ISO 27186:2026

• Abstract:

  This document specifies a four-pole connector system for implantable cardiac rhythm management (CRM) devices that have electrogram sensing and pacing functions with or without defibrillation capability. This document includes requirements for the connector portion of an implantable lead and for the mating connector cavity attached to an implantable pulse generator. Key dimensions and performance requirements are specified together with appropriate test methods. This document establishes two types of connector assembly with their configurations, which are not intended to be interchangeable: a high-voltage connector: a connector that can have either two low-voltage contacts combined with one or two high-voltage contacts, or only two high-voltage contacts; a “low-voltage only connector”: a connector that has either three or four low-voltage contacts. This document specifies a dimensional lockout feature that prevents the low-voltage contacts of the lead connectors from contacting the high-voltage contacts of high-voltage connector cavities. This document does not replace or provide alternatives for unipolar or bipolar connector International Standards that currently exist (such as ISO 11318[2] and ISO 5841-3[1]). This document is not applicable to high-voltage systems with intended outputs greater than 1 000 V or systems with an electric flow greater than 50 A. This document is not applicable to systems which include sensors or unique electrodes that are not capable of conventional pacing electrogram sensing or defibrillation functions. This document does not specify all connector features and it does not address all aspects of functional compatibility, safety or reliability of leads and pulse generators assembled into a system. This document does not include requirements for accessories or adaptors used with four-pole connectors. Refer to Annex P for more information on connector-related products. NOTE 1 The safety, reliability, biocompatibility, biostability and function of any particular part are the responsibility of the manufacturer. NOTE 2 Lead and pulse generator connector systems not conforming to this document can be safe and reliable and can have clinical advantages.

• Status: Published
• Publication Date: 22-Jul-2026
• ICS: 11.040.40 - Implants for surgery, prosthetics and orthotics
• Technical Committee: ISO/TC 150/SC 6 - Active implants
• Drafting Committee: ISO/TC 150/SC 6 - Active implants
• Current Stage: 6060 - International Standard published
• Start Date: 23-Jul-2026
• Due Date: 30-Dec-2025
• Completion Date: 23-Jul-2026

• Revises: ISO 27186:2020 - Active implantable medical devices — Four-pole connector system for implantable cardiac rhythm management devices — Dimensional and test requirements
• Effective Date: 14-Jan-2023

ISO 27186:2026 is an International Standard from ISO for four-pole connector systems in implantable cardiac rhythm management (CRM) devices. It specifies dimensional and test requirements for the connector on an implantable lead and the matching connector cavity on an implantable pulse generator, for devices used for electrogram sensing and pacing, with or without defibrillation capability. It is written for manufacturers, test laboratories, and engineers who need a common interface for implantable leads and pulse generators.

What does ISO 27186:2026 specify?

ISO 27186:2026 specifies the four-pole connector system itself, the two connector types it defines, and the test methods used to verify them. The standard is organized into Scope, Normative references, Terms and definitions, and Requirements, followed by normative and informative annexes.

The scope limits the document to CRM devices with conventional pacing, sensing, and optional defibrillation functions. It also excludes higher-energy systems above the stated limits in the scope and systems using sensors or unique electrodes that are not capable of those conventional functions.

A key part of the organization is the split between lead connector requirements and connector cavity requirements. That separation matters in practice because a lead maker can use the lead-side requirements on their own, while a pulse generator maker can use the cavity-side requirements, and complete system behavior is then verified where needed.

Annex	What it covers
A	Electrical isolation test method
C	Dielectric strength test method
E	Current-carrying test methods
M	Lead connector contact material requirements and test methods
Q	Lead connector insertion force test method
S	Connector cavity insertion and withdrawal test method
P	Connector-related products and adaptors
G, H, I, J, L, O, R, T	Guidance, rationale, and example methods supporting the main requirements

What are the key requirements of ISO 27186:2026?

ISO 27186:2026 sets out the connector geometry, marking, functional fit, electrical performance, and mechanical retention needed for interchangeability. In practice, the standard is about making sure the lead connector and the connector cavity mate correctly, stay electrically isolated where required, and can be inserted and removed without damaging the system.

Connector types and lockout

ISO 27186:2026 defines two non-interchangeable connector assemblies: a high-voltage connector and a low-voltage only connector. The high-voltage version can include low-voltage and high-voltage contacts, while the low-voltage only version uses only low-voltage contacts. The dimensional lockout feature is important because it prevents low-voltage lead contacts from reaching high-voltage cavity contacts.

Lead connector requirements

ISO 27186:2026 specifies lead connector dimensions, contact materials, electrical connections, marking, package labels, and literature in Clause 4.2. For users, this means the lead must be built so the contacts line up with the intended device output and the labeling matches the permitted contact configuration.

Clause 4.2 also links each lead connector contact to a specific and distinct lead. That matters because the document is not only about shape - it also controls which electrode each contact is tied to, so the connector cannot be wired arbitrarily.

