Trophon is an automated disinfection system used to clean ultrasound probes between patients. Made by the Australian company Nanosonics, it uses a hydrogen peroxide mist to achieve high-level disinfection, the standard required for any medical device that contacts mucous membranes. You’ll most commonly find Trophon units in hospitals and clinics that perform transvaginal, transrectal, or other internal ultrasound exams.
Why Ultrasound Probes Need Special Cleaning
Not all medical equipment carries the same infection risk. Devices that only touch intact skin, like a standard abdominal ultrasound probe, need basic cleaning. But probes that enter body cavities or touch mucous membranes are classified as “semi-critical” devices, and they require a much more thorough process called high-level disinfection.
The CDC’s disinfection guidelines are clear on this point: endocavitary probes (vaginal, rectal, or throat ultrasound probes) must be high-level disinfected between every patient. Even when a disposable cover or condom is placed over the probe during the exam, disinfection is still required afterward because those covers can fail, leaving the probe exposed to body fluids and pathogens. For ultrasound probes used during surgery that contact sterile body sites, the standard is even higher: sterilization is preferred, with high-level disinfection as a minimum.
How the Trophon System Works
Traditional high-level disinfection involves soaking probes in liquid chemical solutions, which can be time-consuming and exposes staff to harsh chemicals. Trophon takes a different approach. The system uses a concentrated hydrogen peroxide solution (35%) that it converts into an ultrafine mist inside a sealed chamber. This mist is heated to about 56°C, while the probe itself stays below 40°C, which protects the sensitive electronic components inside the transducer.
A technician places the pre-cleaned and dried ultrasound probe into the Trophon chamber, closes it, and starts the automated cycle. The current model, the trophon2, completes its disinfection and aeration cycle in as little as 4 minutes. That speed matters in busy clinical settings where probes need to be turned around quickly between patients.
One practical advantage is what happens after the cycle. Hydrogen peroxide breaks down into water and oxygen, so the process doesn’t generate toxic waste or leave chemical residues on the probe. This is a meaningful difference from traditional liquid soaks, which can leave traces of disinfectant that require rinsing and careful handling.
What It Disinfects and Where It’s Used
The Trophon system is FDA-cleared for high-level disinfection, which means it’s validated to eliminate a broad range of healthcare pathogens including bacteria, viruses, and fungal organisms on probe surfaces. Importantly, it disinfects not just the tip of the probe that contacts tissue, but also the handle, which can pick up contamination during use.
You’ll encounter Trophon systems most often in OB-GYN offices and departments (for transvaginal ultrasounds), fertility clinics, urology practices, emergency departments, and surgical suites. Any clinical setting that routinely uses internal ultrasound probes is a candidate for the system. It’s designed to be compact enough to sit in or near the exam room rather than requiring probes to be sent to a central processing department.
What This Means If You’re a Patient
If you’ve seen or heard about a Trophon device during a medical visit, it’s simply the machine your healthcare facility uses to sterilize the ultrasound probe before your exam. You may notice a small unit near the ultrasound machine, or staff may mention that the probe has been through its disinfection cycle. The process is entirely automated and standardized, removing the variability that can come with manual soaking methods.
The probe should be at a comfortable temperature when it’s used on you, since the device keeps the probe well below body temperature during the cycle. There are no chemical residues to be concerned about. If you’re having a transvaginal or transrectal ultrasound, your provider will typically still use a disposable probe cover during the exam as an additional layer of protection, even though the probe has already been disinfected.