When it comes to fiber optics in medical devices, cleaning is essential for reliability.
Jay Tourigny, MicroCare
Cleaning sticks or swabs are ideal for cleaning end face connectors. [Image courtesy of MicroCare]
The use of fiber optics in the medical industry is steadily increasing. As the population continues to grow and age, healthcare providers are using fiber optic devices for better patient diagnosis, monitoring and treatment. Today fiber optics are used for minimal invasive surgery (MIS), in sensors inside single-use catheters and endoscopes and for real-time diagnostic imaging with MRI, CT, PET, or SPECT systems.
Like many medical devices, cleanliness is crucial to the performance of fiber optic instruments. The device must perform without fault. One of the main causes of fiber optic instrument failure is the contamination of the fiber optic termini. Dirty fiber connections, also known as end faces, can cause a host of problems ranging from intermittent performance to ruined instruments. That is why cleaning the end faces is crucial to ensure the reliability and performance of fiber optic medical devices.
Identify and remove the contaminant
One of the biggest challenges of end-face contamination is that it can’t be seen with the naked eye. Microscopic dust particles or fingerprint oils typically are only seen with a specialized 200x or 400x inspection scope. A close examination of the connectors is critical to confirm any particles or residue are completely eliminated, thereby ensuring that connections function properly.
The best advice is to inspect, clean, and inspect again before making any fiber-optic instrument connections. Repeat this process until absolutely sure the instrument end faces are clear of all contaminants.
Choose materials engineered for fiber cleaning
The materials used to clean the end faces must be pristine; otherwise, it could make it worse by adding contamination. It may be intuitive to wipe the end face on a gown or a cloth, but under a typical fiber optic inspection scope, those items carry a large variety of contaminants that could soil the connector. Letting connectors touch the floor or even touching the termini with a finger can cause them to be significantly dirtied with dust or skin oil. To avoid further contamination, use products specifically engineered for cleaning fiber optics.
Cleaning wipes and sticks
There are two primary methods available to properly clean fiber optic end faces: a specialty wipe for male connectors and a swab for female connectors. Particulates, oils, and salts are the three basic types of contaminants found on the end faces, all of which require their own cleaning methods.
Particulates are solids that are held on the end face by a static attraction. The best way to clean these types of contaminants is by dissipating the static charge that both attracts and holds them in place. This can usually be done with a specialty cleaning fluid. Cleaning fluid also dissolves the oils found on the fiber.
Salts, on the other hand, are not necessarily fully removed by cleaning fluids alone. While cleaning fluids may quickly rinse away the oils, they tend to leave salt remains behind in the form of a white residue that can be very difficult to remove. Mechanical action that a wipe or a cleaning stick provides is usually combined with a cleaning fluid to fully eliminate oil and salt left on the termini end face.
High-purity cleaning fluid
When cleaning fiber end faces, be sure to use fluids engineered for fiber cleaning. Avoid using aqueous (water-based) cleaning solutions or pure isopropyl alcohol (IPA). Aqueous products are slow to dry and can leave moisture on end faces. If the moisture is not completely removed before the fiber is connected in the sleeve, the laser-energized fiber can instantly vaporize the remaining liquid into a gas, causing an explosion through the sudden expansion of the vapors.
As with water-based cleaners, IPA may explode or catch on fire when left on a highly energized fiber end face. IPA also frequently leaves a hazy film behind when it dries. Instead, use a fast-drying, high-purity fluid engineered specifically for cleaning fiber optics.
Wet to dry cleaning
High-purity cleaning fluids should be used with both wipe and swab applications. However, beware of presaturated cleaning materials. Presaturated wipes and swabs often contain microscopic contaminants drawn from the plastic packaging, which can transfer to the end face during the cleaning process and result in further contamination problems.
Instead, carefully apply a small amount of high-purity cleaning fluid on the corner of a dry wipe or the tip of the swab and then apply to the fiber optic termini. A well-engineered cleaning fluid will not only dissolve oils found on the end face but will help to eliminate the electrostatic charge generated when the applicator is pulled out of its packaging.
Be sure not to touch the wipe or swab area you will be using with your finger or clothing. Should you touch this area or drop it on the ground, discard the wipe or swab and start over. Once the cleaning process is complete, discard the wipe or swab and inspect the end face to ensure all contaminants have been eliminated.
Fiber cleaning means better patient care
The use of thin, small, flexible fiber optics inside catheters and surgical scopes makes it easier for healthcare providers to see and work inside the human body with better comfort for the patient. These fiber optic medical devices help provide better diagnostics, improved medical treatment and better surgical outcomes.
It is imperative to clean the termini end faces properly to ensure reliable performance. Medical providers can’t afford to have a faulty connection, a fire or a fiber optic shut down when there is a patient on the table. To help safeguard device reliability, use specially-engineered fiber optic cleaning products and closely inspect the end faces before connecting. This helps ensure the fiber optic medical devices operate as intended without fault.
For those looking for help in selecting fiber optic cleaning tools and fluids, it’s best to partner with a supplier that specializes in fiber optic cleaning. They can provide advice on the best cleaning solutions and methods to use.
Jay Tourigny is SVP at MicroCare, which offers Sticklers brand fiber cleaning solutions. He has been in the industry for more than 30 years. He holds numerous U.S. patents for cleaning-related products that are used on a daily basis in fiber optic, medical and precision cleaning applications.
The opinions expressed in this blog post are the author’s only and do not necessarily reflect those of MedicalDesignandOutsourcing.com or its employees.