Interference Analysis of One Piece Male Luer Lock ...

JULY 2018WHITEPAPER

www.hcltech.com

INTERFERENCE ANALYSIS OF ONE PIECE MALE LUER LOCK CONNECTOR (COMPLIANCE TO ISO 80369-7) AND TIP PROTECTOR

© 2018, HCL TECHNOLOGIES. REPRODUCTION PROHIBITED. THIS DOCUMENT IS PROTECTED UNDER COPYRIGHT BY THE AUTHOR, ALL RIGHTS RESERVED.

INTERFERENCE ANALYSIS OF ONE PIECE MALE LUER LOCK CONNECTOR AND TIP PROTECTOR | Jul 2018

Table of Contents

Abstract 3

Business Challenge/Needs 4

Definitions 4

Problem Statement 5

Overall Approach of Interference Analysis 5

Conclusion 14

References 14

2



Abstract

In the Healthcare applications and Medical device industry, small bore connectors (Luer) are provided in use with Cap (Tip Protector) to protect the parts (Part mouth, Fluid path etc.) from particulate matter, harmful microorganisms and other foreign matter. The connection between these parts should be easy to remove with minimum removal force by clinicians and patients, whoever is using this product. For this purpose, all the connectors in the medical product assembly are usually designed to fit precisely together with the cap with recommended interference. The interference between two mating parts is contributing a major role for the precise fit when they are assembled.

Generally, the interference analysis ensures the recommended fit to be provided for any mating components. This case study shall be referred for an understanding at a high level for the interference analysis for every caps/connectors/mating components to ensure a good fit between these mating components. This type of analysis can be performed during the design phase of ISO 80369-7 compliance project for a new product design or an existing product which implies a design change especially when the One Piece Male Luer Lock Connector and the cap are required to be assembled.

HCL performed this interference analysis using Computed Aided Design (CAD) 3D models to assess the interference values between One Piece Male Luer Lock (abbreviated as 1PCMLL) Connector and Tip Protector (or Cap) assembly since the Tip Protectors are impacted due to the design change proposed in the 1PCMLL during the design phase for ISO 80369-7 (Corrected version 2016-12-01) standardization. This design change on 1PCMLL has been instigated that in turn, leads to propose a new dimension for the Tip protector to achieve an ideal fit with the Proposed 1PCMLL based on the existing assembly condition. Since the Luer connector is assembled with a Tip Protector, the dimensional changes in one part may affect the interference and contacts area of all the parts in the assembly condition.

3



Business Challenge/Needs

As a part of the compliance process for ISO 80369-7: 2016 all the Luer connectors for the intravascular or hypodermic applications are undergoing Luer design changes or drawing changes which may or may not impact the tip protector design. The design changes in the Luer connectors may affect the interference values between the Luer connecters and Cap/Tip Protectors. The lack of a proper interference fit may lead to induce many risks to end users during product handling with the patients. Therefore, the Cap/Tip Protectors should be altered in a way that the interference values between these mating parts are required to align as equal as possible to the current interference values of the existing mating parts of the same assembly which is in use in the market for a long time considering if no field and customer complaints are reported. Thus, post design phase of ISO 80369-7: 2016 compliance process, an interference analysis between Luer connector and the tip protector plays a major role in the medical field.

Overall, this paper presents an overview of one of the approaches for an Interference Analysis of the One Piece Male Luer Lock Connector (1PCMLL) Vs Tip Protector assembly.

The main intent of this paper is to show the approach of deriving new interference values for an assembly when one of the mating component of the assembly has undergone a design change. The same approach shall be applied to any similar assembly in future.

Definitions

• One Piece Male Luer Lock Connector (1PCMLL): This is a single piece Male Luer part with thread lock. The male Luer component provides a means of making a secure fluid path connection between various IV disposable devices and industry-standard female Luers of mating devices. Simple design variations may allow the attachment of this Luer to a variety of IV tubing sizes.

• Tip Protector: This is acting as a Cap/Protector for the Luer connectors when the Luer connectors are not in use (of therapy), to protect the Luer parts (Part mouth, Fluid path etc.) from foreign matter entering the medical products.

• 1PCMLL Assembly: This refers to One Piece Male Luer Lock assembly consisting of parts - 1PCMLL and Tip protector, as this Luer body component shall be assembled with a tip protector to form the One Piece Male Luer Lock assembly (also referred as 1PC Assembly).

4



5

• Existing: This refers to the current drawing /current revision in use.

