Implantat och biologisk säkerhet - Implants for surgery - Cardiac pacemakers - Part 3: Low-profile. connectors (IS-1) for implantable pacemakers

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1 Implantat och biologisk säkerhet - Implants for surgery - Cardiac pacemakers - Part 3: Low-profile connectors (IS-1) for implantable pacemakers SIS-remiss Remisstiden utgår: Remissen omfattar: ISO/DIS Implants for surgery - Cardiac pacemakers - Part 3: Low-profile connectors (IS-1) for implantable pacemakers - dokument/05. Remisshantering/5.1 Remisser under beredning/2012/ SIS 10385/Remiss10385.doc SIS, Swedish Standards Institute Postadress: STOCKHOLM Telefon: Telefax: Postal address: STOCKHOLM, Sweden Phone: Telefax: SIS is the Swedish member of ISO and CEN Besöksadress: Sankt Paulsgatan 6, Stockholm Organisationsnr: E-post: info@sis.se Office address: Sankt Paulsgatan 6, Stockholm V.A.T. No. SE info@sis.se

2 Implantat och biologisk säkerhet Ditt svar är viktigt Orientering Det är viktigt att svenska företag, myndigheter och andra organisationer får möjlighet att påverka hur standarderna är utformade. Dina synpunkter på standardförslaget bidrar till att testa riktigheten i den kommande standarden och genom ditt svar ökar också möjligheten att standarden kommer att bli använd och accepterad. SIS eftersträvar att miljöhänsyn tas i standardiseringsarbetet. Vi tar därför gärna emot dina synpunkter även när det gäller dessa frågor. Om du vill påverka innehållet i den kommande standarden ska du använda svarsblanketten som är bifogad. Den internationella kommittén ISO/TC 150, i vilken Sverige aktivt deltar har utarbetat det förslag till ISO-standard som presenteras i denna remiss. Avsikten är att förslaget skall fastställas och ges ut som svensk standard utan förnyad remiss när det fastställts som internationell standard. Den slutgiltiga standarden kan i vissa delar komma att avvika från förslaget beroende på resultatet av den internationella remissbehandlingen. För att kunna fastställas som svensk standard måste ISO-standarden vara förenlig med svensk lagstiftning. Det är viktigt att berörda svenska myndigheter klarlägger om förslaget till ISO-standard är förenligt med svensk lagstiftning. Svaren på denna remiss kommer att utgöra underlag för det svenska yttrandet. Kommentarerna ska vara på engelska. Något om förslaget This part of ISO 5841 specifies a connector assembly to be used to connect implantable pacemaker leads to implantable pacemaker pulse generators. Essential dimensions and performance requirements related to connector fit are specified, together with appropriate test methods. Other connector features such as fastening means and materials are not specified in this part of ISO This part of ISO 5841 is applicable only to the form and fit of the connector assembly, and does not address all aspects of functional compatibility, system performance or reliability of different leads and pulse generator assemblies. This part of ISO 5841 supplements ISO only for those pacemaker components which are claimed by their labelling to be fitted with an IS-1 connector assembly part. It does not replace any requirements in ISO NOTE Pacemaker connector assemblies not complying with this part of ISO 5841 may be safe and reliable and may have clinical advantages. Översättning Den engelska texten föreslås ges ut som svensk standard utan översättning. Om ni anser att texten bör översättas ber vi er ange detta i ert svar. Samtidigt ber vi er då meddela om ni är beredda att bidra till de extra arbetsinsatser som dokument/05. Remisshantering/5.1 Remisser under beredning/2012/ SIS 10385/Remiss10385.doc SIS, Swedish Standards Institute Postadress: STOCKHOLM Telefon: Telefax: Postal address: STOCKHOLM, Sweden Phone: Telefax: SIS is the Swedish member of ISO and CEN Besöksadress: Sankt Paulsgatan 6, Stockholm Organisationsnr: E-post: info@sis.se Office address: Sankt Paulsgatan 6, Stockholm V.A.T. No. SE info@sis.se

