REAL-TIME OPTIMIZATION OF PATIENT FLOW IN EMERGENCY DEPARTMENTS. Boaz Carmeli

Transcription

1 REL-TIME OPTIMIZTION OF PTIENT FLOW IN EMERGENCY DEPRTMENTS Boaz Carml

2 REL-TIME OPTIMIZTION OF PTIENT FLOW IN EMERGENCY DEPRTMENTS Rarch Th Subm n Paral Fulfllmn of h Rqurmn for h Dgr of Mar of Scnc n Informaon Managmn Engnrng Boaz Carml Subm o h Sna of h Tchnon - Iral Inu of Tchnology v 5772 Hafa July 212

3 CKNOWLEDGEMENTS Th Rarch Th wa carr ou unr h uprvon of Prof. vha Manlbaum n h Tchnon Faculy of Inural Engnrng an Managmn. Th gnrou fnancal hlp of h Tchnon grafully acknowlg. Par of h Rarch Th wa publh n h Mcal Informac Confrnc unr h followng: E. Vkn, B. Carml, O. Grnhpan, D. Bara, Y. Marmor, MEDL: Maurng of Emrgncy Dparmn apv Loa, MEDINFO 21. B. Carml wa h corrponng auhor for h papr, an conrbu mo of h rqurmn, ngh, oman unranng an chncal archcur.

4 TBLE OF CONTENTS brac... 1 L of cronym... 2 Chapr 1 : Inroucon Th Srucur... 5 Chapr 2 : Emrgncy Dparmn Opraon Th Rol of h ED ED Opraonal Proc ED Opraonal Effcncy Monorng an Conrol Mhoology...18 Chapr 3 : ED Ky Prformanc Incaor Rfrr Ky Prformanc Incaor Th ED Loa KPI: Complx KPI...24 Chapr 4 : Ral Tm ED Monorng ERhyhm: Ral-m Monorng-an-Conrol Sym Th Daa Sourc an h Daa Collcon Layr Th ERhyhm Inpu Layr Th ERhyhm Logc Layr Monorng Dahboar...34 Chapr 5 : Ral-m ED Loa Monorng an Maurmn Dynamc ED Loa Funcon Nural Nwork-Ba Loa Funcon Ung Nural Nwork o Calcula ED Loa Th ED Loa Larnng Mchanm Trackng Loa on Inrnal Rourc Mulpl Vw of ED Loa...44 Chapr 6 : ED Pan Flow Conrol Whch Saon o V Nx Whch Pan o Tra Nx? Opraonally Opmal PTN Conrol Th PTN Sylz Quung Mol Quung Thory an Quung Nwork Mulpl Dcon Th "B" Srvc Polcy...59 Chapr 7 : Whch Pan Shoul b Tra Nx? Smulaon-ba naly Th Smulaon Envronmn Rul Summary of Rul...85 Chapr 8 : Whch Pan Shoul b Tra Nx? Flu Mol naly Problm Dfnon Provng h Daln-Fably Conon Th Trval rrval Ra Ca Varabl rrval Ra unr h Daln Fably Conon Gnral Tm-Varyng rrval Ra...13

5 8.6 Summary of Rul...17 Chapr 9 : Concluon an Fuur Work Forcang an Conrollng ED rrval Ra Nural Nwork-Ba Loa Monorng Exnng h Flu Mol naly ED Prory Quu Suaonal Dplay...19 Bblography...11 ppnx : Inpu Oupu an Conrol Evn OF ERhyhm Daa Evn Conrol Evn Oupu Evn Evn Typ ppnx B: Connu on Loa Paramr Clafcaon Inpu Paramr Throughpu Paramr Oupu Paramr...125

