ASTM F3275-22

Standard Guide for Using a Force Tester to Evaluate Performance of a Brush Part Designed to Clean the Internal Channel of a Medical Device

SIGNIFICANCE AND USE
5.1 This guide provides test methods for evaluating the performance characteristics of a brush part designed to clean internal channel(s) of a medical device.  
5.1.1 The force required to move a brush part within a tube, an indicator of the friction a brush exerts on a surface, is a parameter of cleaning effectiveness and should be measured.  
5.1.2 The removal of soil from a tube by a brush part moved in a tube is a further indicator of the effectiveness of a brush to loosen and remove soil from a tube and should be measured.  
5.2 By providing objective, repeatable methods for evaluating performance, this guide can improve the ability to assess the effectiveness, under test conditions, of various brush part designs.
SCOPE
1.1 Brushes used to clean a medical device after clinical use play an important role in effective reprocessing. This guide describes methods for characterizing, under prescribed laboratory conditions, the efficacy of brush parts designed to clean the internal channels of medical devices. The methods utilize a force tester to mechanically actuate a brush part within a channel: (1) Methods to measure, at an established speed, the force required to move a brush within a channel; (2) Methods utilize the same force tester and protocols to measure soil removal from a soiled tube, another indicator of performance.  
1.2 Inclusions:  
1.2.1 This guide describes objective, quantifiable, and reproducible methods for evaluating the cleaning characteristics of a brush part under prescribed laboratory conditions, with test methods that simulate the cleaning challenge of a defined target area(s) of a medical device. This also makes possible the comparison of one design of a brush part to another.  
1.2.2 In this guide, a brush part is one that is intended to be moved within a tube.  
1.2.3 Tubes used for testing described in this guide are cylindrical and uniform in diameter. The test methods describe may not apply to non-cylindrical tubes.  
1.2.4 By use of this guide, medical device manufacturers can characterize the brush part designed for cleaning their device.  
1.2.5 By use of this guide, manufacturers of cleaning brushes can evaluate and characterize the cleaning performance of their brushes for the target area(s) of medical device(s), including allowing a comparison with existing brush part designs offered on the market. Further, they are able to evaluate modifications to designs and construction that might improve performance.  
1.2.6 This information can also be shared with the users of the brushes (medical device reprocessors) to help them evaluate the performance of commercially available brushes.  
1.3 Exclusions:  
1.3.1 This guide does not assess potential damage that may be inflicted by the brush. For instance, brushes with rigid bristles (for example, stainless steel or other metals) or other abrasive materials are more likely to damage medical devices than brushes with flexible bristles (for example, nylon) or more pliable materials. Potential damage from more abrasive materials should be assessed.  
1.3.2 This guide does not specify acceptance criteria, and the results will be dependent on the specific parameters (for example, test soil, drying time, channel inside diameter and material, and so forth) that are tested.  
1.3.3 This guide is not intended to constitute all steps required to conduct validation of cleaning instructions for a medical device, including the use of brushes for this purpose, but provides methods that may be part of a broader protocol to conduct a complete cleaning instructions validation.  
1.3.4 If a brush is intended to clean a specific device(s), cleaning validation shall include testing with that device(s).  
1.4 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 This standard does not purport to address all of the safety concerns, if an...

General Information

• Status: Published
• Publication Date: 31-Dec-2021
• ICS: 11.040.01 - Medical equipment in general
• Technical Committee: F04 - Medical and Surgical Materials and Devices
• Drafting Committee: F04.15 - Material Test Methods

Relations

• Refers: ASTM F3208-20 - Standard Guide for Selecting Test Soils for Validation of Cleaning Methods for Reusable Medical Devices
• Effective Date: 15-Jul-2020
• Refers: ASTM F3208-19 - Standard Guide for Selecting Test Soils for Validation of Cleaning Methods for Reusable Medical Devices
• Effective Date: 15-Nov-2019
• Refers: ASTM F3208-18 - Standard Guide for Selecting Test Soils for Validation of Cleaning Methods for Reusable Medical Devices
• Effective Date: 01-Oct-2018
• Refers: ASTM F3208-17 - Standard Guide for Selecting Test Soils for Validation of Cleaning Methods for Reusable Medical Devices
• Effective Date: 15-Jan-2017

