Automated Vial Torquing Machine

Sponsor: AlloSourceDirector: Dr. Maureen Lynch

Team 1: Blaire Rodriguez, Abdullah Alkhaldi, Evan Blake, Ben Piquard, Grant Hupp, Jared Moya, Nebiyu Tadesse

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Contents

Executive Summary

Project Background

Design Overview

Testing

Challenges and Final Outcome

The demand for tissue and organ donors is atan all-time high and continues to rise.AlloSource, the sponsor of Team 1, providestissue donations to those in need. Thesetissue donations, known as allografts, areprocessed in an aseptic, clean roomenvironment in which vials are filled withtissue before being capped and sent off.These vials must be torqued to a certain specification to prevent outside aircontamination and maintain the sterileintegrity of the donations.

Executive Summary Project High-Level Goals:

Torque Standard - Vials are torqued to 23 +/- 1 in.lbsAutomation - Vials are torqued with minimal to no operator interactionAssembly - Assembly and disassembly in under 10 minutes.Lightweight - Turntable delivery assembly shall stay under 10 lbs.Size - The full assembly shall fit within an area of 2 ft x 3 ftSterile - Designed to withstand steam sterilization conditions of up to 272°F

Kinex Capper SA-2000-DPB

AlloSource’s current process to cap these vialsinvolves technicians using a torque wrench tomanually tighten them. Consequently, they havecome across technicians incurring wrist motioninjuries due to the repetitive nature of the task. Tomitigate these safety concerns, AlloSource acquireda semi-automated torquing device from KinexCappers. This machine however was not user-friendly and still required too much operatorinteraction. The main goal of our project this year: Minimizeergonomic safety risks and increase productthroughput by retrofitting AlloSource’s KinexCapper.

Project Background

An allograft procedure is an essential medicalprocess that involves the transplant of bone or tissuefrom one person to another. This is very useful whena person encounters a bone, skin, or soft-tissueinjury and could potentially serve as a life-savingprocedure. Since this product deals with materialsthat will have direct bodily human contact, it is ofutmost importance that everything remains asepticthroughout the handling stage. The currentprocedure AlloSource uses to process their allograftsinvolves technicians manually tightening caps to atorque specification. This process is tedious and acause for ergonomic concern of the technicians.

An automated method is preferred tomitigate these adverse health risks. Notonly would this decrease the amount ofwork-related injuries, but also streamlinethe vial torquing procedure. This couldresult in increase throughput andproductivity. This report will describe themission behind the project, provide adesign overview of the prototype brokendown, define analysis processes to come,and lastly, will clearly state and justifyproject budget and timeline.

Available Organ and Tissue Donations

An Aseptic Room at the AlloSource Facility

Design Overview

The objective of this project is to modifythe Kinex Cappers SA-2000-DPB machinein order to automate the capping process aswell as maximize throughput. AlloSourceneeded the entire machine to fit on the 24"by 36" table, while also being able towithstand the cleaning techniques alreadyin place to ensure a clean roomenvironment. To achieve this goal, the team exploreddifferent options to ensure precise vialplacement. Different gripping methods, aconveyor system, and switches were allfeasible solutions. In the end, we chose to design a Genevawheel style drive mechanism withinterchangeable turntables.

Using the disk to hold multiple vials, thefixture will rotate the disks allowing theKinex Capper to rapidly torque multiplevials. Team 1 decided to design a 16"diameter disk manufactured out ofPolysulfone thermoplastic that can houseup to 15 vials. This design and materialfulfilled both the size and sterileconstraints, while minimizing the weight. To properly position the vials under thecapping head repeatedly, we utilized aGeneva wheel--a unique drive mechanismwhere every full rotation of the driver gearindexes the wheel to discrete positions onlydependent on its geometry. The driver gearis driven by a stepper motor in order toachieve precise open-loop control.

Turntable System mounted on BaseplateExploded View of the Turntable System

Vial Turntable

Geneva Wheel

Axle

Geneva Driver

Stepper Motor

Design Overview

In order to give the user an easy interfacewith the machine, a graphical user interface(GUI) was developed and displayed on a3.5-in TFT Touch Screen. For thecontroller, the Arduino Mega was used toincorporate the ATmega 2560 chip fromAtmel. We selected this microcontroller dueto its low cost, Flash Memory and RAMsize, and its large support community. The GUI offers two different modes:: Fully-Autonomous and Semi-Autonomous. TheFully Autonomous Mode gives thetechnician the option to put a full turntableon and let the machine go through andtorque each of the holes containing a vial byjust pressing the "START" button. Theprogress is displayed on the gauge and a"STOP" button is also incorporated just incase the user wants to stop at any stage ofthe process.