3 en översättning skulle kräva. Synpunkter på föreslagen svensk titel tas tacksamt emot. Svensk kommitté Svaren på denna remiss kommer att behandlas av Implantat och biologisk säkerhet, SIS/TK 340, som är svensk referensgrupp för ISO/TC 150 Utredningsarbetet har gjorts av arbetsgrupp Implantat, SIS/TK 340/AG i Frågor Beställning Pris Vilka får remissen? Svar på remissen Anvisningar för remissvar Frågor kring remissen besvaras av Christa Ahlenblom, SIS, telefon: , epost: christa.ahlenblom@sis.se Förslaget kan beställas från Josefine Kayalioglu, SIS, telefon: , epost: josefine.kayalioglu@sis.se Pris för standardförslaget är 400 kronor exkl. moms Remissen har sänts ut till följande: SIS/TK 340, RG 340 Besvara remissen genom att returnera bifogade svarsblankett, till christa.ahlenblom@sis.se. Se anvisningar. Ett remissvar består av två delar: Svarsblankett (där du röstar ja eller nej till förslaget, eller avstår); Kommentarer. Om remissen innehåller flera standardförslag skall ett svar avges för varje ingående standardförslag. I svarsblanketten finns förberedda svarsalternativ för samtliga standardförslag. OBS! Försök inte skilja svarsblankett och kommentarsdelen, eftersom de länkade uppgifterna då försvinner. Så här fyller du i svarsblanketten "Avstår" om du inte är insatt i förslaget och dess konsekvenser eller om du inte har tid eller möjlighet att sätta dig in i förslaget. "Tillstyrker utan kommentarer" om du anser att förslaget kan godtas som standard utan förändringar. "Tillstyrker med kommentarer" om du anser att förslaget kan godtas som standard, fast med de förändringar du angivit i dina kommentarer. "Avstyrker med motivering" om du anser att förslaget innehåller felaktigheter eller är olämpligt att godta som standard. Du måste ange en motivering till avstyrkandet och skälen skall vara av allvarligare karaktär. Ange om du/ni har erfarenhet inom den föreslagna standardens tillämpningsområde och om du/ni haft möjlighet att pröva förslagets tillämpning i er verksamhet. Kom gärna med synpunkter på den föreslagna svenska titeln

4 Om du vill lämna kommentarer Så här fyller du i blanketten för kommentarer Fyll i medföljande blankett för kommentarer enligt anvisningarna nedan, Om standardförslaget är på engelska ska kommentarerna vara på engelska. Detta för att säkerställa en korrekt användning av fackuttryck. För att skapa en ny tabellrad ställer du markören i sista tabellcellen och trycker tab. ID Lämna blankt eller ange en kortform av er identitet som svarslämnare (t.ex. initialer, eller förkortning av företags-/organisationsnamn) Clause No./Subclause No./Annex (e.g. 3.1) För varje kommentar ges en referens till relevant avsnitt i standardförslaget. Paragraph/Figure/Table/Note (e.g. Table 1) Om möjligt preciseras relevant stycke, figurnr, tabellnr, not, eller dylikt i standardförslaget. Type of comment Varje kommentar kategoriseras med någon av förkortningarna te, ed, ge med följande innebörd: te: teknisk kommentar ed: redaktionell kommentar (editorial) ge: generell kommentar Comment (justification for change) Föreslagna ändringar motiveras/förklaras kortfattat. Proposed change För te- och ed-kommentarer ges entydiga förslag till ersättningstext, tillägg eller strykning, gärna enligt följande exempel: Change shall to should. Add the text see enclosure. Remove the text see enclosure.

5 SVARSBLANKETT SIS-remiss (2) e-post: SIS Remissvar Christa Ahlenblom STOCKHOLM SIS/TK 340, Implantat och biologisk säkerhet Svar på SIS-remiss avseende ISO/DIS Senaste svarsdatum Uppgifter om svarslämnaren Företag/Organisation/Myndighet Enskild person Företag/Organisation/Myndighet Handläggare (namn, telefon) Datum Remissvar Avstår Tillstyrker utan kommentarer Tillstyrker med kommentarer Avstyrker med motivering Har erfarenhet inom det område förslaget täcker Har tillämpat förslaget Ej berörd Kommentarer till föreslagen svensk titel SIS, Swedish Standards Institute SIS is the Swedish member of ISO and CEN Postadress: STOCKHOLM Besöksadress: Sankt Paulsgatan 6, Stockholm Organisationsnr: Telefon: Telefax: E-post: Postal address: STOCKHOLM, Sweden Office address: Sankt Paulsgatan 6, Stockholm V.A.T. No. SE Phone: Telefax: info@sis.se

