We’re going to begin a series focusing on some of the key components within an ultrasound probe. Some of these components are high failure items, while others, you may think, are not. All have several aspects in common. If, or when these components fail, they can have a significant impact on the safety, performance, and effectiveness of the probe. Let’s focus on the lens.
Let’s focus on the Lens
The lens, or the acoustic lens may seem quite simple, but it is actually much more complex than it appears, and it serves multiple purposes. End-users sometimes call it the footprint, the membrane, the matching layer, and yes, the rubber thingy on top.
Functions
Focus: As the name implies, the acoustic lens functions similarly to the lenses in our eyes, or the corrective lenses in our glasses or contacts. Although the scanner console performs electronic steering and focusing of the ultrasound energy, the probe’s acoustic lens provides a mechanical focus. It is constructed using very specific materials, molded using very precise dimensions, and it may even have a slight curvature.
Chemical Barrier: If you’ve ever had a sonogram, you know that scan gel is applied to your body, between the probe and your skin, to help improve image quality. Also, probes are cleaned, and may be high-level disinfected, after every use. As such, the lens is designed to serve as a chemical barrier to prevent contaminants from entering the probe housing, damaging the acoustic array and sensitive electronics.
Electrical Isolation: Referring to sensitive electronics, the acoustic array or “crystals” are pulsed with high voltage (typically up to several hundred volts). So as not to expose the patient or sonographer to such a potential, the rubber-like lens serves as an electrical insulator.
Other Notable Requirements: The lens, as well as other components that may contact the patient and sonographer, need to be bio-compatible so as to not induce any adverse reactions. OEMs are required to use materials certified to the ISO 10993 standard for bio-compatibility. The materials also need to be compatible with the dozens of OEM recommended cleaners and disinfectants.
Common Failures
Throughout the lifecycle of an ultrasound probe, the lens may undergo some of the most significant wear of any component. With repeated exposure to harsh chemicals, the lens, and the seal surrounding it, will degrade over time. The lens is also the victim of accidental trauma and physical damage. The smallest cut or opening will permit gel, disinfectants, and other contaminants to enter and degrade the internal components.
Typically, lens damage is not addressed until gels and chemical disinfectants have had the opportunity to induce more severe damage, leading to performance problems. It’s why we stress the importance of sonographers performing routine visual inspections on every probe in their department and informing the Healthcare Technology Management (HTM) team of any concerns as early detection may mitigate extensive damage.
Common Symptoms
When a lens failure has occurred (or is progressing), sonographers may complain of poor or reduced penetration, regional shadowing in the image, and even no image whatsoever. From a QC perspective, you would see changes in uniformity over-time as well as changes in penetration and resolution over-time. What once was, would no longer be achievable.
What’s in it for You
Innovatus Imaging maintains two facilities dedicated to ultrasound probes. Our FDA registered Center for Design and Manufacturing in Denver, Colorado. And, our Center of Excellence for Ultrasound Repair in Tulsa, Oklahoma. Together, these facilities address the entire lifecycle of transducers. Design, engineering, manufacturing and finally restoration to OEM form, fit, and function.
Innovatus Imaging is not just a repair provider, we are your service partner. We are here to assist you and your customers with obtaining the maximum lifespan for your ultrasound probes and MRI coils. We’re able to train HTM teams as well as clinical staff on best-practices for extending the life of your ultrasound probes. For questions, assistance, or more information, please reach out to training@innovatusimaging.com. If you have a failed probe, we can help! We have the most-comprehensive repair capabilities on standard, 3D/4D, and TEE probe models, and welcome the opportunity to assist you.
Background Information
Ultrasound transducers (or probes) are highly complex, Class II medical devices. They have their own unique 510k clearances. We see them all the time on television, in healthcare facilities, and even throughout HTM periodicals. Have you ever given thought to how they are designed, manufactured, tested, and repaired?
A transducer begins life as a series of user needs, intended use(s) and requirements or design inputs. It, ultimately, ends as a finished product. But, there is a tremendous amount of work and testing that occurs in between. This includes electrical, mechanical, acoustic, and chemical verifications and validations. Manufacturers need to ensure they are producing a safe and effective product. Simply put, the output should equal the sum of the design inputs. Or even better, manufacturers answer the question, “Did I make the transducer correctly?”. Furthermore, it is critical that the product meets user needs and intended use(s). Manufacturers answer the following question. Did we make the correct product? Our Denver facility manufactures ultrasound probes from concept to production and must follow FDA regulations every step of the way.
Many of these same manufacturing processes and philosophies are implemented when we engineer solutions for ultrasound probe restoration. Our goal is to return your probe to OEM form, fit, function and intended use. Because we are a manufacturer, we have all the necessary instruments, knowledge, training, scientists, and processes to ensure this outcome. Our engineers also design and manufacture proprietary fixtures based on the specific needs of various OEM makes and models.