6 LIST OF TBLES Tabl 1: Major rvc polcy cla for h PTN...55 Tabl 2: L of Hybr rvc polc...57 Tabl 3: Hybr-approach rvc polc an hr rvc ub-polcy componn Tabl 4: L of proc low-lvl vn...62 Tabl 5: Drbuon of h numbr of ncounr n a ypcal npu...62 Tabl 6: Pan' ncounr rcor Tabl 7: Typcal rag cor rbuon...63 Tabl 8: Typcal rag aln...63 Tabl 9: Pan' ag group wh hr rbuon Tabl 1: Drbuon of h DT xpc au...64 Tabl 11: Trag-rla co Tabl 12: g-rla co Tabl 13: DT-rla co...66 Tabl 14: Polynomal wang m co, akng Expc DT au no accoun...66 Tabl 15: Co-ra funcon for h varou pan cla Tabl 16: PTN rvc polc comparon...71 Tabl 17: Mng aln conran...73 Tabl 18: Mng aln conran along rag cagor...74 Tabl 19: Summary abl for h varou STD an DTD cnaro...74 Tabl 2: Fx arrval ra; havy raffc...75 Tabl 21: Var arrval ra wh avrag blow havy-raffc conon...76 Tabl 22: Var arrval ra wh avrag a havy raffc...77 Tabl 23: Summary of comparon abl...78 Tabl 24: DTD, larg ym; fx arrval ra; havy raffc conon...79 Tabl 25: TD; larg ym; fx arrval ra; havy raffc conon...8 Tabl 26: DTD; mall ym; ralc arrval ra ha avrag n havy-raffc conon...81 Tabl 27: TD; mall ym; ralc arrval ra ha avrag n havy-raffc conon...82 Tabl 28: LOS rbuon for a ym unr varou loa Tabl 29: Daa vn rucur Tabl 3: Conrol vn rucur Tabl 31: TTFE KPI rucur Tabl 32: Suff ulzaon raon KPI rucur Tabl 33: Occupancy lvl KPI rucur Tabl 34: Pan ramn rao KPI rucur Tabl 35: Pan oal ramn m KPI rucur Tabl 36: Evn yp...121

7 LIST OF FIGURES Fgur 1: Schmac vw of h man ED proc...7 Fgur 2: Hourly arrval ra pr pan yp avrag ovr 4 yar...8 Fgur 3: Inrnal proc acvy char., B, an C nca alrnav opraon. Th r o nca h mrgng pon of all alrnav opraon...11 Fgur 4: Inrnal proc aon.., rourc char., B, C, an D alrnav opran; Rorc quu n r; ynchronzaon quu n grn Fgur 5: Th nrnal proc combn acvy-aon char...14 Fgur 6: Monorng an conrol mhoology...18 Fgur 7: Typcal ED monorng-an-conrol componn rucur...27 Fgur 8: Informaon gnra an collc urng h clncal proc...29 Fgur 9: Th ERhyhm EPN mplmn by ung SramBa Fgur 1: Th Occupancy lvl ncaor play ung vral Flx wg...35 Fgur 11: rrval an aff ulzaon nclung forcang...36 Fgur 12: a ngl prcpron; b mul-layr nwork...4 Fgur 13: ED nural nwork vw: Th rangl a oal nuron, hxagon ar h ag nuron, rcangl ar h concp nuron, an amon ar prmv npu ncaor nuron...41 Fgur 14: Dahboar napho; loa valu black ln calcula a h prcn of h avrag grn ln...42 Fgur 15: Tracng loa. Grn ln nca oal loa, orang ln nca hroughpu; h r n h oal loa wa clarly cau by ncrang h hroughpu nuron; w can rac furhr an uc ha h pak n hroughpu wa cau by lvaon of h ED workloa concp nuron...43 Fgur 16: Smula nur, ocor, an pan profl bhavor, whn 1% h avrag aly loa...45 Fgur 17: Ur profl compo of major raw ncaor wgh larn by h ym...45 Fgur 18: ylz quung mol for h "Whch aon o v nx?" problm...48 Fgur 19: ylz quung mol for h PTN quon...51 Fgur 2: Th PTN concpual con r...54 Fgur 21: DTD hrhol algorhm puo co...59 Fgur 22: ypcal ralc arrval ra parn for a mall ED...65 Fgur 23: Co for am pan lnar bfor rachng h four-houraln...68 Fgur 24: Co for all pan, mphazng am an charg ffrnc Fgur 25: LOS rbuon acro ag group Fgur 26: LOS rbuon acro h xpc DT au....85