6 Datum Svarslämnare: Kommentarer på: SIS-remiss Förslag: ISO/DIS (3) 4 5 (6) (7) ID Clause No./ Subclause No./ Annex (e.g. 3.1) Paragraph/ Figure/Table/N ote (e.g. Table 1) Type of comm ent 1 Comment (justfication for changes) Proposed change Fylls i av SIS 1 Type of comment: ge = general te = technical ed = editorial

7 DRAFT INTERNATIONAL STANDARD ISO/DIS ISO/TC 150/SC 6 Secretariat: ANSI Voting begins on Voting terminates on INTERNATIONAL ORGANIZATION FOR STANDARDIZATION МЕЖДУНАРОДНАЯ ОРГАНИЗАЦИЯ ПО СТАНДАРТИЗАЦИИ ORGANISATION INTERNATIONALE DE NORMALISATION Implants for surgery Cardiac pacemakers Part 3: Low-profile connectors (IS-1) for implantable pacemakers Implants chirurgicaux Stimulateurs cardiaques Partie 3: Connecteurs à bas profil (IS-1) pour stimulateurs implantables [Revision of second edition (ISO :2000) and ISO :2000/Cor.1:2003] ICS To expedite distribution, this document is circulated as received from the committee secretariat. ISO Central Secretariat work of editing and text composition will be undertaken at publication stage. Pour accélérer la distribution, le présent document est distribué tel qu'il est parvenu du secrétariat du comité. Le travail de rédaction et de composition de texte sera effectué au Secrétariat central de l'iso au stade de publication. THIS DOCUMENT IS A DRAFT CIRCULATED FOR COMMENT AND APPROVAL. IT IS THEREFORE SUBJECT TO CHANGE AND MAY NOT BE REFERRED TO AS AN INTERNATIONAL STANDARD UNTIL PUBLISHED AS SUCH. IN ADDITION TO THEIR EVALUATION AS BEING ACCEPTABLE FOR INDUSTRIAL, TECHNOLOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT INTERNATIONAL STANDARDS MAY ON OCCASION HAVE TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL TO BECOME STANDARDS TO WHICH REFERENCE MAY BE MADE IN NATIONAL REGULATIONS. RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT, WITH THEIR COMMENTS, NOTIFICATION OF ANY RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE AND TO PROVIDE SUPPORTING DOCUMENTATION. International Organization for Standardization, 2012

8 Copyright notice This ISO document is a Draft International Standard and is copyright-protected by ISO. Except as permitted under the applicable laws of the user s country, neither this ISO draft nor any extract from it may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, photocopying, recording or otherwise, without prior written permission being secured. Requests for permission to reproduce should be addressed to either ISO at the address below or ISO s member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel Fax copyright@iso.org Web Reproduction may be subject to royalty payments or a licensing agreement. Violators may be prosecuted. ii ISO 2012 All rights reserved

9 Contents Page Foreword... iv Introduction... v 1 Scope Normative references Terms and definitions Requirements General Lead connector Design requirements Performance requirements Marking Connector cavity Design requirements Performance requirements Marking... 5 Annex A (normative) Lead connector electrical impedance test method... 8 A.1 General... 8 A.2 Specimen preparation... 8 A.3 Reagent and materials... 8 A.4 Procedure... 8 Annex B (informative) Rationale B.1 Need for connector standard B.2 Selection of basic design concept B.3 Rationale for specific clauses B.3.1 Clause 1 Scope B.3.2 Clause 4 Requirements ISO 2012 All rights reserved iii