Lead connector functional performance

ISO 27186:2026 requires the lead connector to pass functional fit, tensile load, deformation, seal zone, electrical isolation, dielectric strength, current-carrying, corrosion/environmental, insertion force, and fatigue-related checks in Clause 4.3. These are qualification requirements, not routine production tests, and the standard allows equivalent or more stringent methods except where the document must be used in dispute.

The practical effect is that the lead has to remain mechanically sound and electrically stable when it is handled, inserted, and later coupled with a pulse generator. That matters because a lead that is dimensionally correct but too flexible, too hard to insert, or too weak at the contacts can fail in use.

Connector cavity requirements

ISO 27186:2026 specifies the connector cavity dimensions, electrical connections, marking, labels, and literature in Clause 4.4, then defines cavity insertion, retention, withdrawal, ring contact load, seal zone load, electrical isolation, dielectric strength, current-carrying, and contact resistance stability in Clause 4.5. In practice, the cavity must grip the lead correctly, seal and isolate the contacts, and maintain usable electrical contact under load.

The standard also distinguishes the high-voltage and low-voltage only cavity versions in the permitted configurations. That distinction matters because it supports safe pairing of leads and generators and helps prevent unintended use of a cavity with the wrong therapy type.

Test methods and annexes

ISO 27186:2026 places the formal test methods in annexes. Annex A covers electrical isolation, Annex C dielectric strength, Annex E current-carrying, Annex M contact materials, Annex Q lead insertion force, and Annex S cavity insertion and withdrawal force. In practice, these annexes are the verification tools a manufacturer uses to show a design meets the main requirements.

The document also states that the test methods are type tests and should be run under ambient conditions unless otherwise specified. Manufacturers are responsible for preconditioning and sample selection that reflect the product as shipped, which matters because connector behavior can change after packaging, sterilization, or handling.

Marking and permitted configurations

ISO 27186:2026 uses marking symbols and connection tables for leads and pulse generator cavities, including IS4 and DF4 configurations. Those tables matter because they define which electrical contact patterns are allowed and how the connector type is identified on the device.

What terms does ISO 27186:2026 define?

ISO 27186:2026 defines the terms used to describe the connector geometry and function. The most useful ones for design and procurement are:

• connector system - the joined assembly of a lead connector and a connector cavity.
• connector cavity - the cavity in the pulse generator that receives the lead connector.
• lead connector - the part of a lead intended to be inserted into the connector cavity.
• high-voltage connector - a lead connector or connector cavity with at least one high-voltage contact.
• low-voltage only connector - a lead connector or connector cavity with only low-voltage contacts.
• pristine contact zone - the lead-side area intended to make electrical contact with the mating cavity contact.
• functional seal zone - the cavity-side area intended to make sealing contact with the lead connector.
• insertion indicator zone - the area on the lead connector used for visual confirmation of full insertion.

Who uses ISO 27186:2026?

ISO 27186:2026 is used by manufacturers of implantable CRM leads and pulse generators, including products for pacing, sensing, and defibrillation. It is also used by test laboratories that run qualification tests for dimensional fit, insertion force, dielectric strength, isolation, and current carrying.

Quality, regulatory, and design assurance teams use the document to confirm that connector designs are compatible and that the chosen materials and contact interfaces have been verified. Buyers and sourcing teams can use it to check whether a lead or pulse generator claims compatibility with the four-pole interface defined by the standard.

What changed in ISO 27186:2026 from the previous edition?

ISO 27186:2026 is the third edition and it cancels and replaces ISO 27186:2020. The foreword states that the document was technically revised.

The stated changes are:

• a lead connector insertion force requirement was added in Clause 4.3.10
• a test method for lead insertion force was added in Annex Q
• rationale for lead insertion force was added in Annex R
• the connector cavity insertion and withdrawal force requirements in Clause 4.5.1 were revised for better accuracy and reproducibility
• a test method for those connector cavity forces was added in Annex S
• rationale for those connector cavity forces was added in Annex T
• clause headings and annex titles were aligned with the main text
• editorial changes were made throughout

Which standards are used with ISO 27186:2026?

ISO 27186:2026 cites these normative references:

• ISO 7436 - for slotted set screws with cup point, relevant to securing mechanisms such as set screws
• ASTM B348 - titanium and titanium alloy bars and billets, relevant to implant material selection
• ASTM F562 - wrought cobalt-nickel-chromium-molybdenum alloy for surgical implants, relevant to lead connector contacts
• ASTM F746 - pitting or crevice corrosion of metallic surgical implant materials, relevant to corrosion evaluation

The document also works alongside related connector and device standards named in the text and bibliography, especially:

• ISO 5841-3 - existing low-profile connector standard for implantable pacemakers
• ISO 11318 - existing DF-1 connector assembly standard for implantable defibrillators
• ISO 14708-2:2019 - referenced in fatigue guidance for four-pole connectors
• ISO 14708-1 and ISO 14708-6 - general active implantable medical device standards listed in the bibliography for the wider device context

What does the ISO 27186:2026 document contain?

