A Trophon is an automated disinfection device used to clean ultrasound probes between patients. Made by the Australian company Nanosonics, it replaces the older method of manually soaking probes in chemical baths. The device is most commonly found in hospitals, imaging centers, and OB-GYN offices where internal ultrasound probes need to be sterilized to a high level before reuse.
Why Ultrasound Probes Need Special Cleaning
Not all ultrasound probes are the same. External probes that glide over your skin pose relatively low infection risk. But internal probes, like the transvaginal probes used in pelvic exams or the transrectal probes used in prostate imaging, come into direct contact with mucous membranes. These surfaces can harbor bacteria, viruses, and fungi, making thorough disinfection critical between patients.
The standard required for these probes is called high-level disinfection, or HLD. This level of cleaning eliminates virtually all microorganisms, including hard-to-kill pathogens like tuberculosis bacteria, herpes simplex virus, and poliovirus. For years, the standard approach was to soak probes by hand in chemical solutions like glutaraldehyde. That process is effective when done correctly, but it relies heavily on the person performing it. Manual soaking is prone to operator error and variability, and the chemicals involved can be toxic to staff who handle them repeatedly.
How the Trophon Works
The Trophon uses a concentrated hydrogen peroxide solution as its disinfectant, but it doesn’t simply soak the probe. Instead, the device sonically activates the hydrogen peroxide to create an ultra-fine mist made of particles smaller than a micron. This mist envelops the probe’s surface and generates a large number of free radicals with strong oxidizing properties. Those free radicals are what actually destroy pathogens, breaking apart the outer structures of bacteria, viruses, and fungal spores on contact.
The whole cycle is automated. A technician places the probe into the device, closes it, and presses start. The machine handles the timing, chemical concentration, and exposure on its own, removing the guesswork that comes with manual methods. A typical cycle takes around seven minutes, after which the probe is ready for the next patient.
What It’s Validated to Kill
The Trophon has been tested against a broad range of pathogen categories to meet high-level disinfection standards. FDA testing records show the device was validated using efficacy tests for bacteria, viruses (including poliovirus type 1 and herpes simplex virus type 1), mycobacteria (the category that includes tuberculosis), and fungi. These tests follow standardized methods established by the AOAC, which sets the benchmarks for disinfection performance in the United States.
Safety for Patients and Staff
One of the main reasons clinics adopt the Trophon is safety. Traditional manual soaking chemicals like glutaraldehyde are effective disinfectants but can irritate the skin, eyes, and respiratory tract of healthcare workers who use them daily. The Trophon’s hydrogen peroxide mist breaks down into water and oxygen after the cycle completes, leaving no significant chemical residues on the probe and producing no hazardous waste. FDA review documents note that the device uses smaller quantities of disinfectant compared to manual methods and has no significant adverse effects on the ultrasound probes themselves.
For patients, this means the probe that’s used during your exam has been through a standardized, trackable cleaning process rather than one that depends on an individual technician following every step of a manual protocol correctly.
FDA Classification and Clinical Standards
The Trophon is classified by the FDA as a Class II medical device, the same regulatory tier as powered surgical instruments and many diagnostic tools. This classification requires the manufacturer to demonstrate that the device is substantially equivalent to existing approved disinfection methods in both safety and effectiveness. The device and its associated components have received multiple FDA 510(k) clearances, each requiring documented testing against recognized performance standards for electrical safety, biocompatibility, and disinfection efficacy.
Where You’ll Encounter One
If you’ve had a transvaginal ultrasound, a transrectal ultrasound, or certain other internal imaging procedures, there’s a good chance the probe was cleaned using a Trophon. The device has become widely adopted in radiology departments, fertility clinics, emergency departments, and OB-GYN practices. You might see it sitting near the ultrasound machine itself, a compact unit roughly the size of a large coffee maker, or it may be in a separate cleaning area out of sight.
Some clinics display a sticker or notice near the exam room indicating they use automated high-level disinfection. If you’re curious about how your facility cleans its probes, it’s a reasonable question to ask before a procedure. The shift from manual chemical soaks to automated systems like the Trophon has been one of the more significant changes in ultrasound infection control over the past decade.