10 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. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 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 which has been technically revised. ISO 5841 consists of the following parts, under the general title Implants for surgery Cardiac pacemakers: Part 2: Reporting of clinical performance of populations of pulse generators or leads Part 3: Part 3: Low-profile connectors (IS-1) for implantable pacemakers iv ISO 2012 All rights reserved

11 Introduction The development of this part of ISO 5841 was prompted by the concern of clinicians over the variety of apparently similar but incompatible pacing leads of the low-profile in-line type. (Because the major diameter of such leads is 3,2 mm, these connectors were frequently referred to as 3,2 mm leads.) The purpose of this part of ISO 5841 is to specify a standard connector assembly, IS-1, to allow leads and pulse generators from different manufacturers to be interchangeable. The safety, reliability and function of a particular connector part are the responsibility of the manufacturer. Annex A gives a test method for lead connector impedance. Annex B provides a rationale: it is recommended that this annex be read before using this part of ISO 5841 so that the user is informed about its limited objectives. ISO 2012 All rights reserved v

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13 DRAFT INTERNATIONAL STANDARD ISO/DIS Implants for surgery Cardiac pacemakers Part 3: Low-profile connectors (IS-1) for implantable pacemakers WARNING Do not use the connector cavity specified in this part of ISO 5841 if the implantable pulse generator is capable of introducing dangerous nonpacing signals (e.g. defibrillation signals) through an IS-1 connector (see 4.3.3). 1 Scope This part of ISO 5841 specifies a connector assembly to be used to connect implantable pacemaker leads to implantable pacemaker pulse generators. Essential dimensions and performance requirements related to connector fit are specified, together with appropriate test methods. Other connector features such as fastening means and materials are not specified in this part of ISO This part of ISO 5841 is applicable only to the form and fit of the connector assembly, and does not address all aspects of functional compatibility, system performance or reliability of different leads and pulse generator assemblies. This part of ISO 5841 supplements ISO only for those pacemaker components which are claimed by their labelling to be fitted with an IS-1 connector assembly part. It does not replace any requirements in ISO NOTE Pacemaker connector assemblies not complying with this part of ISO 5841 may be safe and reliable and may have clinical advantages. 2 Normative references The following referenced documents are indispensable for the application 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 :2012, Cardiac pacemakers Part 1: Implantable pacemakers 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO and the following apply. 3.1 connector assembly assembly consisting of a lead connector and a connector cavity for the electrical and mechanical connection of a lead to a pulse generator 3.2 lead connector that part of the connector assembly attached to a lead (see Figure 1) ISO 2012 All rights reserved 1

14 3.3 connector cavity that part of the connector assembly attached to the pulse generator (see Figure 3) 3.4 sealing ring circumferential barrier intended to maintain the electrical insulation between electrically isolated parts of the connector assembly when implanted 3.5 seal zone surface in the connector cavity on which one or more sealing rings on the lead connector are intended to bear 3.6 connector cavity GO gauge tool for assessing the ability of a connector cavity to accept a lead connector of maximum size (see Figure 5) 3.7 lead connector GO gauge tool for assessing the ability of a lead connector to be inserted into a connector cavity of minimum size (see Figure 2) 3.8 lead connector ring <for a bipolar lead> outermost conductive element of the lead connector intended to contact the outermost conductive element of the connector cavity 3.9 lead connector pin <for a bipolar lead> innermost conductive element of the lead connector intended to make electrical contact with the innermost conductive element of the connector cavity 3.10 lead connector pin <for a unipolar lead> conductive element of the lead connector intended to contact the innermost (or only) conductive element of the connector cavity 3.11 ring set screw set screw in a bipolar connector cavity which is intended to contact the lead connector ring 4 Requirements 4.1 General The test methods provided for the performance requirements that follow are type (qualification) tests. Equivalent test methods may be used. However, in the event of a dispute, the test methods described in this part of ISO 5841 shall be used. 4.2 Lead connector Design requirements Sealing rings At least one sealing ring shall be provided in each of two sealing-ring zones on the lead connector and be located as specified in Figure 1. 2 ISO 2012 All rights reserved

