Robust Design Inspiring Confident Use
Surgery can present one of the most demanding environments for product design. Everything has to work perfectly the first time, or there could be severe consequences. It takes attention to detail and a thorough understanding of operatory procedures to design a surgical product. Abbott Medical Optics came to Priority Designs for collaboration in designing and engineering in this difficult environment because of our experience with complex part design and understanding of the stresses of a medical environment. They needed confidence in the new part design to justify investment in new tooling with a successful and reliable product upgrade.
A Delicate Procedure
During cataract surgery, viscoelastic fluid must be carefully inserted into the patient’s eye with a syringe. The surgeon’s hand must be steady, and they need total control over cannula placement and the operation of the plunger. Abbott Medical Optics sought to develop a better finger grip that mounts to the syringe. It would give surgeons a sturdier hand hold while performing this delicate action. The more easily a surgeon can use their tools, the more peace of mind for surgeons, and better care for patients.
The grip required two main features: reliable securement to the syringe, and the ability to rotate the syringe within the grip to choose the position of the curved cannula for their desired angle of entry. Meeting these competing needs in an easily manufacturable design provided a good challenge for Priority Designs’ engineering team.
Iterative Design
Priority Designs began development on a single-use finger grip that would remain in place, no matter what kind of force the surgeon applied to the syringe. Mechanical engineering provided plastic part design and developed multiple design options using “engineering CAD”. The geometry was carefully designed to allow just the right amount of flex in just the right location. Using Finite Element Analysis (FEA) evaluations to determine the break-away force when depressing a plunger, they verified component and material properties. Industrial designers developed the look and feel of the syringe, shaping zones that touch gloved hands with comfortable, smooth surfaces.
Priority Designs’ prototyping team crafted many high-fidelity rapid prototype models to test ease of assembly, usability, and feel in the hand to refine the design throughout the process. Many iterations were meticulously designed and rigorously tested until the best solution was developed.
Finally, engineers created tool-ready “production CAD” and helped with problem-solving manufacturing solutions with the molding vendor.
Ease of Use
The new finger grip solidly clamps to the syringe with molded plastic springs. These springs accommodate a small range of critical diameters within tooling tolerances. The assembly process is simple and reliable:
- The syringe is inserted into the grip.
- The locking tabs flex to accept the syringe, then bend and secure the syringe in place.
- The syringe will not move in or out of the finger grip, but just enough tolerance was allowed to let it rotate as the surgeon desires.
This design gives the surgeon total control over the syringe while providing a sturdy and robust hand-hold.
Successful Development
The new finger grip provides a rock-solid connection which ensures confident use of the syringe. The efficient design for A/B tooling optimizes cost of assembly and disposal. Priority Designs’ collaboration with Abbott Medical Optics resulted in an affordable, reliable, and easy-to-use solution for a challenging environment.
