Constant innovation and advancing medical device designs are part of the reason Becton Dickinson helps to save the lives of patients every day. We all know the role of safety in new product development. However, testing and Validation solutions are not always as clear-cut as they may seem.

During the new product development stage of the Barricor component, BD was not alone in the challenges they faced with this clever device. From tooling and fixturing to measuring, this component presented many challenges. But consequently provided the best learning experiences the team at Verus has possibly experienced.

Glen Miller, Senior Metrology Engineer at BD Plymouth was instrumental in the project from the initial contact with Verus, sharing his years of expertise during the fixture POP stage to implementing the final installation on site. Working with the team in Franklin Lakes, including Mukund Patankar, Sr. Staff Engineer, and Mike Ross, Staff Research and Development Engineer, collaboratively found a solution to solve the challenges this component brought. 

From Concept to Completion

Verus attended a collaborative meeting with OGP in BD Plymouth to discuss a solution for the Barricore component. In attendance was Glen Miler, Senior Metrology Engineer, Jamie Tabb, Quality Engineer (Projects), and Tom Stimson who was the project lead and finally Graham Shaw from OGP.

Verus proposed a course of action to BD considering the complexity involved in this solution. Along with a proposal on capabilities and timelines, Verus proposed to initiate the project with a test unit.

The proof of principle was successful, and the team quickly got to work on the production fixture. 

The BD team placed the order for the vision machine which OGP delivered to Verus in Sligo. Upon completion of the 32-station fixture, the measurement machine arrived. This meant the team could then combine the fixture and the OGP to undertake rigorous testing.

Verus achieved a fill Gauge R&R in Ireland to prove out the fixture and the transfer system. This team could then complete programs collaboratively with OGP. The entire system, Gauge R&R and program were then shipped to BD Plymouth for an on-site install and full MSA.

An initial single station fixture was developed in Franklin Lakes achieving results of sub 30% Gauge R&R. Verus engaged from a production perspective to improve the results. We got it to 15% thanks to the collaborative process to all the team involved as well as Verus’ expertise and capabilities.

As demand ramped up, two repeat projects followed for 128-station versions of the original 32-station fixture. In BD Plymouth currently, there are two 128-station fixtures, one 32-station fixture, and a transfer system. Verus remains in constant communication with the engineers involved in this project as they overcome internal challenges with this component, looking towards the next steps. 

The Barricor Component

The component itself is very complex, intricate, and extremely unreceptive to touch given that it is produced using an exceptionally flexible rubber.

Although the Barricor is minuscule in size, the effect this component has on the process of separating blood and plasma is gigantic. The purpose of the component is to separate the plasma layer. Centrifugation causes the red blood cells to pack at the bottom of the tube with Barricor closely following and providing a barrier between the cells and plasma.

5 Critical Dimensions in 4 Different Positions.

The Barricor must rotate to 4 orientations, in a multi-position situation to access all 5 critical dimensions.

What Challenged verUS The Most?

To ensure the integrity of the measurements, given the nature of the material used, the holding solution must give access to all dimensions needed without compromising the rubber profiles.

From the rubber bung rite down to the chin strap, each profile comprises the rubber material. This proved many challenges from a fixturing perspective. The surfaces also change in geometry as they are rotated. The rubber molds down and around the component and back up.

The A datum is 4 small flat pads on the bottom of the component. Critical to the measurement the A datum stops the part pivoting through its 3 degrees of freedom. The pitch and the yaw control the Z position. It controls the part from spinning or falling. It also controls the position in the direction of the Z height. So, once we know it’s resting on that face and know where the face is, we can then control it.

Measuring The Untouchable

At Verus there is a widely held philosophy, that the fixture is there to hold the part, not to control its position. The team achieves this through innovative design and incorporating flex into the fixture to allow the part to move within reason. Therefore, the machine can then locate the part and attain its datum structure. 

However, this was certainly not the case with the Barricor. There was no physical way to hold this component to then access the datum structure. The plastic aspect of this component is the only material that can be held without compromising the geometry of the part. And yes, you guessed it, the datum structure is located in the plastic. With no alternative resolution, the fixture was used in this instance to control all the positioning of the part. That being said, the innovation incorporated into this solution knows no bounds.

Using the fixtures to control the positioning of the component does not come without its challenge when accessing all 5 critical dimensions in a total of 4 different positions. The fixture nests into the modest hollow using pins. However, once you rotate the fixture the component would fall off those pins.

So, what is the solution? The design team at Verus incorporated a small hook to grab into the hollow. This design aspect allowed the part to pull onto the pins because the channel is plastic. This ensures that the part does not gravitate when we rotate by 90-degree increments as it stays pulled onto the pins.

Getting it off the Molding Machine and on to the Fixture

Developing an innovative fixture to hold the Barricor component is only part of the solution. But how do you get the component from the molding machine to the fixture without touching it and causing changes to the part’s geometry?

Robotics, Hydraulics, and Transfer Systems

Incorporated beside the injection molding machine is an end-of-arm robot. Originally the robot used beside the cube mold was a 32. The robot offloads 8 components at a time to one of four transfer trays inside the system. The robot replicates the process, filling the 32-stations. There are 4 red lights that look across the rail to make sure the parts are located correctly.

Once this process is complete, outside the cage is a hatch system controlled by a green button. Once pushed it allows you to reach into the robot facility and take the 4 rails. The operator can then move the rails into a base plate and onto the transfer system.

The air pressure gauge is then set at 3.5 bar on the transfer system awaiting the loaded parts.

Using the lifting positions, the robot rail is loaded onto the cross-slide. The operator can then visually check the parts to ensure they are square and located down on their nests. The operator then switches on the air and presses the yellow knobs at the top of the system. The component then visibly lifts out of its nest.

Why The BD Partnership is so Important to Verus

The long-standing partnership between Verus + Becton Dickinson is based on clarity, communication, trust, and shared expertise. What once seemed like a near-impossible task, these four pillars of our partnership were demonstrated throughout and are the reason for the successful completion of the Barricor project. 

To find out more about the Verus + BD partnership, contact our Business Development Manager Tracey Flynn on +353 (0)76 661 9000. To find out more about our turnkey metrology solutions, contact our COO Michael Nugent on +353 (0)71 91 43506 (ext. 215).