15 Dimensions in millimetres Key 1 Lead connector ring on bipolar leads. a b c d Optional tooling mark zone. Optional index mark alignment zone. Leading edge of first sealing ring. Sealing ring zone. Sealing rings as shown are for illustration only and are not restricted as to shape, size or number. e f Centreline of first sealing ring in its undeflected position. If the section between datum A and datum B is rigid, these two diameters shall be concentric within 0,13 mm. g Zone in which the (3,1 0,3) mm diameter applies. h The diameter dimensions of the soft sections of the lead may be determined as the mean value of three measurements taken at locations oriented approximately 120 apart around the principal axis of the lead connector. i Break sharp corner. Figure 1 Lead connector ISO 2012 All rights reserved 3

16 Dimensions The lead connector shall have the dimensions specified in Figure Lead connector: electrode continuity and function The lead connector pin shall be in electrical continuity with the stimulating electrode of the lead. The lead connector ring, if used, shall be in electrical continuity with an electrode having pacing and electrogram-sensing functions and which is other than the electrode that is in electrical continuity with the lead connector pin Performance requirements Maximum insertion and withdrawal force of lead connector GO gauge As shipped, the lead connector shall fit completely into the lead connector GO gauge specified in Figure 2 with a maximum insertion and withdrawal force of 14 N and shall conform to the requirements of Figure Electrical impedance between conducting parts The minimum electrical impedance between conductive elements intended to be electrically insulated by the sealing rings shall be 50 k. Compliance shall be determined by the test method described in Annex A Deformation due to set-screw forces Securing mechanism forces shall not deform the lead connector to the extent that insertion and withdrawal forces are excessive. Compliance shall be determined as follows. Insert the lead connector into a connector cavity which conforms to Figure 3. Fasten the lead connector in the centre of zones 6 and 7 (see Figure 3) by two M2 set screws with cup point at a torque of 0,15 N m 0,01 N m. Then retract the set screws. The lead connector withdrawal force shall not exceed 14 N and shall comply with the insertion and withdrawal force requirement as specified in Effect on unipolar lead connector of ring set screw of bipolar connector cavity The ring set screw shall not affect the function of a unipolar lead. Compliance shall be determined as follows. Carry out the test described in and then check that the electrical function of the lead has not been affected by carrying out the tests described in and Marking Marking shall be permanent and legible. The lead connector shall be marked with the symbol IS-1 as shown in Figure 4, with the size appropriate for the connector assembly part being marked. For unipolar lead connectors, each connector shall be marked with the letters UNI ; for bipolar lead connectors, each connector shall be marked with the letters BI as shown in Figure 4. An optional index mark may be provided as an alignment aid. If such a mark is provided, it shall be located in zone 3 as shown in Figure 3. 4 ISO 2012 All rights reserved

17 4.3 Connector cavity Design requirements The connector cavity dimensions shall be as specified in Figure Performance requirements Insertion: connector cavity GO gauge The connector cavity shall accept the GO gauge specified in Figure Maximum insertion force: gauge pin In the zone designated as 5 in Figure 3, the cavity shall accept a gauge pin with a diameter of 2, 7 0 0, 007 mm, with a finish not exceeding 0,4 µm. The force required to insert the gauge pin shall not exceed 9 N Marking The pulse generator shall be marked with the symbol IS-1 as shown in Figure 4, with the size appropriate for the connector assembly part being marked. This marking shall not be applied if the pulse generator is capable of introducing dangerous nonpacing signals through an IS-1 lead connector. Dimensions in millimetres Key 1 Vent hole Surface roughness on all bore diameters shall be Material: poly(methyl methacrylate). Figure 2 Lead connector GO gauge ISO 2012 All rights reserved 5

18 Dimensions in millimetres a Stabilization zone 1. b c d e f g h i j Seal zone 2 for lead connector sealing rings. Seal zone 3 for lead connector sealing rings. When lead is locked in place, lead axis shall not be displaced from connector cavity centreline by more than 0,10 mm. Zone 5 for gauge pin insertion force requirement. Lead connector ring contact zone 6. (Diameter dimension does not apply to spring contacts.) Lead connector pin contact zone 7. (Diameter dimension does not apply to spring contacts.) Break sharp corner. Zone 2 only. Zone 3 only. NOTE 1 The entry to the connector cavity should include a transition (i.e. chamfer, counterbore, etc.) in order to minimize seal distortion when inserting the lead connector into the connector cavity. NOTE 2 The minimum cavity depth of 5 mm occurs when zone 2 is at the minimum tolerance and zone 1 is 2 mm. Figure 3 Connector cavity 6 ISO 2012 All rights reserved