8 Fgur 27: Th ylz flu mol for h PTN quon...86 Fgur 28: Cumulav arrval an parur work Fgur 29: no aln-fabl α...9 Fgur 3: Fnng h of pon...93 Fgur 31: Conrucng δ*...94 Fgur 32: Lf ync pon an rgh ync pon...95

9 BSTRCT Emrgncy Dparmn ED ar hcc, hghly ochac nvronmn ha al wh human lv unr vr rourc rrcon. ED pronnl mu prov qualy clncal rvc an manan an accpabl lvl of pan afacon whl ung lm opraonal rourc. In h work w conr h rqur faur an man characrc of a ral-m ED monorng-an-conrol ym. W hn focu on wo pcfc applcaon, namly monorng h ral-m ED loa an opmzng nrnal ED pan flow hrough ral-m conrol. goo ral-m monorng-an-conrol ym prov a holc vw of h nr ED opraon, mphazng nformaon collcon, analy an play. W analyz h ED opraon from mulpl mnon an vwpon,.g., akng clncal, opraonal, an rvc-lvl apc no accoun. W focu on monorng approach an opmzaon chnqu ha can b ploy an u whn a ral-m ED monorng-an-conrol ym. W vlop an nnovav loa monorng an maurmn approach ba on a nural nwork paragm. W hu nabl aapaon of h loa funcon no a pcfc ED ng, ung ubjcv loa prcpon prov by a pcfc ur or a ur group. W analyz rvc polc o opmz h ED pan by arng h followng quon: Whch pan houl a phycan ra nx? For ha, w prov an opmal conrol, ba on a flu mol analy an cr vn mulaon. Dployng h rulng rvc polc whn a ral-m monorng-an-conrol ym woul nabl ED managmn an aff o mprov ovrall ED opraon. 1

10 LIST OF CRONYMS DT TD TS BM CEP CLPC CPUR CT DES DFC DTD ED EMR EMS EP EPN FCFS FT GPS GTD HMO HTTP ILT IP IT IPF m, Dcharg, Tranfr apv Thrhol uralaan Trag Scal Bun cvy Monorng Complx Evn Procng Connu Loa Paramr Clafcaon Car Pronnl Ulzaon Raon Compurz Tomography Dcr Evn Smulaon Daln-Fably Conon Dynamc Thrhol Emrgncy Dparmn Elcronc Mcal Rcor Emrgncy Mcal Srvc Evn Procng gn Evn Procng Nwork Fr Com Fr Srv Fa Track Global Poonng Sym Gry Thrhol Halh Mannanc Organzaon Hypr Tx Tranfr Proocol Inoor Locaon Trackng In Proc Informaon Tchnology IP pan Fr 2

11 KPI LIMS LOS LSP MIS MRI N NF PCS PHO PPE PTN PUR QED RFID RSP STD TCP/IP TSLD TTFE UI Ky Prformanc Incaor Lab Informaon Managmn Sym Lngh of Say Lf Sync Pon Managmn Informaon Sym Magnc Ronanc Imagng Nwly rrv Nwly rrv Fr Pcur rchv an Communcaon Sym Phycal Occupancy Proacv Pro Equaly Pan o Tra Nx Pan Ulzaon Rao Qualy an Effcncy Drvn Rao Frquncy Infcaon Rgh Sync Pon Sac Thrhol Tranmon Conrol Proocol/Inrn Proocol Thrhol Tm Tll Fr Encounr Ur Inrfac 3