• New or Proposed: This refers to the future revision of an existing component and yet to be issued/effective for use.

• CAD model: This refers to generic CAD (Computer Aided Design) solid model for 1PC Male Luer Lock and Tip Protector part/assembly (Information to create CAD model for one piece Luer body and Tip Protector based on existing drawing).

Problem Statement

The current Male Luer Connector design has been found out of compliance due to new standard ISO 80369-7 compliance implementation and proposed with new design change for compliance. The design change in the Luer connector has occurred in the thread profile which contacts the outer ribs of Tip Protector. Hence the interference values between the thread crest diameter of the Luer Connector and the outer rib diameter of Tip Protector will also impact and leads to analyze the assembly conditions. A poor interference fit between these mating parts may lead to the following Risks.

• Slack Assembly - Leads to Expose of Particulate Matter, harmful microorganisms and other foreign matter.

• Tight Assembly - Leads to high friction and rubbing between two mating surfaces and hence required a high removal force to disengage.

Due to this change on Luer Connector, Tip Protector contact area was analyzed for any assembly and manufacturing impacts.

Overall Approach of Interference Analysis

Proposed 1PCMLL and Existing Tip Protector has been found with a tight fit and high friction during assembly and needs more force than the required removal force to disengage the assembly. Multiple CAD Analysis steps and calculations were carried out to assess interference values in the assembly based on the Existing 1PCMLL and the Existing Tip Protector to propose a dimensional change in New Tip Protector by adding or removing the material that will provide the recommended fit in the future assembly condition.

Different levels of interference (High, Medium, Light) values from this analysis were determined (Refer Table 1 below) that provides a proposed dimension for the New Tip Protector design. The design or dimension of 1PCMLL during this analysis was suggested not to be altered as it already imposed a mold change for ISO 80369-7 standard dimensional requirements.



6

Calculations were performed for 1PCMLL and Tip Protector by considering the critical dimensions that are affecting the interference values in the assembly condition. The thread diameter at the crest from Existing 1PCMLL and Diameter across the ribs from Existing Tip Protector are considered as critical dimensions for CAD Analysis and are analyzed for impact fit during assembly (Refer to Step 1).

High Level Process Flow Chart for Interference Analysis:

High Level Process Flow Chart for Interference Analysis

Interference Fit Analysis

Case 1 (High)

Case 2 (Medium)

Case 3 (Low)

Maximum Tip Ø A

Interference Value Per Side

= (A-X)/ 2


= (B-Y)/ 2


= (C-Z)/ 2

Minimum 1PCMLL

Ø X

Minimum Tip Ø C

Maximum 1PCMLL

Ø Z

Nominal 1PCMLL

Ø Y

Nominal Tip Ø B



7

Step 1: Interference Analysis Between Existing 1PCMLL vs. Existing Tip Protector (Existing Assembly Condition)

The below figure shows a pictorial representation of mating points of two mating surfaces.

Interference analysis between two mating parts was carried out for various assembly conditions (Cases) as below.

Case 1- High Interference Fit

Figure 11: Area of Interference - Ribs (Existing Tip Protector) with Round Thread (Existing 1PCMLL)

Figure 2: Case 1 - High Interference Fit (Max Tip Vs Min Luer)

1 All the Figures (Figure 1 to Figure 5) are the extraction from CAD Model created in the PTC Creo Parametric 3.0 Date Code M090

Area of InterferenceRibs (Tip Protector) with

Round Thread of Existing 1PCMLL

Ribs Material

Mating Surfaces

Round Thread

Existing Tip Protector

Existing 1PCMLL


Existing 1PCMLL



8

Case 2- Medium Interference Fit

Case 3- Light Interference Fit

Summary

Figure 3: Case 2 - Medium Interference Fit (Nominal Tip Vs Nominal Luer)

Figure 4: Case 3 - Light Interference Fit (Min Tip Vs. Max Luer)

Table 1: Interference Analysis Results

Existing 1PCMLL Vs Existing Tip Protector Interference Check per side (High, Medium, Light)

Tolerance Range

Tip Protector Diameter

(0.292±0.0022)

1PCMLL Diameter

(0.284±0.002)

High(0.294 Vs.

0.282)

Medium (0.292 Vs.

0.284)

Light (0.290 Vs.