ISO 27186:2026 contains detailed dimensional figures for lead connectors and connector cavities, including contact zones, seal zones, grip zones, and lockout-related features. It also contains marking tables that map connector symbols to permitted electrical connections, which is useful when checking device labeling and compatibility.

The annexes provide qualification methods for electrical isolation, dielectric strength, current carrying, contact material performance, insertion force, and insertion-withdrawal behavior. Several informative annexes explain the rationale behind the limits and test setups, including guidance on fatigue, seal zone materials, contact resistance stability, creep considerations, and connector-related products and adaptors.

For engineering work, the document is most useful as a design-and-verification package: it tells you what the connector geometry should be, how the contacts are assigned, and how to test the assembly before use in an implantable CRM system.

International
Standard
ISO 27186
Third edition
Active implantable medical
2026-07
devices — Four-pole connector
system for implantable cardiac
rhythm management devices —
Dimensional and test requirements
Dispositifs médicaux actifs implantables — Systèmes de
branchement à quatre pôles pour dispositifs implantables de
gestion du rythme cardiaque — Exigences de dimensions et
d'essai
Reference number
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Requirements . 5
4.1 General .5
4.2 Lead connector physical requirements .5
4.2.1 Dimensions .5
4.2.2 Materials .10
4.2.3 Lead connector electrical connections .10
4.2.4 Lead marking .10
4.2.5 Lead package labels and literature . 12
4.3 Lead connector functional requirements . 12
4.3.1 Functional fit check . 12
4.3.2 Tensile loads . 13
4.3.3 Deformation due to pin contact forces . 13
4.3.4 Deformation due to ring contact forces . 13
4.3.5 Seal zone requirement . .14
4.3.6 Electrical isolation requirement . 15
4.3.7 Dielectric strength requirement . 15
4.3.8 Current-carrying requirement . 15
4.3.9 Corrosion and environmental requirement . 15
4.3.10 Lead connector insertion force . 15
4.3.11 Lead connector fatigue strength . . 15
4.4 Connector cavity physical requirements . 15
4.4.1 Dimensions . 15
4.4.2 Connector cavity electrical connections .17
4.4.3 Connector cavity and pulse generator marking .18
4.4.4 Pulse generator labels and literature .18
4.5 Connector cavity functional requirements .19
4.5.1 Insertion force .19
4.5.2 Retention force . 20
4.5.3 Withdrawal force . 20
4.5.4 Ring contact load . 20
4.5.5 Seal zone load requirement .21
4.5.6 Electrical isolation requirement .21
4.5.7 Dielectric strength requirement .21
4.5.8 Current-carrying requirement (high-voltage connector cavity) .21
4.5.9 Contact resistance and stability .21
Annex A (normative) Electrical isolation test method .22
Annex B (informative) Rationale for electrical isolation test .27
Annex C (normative) Dielectric strength test method .29
Annex D (informative) Rationale for dielectric strength test .34
Annex E (normative) Current-carrying test methods .38
Annex F (informative) Rationale for current-carrying tests .44
Annex G (informative) Guidance for evaluating high cycle fatigue of four-pole connectors .46
Annex H (informative) Guidance on selecting materials for lead connector seal zones .47
Annex I (informative) Seal zone creep .49

iii
Annex J (informative) Contact resistance stability — Example test method .53
Annex K (informative) Rationale for contact resistance stability example test .56
Annex L (informative) Guidance on selecting materials for electrical contacts .58
Annex M (normative) Lead connector contact material requirements and test methods .60
Annex N (informative) Rationale for lead connector contact material requirements .63
Annex O (informative) Rationale for standardization and standard requirements .69
Annex P (informative) Connector-related products and adaptors .75
Annex Q (normative) Lead connector insertion force test method .77
Annex R (informative) Rationale for lead connector insertion force test .86
Annex S (normative) Connector cavity insertion and withdrawal test method .93
Annex T (informative) Rationale for connector cavity insertion and withdrawal test .99
Bibliography .107

iv
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 150, Implants for surgery, Subcommittee SC 6,
Active implants.
This third edition cancels and replaces the second edition (ISO 27186:2020), which has been technically
revised.
The main changes are as follows:
— the requirement in 4.3.10 and the test method in Annex Q for lead insertion force have been added and
the rationale for both has been added in Annex R;
— the requirement in 4.5.1 for connector cavity insertion and withdrawal force have been revised to
improve accuracy and reproducibility, the test method for these has added in Annex S, and the rationale
for both has been added in Annex T;
— the heading of 4.3.1 has been revised to distinguish this requirement from the lead insertion force
requirement;
— the clause headings within Annex O have been aligned with those in the main text;
— annex titles have been aligned to better reflect content;
— editorial changes have been made to the main text and annexes have referred to in the main text where
relevant.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

v
Introduction
The four-pole connector system was created to reduce:
— the number of individual lead connectors,
— pocket bulk associated with existing bifurcated or trifurcated leads,
— interaction of lead bodies in the pocket, and
— set screw connections.
The four-pole connector system is intended to provide interchangeability between implantable leads and
pulse generators from different manufacturers.

