Trans-Skull Ultrasound Scanner for Diagnosis of Rhino-Sinusitis

Delphion, Lisle, Illinois

Rhino-sinusitis, or sinus infection, is an inflammation of the paranasal sinuses, which can be caused by different conditions (bacterial, fungal, viral, allergic, or autoimmune). Bacterial rhino-sinusitis is currently assessed by puncture or imaging techniques (x-ray or CT) in order to detect the presence of an air-fluid level within the paranasal sinuses. The absence of this level is significant enough to rule out bacterial infection. The system presented in this innovation provides a reliable, non-invasive, and low-cost procedure to evaluate the presence of fluid inside the paranasal sinuses by means of an ultrasound scan.

The system transmits a high-amplitude acoustic wave through the maxillar bone towards the back wall of the sinus cavity in the inner side of the bone. The air chamber present in a normal sinus prevents the ultrasound propagation (only one echo from the front wall of the paranasal sinus is produced). If the sinus is infected, it will be filled with fluid that conducts the ultrasound, and a second echo from the back wall will be generated.

This system provides a compact method for assessing the presence of viable bacteria inside the paranasal cavities without having to rely on imaging techniques with ionizing radiation. It deploys a compact, low-cost, and portable ultrasonic echo apparatus (A-Scan) as its basic system, and measures with high resolution the echoes generated by the inner sinus (fluid or air).

The low cost of the system is achieved by the deployment of standard high-frequency piezoelectric composites coupled with a linear classifier matched to the time response of the ultrasound probe. This results in higher signal to noise ratios (SNR) and better sensitivity to detect fluids inside the sinus (see figure). The system uses a frequency in the range 8-10 MHz, resulting in higher sensitivity. The compensation for the reflection loss and scattering caused by the tissue under study are compensated by means of matched filters (increased SNR) and blind equalizers.

This technology is offered by Delphion. For more information, view the yet2.com TechPak at http://info.hotims.com/22916-170 .