Overview

ASTM F3275-22 is the ASTM International standard guide for using a force tester to evaluate the performance of a brush part designed for cleaning the internal channels of medical devices. Effective cleaning of internal lumens is critical for infection prevention and successful reprocessing in healthcare settings. This guide details objective, repeatable laboratory methods to measure cleaning efficacy and comparative performance of brush parts intended for device channels.

Testing as outlined in ASTM F3275-22 allows manufacturers and reprocessors to quantitatively assess attributes such as cleaning force and soil removal, key indicators of the brush's performance. The standard is applicable to cylindrical, uniform devices and supports the evaluation and comparison of new and existing brush designs.

Key Topics

• Force Testing for Cleaning Effectiveness

  • Measures the force required to move a brush part within a channel, providing data on friction and contact effectiveness.
  • Allows for comparisons between brush designs or modifications.

• Soil Removal Assessment

  • Evaluates the ability of a brush part to remove test soils from a simulated device channel.
  • Utilizes weighing of tubes before and after testing to determine cleaning performance.

• Test Apparatus and Protocols

  • Describes the use of a programmable force tester, mounting apparatus, and clinically relevant tube sizes and materials.
  • Emphasizes the importance of consistent speed, distance, and cycles for repeatability.

• Selection of Tubes and Test Soils

  • Specifies matching tube diameter and material to intended device channels.
  • Recommends test soils reflect real-world contamination per referenced standards and guidelines.

• Reporting and Documentation

  • Advocates for detailed reporting of brush and tube composition, test parameters, and quantitative results for both force and soil removal.

Applications

ASTM F3275-22 is highly relevant for:

• Medical Device Manufacturers:

  • Characterize and document the cleaning efficacy of brushes intended to reprocess their devices.
  • Benchmark new brush designs or improvements for internal channel cleaning.

• Brush Manufacturers:

  • Objectively evaluate brush performance for specific device applications.
  • Support design enhancements and competitive claims about cleaning performance.

• Medical Device Reprocessors:

  • Assess commercial brush options to ensure effective cleaning in clinical reprocessing workflows.
  • Reference quantitative test data when validating or selecting cleaning accessories.

• Regulatory and Compliance Personnel:

  • Use standardized quantitative methods to support validation of cleaning instructions within medical device reprocessing protocols.

This guide is especially valuable for ensuring cleaning accessories meet the performance expectations necessary for safe medical device use.

Related Standards

• ASTM F3208: Guide for Selecting Test Soils for Validation of Cleaning Methods for Reusable Medical Devices.
• ISO 17664: Processing of health care products - Information to be provided by the medical device manufacturer for the processing of medical devices.
• ISO 15883-1 & ISO/TS 15883-5: Standards for washer-disinfectors and cleaning validation.
• AAMI TIR12 & TIR30: Guidance on designing, testing, labeling, and validating cleaning methods for reusable medical devices.
• FDA Guidance: Reprocessing Medical Devices in Health Care Settings.

By referencing these international and U.S. standards and guidance documents, ASTM F3275-22 positions itself within a robust regulatory and technical framework for medical device reprocessing.