vi
International Standard ISO 27186:2026(en)
Active implantable medical devices — Four-pole connector
system for implantable cardiac rhythm management devices
— Dimensional and test requirements
WARNING — The low-voltage only connector cavity specified in this document is not to be used
if the implantable pulse generator is capable of introducing dangerous non-pacing stimuli (e.g.
defibrillation shocks) through the contacts of that connector cavity. Likewise, the high-voltage lead
connector specified in this document is not to be used on leads intended for low-voltage only therapy.
1 Scope
This document specifies a four-pole connector system for implantable cardiac rhythm management (CRM)
devices that have electrogram sensing and pacing functions with or without defibrillation capability. This
document includes requirements for the connector portion of an implantable lead and for the mating
connector cavity attached to an implantable pulse generator. Key dimensions and performance requirements
are specified together with appropriate test methods.
This document establishes two types of connector assembly with their configurations, which are not
intended to be interchangeable:
— a high-voltage connector: a connector that can have either
— two low-voltage contacts combined with one or two high-voltage contacts, or
— only two high-voltage contacts;
— a “low-voltage only connector”: a connector that has either three or four low-voltage contacts.
This document specifies a dimensional lockout feature that prevents the low-voltage contacts of the lead
connectors from contacting the high-voltage contacts of high-voltage connector cavities.
This document does not replace or provide alternatives for unipolar or bipolar connector International
[2] [1]
Standards that currently exist (such as ISO 11318 and ISO 5841-3 ).
This document is not applicable to high-voltage systems with intended outputs greater than 1 000 V or
systems with an electric flow greater than 50 A.
This document is not applicable to systems which include sensors or unique electrodes that are not capable
of conventional pacing electrogram sensing or defibrillation functions.
This document does not specify all connector features and it does not address all aspects of functional
compatibility, safety or reliability of leads and pulse generators assembled into a system.
This document does not include requirements for accessories or adaptors used with four-pole connectors.
Refer to Annex P for more information on connector-related products.
NOTE 1 The safety, reliability, biocompatibility, biostability and function of any particular part are the responsibility
of the manufacturer.
NOTE 2 Lead and pulse generator connector systems not conforming to this document can be safe and reliable and
can have clinical advantages.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 7436, Fasteners — Slotted set screws with cup point
ASTM B348, Standard Specification for Titanium and Titanium Alloy Bars and Billets
ASTM F562, Standard Specification for Wrought 35Cobalt-35Nickel-20Chromium-10Molybdenum Alloy for
Surgical Implant Applications
ASTM F746, Standard Test Method for Pitting or Crevice Corrosion of Metallic Surgical Implant Materials
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
axial pin movement
M
axial movement of a lead connector pin (3.18) with reference to the lead connector (3.16) body as present in
some designs, particularly those with a rotating connector pin
3.2
bipolar
having two poles or electrodes
3.3
connector system
assembly consisting of a lead connector (3.16) and a connector cavity (3.4) that are electrically and
mechanically joined
3.4
connector cavity
cavity within the pulse generator (3.27) which is intended to receive a lead connector (3.16)
3.5
contact mechanism
conductive hardware within the connector cavity (3.4) provided for making electrical connection to
corresponding contacts on a lead connector (3.16)
3.6
distal
farthest from a point of reference
Note 1 to entry: The point of reference for a lead is the lead connector pin (3.18). Therefore, the most distal electrode of
a lead is the electrode that is farthest from the lead connector pin.
3.7
fixation zone
specified area on the lead connector pin (3.18) and within the connector cavity (3.4) where the lead connector
(3.16) is mechanically secured within the connector cavity

