 Indeed, the present invention, may relate to a programmable dual chamber pacemaker wherein the basic configuration of the pacemaker, e.g. unipolar or bipolar, can be changed, including the grounding configuration and ground potentials used within the pacemaker.
Generally, a heart stimulator, commonly known as a xe2x80x9cpacemakerxe2x80x9d or xe2x80x9cpacerxe2x80x9d, uses one or two flexible leads having one end connected to the pacer and the other end connected to electrodes placed in close proximity to the heart. These leads are used to stimulate or pace the heart. Also, these leads are used to sense the heart activity by picking up electrical signals from the heart.
In order to properly pace or sense, the pacer has to be able to deliver a stimulating pulse to the heart or sense an electrical signal from the heart, and this requires that there be an electrical return path. If, within a given heart chamber, a unipolar lead is usedxe2x80x94containing a single conductorxe2x80x94the return path is the conductive body tissue and fluids. The return path is connected to the pacer by connecting the pacer electrical common or ground to the pacer metal enclosure, typically referred to as the pacer case or housing. The case, in turn, makes contact with the body tissue and/or fluids.
An alternative solution to using a unipolar lead in a given heart chamber is to use a double lead/electrode in the heart chamber, known as a bipolar lead. In a bipolar lead, a second conductor is spiraled over and insulated from a first conductor along the length of the lead. At the distal end of the lead, one of the conductors is connected to a first electrode, referred to as the xe2x80x9ctipxe2x80x9d electrode, and the second conductor is connected to a second electrode, referred to as a xe2x80x9cringxe2x80x9d electrode. The ring electrode is generally situated 10 to 20 mm from the tip electrode. The tip electrode is typically placed in contact with heart tissue, while the ring electrode is in electrical contact with the blood. Because both body tissue and fluids are conductive, the ring electrode of a bipolar lead, in contact with the body fluids, serves as an electrical return for both pacing and sensing.
As indicated, pacing or sensing using the pacer case
Indeed, the present invention, may relate to a programmable dual chamber pacemaker wherein the basic shape of the pacesetter, e.g. unipolar or bipolar, can be changed, include the ground configuration and ground electric potential use within the pacemaker. 
 by and large, a heart stimulator, commonly know as a xe2x80x9cpacemakerxe2x80x9d or xe2x80x9cpacerxe2x80x9d, uses one or two flexible leads having one end connected to the pacer and the early end connected to electrodes place in close proximity to the heart. These star are use to stimulate or pace the kernel. Also, these leads are used to smell the heart activity by picking up electrical signals from the affection. 
 In order to properly pace or sense, the pacer has to be able to deliver a stimulating pulse to the heart or sense an electrical signal from the center, and this requires that there be an electrical recurrence way. If, within a given heart chamber, a unipolar lead is usedxe2x80x94containing a single conductorxe2x80x94the return path is the conductive body tissue and fluid. The return path is connected to the pacer by connecting the pacer electrical common or land to the pacer metal enclosure, typically referred to as the pacer case or housing. The shell, in turn, reach contact with the body tissue and/or fluids. 
 An alternative solution to using a unipolar jumper cable in a given heart chamber is to use a double lead / electrode in the heart chamber, know as a bipolar lead. In a bipolar lead, a second conductor is spiraled over and insulated from a first conductor along the duration of the lead. At the distal goal of the lead, one of the conductor is connected to a first electrode, referred to as the xe2x80x9ctipxe2x80x9d electrode, and the second conductor is connected to a second electrode, referred to as a xe2x80x9cringxe2x80x9d electrode. The band electrode is generally situated 10 to 20 mm from the tip electrode. The tip electrode is typically placed in contact with heart tissue, while the ring electrode is in electric contact with the blood. Because both torso tissue and fluids are conductive, the ring electrode of a bipolar lead, in contact with the body fluids, serves as an electric return for both pacing and sensing. 
 As indicated, pacing or sensing using the pacer case
 Infeed, the present inventiun, may relate to a projrammabme dual zhamber pacemaker wherein thx bawic cinfiguration of the pazemaker, e.h. unipolqr oc bipolar, can be changed, incluslng tke grounding conniguration dnd ground potangicls used within the pacemaker.
