Robotic Assembly is a Lesson in Extreme Precision
Case Study: Seymour Advanced Technologies Successfully Uses Semi-Autonomous Automation to Ensure Precision in Medical Device Assembly
Situation:
An ophthalmic pharmaceutical company has developed a micro needle for use in ocular surgery. In the medical industry, it’s critical that assembly is both seamless and sterile, and this company recognized the need for a more efficient way to assemble these micro needles. The goal was to significantly reduce bioburden while also increasing productivity by approximately 70%. Facing this aggressive goal, it was of the utmost importance to engage an automation engineer who could start from scratch and build an entirely new robotic solution to meet their very specific needs. After searching for an expert with this level of expertise, the company enlisted the help of SEYMOUR Advanced Technologies (SAT), an autonomous industrial technology provider, to create a one-of-a-kind robotic semi-autonomous machine that could automate an extremely precise assembly process of a surgical tool.
Challenge:
To create an automated, sterile, and precise assembly process for taking a 25 mm long rod and precisely inserted into a hollow cylinder with, only 60 microns (0.0015″, ¼ to ⅓ human hair) of clearance.
In the current manufacturing environment, this process is performed manually using a high-powered magnifying glass and human hands. This is extremely tedious and time-consuming—an average of only 63 microneedles per hour can be accurately produced this way. There is also a significant amount of waste due to needle breakage during the insertion process. Additionally, there is an increased chance of contamination from bioburden.
This initiative will solve many problems for the pharmaceutical company: expedite the assembly process, eliminate unnecessary waste and cost, and sterilize the workspace. When working on the assembly process, SAT noticed one common challenge—the needle was not in the exact same location at every pull of the robot, making the insertion process extremely difficult.
Solutions:
This is where a precise, engineered approach makes things interesting. SAT created SEYMOUR TRI-21, a semi-autonomous machine that capitalizes on precision, sterilization, and waste elimination. It contains three 6-axis robots with an objective to take the syringe from Point A to Point B, inserting the wire into the needle without fail. What makes the SEYMOUR TRI-21 solution even more reliable is that the company’s microneedle will now be produced in a fully automated environment, versus the manual and semi-automated processes used by other manufacturers.
One of a kind:
This one-of-a-kind process starts out with the object being picked up and placed under a micro resolution camera that uses variable strobing technology, also known as structured light modularization, to detect “shadows” in order to find where physical parts of the object are in a certain vicinity. The thickness, length, and straightness are then calculated. SAT then uses this raw data to calculate the relative positional error and move the robots to a new position that allows accurate assembly. This process is critical as the internal parts “float” inside the shell that is picked up. So, even though they are repeatable, the window in which they repeat is much larger than the tolerance for assembling the parts, without probable interference.
Precision:
As previously stated, the automation process had to be extremely precise due to the properties of the elements being assembled. This is why SAT implemented machine learning. It allows SAT to automatically track data, learn from previous cycles, then adjust and streamline for future cycles—ensuring each needle insertion will align the wire and needle perfectly. The target acceptable success rate is 90% or higher with a 70% increase in productivity, both of which will be achieved with the SEYMOUR TRI-21.
Design:
It was important for the design of the SEYMOUR TRI-21 to be tailored to the company’s needs. During the Discovery Phase of the project, SAT considered all of its wants and needs, then created a machine that checked all the boxes.
Diagnostic handle:
SAT reconfigured the perpendicular handle to a parallel position, giving it more predominance while also allowing minimal restriction of movement for the user.
SAT then established a process for data to be fed to the handle, translated through color modes that alert the operator as to the health of the machine to help them manage maintenance and upkeep.
ISO 7 level cleanroom:
The Seymour TRI-21 was created with medical-grade glass to control the amount of particulate matter that can enter the machine to ensure that all units are sterile to an ISO 7 level requirement. Dry bearings were also used, removing grease contaminants from the manufacturing environment. The robotic arms are also certified up to ISO 4.
The Internet of Things (IoT):
In line with Industry 4.0, the connected ecosystem of the IoT, SAT will provide the company with a remote computer interface, allowing them to operate the
machine remotely on their phone or tablet via an app.
Monitoring:
A machine that builds the parts for another machine needs to be better monitored than the machine that built it. Elements such as force, torsion, velocity, acceleration, time, pressure, volume, weights and masses, translation, and rotation need to be monitored.
The seven SI base units are comprised of:
Length – meter (m)
Time – second (s)
Amount of substance – mole (mole)
Electric current – ampere (A)
Temperature – kelvin (K)
Luminous intensity – candela (cd)
Mass – kilogram (kg)
By monitoring these, or a subset of these that pertain to the product, the SAT solution can then verify that the product becomes both repeatable and predictable, ultimately improving and evolving technology.
SAT also monitors and provides data to support the operation and directions. There are a plethora of variables that affect product quality, but only a small window where products operate consistently. This is referred to as the “quality window.” Ten times the resolution into a measurement is needed to verify that measurement. So, for this project that required a quality window of 60 microns (roughly 0.0105 inch or 1/25 of a human hair) was needed.
Small footprint:
In the current 1,000 sq. ft. cleanroom space, the company can have a maximum of two people working per 8-hour shift. Each person can produce approximately 63 units per hour (1/min.) during a shift for an average of 500 units per shift. The new 60″w x 42″d x 77″h SEYMOUR TRI-21 and one operator will now be able to produce approximately 250 units per hour (4/min.) during an 8-hour shift for an average of 2,000 units per shift (a 400% increase in production).
Additionally, these modular robotic machines can be used for R&D as well as for GMP commercial use. Six different pieces of equipment can now be placed in the same clean room, working independently, having anywhere from two to 10 operators working at one time.
Projected Results:
Once the ophthalmic pharmaceutical company fully implements the use of SEYMOUR TRI-21, they will increase productivity by at least 70% and achieve a success rate of 95% or higher, and have a significant reduction in bioburden. Over the next year, the company will be adding six additional SAT robots to their line, allowing them to increase their production by 2000% by the end of 2022.
Client’s Thoughts on SAT:
“Our partnership with SEYMOUR Advanced Technologies has been great,” said E. Kibby, Manager, Process Development Engineering. “They are very accepting of new ideas and open to collaboration. We’re able to give them enough rope and let them do what they do best. It has been an outstanding partnership.”