The Semi-Autonomous mode wascreated to give the technician individualfeed control. The page offers 4 buttons,main ones being the "Advance Forward","Advance Backward" and "Torque". The"Advance Forward" and "AdvanceBackward" buttons just advance the diskby one hole clockwise and counter-clockwise respectively. The "Torque"button initiates the torquing process. The stepper motor drives the genevawheel and the torquing process is initiatedby the solenoid. The stepper motor iscontrolled using the A3967 MicrosteppingDriver and the solenoid is controlled usingthe RFP30N06LE N-Channel MOSFET.

Fully Autonomous Mode Selection Display Semi-Autonomous Mode Selection Display

Testing

This Test Plan will be divided into two main sections: [1] Specification Tests[2] Functionality Tests These two types of tests will provide Team 1 with the data necessary to confirm that thespecifications agreed upon with AlloSource are satisfied and that the custom mechanical,electrical, and software components are fully functional.

Desired Outcomes

Data Analysis & ReportingThe specification tests, unless otherwise noted, all have measurable values that are defined ineach test sub-section. Each test will confirm that the proper relationship with the collected data anddefined specifications agree with each other and if not, the proper design or manufacturingchanges will be implemented until the specifications are met. The functionality tests will ensureproof of concept and will help Team 1 catch any design flaws or interference present on sub-assembly and full-assembly levels.

Revised Test Plan Due to COVID-19 and lack of resources, Team 1 was unable to fully execute the initial Test Plan.The following tests were affected: Vial Torquing and Indication Test Automation InspectionAssembly Test Lightweight Test Size Inspection Sterility Test

no longer viable without further manufacturing can no longer test with technicians, but still viable can no longer test with technicians, but still viable

viable once full assembly completeviable once full assembly completeviable once full assembly complete

Testing

During the Full Assembly Functionality Test,the stepper motor angular velocity was toofast, causing jolting in the system duringVial Turntable rotation. The team addedextra weight onto the geneva wheel andrealized that the weight of the Vial Turntablewas not the issue. It was determined themoment of inertia of the Vial Turntable wastoo large for the stepper motor to overcome,due to the disk's large diameter.

Motion TestingVial Pathway ClearanceThe Vial Turntable was designed with theidea that all four vial grippers would be ableto grip the vial from the furthest placement.However, after running the Full AssemblyFunctionality Test, the grippers needed tobe placed in a specific orientation toachieve proper vial grip and torqueactuation. The vials follow the circular pathshown in red. For a clear path, grippers 1and 3 needed to be pushed all the wayback while 2 and 4 are placed so that thevial will be both gripped and able to clearwith no mechanical interference.

The initial stepper motor angular velocitywas set to 150 rev/min, but was changed toa more conservative value of 19 rev/min.This change allowed the Vial Turntable toturn with no jolting.

Moment of Inertia (Disk) I = (1/2)MR^2

where, M = massR = radiusAnnotated Top View of Full Assembly

Geneva wheel with 2.5-lb additional load

Challenges and Outcome

There were two overarching challenges of this project - to specify and deliver a design which conformedto clean room standards; and to retrofit the existing machine with unitize-able systems. This impliedseveral requirements: resilient raw materials, ease of assembly and disassembly, and the ability tointerface with the capping machine's existing and proprietary designs. The design materials had to becapable of withstanding multiple cycles of high temperature, high pressure, and strong chemical cleanerswithout degradation. Along with this, the entire assembly had to be easily assembled and disassembledfor these sanitation measures.

The final outcome was a success and resulted in an efficient and reliable automated system, capable ofincreased throughput with minimal operator interaction. The team was able to execute on the goal ofmitigating the ergonomic risk associated with the current process in place. The design incorporatesinterchangeable 'turntables' which stage 15 vials at a time. These turntables can be pre-loaded andquickly changed out to expedite the capping process. This will allow technicians to stage many of theseturntables for hands-free capping. The system includes a 'fully-autonomous' and 'semi-autonomous' mode which the technician can choosefrom the human-machine interface touchscreen. This will either process an entire turntable or allow thetechnician to cap one-by-one for a partially filled disk.

Kinex SA-2000-DPB capping machine retrofitted with Team 1's automated delivery system. Render on the left, actual assembly on the right