12 CHPTER 1: INTRODUCTION n Emrgncy Dparmn ED a hcc, hghly ochac, nvronmn ha al wh human lv unr vr rourc rrcon. ED pronnl mu prov qualy clncal rvc, an manan an accpabl lvl of pan afacon whl ung lm opraonal rourc. Th rarch m from h n for ED managmn o opmz ED opraon. Spcfcally, w focu on h opmzaon approach ha m from h ably o monor an conrol ED opraon n ral-m. vanc n Informaon Tchnology IT rflc n h xnv u of hopal IT ym uch a m, Dcharg, Tranfr DT, Elcronc Mcal Rcor EMR ym, Pcur rchv an Communcaon Sym PCS an alk, a wll a by h mplmnaon of nw RFID-ba chnolog for rackng human an qupmn movmn. Th avanc ugg nw monorng an conrol opporun. Such chnolog may prov ED managmn wh a holc vw of h currn ED uaon an nabl h vlopmn of ral-m opmzaon whch am a mprovng h ED clncal an opraonal nvronmn. In h work, w prn h rqur faur an man characrc of a ral-m ED monorng-an-conrol ym. W hn focu on wo pcfc applcaon, namly monorng h ral-m ED loa an opmzng nrnal ED pan flow va ralm conrol. Through h wo applcaon, w monra wo farly ffrn rarch chnqu. W analyz h ED loa problm ung arfcal nllgnc,.., nural nwork, amng a capurng h ED opraonal characrc whl rang a a black-box, bypang h n o ply unran nrnal bhavor. W u a omwha ffrn rarch approach for h con applcaon. Spcfcally, w ar h "Whch pan o ra nx?" quon, ung a al quung mol ha k o mahmacally unran mcro-bhavor an hn opmz. goo ral-m monorng-an-conrol ym prov a holc vw of h nr ED opraon, mphazng nformaon collcon, analy an play. Th ED opraon houl b analyz from mulpl mnon an vwpon, akng clncal, opraonal, an rvc-lvl apc no accoun. Th rarch focu on monorng approach an opmzaon chnqu ha can b ploy an u whn a ralm ED monorng-an-conrol ym. Th ED par of a broar clncal an opraonal coym hrough whch pan flow. Pan arrv a h ED from varou plac, an unr varou clncal conon, wh a hghly var arrval ra. From h ED, pan ar hr am o on of h hopal war, n back hom, or ranfrr o anohr clncal facly. Thu, h npu an oupu pan flow mu alo b conr whl analyzng an opmzng ED opraon. Influncng pan flow xrnal o h ED by conrollng 4

13 h ED arrval ra, allowng far amon, or rucng hopal occupancy, byon h cop of h rarch. W hu focu on h ED nrnal pan flow proc, akng xrnal opraon a a gvn. 1.1 Th Srucur Th r of h h rucur a follow. In Chapr 2, w prov a al crpon of h ED opraonal nvronmn an h urrounng affcng. W hn prn a clafcaon of m-rla opmzaon cagor, namly ragc, accal, an ral-m, whch characrz h focu of h rarch. W conclu Chapr 2 by prnng a monorng-an-conrol mhoology ha prov h founaon for h r of h work. In Chapr 3, w urvy h mo mporan ED ky prformanc ncaor, wh pcal anon o ncaor ha affc h ED loa. In Chapr 4, w nrouc ERhyhm, an ED ral-m monorng-an-conrol ym, an prn ky concp. In Chapr 5, w cu an nnovav approach for ralm ED loa monorng ba on nural nwork. In Chapr 6, w prn wo major ED pan-flow conrol problm, namly: "whr houl a pan go nx?" an "whch pan houl a phycan ra nx?" PTN; w connu wh a horcal cuon of h con quon. Chapr 6 conclu by propong a hurc rvc polcy ha b ar h PTN quon, whch h man fnng of h rarch. In Chapr 7, w prov a mulaon-ba analy for varou rvc polc ha ar h PTN quon. In Chapr 8, w gv a complmnary mahmacal analy of a flu-mol for a ylz vron of h PTN quon an prn an opmal conrol for. W conclu h h wh concluon an a for fuur work. 5