0.286)

Total Interference

per side

Min 0.290 0.282

0.006 0.004 0.0020.004 (0.006

- 0.002)Nom 0.292 0.284

Max 0.294 0.286



Existing 1PCMLL

Existing 1PCMLL

2 All dimensions/values mentioned in this paper are in inches unless otherwise specified



9

Result:

The current total interference per side is calculated as 0.004 (0.006 - 0.002 = 0.004) for existing assembly condition. The High, Medium, Light interference values from the above analysis will be the recommended interference fit for any future Tip Protector design update and confirmed that there is no field and customer complaints received. Based on the above analysis, further calculations/analysis will be performed to find out the amount of material to be sheared off from the Existing Tip Protector along the rib diameter to attain the recommended interference fit and by meeting High, Medium and Light interference fit values per Table 1.

Step 2: Interference Analysis Between Proposed 1PCMLL and Existing Tip Protector (Future Assembly Condition)

The existing 1PCMLL has been designed with Rounded thread profile. The existing 1PCMLL drawing is being revised with new trapezoidal thread profile (Including Crest diameter) for ISO 80369-7 standard compliance. The interference calculations were repeated like Case 1, 2 and 3 conditions of Step 1 by considering the diameter across the ribs 0.292 ± 0.002 (Existing Tip Protector) and the thread crest diameter 0.280 ± 0.003 (Proposed 1PCMLL for ISO 80369-7 dimensional compliance) and derived the three levels of interference fit (High, Medium, Light) to understand the impact in the interference values due to changes in the proposed 1PCMLL.

Result:

The High, Medium and Light interference values from above analysis are not equivalent to the interference values of existing assembly conditions per Table 1 of Step 1. The total interference value per side of 0.005 from Table 2 will be considered as preferable shear off material in Existing Tip Protector and the assessment will be carried out in the further step to meet current assembly condition per Table 1 of Step 1.

Summary

Table 2: Interference Analysis Summary

Proposed 1PCMLL Vs Existing Tip Protector Interference Check per side (High, Medium, Light)

Tolerance Range


(0.292±0.002)

1PCMLL Diameter

(0.280±0.003)

High(0.294 Vs.

0.277)

Medium (0.292 Vs.

0.280)

Light (0.290 Vs.

0.283)

Total Interference

per side

Min 0.290 0.277

0.008 0.006 0.0030.005 (0.008

- 0.003)Nom 0.292 0.280

Max 0.294 0.283



10

Step 3: Interference Analysis Between Proposed 1PCMLL and New Tip Protector (Future Assembly Condition)

As per Step 2, analysis for Step 3 was carried out with the Tip Protector diameter across the ribs 0.287 ± 0.002 (New Tip Protector) which was derived by shear off the material 0.005 and Thread diameter at the crest 0.280 ± 0.003 (Proposed 1PCMLL) assembly conditions and determined the new interference fit like Case 1, 2 and 3 of Step 1.


Result:

The calculated interference values did not meet the interference values in Table 1 of Step 1. The tolerance of the Tip Protector diameter can be revised to achieve the desired interference fit in the further step.

Step 4: Interference Analysis Between Proposed 1PCMLL and New Revised Tip Protector (Revised Rib Ø 0.288 ± 0.001 - Future Assembly Condition)

As per Step 3, analysis for Step 4 was carried out with the Thread diameter at the crest 0.280 ± 0.003 (Proposed 1PCMLL) and Tip Protector diameter across the ribs 0.288 ± 0.001 (New revised Tip Protector) which was derived by revising the tolerance from ± 0.002 to ± 0.001 assembly conditions and determined the new interference fit like Case 1, 2 and 3 of Step 1.


Summary

Summary

Proposed 1PCMLL Vs New Tip Protector Interference Check per side (High, Medium, Light)

Tolerance Range


(0.287±0.002)

1PCMLL Diameter

(0.280±0.003)

High(0.289 Vs.

0.277)

Medium (0.287 Vs.

0.280)

Light (0.285 Vs.

0.283)

Total Interference

per side

Min 0.285 0.277

0.006 0.003 0.0010.005 (0.006 - 0.001)

Nom 0.287 0.280

Max 0.289 0.283

Proposed 1PCMLL Vs Revised Tip Protector Interference Check per side (High, Medium, Light)

Tolerance Range


(0.288±0.001)

1PCMLL Diameter

(0.280±0.003)

High(0.289 Vs.

0.277)

Medium (0.288 Vs.

0.280)

Light (0.287 Vs.