3.8
four-pole
having four poles or electrodes
Note 1 to entry: Generally, a four-pole implantable cardiac defibrillator (ICD) lead has two low-voltage (3.21) electrodes
and two high-voltage (3.12) electrodes. A four-pole low-voltage only lead has four low-voltage electrodes.
3.9
functional contact zone
area within the connector cavity (3.4) where electrical contact with a lead connector (3.16) occurs
3.10
functional seal zone
area within the connector cavity (3.4) where sealing contact with a lead connector (3.16) occurs
3.11
grip zone
area of the lead connector (3.16) which is provided for grasping during insertion and withdrawal of the lead
connector from the connector cavity (3.4)
3.12
high voltage
electrical potential greater than 20 V and that can go up to 1 000 V
Note 1 to entry: High voltages are generally used for defibrillating the heart.
3.13
high-voltage connector
lead connector (3.16) or connector cavity (3.4) that has at least one high-voltage (3.12)
Note 1 to entry: A high-voltage connector can also contain low-voltage (3.21) contacts.
3.14
insertion indicator zone
area on the pin of the lead connector (3.16) allocated for manufacturers to provide a visual indicator for use
in verifying full insertion of a lead connector into a connector cavity (3.4)
3.15
integrated bipolar
two lead poles or lead electrodes (3.20) that are electrically common
Note 1 to entry: A typical integrated bipolar ICD lead has a distal (3.6) shock electrode that doubles as a proximal
(3.26) pace or sense ring electrode and is electrically attached to two separate lead connector contacts (3.17).
3.16
lead connector
part of a lead that is intended for insertion into the connector cavity (3.4) of a pulse generator (3.27)
3.17
lead connector contact
conductive element on the lead connector (3.16) which include the lead connector pin (3.18) and lead
connector rings (3.19)
3.18
lead connector pin
most proximal (3.26) conductive element of a lead connector (3.16) provided for making electrical contact as
well as for securing the lead connector within the connector cavity (3.4)

3.19
lead connector ring
annular conductive element on the lead connector (3.16) intended for making electrical contact within the
connector cavity (3.4)
Note 1 to entry: The four-pole (3.8) connector has three lead connector rings and a lead connector pin (3.18).
3.20
lead electrode
distal (3.6) part of a lead through which electrical impulses are transmitted to or from cardiac tissue
Note 1 to entry: High-voltage (3.12) electrodes are capable of delivering high-voltage electrical impulses. Low-voltage
(3.21) electrodes are used for transmitting and sensing low-voltage impulses and are generally not suitable for
delivering high-voltage.
3.21
low-voltage
electrical potential less than or equal to 20 V
Note 1 to entry: Low voltage is generally used for pacing and sensing the heart.
3.22
low-voltage only connector
lead connector (3.16) or connector cavity (3.4) that has only low voltage (3.21) contacts
3.23
pin visibility zone
area within the connector cavity (3.4) which is allocated for visual verification that the lead connector (3.16)
is fully inserted
Note 1 to entry: The pin visibility zone corresponds to the insertion indicator zone (3.14) of the lead connector.
3.24
pristine contact zone
area on the lead connector (3.16) intended for making electrical contact with the mating contact in the
connector cavity (3.4)
Note 1 to entry: The pristine contact zones of the lead connector align with the functional contact zones (3.9) of the
connector cavity when the connectors are mated.
3.25
pristine seal zone
area on the lead connector (3.16) intended for sealing with the mating seals in the connector cavity (3.4)
Note 1 to entry: The pristine seal zones of the lead connector align with the functional seal zones (3.10) of the connector
cavity when the connectors are mated.
3.26
proximal
nearest to a point of reference
Note 1 to entry: The point of reference for a lead is the lead connector pin (3.18). Therefore, the most proximal electrode
of a lead is the electrode closest to the lead connector pin.
3.27
pulse generator
device that delivers electrical energy to affect cardiac rhythms
3.28
sealing mechanism
circumferential barriers within the connector cavity (3.4) intended to maintain electrical isolation between
electrically insulated parts of an assembled and implanted connector system (3.3)

3.29
securing mechanism
mechanism within the connector cavity (3.4) intended for mechanically securing the lead connector (3.16)
EXAMPLE Set screw.
3.30
strain relief zone
area on the lead connector (3.16) provided for making a gradual transition from a more rigid section to a
more flexible section
Note 1 to entry: The gradual transition results in an area over which strain is distributed so that concentrated
mechanical forces do not occur when the lead is flexed.
3.31
tripolar
having three poles or electrodes
4 Requirements
4.1 General
Not all connector features or pulse generator features are specified nor do the requirements in this document
address all aspects of functional compatibility, safety or reliability of leads and pulse generators assembled
into a system. Each manufacturer is responsible for any requirements and tests necessary to address these
as well as the biocompatibility and biostability of their material choices.
The test methods provided for the requirements are type (qualification) tests and are not intended to be
used as routine production tests. Alternate test methods may be used, including those which result in
equivalent or more stringent test conditions. However, in the event of dispute, the test methods described in
this document shall be used.
The following tests shall be conducted under ambient conditions unless otherwise specified. Each
manufacturer is responsible for any preconditioning required to represent “as-shipped” configurations, as
well as for selection of appropriate sample sizes.
Leads and pulse generators marked in accordance with Table 1 and Table 2 shall conform with all
requirements in this document.
Refer to Annex O for the rationale on standardization and for more information on the requirements in this
clause.
4.2 Lead connector physical requirements
4.2.1 Dimensions
4.2.1.1 General
Lead connectors shall have the dimensions specified in Figure 1 and Figure 2 and shall meet the requirements
in 4.2.1.2 to 4.2.1.11 in accordance with each zone.
4.2.1.2 Total axial pin movement, M
Total axial pin movement is the difference in lead connector pin length from when the connector pin is
fully seated against datum A to when the connector pin is fully extended from datum A. The total axial pin
movement shall not be greater than 0,25 mm.