19 Figure 4 Symbols/letters for designating connector assembly parts Dimensions in millimetres a Knurled. Figure 5 Connector cavity GO gauge ISO 2012 All rights reserved 7

20 Annex A (normative) Lead connector electrical impedance test method A.1 General This annex describes the test to be employed to determine compliance with This is a type (qualification) test and is not intended to be used as a routine production test. The manufacturer may use equivalent test methods. However, in case of dispute the following test method shall prevail. A.2 Specimen preparation Lead connectors for the test shall be in the condition as shipped to the customer. A.3 Reagent and materials A.3.1 Test cavity, simulating a connector cavity constructed in compliance with Figure A.1 with provision for offsetting the axis of the lead connector under test by 0,10 mm. A.3.2 Saline solution, approximately 9 g/l at 37 C 5 C. A.3.3 Test signal. Frequency: One frequency between 50 Hz and 120 Hz; Voltage: One voltage between 100 mv RMS and 250 mv RMS. A.3.4 Electrical impedance-measuring device. A.3.5 Reference electrode with minimum area of 500 mm 2. A.4 Procedure A.4.1 Immerse the test cavity (A.3.1) in the saline solution (A.3.2). Insert the lead connector (see A.2) into the cavity, ensuring that no air bubbles are trapped and that the lead connector axis is offset 0,10 mm relative to the test cavity axis. Do not immerse distal conducting parts in the saline solution. If a unipolar lead connector is being tested, remove a cap screw (see Figure A.1) from the ring zone of the test cavity. A.4.2 Immerse the reference electrode (A.3.5) in the saline solution not less than 50 mm from the test cavity. A.4.3 A.4.4 Measure the electrical impedance at the start of the test and after ten days. Impedance shall exceed the requirement in between the: a) pin and ring; b) pin and saline solution; c) ring and saline solution (bipolar only). 8 ISO 2012 All rights reserved

21 Dimensions in millimetres Item Description Material 1 Set screw, M2 Stainless steel 2 Cap screw Polyacetal 3 Seal Silicone 4 Connector block Stainless steel 5 Housing Epoxy Figure A.1 Lead connector impedance test cavity ISO 2012 All rights reserved 9

22 Annex B (informative) Rationale B.1 Need for connector standard NOTE This annex provides a historic rationale for this part of ISO 5841, including reasons for specific requirements. Clinicians have observed that the constructional differences between connector assemblies that are apparently similar may lead to pulse generators and leads being connected which do not seal properly and, therefore, form an unreliable pacemaker. A standard connector assembly reduces the likelihood of the connection of incompatible leads and pulse generators. The development of smaller pacemakers has led to the need for low-profile connector assemblies. By including both terminals in one connector assembly, a substantial reduction in the size of the pulse generator is accomplished, particularly in dual-chamber models. With faulty or damaged sealing, the sensing of intracardiac signals may be impaired, the output pulse amplitude may be reduced, the pulse generator battery may discharge more rapidly due to the shunting effect of leakage and, in the case of dual-chamber pacemakers, may result in voltage signals from one connector assembly inhibiting the function of the other (i.e. cross-talk). Adaptors have been supplied for many years to allow connection between dissimilar styles of connector assemblies. However, adaptors add complexity to the clinical procedure, as well as another component in the system with the potential to fail, and therefore the need for them should be minimized. During the time of transition to full use of the IS-1 connector assembly, the number of leads currently implanted in patients which do not conform to this part of ISO 5841 will gradually decrease over a period of several years, as clinicians should be aware. These leads may require either pulse generators of different dimensions or with seals in the connector cavity, or it will be necessary to adapt a connector cavity complying with this part of ISO 5841 to the implanted lead. The adaptor requires an IS-1 lead connector at one end and an appropriately-configured connector cavity on the other end. B.2 Selection of basic design concept The decision on a basic design concept has focused on the sealing mechanism. The sealing elements are installed on the lead connector. Provision of seals on the lead permits a smaller connector cavity and, therefore, a smaller pulse generator than would be possible with seals in the connector cavity. To allow manufacturers options with regard to the specific sealing ring design, no requirements are provided regarding the specific configuration or material of the seals. The provision for inclusion of seals within the connector cavity was considered as a means of allowing for backward compatibility with already existing lead connector designs. This was ultimately rejected because of the effort that would be required to specify fully a system with backward compatibility. It is recognized that such backward-compatibility designs will be left to the manufacturer. B.3 Rationale for specific clauses B.3.1 Clause 1 Scope Functional compatibility between leads and pulse generators is also determined by other aspects of the pacemaker, such as electrode area and the nature of its contact with tissue. Fastening methods are not specified in this part of ISO 5841, so as to allow manufacturers to explore new methods of ensuring contact 10 ISO 2012 All rights reserved

