human nasal cavity under a variety of different circumstances. These techniques are also utilized to investigate odorant distribution within the nasal cavity as well as investigating the airflow and odorant distribution in other mammals. Using these techniques, we can achieve a full picture of the airflow and odorant distribution within the nasal cavity without the need for invasive procedures.   



Title: “Non-invasive Nasal Aid to Improve Nasal Obstruction Symptoms”
Agency: Ohio State Dept. of Education, Accelerator Awards

Budget: 1 year direct cost $150,000
PI: Kai Zhao
Funding Period: 06/01/2020-5/31/2021

Title: “Optimizing surgical outcomes to olfactory losses through endoscopic sinus surgery simulator”

Agency: NIH-NIDCD R21 DC017530 

Budget: 2 year direct cost $275,000

PI: Kai Zhao

Funding Period: 03/01/2019-03/01/2021


“Sinonasal Visualization and Quantification of the Effect of Oxymetazoline Nasal Spray”

Agency: Bayer, Inc., PI: Kai Zhao (submitted, 1 year total cost $120,000)


 “Optimizing topical drug delivery for personalized treatment of chronic rhinosinusitis”,

Agency: NIH-NHLBI, R01, PI: Kai Zhao (to be submitted, 5 year total cost $2,595,017)


 “Novel treatment options for conductive olfactory losses & nasal obstruction symptoms”,

Agency: NIH-NIDCD, R01, PI: Kai Zhao (to be submitted, 5 year total cost $1,900,000)


“Use of marangoni force to improve topical drug delivery”,

Agency: NIH-NIDCD, R21, PI: Kai Zhao (to be submitted, 2 year total cost $400,000)


Li C., Dong H., and Zhao K. (2020) Dual functions of insect wings in an odor-guided aeronautic navigation, Journal of Fluids Engineering 142(3), 030902. doi.10.1115/1.4045946

Zhao K., Kim K., Craig JR., Palmer JN. (2020) Using 3D printed sinonasal models to visualize and optimize personalized sinonasal sinus irrigation strategies, Rhinology (in press).

Malik J, Thamboo A, et al. The cotton test redistributes nasal airflow in patients with empty nose syndrome. Int Forum All Rhinol. 2020 Jan 17. doi: 10.102/alr.22489

Wu Z., Craig JR., Maza G., Li C., Otto BA., Farag AA., Carrau RL., Zhao K. (2020) Peak sinus pressures during sneezing in healthy controls and post-skull base surgery patients, Laryngoscope,  doi:10.1002/lary.28400.

Malik J, Li C, Maza G, et al. Computational fluid dynamic analysis of aggressive turbinate reductions: is it a culprit of empty nose syndrome? Int Forum Allergy Rhinol. 2019.

Li C., Maza G., Farag A.A., Krebs J.P., Deshpande B., Otto B.A., Zhao K. (2019) Asymptomatic vs. symptomatic septal perforations: A computational fluid dynamics examination, International Forum of Allergy Rhinol, 9(8):883-890. PMCID: PMC6750740, doi: 10.1002/alr.22337.

Mason E.C., McGhee S., Zhao K., Chiang T., Matrka L. (2019) The application of computational fluid dynamics in the evaluation of laryngotracheal pathology, Annals of otology rhinology & laryngology, May 128(5):453-459. PMCID: PMC6753835, doi: 10.1177/0003489419826601

Alam S., Li C., Bradburn K.H., Zhao K., Lee T.S. (2019) Impact of middle turbinectomy on airflow to the olfactory cleft: A computational fluid dynamics study, American J of Rhinology and Allergy, May 33(3):263-268,  PMCID: PMC6535904, doi: 10.1177/1945892418816841.

Maza G., Li C., Krebs J.P., Otto B.A., Farag A.A., Carrau R.L., Zhao K. (2019) Computational fluid dynamics after endoscopic endonasal skull base surgery - possible ENS in the context of middle turbinate resection, International Forum of Allergy Rhinol Feb; 9(2):204-211. PMC6358472, doi: 10.1002/alr.22236

*See publications tab to see full publication list


 Zhao K., 3D printed personalized nasal replica and attachments to visualize and optimize nasal sinus irrigation strategy (US 62/839,423, provisional US patent filed 4/26/2019)

Zhao K., Nasal plug (PCT/US 2018/021464, PCT/US patent filed on 3/08/2018, US patent pending US 16/491,958)

Zhao K., Kim K., Modified Nasal Plug for Nasal Airflow Modulation (US 62/979,707, provisional US patent filed 02/21/2020) 


Nasal obstruction: This ongoing study aims to develop and validate an objective diagnostic tool by combining novel computational models with sensory measurements, which would enable patients and clinicians to make informed, personalized treatment/surgery strategy. This project has also led to invention of novel non-surgical treatment option. Specific areas:

*             Turbinate hypotrophy

*             Septal deviation

*             Septal perforation

*             Empty Nose syndrome

*             Skull base patients

*             Obstruction related smell loss

Nasal drug delivery: This ongoing study uses computational models and 3D printing to optimize surgical impact for nasal drug delivery. The project also explores novel drug delivery methodology.

Endoscopic sinus surgery simulator: This ongoing study aims to develop and validate a virtual endoscopic sinus surgery simulator to simulate, predict, and optimize surgical approaches that may improve clinical practice and offer personalized medicine in the future.

Olfaction function and Training: Investigating the impact of nasal aerodynamics on olfactory function; the use of olfactory training and novel modulation of nasal airflows to improve olfactory function in both healthy controls and patients with reported smell losses.