4.2.1.3 Pristine contact zones
The minimum length of each of the pristine contact zones, expressed in millimetres, shall be:
0,90 + M
where M is the total axial pin movement in millimetres.
Lead connectors shall have an electrically conductive contact surface over the entire length of each of the
pristine contact zones. Contact surfaces may extend beyond the pristine contact zones.
The surface roughness in these zones shall be of a maximum Ra = 0,8 µm. The entire surface area shall
be considered when measuring surface roughness. No indentations, protrusions, gaps or steps exceeding
surface roughness allowance are allowed in these zones.
4.2.1.4 Pristine seal zones
The minimum length of each pristine seal zone, expressed in millimetres, shall be:
1,81 + M
where M is the total axial pin movement in millimetres.
Lead connectors shall have a seal surface over the entire length of each of the pristine seal zones. Seal
surfaces may extend beyond the pristine seal zones. No indentation, protrusions, gaps or steps exceeding
surface roughness allowance are allowed in these zones.
For surfaces of materials with hardness 75D or less, the surface roughness in this zone shall be a maximum of
Ra = 0,8 µm. The entire surface shall be considered when measuring surface roughness except that uniform
linear protrusions, such as caused by mould parting lines, may be excluded from the measurement if they do
not exceed 0,025 mm in height as measured radially or 0,12 mm in width.
For surfaces in this zone made from materials with hardness above 75D, the surface roughness shall be a
maximum of Ra = 0,4 µm when the entire surface is considered, including any uniform linear protrusions.
4.2.1.5 Lead connector body
The diameter for all conductive components and surfaces within this zone shall be 3,2 mm ± 0,03 mm.
The diameter for all non-conductive components and surfaces within this zone shall be 3,2 mm ± 0,05 mm.
For all areas in this zone except pristine seal zones and pristine contact zones, the following requirements
shall be applied.
a) Any radial steps or protrusions, such as those caused by a mismatch of adjacent components or by
welds, shall not exceed 0,05 mm (in height) and shall not cause the diameter to go outside the tolerance
specified with the following exception. Uniform linear protrusions that do not exceed 0,025 mm in
height as measured radially or 0,12 mm in width are allowed only for surfaces of materials that are at 75
Shore D or below.
b) Any gap shall not exceed 0,1 mm in width when measured to include all edge breaks at the gap edge.
There shall not be more than one gap between each pristine zone. For any gap that meets these
requirements, the area within the gap need not meet the other requirements of this subclause, for
example, diameter and radial step requirements.
c) Any indentations, such as holes or weld depressions, shall not exceed 0,5 mm in diameter.
d) The surface roughness for Key 3 of Figure 1 shall be of a maximum Ra = 0,8 µm from datum A to
16,04 mm and shall be of a maximum Ra = 1,6 µm from 16,04 mm to the transition Key 7, excluding the
chamfer area. Surface finish measurements are not required to include any surface features that meet
the requirements in a) to c).
4.2.1.6 Strain relief zone
The diameter in the strain relief zone shall be 4,1 mm maximum and 3,8 mm minimum.
4.2.1.7 Grip zone
The diameter in the grip zone shall be 4,3 mm maximum.
4.2.1.8 Chamfer zone
The length of the chamfer in the chamfer zone, expressed in millimetres, shall be:
a) minimally: 0,35;
b) maximally:
0,7 – M
where M is the total axial pin movement in millimetres.
4.2.1.9 Transition zone
The transition between the ∅3,2 mm nominal and the ∅4,1 mm maximum shall occur within the theoretical
envelope between datum B and Datum C. Datum B is defined by the 60° angle and the intersection of the
∅4,1 mm at the 17,7 mm dimension. Transition geometry does not need to match this angle.
The diameter in the transition zone shall not exceed 4,1 mm.
4.2.1.10 Insertion indicator zone
The insertion indicator zone is provided for an optional insertion indicator. If an insertion indicator is
present, it shall meet the following requirements.
a) The indicator shall not extend beyond the zone.
b) The proximal edge shall meet the 5,10 mm ± 0,10 mm dimension.
00, 3
c) The diameter shall fall within the nominal diameter specified and the tolerance of mm.
01, 0
d) Any gaps shall not exceed 0,10 mm in width. For any gap that meets this requirement, the area within
the gap does not to meet the other requirements of this subclause, such as the diameter and radial step
requirements.
e) Any radial steps shall not exceed 0,05 mm.
4.2.1.11 Pin pristine contact zone
Lead connectors shall have an electrical contact surface over the entire length of this zone.
The surface roughness in this zone shall be of a maximum Ra = 0,8 µm.