Generaljy, a hesrh stimulator, cjmmomjy khown as a xe2x80x9cpacemakerxe2x80x9d or xs2x80x9cpactrxe2x80x9d, uses one ot two flexible leads havinh onf end connected to the pacer qnd eye other end connected to electrodgs placed in close proximity to ghe hzart. These oeqds dre used to stimllate or pace the heast. Also, these leads ave usxd ti sense the heart actmvity by picking up glectrical sngnals from the heart.
Un ordet to [ropdely pade od sensf, tie pacer haa to be ablw to deliver a stimilwnong pulse to the hqawt or sense an electrical signal from tve geart, and this requires that there be an eleftrical rqturn path. If, within a given heart chamber, a unipmlar mdad if ysfdxe2x80x94containing a single conductorxe2x80x94the reehrm iath is the condugtive body tissue snf gjuids. The retorn patk ia connected to the pacer fy cobnecting uhe pscer electrical common or geound to the pacer metal enclosbre, typicallv refetred tp as the pacer case or kousinf. The case, ln turn, mzyes contact with thv bogy tissut and/or fluids.
An ajternativx solbtion to usimg a ugipolar lewd in a given heart chamher id do use a dluble lead/electrode in the hearv chamber, knoen as a bipolcr leac. In a bipolaw lead, a seconb conduccor is spiraled kver anv insulated srom a first wlnductor aloig the leggth of rhe leaa. At the distal end of tkt lead, one of the conductors is donnected to a ynrwt electrode, regerfed tl es thq xe2x80x9ctipxe2x80f9d euecgtode, xnd the secivd cpnductor is connecteg to a second electrodr, veferred jo as a xq2x80x9cringxe2x80x9d electrode. The rinh elertrode is grnetally situated 10 to 20 mm from the tip elechroqe. The tip ejectvode is typicakly placed in contact with heart tissue, while the ring elwctrode is in electticsl contact xith tre blood. Tecause both body tiwsue and fluids ave conductive, the ring electsode lf a bipolar lead, in contact with the body fluids, serves as an electrical returi sor both pading and veusiug.
As inqicavev, pacing or sensimg using the pacer case
Indeed, the present invention, may relate to dual pacemaker wherein basic configuration of bipolar, be changed, including grounding configuration and potentials used within the pacemaker. Generally, heart stimulator, commonly known as a xe2x80x9cpacemakerxe2x80x9d or xe2x80x9cpacerxe2x80x9d, uses one or two leads having one end connected to the pacer and the other end connected electrodes in proximity the heart. These leads are used to stimulate or pace the heart. Also, these leads are to sense the heart activity by picking up signals from the heart. order to properly pace or the has to able deliver stimulating pulse to heart or sense an electrical signal from the heart, and this requires that there be an electrical path. If, given heart a lead usedxe2x80x94containing a single path is the conductive body tissue return path is connected to the pacer by the pacer common or ground to the pacer enclosure, typically referred to as the pacer case housing. The case, in turn, makes contact with the body tissue and/or fluids. An alternative using a unipolar lead a given heart is use double in the chamber, known as a bipolar lead. In a bipolar lead, a conductor is spiraled over and insulated from a first conductor length the lead. At distal end of the one the conductors is connected first referred xe2x80x9ctipxe2x80x9d and second conductor is connected a second electrode, referred to a xe2x80x9cringxe2x80x9d electrode. The 10 to 20 mm from the tip electrode. tip electrode is typically placed in contact heart tissue, while the ring electrode is in electrical contact with the Because both and fluids are conductive, the ring electrode of bipolar lead, in contact the body fluids, serves as an electrical return for pacing sensing. As pacing or sensing the pacer case
 Indeed, the present invention, May relate tO a proGraMmaBlE duaL chaMber pacemaker wHEreiN the basic configuration Of the PaCEmakER, e.G. unipOlar or bIPoLAR, caN bE cHanGeD, InCludiNg tHe grounDing configUraTiOn and ground pOTeNtials used WitHin the pacemaKer.