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Keywords: ASTM F3275-22, medical device brush performance, cleaning validation, force tester, internal channel cleaning, soil removal, brush design testing, medical device reprocessing, laboratory methods, cleaning efficacy standard.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F3275 − 22
Standard Guide for
Using a Force Tester to Evaluate Performance of a Brush
Part Designed to Clean the Internal Channel of a Medical
Device
This standard is issued under the fixed designation F3275; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope evaluate modifications to designs and construction that might
improve performance.
1.1 Brushes used to clean a medical device after clinical use
1.2.6 This information can also be shared with the users of
play an important role in effective reprocessing. This guide
the brushes (medical device reprocessors) to help them evalu-
describes methods for characterizing, under prescribed labora-
ate the performance of commercially available brushes.
tory conditions, the efficacy of brush parts designed to clean
the internal channels of medical devices. The methods utilize a 1.3 Exclusions:
force tester to mechanically actuate a brush part within a 1.3.1 This guide does not assess potential damage that may
channel: (1) Methods to measure, at an established speed, the be inflicted by the brush. For instance, brushes with rigid
force required to move a brush within a channel; (2) Methods bristles (for example, stainless steel or other metals) or other
utilize the same force tester and protocols to measure soil abrasive materials are more likely to damage medical devices
removal from a soiled tube, another indicator of performance. thanbrusheswithflexiblebristles(forexample,nylon)ormore
pliable materials. Potential damage from more abrasive mate-
1.2 Inclusions:
rials should be assessed.
1.2.1 This guide describes objective, quantifiable, and re-
1.3.2 This guide does not specify acceptance criteria, and
producible methods for evaluating the cleaning characteristics
the results will be dependent on the specific parameters (for
ofabrushpartunderprescribedlaboratoryconditions,withtest
example, test soil, drying time, channel inside diameter and
methodsthatsimulatethecleaningchallengeofadefinedtarget
material, and so forth) that are tested.
area(s) of a medical device. This also makes possible the
1.3.3 This guide is not intended to constitute all steps
comparison of one design of a brush part to another.
required to conduct validation of cleaning instructions for a
1.2.2 In this guide, a brush part is one that is intended to be
medical device, including the use of brushes for this purpose,
moved within a tube.
but provides methods that may be part of a broader protocol to
1.2.3 Tubes used for testing described in this guide are
conduct a complete cleaning instructions validation.
cylindrical and uniform in diameter. The test methods describe
1.3.4 If a brush is intended to clean a specific device(s),
may not apply to non-cylindrical tubes.
cleaning validation shall include testing with that device(s).
1.2.4 By use of this guide, medical device manufacturers
can characterize the brush part designed for cleaning their 1.4 Units—The values stated in SI units are to be regarded
device. as standard. No other units of measurement are included in this
1.2.5 By use of this guide, manufacturers of cleaning standard.
brushes can evaluate and characterize the cleaning perfor-
1.5 This standard does not purport to address all of the
mance of their brushes for the target area(s) of medical
safety concerns, if any, associated with its use. It is the
device(s), including allowing a comparison with existing brush
responsibility of the user of this standard to establish appro-
part designs offered on the market. Further, they are able to
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accor-
dance with internationally recognized principles on standard-
This guide is under the jurisdiction of ASTM Committee F04 on Medical and
Surgical Materials and Devices and is the direct responsibility of Subcommittee
ization established in the Decision on Principles for the
F04.15 on Material Test Methods.
Development of International Standards, Guides and Recom-
Current edition approved Jan. 1, 2022. Published January 2022. Originally
mendations issued by the World Trade Organization Technical
approved in 2019. Last previous edition approved in 2019 as F3275 – 19. DOI:
10.1520/F3275-22. Barriers to Trade (TBT) Committee.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F3275 − 22
2. Referenced Documents 3.2.6 moving the brush part—the movement of the brush