0.283)

Total Interference

per side

Min 0.287 0.277

0.006 0.004 0.0020.004 (0.006

- 0.002)Nom 0.288 0.280

Max 0.289 0.283



11

Result:

The derived interference values are equal to recommended interference values in Table 1 of Step 1 for existing assembly condition. This Interference analysis as in Step 4 is the anticipated assembly fit for any future Tip Protector design changes. Though, the revised dimension 0.288 ± 0.001 is not considered for Tip Protector design change due to its tighter tolerance (±0.001) on the tip protector diameter as Mold Engineering team in general, recommends to maintain the minimum tolerance limits in most of the industries due to mold steel building concerns. The tolerance for Tip Protector diameter across the ribs shall be revised again in the further step to find new interference values as close to existing assembly values as possible.

Note: This step 4 result is more relevant and shall be considered for any future design changes on Tip Protector if there are no concerns on the tolerance limits from mold steel modification stand point.

Step 5: Interference Analysis Between Proposed 1PCMLL and New Recommended Tip Protector (Revised Rib Ø 0.288 ± 0.002 - Future Assembly Condition)

Due to tighter tolerance and mold concerns as per the result of Step 4, again the interference calculations were repeated by considering the thread diameter at the crest 0.280 ± 0.003 (Proposed 1PCMLL) and the Tip Protector diameter across the ribs 0.288 ± 0.002 (Revised Tip Protector) which was derived by revising the tolerance from ± 0.001 to ± 0.002 and determined the new interference fit similar to Case 1, 2 and 3 of Step 1.

Figure 5: Case 1 - High Interference Fit (Max Vs Min)

Case 1- High Interference Fit (Max Vs Min)

New Recommended Tip Protector Proposed 1PCMLL



12

Case 2- Medium Interference Fit (Nominal Vs Nominal)

Case 3- Light Interference Fit (Min Vs. Max)

Figure 6: Case 2 - Medium Interference Fit (Nominal Vs Nominal)

Figure 7: Case 3 - Light Interference Fit (Min Vs. Max)


Summary

Proposed 1PCMLL Vs New Recommended Tip Protector

Interference Check per side (High, Medium, Light)

Tolerance Range


(0.288 ± 0.002)

1PCMLL Diameter

(0.280±0.003)

High(0.290 Vs.

0.277)

Medium (0.288 Vs.

0.280)

Light (0.286 Vs.

0.283)

Total Interference

per side

Min 0.286 0.277

0.006 0.004 0.0010.005 (0.006 - 0.001)

Nom 0.288 0.280

Max 0.290 0.283

New Recommended Tip Protector

New Recommended Tip Protector

Proposed 1PCMLL

Proposed 1PCMLL



13

Result:

The derived Light, Medium and High interference fits are the recommended and concluded values to update the existing drawing with above specified tolerances for New Tip protector design and meets as close as to existing assembly condition as possible, even though light interference has a slight difference on only the low side.

Impact Analysis of Tip Protector Design Change (New Rib Ø 0.288 ± 0.002) - Cross Reference Check with Existing 1PCMLL:

In order to understand the New Tip protector impacts on Existing 1PCMLL, the New Tip Protector was verified for its suitability with Existing 1PCMLL as similar to Case 1, 2 and 3 in Step 1. In this analysis, New Tip Protector diameter across the ribs was maintained as 0.288 ± 0.002 per Step 5 and the Existing 1PCMLL thread diameter at the crest was kept as 0.284±0.002.

Result:

The High, Medium, Light interference values are not equal to recommended interference fit in Table 1 of Step 1, therefore it is not recommended to use the New Tip Protector with the Existing 1PCMLL in any of the products in the future.


Summary

Existing 1PCMLL Vs New Tip Protector Interference Check per side (High, Medium, Light)

Tolerance Range


(0.288±0.002)

1PCMLL Diameter

(0.284±0.002)

High(0.290 Vs.

0.282)

Medium (0.288 Vs.

0.284)

Light (0.286 Vs.

0.286)

Total Interference

per side

Min 0.286 0.282

0.004 0.002 0.0000.004 (0.004

- 0.000)Nom 0.288 0.284

Max 0.290 0.286



Conclusion

The recommended (optimal) Tip Protector diameter across the ribs was calculated and concluded as 0.288 ± 0.002 (New Tip Protector diameter) per Table 5 in Step 5 compared to 0.292 ± 0.002 (Existing Tip Protector diameter) in this design condition where similar types of 1PCMLL and Tip protector will be used in any of the medical products. As a result, Existing Tip Protector ribs shall be sheared off by 0.002 (0.0508 mm) across the diameter and the mold steel shall be modified as required.