Dimensions in millimetres
Key
1 pristine contact zones
2 pristine seal zones
3 lead connector body
4 strain relief zone
5 grip zone
6 chamfer zone
7 transition zone
8 total axial pin movement, M
NOTE The diameter dimensions of the soft sections, in Key 4, Key 5 and Key 7, of the lead can be determined as the
mean value of three measurements taken at locations oriented approximately 120° apart around the principal axis of
the lead connector.
Figure 1 — Four-pole lead connector body

Dimensions in millimetres
a) High-voltage lead connector pin
b) Low-voltage only lead connector pin
Key
1 pin fixation zone
2 pin pristine contact zone
3 insertion indicator zone
a
The dimension applies only when all axial movement has been biased by seating the connector pin against
the connector body.
b
The dimension applies to the notch feature. The notch feature is optional and may be omitted.
Figure 2 — Four-pole lead connector high-voltage and low-voltage only pin details

4.2.2 Materials
4.2.2.1 Contact materials
Refer to Annex L for guidance on selecting materials for lead connector contacts.
4.2.2.2 Seal surface material
Lead connector seal zone materials are not specified. Refer to Annex H for guidance on selecting materials
for sealing surfaces.
4.2.3 Lead connector electrical connections
4.2.3.1 Each lead connector contact shall be in electrical continuity with the specific and distinct lead
electrode described in Table 1 in accordance with the appropriate configuration, when the following applies:
— “low-voltage” refers to stimulating electrodes having pacing and electrogram sensing function;
— “high-voltage” refers to stimulating electrodes having high-voltage defibrillation capability;
— “open” refers to lead connector contacts that are not in electrical continuity with any lead electrode.
Ring 2 and ring 3 contacts of high-voltage lead connectors shall not be in direct electrical continuity with
lead electrodes that are not intended for high-voltage because they can be exposed to high voltage during
use.
4.2.3.2 The lead connector pin of low-voltage only lead connectors shall conform to Figure 2 b).
4.2.3.3 The lead connector pin of high-voltage lead connectors including integrated bipolar connectors
shall conform to Figure 2 a).
4.2.4 Lead marking
4.2.4.1 Marking symbol
Lead connectors shall be marked with the appropriate symbol in accordance with Table 1 and sized
appropriately for the component being marked.
4.2.4.2 Marking location
Marking shall be located in the marking zone (see Figure 3).
4.2.4.3 Marking orientation
Marking shall read left to right when the lead connector is oriented with the connector pin to the left.
NOTE It is the responsibility of the manufacturer to ensure marking on lead connectors is permanent and legible
under intended use conditions.

Dimensions in millimetres
Key
1 marking zone
2 lead connector pin
3 lead connector ring 1
4 lead connector ring 2
5 lead connector ring 3
Figure 3 — Identification of lead connector contacts
Table 1 — Lead marking symbols and electrical connections within the lead — Permitted
configurations
Configuration
and marking Connector pin Ring 1 Ring 2 Ring 3
symbol
nd rd
most distal 2 most distal 3 most distal most proximal
IS4-LLLL low-voltage low-voltage low-voltage low-voltage
electrode electrode electrode electrode
nd rd
most distal 2 most distal 3 most distal
Low-voltage
IS4-LLLO low-voltage low-voltage low-voltage open
only
electrode electrode electrode
nd
most distal 2 most distal most proximal
IS4-LOLL low-voltage open low-voltage low-voltage
electrode electrode electrode
nd
most distal 2 most distal most distal most proximal
DF4-LLHH low-voltage low-voltage high-voltage high-voltage
electrode electrode electrode electrode
nd
most distal 2 most distal most distal
High-voltage DF4-LLHO low-voltage low-voltage high-voltage open
electrode electrode electrode
most distal most proximal
DF4-OOHH open open high-voltage high-voltage
electrode electrode
most distal most distal most distal most proximal
DF4-LLHH low-voltage high-voltage high-voltage high-voltage
a
electrode electrode electrode electrode
Integrated
bipolar
most distal most distal most distal
DF4-LLHO low-voltage high-voltage high-voltage open
a
electrode electrode electrode
a
For integrated bipolar leads, the most distal high-voltage electrode may also be used for low-voltage pacing and sensing
function.
4.2.5 Lead package labels and literature
Package labels and product literature are the responsibility of the lead manufacturer; however, the
appropriate marking symbols shown in Table 1 should be used at all times when referring to lead connectors
conforming to this document.
NOTE The four-pole lead connectors specified in this document is not necessarily compatible with the wide
variety of existing analyser cables that are currently used with other connectors [such as lead connectors defined
[1] [2]
by ISO 5841-3 (IS-1) and ISO 11318 (DF-1)]. Specifically, the terminals of some analyser cables can result in
bridging and shorting of the more closely-spaced lead connector contacts of the four-pole connector. Bridging and
shorting during an implant procedure can result in erroneous measurements of performance characteristics (e.g. R
waves, P waves, impedances, pacing thresholds) or a temporary inability to provide pacing therapy. Manufacturers
are individually responsible for providing appropriate warnings, education or other means of mitigating the risk of
bridging and shorting as can occur due to use of analyser cable terminals with their respective lead connectors. See
also Clause P.3.
4.3 Lead connector functional requirements
4.3.1 Functional fit check
4.3.1.1 Test method
Insert the lead connector into the lead connector go gauge conforming to Figure 4. Perform this test both
with the lead connector in an initial state and after a 10 d minimum soak in saline (nominally 9 g/l at
37 °C ± 5 °C).
Dimensions in millimetres
a
The maximum diameter of 3,28 mm exceeds the largest permissible lead diameter by 0,03 mm to
accommodate axis curvature of the lead connector or localized offsets that can be present between lead
connector components.
b
The maximum radius or chamfer is 0,20 mm.
c
The maximum radius or chamfer is 0,1 mm.
d
The materials are: steel, stainless steel, titanium, titanium alloys or 35Cobalt-35Nickel-20Chromium-
10Molybdenum alloy specified in ASTM F562.
e
The maximum edge break is 0,05 mm.
Figure 4 — Lead connector go gauge