2 part inside the tube.
2.1 ASTM Standards:
3.2.7 outside diameter (OD)—the external diameter of a
F3208 Guide for Selecting Test Soils for Validation of
lumen/tube or brush part.
Cleaning Methods for Reusable Medical Devices
3.2.8 soiled tube—for the purposes of this document, refers
2.2 ISO Standards:
to a tube that has been inoculated with test soil.
ISO 17664 Processing of health care products—Information
to be provided by the medical device manufacturer for the
3.2.9 surface roughness—the shorter frequency of real sur-
processing of medical devices
faces relative to the troughs.
ISO 15883-1 Washer-disinfectors—Part 1: General
3.2.10 tube—for the purposes of this document, refers to the
requirements, terms and definitions and tests
tube that is mounted into the jig.
ISO/TS 15883-5 Washer-disinfectors—Part 5: Performance
requirements and test method criteria for demonstrating
4. Summary of Practice
cleaning efficacy
4 4.1 This guide provides details for testing the resistance of
2.3 AAMI Documents:
a brush part moved inside a tube to simulate the resistance of
AAMITIR12 Designing,testingandlabelingreusablemedi-
a brush used to clean the internal channels of a medical device.
cal devices for reprocessing in health care facilities: A
4.2 This guide also provides details for soiling a tube,
guide for medical device manufacturers
moving a brush part inside that tube, and measuring the soil
AAMI TIR30 A compendium of processes, materials, test
removed from that tube to simulate the cleaning of the internal
methods, and acceptance criteria for cleaning reusable
medical devices channels of a medical device.
2.4 FDA Document:
4.3 Tubesizeshouldbeselectedbasedupontherangeofthe
Reprocessing Medical Devices in Health Care Settings: inside diameter (ID) of the different lumens the brush is
Validation Methods and Labeling Guidance for Industry
intended to clean.
andFoodandDrugAdministrationStaff,issuedMarch17,
4.4 Composition and application of the test soil should be
based upon an evaluation of the clinical use of the device
(Guide F3208, ISO 17664, AAMI TIR12, AAMI TIR30).
3. Terminology
3.1 Definitions:
5. Significance and Use
3.1.1 cleaning—removal of contamination from a medical
5.1 This guide provides test methods for evaluating the
device to the extent necessary for further processing or for its
performance characteristics of a brush part designed to clean
intended use.
internal channel(s) of a medical device.
3.2 Definitions of Terms Specific to This Standard:
5.1.1 The force required to move a brush part within a tube,
3.2.1 brush part—working end of the brush that is intended
an indicator of the friction a brush exerts on a surface, is a
to come in contact with the targeted internal surface(s) of the
parameter of cleaning effectiveness and should be measured.
lumen/tube.
5.1.2 Theremovalofsoilfromatubebyabrushpartmoved
in a tube is a further indicator of the effectiveness of a brush to
3.2.2 extraction of the brush part—depending upon the
loosen and remove soil from a tube and should be measured.
method used, this may be the exit of the proximal end of the
brushpartfromthetube(Section8);ortheexitofthedistalend
5.2 By providing objective, repeatable methods for evaluat-
of the brush part from the distal end of the tube (Section 9).
ing performance, this guide can improve the ability to assess
3.2.3 insertion of the brush part—the introduction of the the effectiveness, under test conditions, of various brush part
proximal end of the brush part to the proximal end of the tube.
designs.
3.2.4 inside diameter (ID)—the internal diameter of a
6. Description of Test Apparatus
lumen/tube.
6.1 A force testing machine with moving crosshead, a load
3.2.5 jig—the apparatus which holds the lumen or tube still
cell, a chuck for holding the brush part, a set of tubes with
on the force tester during testing.
various diameters for the brush part to be actuated into, and a
holder for the tubes (see Fig. 1).
2 6.1.1 The crosshead shall be programmable for the speed
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM and the distance it actuates.
Standards volume information, refer to the standard’s Document Summary page on
6.1.2 The force required to actuate the brush part up and
the ASTM website.
down shall be measured.
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
6.1.3 The chuck attaches to the crosshead and holds the
4th Floor, New York, NY 10036, http://www.ansi.org.
Available from Association for the Advancement of Medical Instrumentation
brush part in place. The chuck must be able to tighten on the
(AAMI), 4301 N. Fairfax Dr., Suite 301, Arlington, VA 22203-1633, http://
brush part and hold it securely in place.
www.aami.org.
