Example of a powered surgical hand tool.
Example of a powered surgical hand tool.
Portescap

Partnering for advanced surgical hand tools

Cost-optimized sterilizable motors bring high-quality surgical care to more patients

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May 22, 2021

Surgeons worldwide have come to favor advanced surgical hand tools for their effectiveness and successful patient outcomes. In order to keep costs in check, these sophisticated tools are re-used many times. In between procedures, the tools require steam sterilization, or autoclaving. While Tier-I surgical centers can afford frequent re-use of premium surgical tools, this model is often too expensive for smaller-scale Tier-II and Tier-III operations who typically seek lower-cost surgical tools that sacrifice performance and reliability.

However, with the right motor, designers can create affordable surgical tools with high quality and durability, allowing cost-sensitive surgical centers to deliver top-of-the-line care that saves more lives and improves outcomes for more patients.

Cost-sensitive markets for surgical hand tools
Asia represents the primary market for cost-sensitive surgical tools. Medical tourism, socio-economic growth and better awareness of surgical options are driving up the number of surgeries in the region. In addition, its aging population is experiencing higher rates of arthritis and other age-related conditions that often require surgical intervention while younger populations seek more surgical care due to their active lifestyles. Globally, rural areas demand more lower-priced tools because local hospitals may not have the patient throughput to amortize premium tool costs.

Surgical hand tool design
Conventional corded and pneumatic hand tools using AC motors are giving way to battery powered tools with lightweight brushed DC or brushless DC (BLDC) motors. However, the low-cost brushed DC and BLDC motor options are plagued by performance issues and less durability due to steam sterilization. Because they’re also larger and heavier in order to meet speed and torque needs, they have poor ergonomics, require larger and heavier batteries and dissipate more heat into the surgeon’s hand.


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Example of a powered surgical hand tool.

 

Without a cost-effective, high-performance motor option available, some surgical hand tool designers will select a motor that cannot survive sterilization. They can add protective sealing in the hand casing, but this creates bulkier tool designs that do not withstand the autoclave. Unlike other electrical components that the tool designer may be able to protect, a motor has a shaft that passes through it which gives moisture a direct path for moisture to reach sensitive electronics. This pathway is especially vulnerable to pressurized steam.

Look for motor suppliers with surgical hand tool experienceAn autoclavable motor supplier with experience in the surgical hand tool industry knows how to seal the electronic portion of the motor from the rotating shaft — a measure that cannot be performed at the tool level. By choosing a motor supplier without this experience, the cost savings of using a non-autoclavable motor are usually offset by higher development costs as well as increased costs elsewhere in the tool. Inferior durability through autoclaving also results in higher total cost of ownership for the customer because they must either risk cancelling surgeries while replacing a failed tool or purchase extra tools as backups.

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How steam sterilization works.

 

Another alternative is to avoid sterilizing the motor by placing it in a part of the tool that is protected from contamination during surgery and then removing it prior to sterilizing the hand tool. However, this approach is generally considered less safe because contaminants can still reach the motor via the coupling to the drill or saw bit. In order to match the safety standards of Tier-I products, Tier-II and Tier-III hospitals must upgrade to fully sterilizable hand tools that have fully sterilizable motors.

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Benefits of early engagement with a motor supplier.

 

 

Autoclavable motion solution options
Regardless of the number of cycles the tool is designed to last, the best way to achieve high safety and reliability for the life of the tool is to use a motor that incorporates autoclave resistance features. For tools designed for Tier-I markets, high-end motor options will include all the necessary material choices and sealing required to maximize the life of the tool through repeated autoclave sterilization. The additional surgeries performed per tool will more than pay for the additional purchase price. But for tools targeting Tier-II and Tier-III markets, the useful life of the tool may be limited for other reasons and high-end motor features will not return value. In this case, a motor that offers a selective combination of autoclave resistance features will deliver the best outcomes and lowest cost per surgery.

While this article has focused on the motor, gearing and controls are also degraded by the autoclave and must also be part of the life target and sterilization protection considerations. A full motion solution provider with experience in the surgical hand tool market will have options for motors, gear heads and controllers covering various life targets and cost limits. To best take advantage of the provider’s full breadth of products, customization capabilities and design consultation expertise, be sure to collaborate with them at the concept or even ideation stage of device development.

For more information, contact an engineer.