4.3.1.2 Requirement
Both initially and after soaking, the force to fully insert the lead connector into the lead connector go gauge
shall be less than 4,5 N. The lead connector is considered fully inserted into the gauge when the connector
pin is visible outside the 1,43 mm diameter. The lead connector need not be bottomed out in the gauge in
order to be considered fully inserted.
4.3.2 Tensile loads
4.3.2.1 Test method
Soak the lead connector in saline (nominally 9 g/l at 37 °C ± 5 °C) for 10 d minimum prior to testing. After
soaking and while in a wetted state, fasten the lead connector at the lead connector pin and apply a tensile
load of 14 N minimum at the grip zone. Maintain the load for at least 10 s. Repeat tensile loading a minimum
of five cycles.
4.3.2.2 Requirement
After tensile loading the lead shall meet the linear dimensions in Figure 1 and Figure 2 measured from
datum A and the requirements of 4.2.1.2, 4.3.6, 4.3.7 and 4.3.8.
4.3.3 Deformation due to pin contact forces
4.3.3.1 Test method
Insert the lead connector into a test cavity that conforms to the bore dimensions of Figure 7 a) for high-
voltage and Figure 7 b) for low-voltage only and which has M2 screw threads located within the functional
pin contact zone. Use an M2 titanium grade 5 as described in ASTM B348, 860 MPa minimum tensile
strength, set screw with cup point in accordance with ISO 7436.
Tighten the screw to a torque of 0,15 N·m ± 0,01 N·m. Maintain the load for 10 s minimum and then release
the set screw.
4.3.3.2 Requirement
The force to withdraw the lead connector from and re-insert it into the test cavity shall not exceed 4,5 N.
After removal, the lead connector shall meet the contact zone diameter requirements in Figure 2.
For lead connector designs utilizing a through-hole for stylets, it is recommended that the manufacturer
verify that the through-hole is still functional following application of the set screw load.
NOTE 1 It is recognized that at the time of publication of this document, most manufactured devices utilize 2–56
hexagon head set screws for lead connector retention. Although they are similar in size, the equivalency between the
two types of set screw has not been established. Therefore, an M2 set screw is specified herein for use in a dispute.
NOTE 2 Additional testing can be necessary to confirm that the insertion indicator withstands other handling and
implant conditions such as attachment of patient cable alligator clips.
4.3.4 Deformation due to ring contact forces
4.3.4.1 Test method
Use two aligned metal blade indenters that conform to Figure 5 to apply a compressive load to the outer
diameter of each ring in the pristine contact zone (see Figure 1). Apply a minimum load of 9 N and maintain
the load for a minimum of 10 s.

Dimensions in millimetres
a
The materials are: steel, stainless steel, titanium, titanium alloys or 35Cobalt-35Nickel-20Chromium-
10Molybdenum alloy specified in ASTM F562.
Figure 5 — Ring contact force test fixture
4.3.4.2 Requirement
After application and release of the load, the lead connector shall meet the requirements of 4.2.1.5 with the
exception of the surface roughness requirement, the functional check of 4.3.1 and the electrical requirements
of 4.3.6, 4.3.7 and 4.3.8.
4.3.5 Seal zone requirement
There are no functional requirements for seal zones. See Annex H for guidance on selecting materials for
lead connector seal zones. See Annex I for guidance on evaluating seal surfaces for creep performance.

4.3.6 Electrical isolation requirement
The lead connector shall provide electrical isolation between each of the lead connector contacts and
between the contacts and the surrounding fluid. Conformity shall be determined as described in Annex A.
More information, including the rationale, can be found in Annex B.
4.3.7 Dielectric strength requirement
The
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