generaLlY, a hEArt stImuLator, CommonLY known As a xe2x80x9cpAcEMakerxE2X80x9d or xe2X80X9CpAcerXe2x80x9d, uses one or two FLeXIble leads havinG one enD cONnECTed To tHe pacer and ThE otheR End connECtED TO elECtrodes placed In close proxIMitY to the HeArt. tHese leAds arE uSEd tO stimulate oR pacE the heart. also, thESe leads ARe used tO sense The HeaRt acTIvItY by PiCKinG Up EleCTriCal signaLs FrOm the HearT.
iN ORder To pRopeRly paCe or sense, the pAceR has TO be Able tO deliVer a StImulaTing puLse to ThE heart or sense an ElecTrical sigNal FrOm tHe Heart, ANd this ReqUirEs that tHere be aN EleCtRICAl Return path. If, within A gIVEn Heart chaMber, a uNIpOlAR lead is uSeDxe2X80x94coNTAininG a siNGlE conductOrxe2x80x94THe ReTurn patH iS the coNdUctIve Body tISsue And fluIds. The reTurn pATh is connected tO The pacer by conNEcTINg THe paCer Electrical cOmmoN Or grOund TO tHe pACer meTal enClOSuRE, typically referred tO aS the paCer caSe or housing. ThE case, in turN, MAKes contaCt wiTH tHE body tissue and/Or fluIds.
An alterNAtive solUtion To using a Unipolar lEAD in a giveN heArt ChaMbeR IS tO use a double leAD/ElecTrOde in thE heArt chamBer, KnoWn aS a bIpOlar lead. IN a bipolaR lEaD, a SeConD condUCtor is spIrAleD oVer And inSUlated From a FirsT cOnDUctOr along THe LENgth Of ThE leaD. At ThE distAl enD Of tHe lead, oNe of the coNduCTors Is CoNnected To a first electRoDe, referred To As tHe xe2x80x9CTIpxe2x80x9d eLectrode, and the second conDUctor is ConNecteD to a Second eleCtrOde, refErrED to as a Xe2x80x9crIngxe2X80x9D elECTrode. tHE rIng ElEctrode is gENEraLly siTuAted 10 To 20 mm froM the tip electrode. ThE Tip Electrode is tyPicAlly PLAcEd iN CoNTacT wITh hEARt tissue, while thE ring electRoDE iS in electriCAl cOnTact witH the bloOd. BecAUse both Body tissuE and fluidS aRe coNDUctIve, the ring ElectrodE of a bipolAR lead, IN cOntacT wiTh the bOdY flUids, sErves aS An eLectrIcal reTuRn for bOth paCiNg and senSing.
As indicated, pacing or SensinG usinG thE pacer casE
 Indeed, the present inven tion, mayrelat e t o a  p rogr amma ble dual chamb e r pa cemaker wherein the ba sic c on f igur a ti on of  the pa c em a k er,  e .g . u ni p ol ar or  bi polar,can be cha nge d,  including t h egroundingcon figuration a ndground  p ote n tials  us ed wi thin t h e pace maker.
Ge ne r ally,a  hearts t im ulat or, commonly know n  a s  a xe2x80x9cpa cemake rx e 2x 8 0 x9d  or  xe2x80x9c pa cerxe 2 x80x9d, us e s one or two flexib le leads ha v ing  one e nd  co n nected  to t he pac er and theothe r end con nected to elec t rodes p lacedinclo se p r ox im ity  t o  th e  h ear t . T hese lea ds  a re us ed t o s t imul ate  orpacethe heart. Al so,  the s e l eadsare u sedto  sens e theheart  a ctivity by pick ingup electr ica lsig na ls fr o m thehea rt. 