Tip Protector drawing will be revised accordingly as per the interference analysis and CAD analysis results. The proposed dimension of the Tip Protector diameter across the ribs allows to achieve the recommended interference fit for Proposed 1PCMLL from this analysis. Actual samples of New Tip Protector from modified mold will be tested again with Proposed 1PCMLL for verification of the torque and Tip Protector removal force per the component functional requirements to confirm that the same interference fit shall be achieved with the Proposed 1PCMLL in future.

References

• https://www.iso.org/home.html

• https://www.fda.gov

• http://stayconnected.org/frequently-asked-questions/

• ISO 80369-7 (Corrected version 2016-12-01) Small-bore connectors for liquids and gases in healthcare applications — Part 7: Connectors for intravascular or hypodermic applications

14



Author Info

Anguraj Vazhavanthan

Anguraj Vazhavanthan has a Bachelor’s Degree in Mechanical Engineering. He has 6 years of experience, of which he spent 3 years in Medical Device Industry Domain - Specializing in Product Compliance, Product Design, Test method Validation and Design History File remediation. He also worked in Special Purpose Machine design and Product design in the core Engineering field.

Suresh Kumar Rajasekaran

Suresh Kumar Rajasekaran has a Masters’ in Business Administration in Operation Management and completed Bachelors’ in Mechanical Engineering. He has over 15 years’ experience, of which 6 years in Medical device industry product development and ISO 80369-7, ISO 7886-1/2, ISO 594-1/2 standard compliance program as a Technical R&D Lead for Syringes, Needles, IV connectors, Pharmacy products. He also worked in Rail systems, Mobile cranes, Industrial systems, and Manufacturing process in the core Engineering field.

15

About HCL Technologies

HCL Technologies (HCL) is a leading global IT services company that helps global enterprises re–imagine and transform their businesses through digital technology transformation. HCL operates out of 32 countries and has consolidated revenues of US$ 6.97 billion, for 12 months ended 31st December, 2016. HCL focuses on providing an integrated portfolio of services underlined by its Mode 1–2–3 growth strategy. Mode 1 encompasses the core services in the areas of Applications, Infrastructure, BPO, and Engineering & R&D services, leveraging DRYiCE™Autonomics to transform clients’ business and IT landscape, making them ‘lean’ and ‘agile’. Mode 2 focuses on experience–centric and outcome–oriented, services such as Digital and Analytics Services (BEYONDigital™), IoT WorKS™, Cloud and Security, utilizing DRYiCE™ Orchestration to drive business outcomes and enable enterprise digitalization. Mode 3 strategy is ecosystem–driven, creating innovative

IP–partnerships to build products and platforms business.

HCL leverages its global network of integrated co-innovation labs, and global delivery capabilities to provide holistic multi–service delivery in key industry verticals including Financial Services, Manufacturing, Telecommunications, Media, Publishing, Entertainment, Retail CPG, Life Sciences Healthcare, Oil & Gas, Energy & Utilities, Travel, Transportation & Logistics and Government. With 120,000 professionals from diverse nationalities, HCL focuses on creating real value for customers by taking ‘Relationships Beyond the Contract’. For more

information, please visit www.hcltech.com.

About HCL Enterprise

HCL is a $7.5 billion leading global technology and IT enterprise comprising two companies listed in India – HCL Technologies and HCL Infosystems. Founded in 1976, HCL is one of India’s original IT garage start-ups. A pioneer of modern computing, HCL is a global transformational enterprise today. Its range of offerings includes product engineering, custom & package applications, BPO, IT infrastructure services, IT hardware, systems integration, and distribution of information and communications technology (ICT) products across a wide range of focused industry verticals. The HCL team consists of over 120,000 ideapreneurs of diverse nationalities, who operate from 32 countries including over

500 points of presence in India. HCL has partnerships with several leading global 1000 firms, including leading IT and technology firms. For more information, please www.hcl.com

Hello there! I am an Ideapreneur. I believe that sustainable business outcomes are driven by relationships nurtured through values like trust, transparency and flexibility. I respect the contract, but believe in going beyond through collaboration, applied innovation and new generation partnership models that put your interest above everything else. Right now 120,000 Ideapreneurs are in a Relationship Beyond the Contract™ with 500 customers in 32 countries. How can I help you? W

I-103

2173

1277

0801

-EN

00G

L

Interference Analysis of One Piece Male Luer Lock ...

Documents

Transcript of Interference Analysis of One Piece Male Luer Lock ...