6.1.4 The tubes should be composed of a material similar to
https://www.fda.gov/downloads/medicaldevices/deviceregulationandguidance/
guidancedocuments/ucm253010.pdf the composition of the lumens of medical devices. The tubes
F3275 − 22
of; (2) the surface finish (for example, machined, ground,
polished); and (3) the device geometry (that is, crevices,
ridges).
7.1.2.1 The same brush may be used on more than one type
of device and therefore different substrates may be selected to
evaluate performance.
7.1.3 The tube should be the same length as the brush part,
suchthatthedistalendofthebrushreachesthedistalendofthe
tube.
7.2 Selection of Test Soil and Application Method:
7.2.1 The test soil should be similar in composition and
physical qualities to the clinical soil the medical device comes
in contact with during use (Guide F3208, AAMI TIR12).
7.2.2 The application of the soil should simulate the worst-
casesoilingthatamedicaldeviceislikelytoexperienceduring
clinical use (see Guide F3208 and FDA Guidance Document
(2015) for discussion of methods for determining worst-case
soiling).
7.2.3 Thetimethesoilisallowedtodryonthesurfaceofthe
tube should simulate worst-case drying during clinical use.
7.2.4 A cleaning solution that is similar to the cleaning
solution likely to be used to clean the device after clinical use
should be selected (AAMI TIR12, AAMI TIR30).
7.2.5 The testing protocol shall specify the number of
replicates (AAMI TIR30 recommends a minimum of three).
8. Procedure for Testing Resistance in a Tube by
Actuation
8.1 Mountthebrushpartinthechuckoftheforcetester(see
FIG. 1 Force Testing Machine
Fig. 2).
8.1.1 Alternative methods for holding the brush part may be
employed,dependingonthesizeandconfigurationofthebrush
should have accurate inner diameters similar to the diameters
head. One alternative is a vice grip.
of the lumens of medical devices.
6.1.5 The tube holder should be able to accommodate the 8.2 Select the tube for testing (see 7.1.1) and mount to the
base of the force tester (see Fig. 3).
outer diameter of the tubes, and secure them in place.
6.2 Sensitive Analytical Scale: 8.3 Alignthebrushpartatthemouthofthetube(seeFig.4).
To ensure a smooth transition, it will likely be necessary to
6.2.1 To determine the weight differences in the soiled
tubes, the scale shall be sensitive to at least 0.1 mg. align the brush while minimally inserted into the tube. This
should be done so that the longitudinal axis of the tube sample
6.2.2 The scale shall have a large enough stage to weigh the
selected tube size. is aligned with the longitudinal axis of the bru
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F3275 − 19 F3275 − 22
Standard Guide for
Using a Force Tester to Evaluate Performance of a Brush
Part Designed to Clean the Internal Channel of a Medical
Device
This standard is issued under the fixed designation F3275; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 Brushes used to clean a medical device after clinical use play an important role in effective reprocessing. This guide describes
methods for characterizing, under prescribed laboratory conditions, the efficacy of brush parts designed to clean the internal
channels of medical devices. The methods utilize a force tester to mechanically actuate a brush part within a channel: (1) Methods
to measure, at an established speed, the force required to move a brush within a channel; (2) Methods utilize the same force tester
and protocols to measure soil removal from a soiled tube, another indicator of performance.
1.2 Inclusions:
1.2.1 This guide describes objective, quantifiable, and reproducible methods for evaluating the cleaning characteristics of a brush
part under prescribed laboratory conditions, with test methods that simulate the cleaning challenge of a defined target area(s) of
a medical device. This also makes possible the comparison of one design of a brush part to another.
1.2.2 In this guide, a brush part is one that is intended to be moved within a tube.
1.2.3 Tubes used for testing described in this guide are cylindrical and uniform in diameter. The test methods describe may not
apply to non-cylindrical tubes.
1.2.4 By use of this guide, medical device manufacturers can characterize the brush part designed for cleaning their device.
1.2.5 By use of this guide, manufacturers of cleaning brushes can evaluate and characterize the cleaning performance of their
brushes for the target area(s) of medical device(s), including allowing a comparison with existing brush part designs offered on
the market. Further, they are able to evaluate modifications to designs and construction that might improve performance.