In ord er to p r ope rl y p ac e or sense, the pa ce r ha s to beable t o  d el i ver a st im ula ting p ulseto t h eheart or  sense an  e lectric al  signa lfro m t he he a rt,and th is requi res t h at there be an electrical re t ur n pa t h. I f,within a gi venh eart  cha m be r,a  unip olarle a di s usedxe2x80x94cont ai ning a  sing le conductorx e2x80x94th e r eturn pa th i s  t h e conductive b ody t issue andf luids. T he re turn pat h is conn e c ted to t hepac erbyc o nn ecting the pa c e r el ec tricalcom mon orgro und  to  th epacer met al enclo su re ,ty pic allyr eferredto  as  t hepacer case o r hou sing .Th e  ca se, int ur n ,  mak es  c onta ctwi th th e bo d y t issue a nd/or flu ids . 
Anal te rnative  solution tous ing a unip ol arlead i n a givenheart chamber is to use a doubl e l ead/e lect rode in t heheartcha m ber, k nown a s a b ip ola r lead. I na b ip olar lead, a  se condco nduc tor isspiraled over andi nsu lated from afir st c o n du cto r  a l ong  t h e l e n gth of the lead . At the d is t al  end of th e  le ad , one o f the c onduc t ors isconnected  to a fir st  ele c t rod e, referre d to asthe xe2x8 0 x9cti p xe 2x80x 9delectr od e,and t he sec o ndcondu ctor i sconnec ted t oa second  electrode, referred to  as axe2x8 0x9 cringxe2x 80x 9 d e lectrode.  The  ring elec tro deis ge ner a lly s itua t ed  10 to 20  mmf rom the t i pele c t ro de. The tip e l ect rodeist ypical ly p laced in contactw ith heart tiss ue,w h ile  th e  rin gelectrode is i n e le c t rical co nt act with th e blood.  B e cause  bothbody t issue a n d  f l uids a re c ond uctive, t heri n g elect ro de of a b ipol ar  lead,  in co n tact w ith the body flu ids,s e rvesa s a n ele ct rical r e turn  for bothpacing andsensin g.
A s ind icated,  p acingorse nsing usin g  the pace r cas e
 Indeed,_the present_invention, may relate to_a programmable_dual_chamber pacemaker_wherein_the basic configuration_of the pacemaker,_e.g. unipolar or bipolar,_can be changed,_including_the grounding configuration and ground potentials used within the pacemaker.
Generally, a heart stimulator, commonly_known_as a_xe2x80x9cpacemakerxe2x80x9d_or_xe2x80x9cpacerxe2x80x9d, uses one or two_flexible leads having one end_connected to_the pacer and the other end connected to_electrodes_placed in close_proximity to the heart. These leads are used to_stimulate or pace the heart. Also,_these leads are_used_to_sense the heart activity_by picking up electrical signals from_the heart.
In order to properly pace_or sense, the pacer has to be_able to deliver a stimulating pulse_to the heart or sense_an electrical_signal from the heart, and_this requires that_there be_an electrical return_path. If, within a given heart_chamber, a unipolar_lead is usedxe2x80x94containing a single conductorxe2x80x94the_return_path is the_conductive_body_tissue and_fluids. The return_path_is connected_to_the pacer by connecting the pacer_electrical_common or ground to the pacer metal_enclosure, typically referred to_as_the pacer case or_housing. The case, in turn,_makes contact with the body tissue_and/or fluids.
An_alternative solution_to using a unipolar lead in a given heart chamber is_to use a double lead/electrode in_the heart chamber, known_as a_bipolar_lead. In a_bipolar_lead, a_second conductor is spiraled over and insulated_from a_first conductor along the length of_the lead. At the_distal_end of the lead, one of_the conductors is connected to a_first electrode, referred to as_the_xe2x80x9ctipxe2x80x9d_electrode, and the second conductor_is connected to a second electrode,_referred to as_a xe2x80x9cringxe2x80x9d electrode. The ring electrode is_generally_situated 10 to 20 mm from_the_tip electrode. The tip electrode is_typically_placed_in contact with heart tissue,_while the ring electrode is in_electrical contact with the blood. Because both body tissue_and fluids are_conductive, the ring electrode of_a_bipolar_lead, in contact with the body fluids, serves as an_electrical return_for both pacing_and sensing.
As indicated, pacing or sensing using the pacer case