23 between connector-cavity terminals and lead-connector terminals. Thus, no restriction has been placed on lead connectors to accommodate fastening methods other than set screws. The IS-1 connector is intended for pacing functions and may be incorporated in leads and/or pulse generators that provide other functions (e.g. defibrillation), provided that all the requirements of this part of ISO 5841 are met in such use. Whichever fastening method is used, it is considered to be the responsibility of the manufacturer to ensure adequate retention of the lead, and that the lead has adequate proximal strength between the anode and cathode to withstand the largest-value insertion and withdrawal forces allowed by this part of ISO 5841 without compromising the lead integrity or the ability to meet the dimensional or electrical requirements of this part of ISO B.3.2 Clause 4 Requirements B Subclauses and 4.3.1: Design requirements Unipolar and bipolar versions of the connector assembly are specified to be completely interchangeable due to the now wide availability of programmable and automatic bipolar to unipolar features. The possibility of damage to a unipolar lead when fastened in a bipolar pulse generator is addressed by a performance test. The connector cavity in Figure 3 has a 12 mm long zone in which the diameter is not mandated. This zone allows manufacturers the option to incorporate design features such as chamfers, counterbores, etc. in order to minimize seal distortion when inserting the lead connector into the connector cavity. Seal distortion can result in seal damage and/or increased insertion force. B Subclauses and 4.3.2: Performance requirements The use of GO gauges permits the assessment of the fit between connector elements without requiring design-restrictive specifications regarding the sealing dimensions and materials. The GO gauge maximum insertion and withdrawal forces specified will result in acceptable clinical handling conditions. B Subclauses and : Insertion and withdrawal force requirements This requirement ensures that the lead connector can be engaged and disengaged in the clinical setting without undue force that may complicate the procedure and damage the lead. B Subclause : Resistance between electrical contacts A minimum of 50 k is required to ensure that signals from the heart are not shunted, causing sensing to be compromised. In general, 50 k is in excess of 10 times the maximum source impedance of intracardiac signals seen by the pacemaker. Shunt paths due to other features of a connector assembly reduce the overall resistance. These have not been considered in the requirement. The test method given in annex A provides a worst-case test by having the test cavity sealing areas at maximum dimension and a 0,1 mm offset of the lead connector axis, a condition that minimizes the sealing capability of the lead connector under test. B Subclause : Deformation of lead connector due to set screw force This test demonstrates that adequate strength exists in the lead connector terminals so that the lead is not damaged. B Subclause : Protection of unipolar lead in bipolar pulse generator When a unipolar lead is inserted into a bipolar pulse generator, a set screw in the lead connector-ring contact zone may damage the lead if it is tightened due to the absence of a lead connector ring on the unipolar lead connector. This is a performance rather than a design requirement, so that a manufacturer may choose the method of protection to be used. ISO 2012 All rights reserved 11

24 In practice, a higher torque than that specified in these test procedures ( and ) could be applied by the operator that may result in damage to the lead connector. Manufacturers should provide warnings to this effect in the accompanying documentation. 12 ISO 2012 All rights reserved