1.2.6 This information can also be shared with the users of the brushes (medical device reprocessors) to help them evaluate the
performance of commercially available brushes.
1.3 Exclusions:
1.3.1 This guide does not assess potential damage that may be inflicted by the brush. For instance, brushes with rigid bristles (for
This guide is under the jurisdiction of ASTM Committee F04 on Medical and Surgical Materials and Devices and is the direct responsibility of Subcommittee F04.15
on Material Test Methods.
Current edition approved Jan. 15, 2019Jan. 1, 2022. Published February 2019January 2022. Originally approved in 2019. Last previous edition approved in 2019 as
F3275 – 19. DOI: 10.1520/F3275-19.10.1520/F3275-22.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F3275 − 22
example, stainless steel or other metals),metals) or other abrasive materials,materials are more likely to damage medical devices
than brushes with flexible bristles (for example, nylon) or more pliable materials. Potential damage from more abrasive materials
should be assessed.
1.3.2 This guide does not specify acceptance criteria, and the results will be dependent on the specific parameters (for example,
test soil, drying time, channel inside diameter and material, and so forth) that are tested.
1.3.3 This guide is not intended to constitute all steps required to conduct validation of cleaning instructions for a medical device,
including the use of brushes for this purpose, but provides methods that may be part of a broader protocol to conduct a complete
cleaning instructions validation.
1.3.4 If a brush is intended to clean a specific device(s), cleaning validation shall include testing with that device(s).
1.4 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this
standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
F3208 Guide for Selecting Test Soils for Validation of Cleaning Methods for Reusable Medical Devices
2.2 ISO Standards:
ISO 17664 Processing of health care products—Information to be provided by the medical device manufacturer for the
processing of medical devices
ISO 15883-1 Washer-disinfectors—Part 1: General requirements, terms and definitions and tests
ISO/TS 15883-5 Washer-disinfectors—Part 5: Performance requirements and test method criteria for demonstrating cleaning
efficacy
2.3 AAMI Documents:
AAMI TIR12 Designing, testing and labeling reusable medical devices for reprocessing in health care facilities: A guide for
medical device manufacturers
AAMI TIR30 A compendium of processes, materials, test methods, and acceptance criteria for cleaning reusable medical
devices
2.4 FDA Document:
Reprocessing Medical Devices in Health Care Settings: Reprocessing Medical Devices in Health Care Settings: Validation
Methods and Labeling Guidance for Industry and Food and Drug Administration Staff, issued March 17, 2015
3. Terminology
3.1 Definitions:
3.1.1 cleaning—removal of contamination from a medical device to the extent necessary for further processing or for its intended
use.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 brush part—working end of the brush that is intended to come in contact with the targeted internal surface(s) of the
lumen/tube.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Available from Association for the Advancement of Medical Instrumentation (AAMI), 4301 N. Fairfax Dr., Suite 301, Arlington, VA 22203-1633, http://www.aami.org.
https://www.fda.gov/downloads/medicaldevices/deviceregulationandguidance/guidancedocuments/ucm253010.pdf
F3275 − 22
3.2.2 extraction of the brush part—depending upon the method used, this may be the exit of the proximal end of the brush part
from the tube (Section 8); or the exit of the distal end of the brush part from the distal end of the tube (Section 9)).
3.2.3 insertion of the brush part—the introduction of the proximal end of the brush part to the proximal end of the tube.
3.2.4 inside diameter (ID)—the internal diameter of a lumen/tube.
3.2.5 jig—the apparatus which holds the lumen or tube still on the force tester during testing.
3.2.6 moving the brush part—the movement of the brush part inside the tube.
3.2.7 outside diameter (OD)—the external diameter of a lumen/tube or brush part.
3.2.8 soiled tube—for the purposes of this document, refers to a tube that has been inoculated with test soil and placed inside the
tube.soil.
3.2.9 surface roughness—the shorter frequency of real surfaces relative to the troughs.
3.2.10 tube—for the purposes of this document, refers to the tube that is mounted into the jig.
4. Summary of Practice
4.1 This guide provides details for testing the resistance of a brush part moved inside a tube to simulate the resistance of a brush
used to clean the internal channels of a medical device.
4.2 This guide also provides details for soiling a tube, moving a brush part inside that tube, and measuring the soil removed from
that tube to simulate the cleaning of the internal channels of a medical device.
4.3 Tube size should be selected based upon the range of the inside diameter (ID) of the different lumens the brush is intended
to clean.
4.4 Composition and application of the test soil should be based upon an evaluation of the clinical use of the device (Guide F3208,
ISO 17664, AAMI TIR12, AAMI TIR30).
5. Significance and Use
5.1 This guide provides test methods for evaluating the performance characteristics of a brush part designed to clean internal
channel(s) of a medical device.
5.1.1 The force required to move a brush part within a tube, an indicator of the friction a brush exerts on a surface, is a parameter
of cleaning effectiveness and should be measured.
5.1.2 The removal of soil from a tube by a brush part moved in a tube is a further indicator of the effectiveness of a brush to loosen
and remove soil from a tube and should be measured.
5.2 By providing objective, repeatable methods for evaluating performance, this guide can improve the ability to assess the
effectiveness, under test conditions, of various brush part designs.
6. Description of Test Apparatus
6.1 A force testing machine with moving crosshead, a load cell, a chuck for holding the brush part, a set of tubes with various
diameters for the brush part to be actuated into, and a holder for the tubes (see Fig. 1).
6.1.1 The crosshead shall be programmable for the speed and the distance it actuates.
F3275 − 22
FIG. 1 Force Testing Machine
6.1.2 The force required to actuate the brush part up and down shall be measured.
6.1.3 The chuck attaches to the crosshead and holds the brush part in place. The chuck must be able to tighten on the brush part
and hold it securely in place.
6.1.4 The tubes should be composed of a material similar to the composition of the lumens of medical devices. The tubes should
have accurate inner diameters similar to the diameters of the lumens of medical devices.
6.1.5 The tube holder should be able to accommodate the outer diameter of the tubes, and secure them in place.
6.2 Sensitive Analytical Scale:
6.2.1 To determine the weight differences in the soiled tubes, the scale shall be sensitive to at least 0.1 mg.
6.2.2 The scale shall have a large enough stage to weigh the selected tube size.
7. Selection Criteria for Tubes and Test Soils
7.1 Selection of Tubes for Testing:
7.1.1 The internal diameter (ID) of the tube should be equivalent to the ID of the channel of the medical device(s) the brush is
intended to clean.
7.1.1.1 Often there is a range of channel IDs that a brush is intended to clean. At a minimum, the tubes should include the smallest
and largest channel IDs of that range.
F3275 − 22
7.1.2 The physical characteristics of the internal surface of the tube should be similar to the physical characteristics of the surface
of the medical device(s) the brush is intended to clean. This includes the surface roughness and any geometric features like
crevices, ridges, and so forth (AAMI TIR30). The following should be considered in the selection of surface substrate for testing:
(1) the material (that is, stainless steel, polytetrafluoroethylene, silicone, and so forth) the tube is made of; (2) the surface finish
(for example, machined, ground, polished); and (3) the device geometry (that is, crevices, ridges).
7.1.2.1 The same brush may be used on more than one type of device and therefore different substrates may be selected to evaluate
performance.
7.1.3 The tube should be long enough that the brush part can be completely inserted without reaching the the same length as the
brush part, such that the distal end of the tube, a minimum of 2× the length of the brush part.brush reaches the distal end of the
tube.
7.2 Selection of Test Soil and Application Method:
7.2.1 The test soil should be similar in composition and physical qualities to the clinical soil the medical device comes in contact
with during use (Guide F3208, AAMI TIR12).
7.2.2 The application of the soil should simulate the worst-case soiling that a medical device is likely to experience during clinical
use (see Guide F3208 and FDA Guidance Document (2015) for discussion of methods for determining worst-case soiling).
7.2.3 The time the soil is allowed to dry on the surface of the tube should simulate worst-case drying during clinical use.
7.2.4 A cleaning solution that is similar to the cleaning solution likely to be used to clean the device after clinical use should be
selected (AAMI TIR12, AAMI
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