14 CHPTER 2: EMERGENCY DEPRTMENT OPERTIONS Emrgncy parmn rv mulpl purpo n h ovrall hopal ng. Hopal a cnral locaon n whch a pcalz aff prov h b pobl ramn o pan ung a-of-h-ar clncal procur an h mo avanc qupmn. Th hopal' man goal o prov h b pobl car o pan whn a conroll co. hopal a complx opraonal nvronmn, gn o ar a w vary of pan' clncal n. Th parmn, or war, h cor hopal' clncal an opraonal un. In gnral, ach war pcalz n rang pan unr mlar clncal conon, uch a oncology, carology, nrnal, an o forh. n mrgncy parmn omwha ffrn. Th ED gn o prov a mcal ramn facly pcalzng n acu car of pan who arrv whou a pror apponmn [ 7]. Du o h unplann naur of pan ananc, h parmn mu prov nal ramn for a broa pcrum of lln an njur, om of whch may b lf-hranng an rqur mma anon. uch, h ED alo rv a h hopal' man gaway for arrvng pan. Numrou yp of ED ng ar foun n ffrn par of h worl, an vn whn h am counry. ED yp wr vlop ovr h yar followng wo man mol known a h nglo-mrcan mol an h Franco-Grman mol [ 15]. Th nglo-mrcan mol ugg an acu car facly, or a un whn h hopal ha rv a boh h gaway o h hopal an h provr of mrgncy mcal car for arrvng pan. Th Franco-Grman mol, on h ohr han, mphaz h valuaon an ramn of pan bfor arrvng o h hopal,.g., a h pan' hom or n h ambulanc by mrgncy mcal rvc. In h ca, h pan gvn fr-a or pr-hopal mrgncy mcal car an, n ca hopalzaon rqur, h ED rv a an nrma rour o h rlvan hopal war. Th mol ffr boh n hr clncal ng a wll a n hr opraonal ng. Our rarch focu on an ED ha follow h nglo-mrcan mol, namly, an ED ha prov acu car ramn arg a chargng pan o hr hom a wll a nal agno for pan who wll b am no on of h hopal war. 2.1 Th Rol of h ED Th rol of h ED can b analyz along h abovmnon wo complmnary apc clncal an opraonal. From h clncal prpcv, h ED' man goal o prov appropra ramn for a broa pcrum of lln an njur whn a broa pcrum of vry lvl. From h opraonal prpcv, h ED proc houl b gn n a way ha allow car pronnl o ffcnly rach a con a o whr a pan houl go nx, an hn o ac upon. Th ED opraonal proc o no an on own bu gn o b uppor clncal goal. Th ED, 6

15 unr opraonal rol, can b hough of a a pan rour, roung pan afly an ffcnly o uabl naon. Proc a h ED can hu b vw an analyz along hr clncal an opraonal apc. In h nx con, w prov a al analy of h hgh-lvl ED opraonal proc, mphazng hr rla clncal apc. 2.2 ED Opraonal Proc W u h concpual npu-hroughpu-oupu mol ugg by pln al. [ 17] o crb an analyz h varou hgh-lvl ED opraonal proc. Th ovrall vw of ha mol pc n Fgur 1. Th npu, or arrval, proc al wh apc rla o pan' arrval a h ED. In Scon 2.2.1, w cu n mor al h varou facor affcng h proc. I mporan o no ha h ED managmn, an vn hopal managmn, ha mnmal conrol ovr h arrval proc. Th hroughpu, or nrnal, proc, ar rla o h acual acv happnng whn h ED. Th proc nvolv h pan' clncal amn, ramn, an roung. Th proc hu mak up h cor of h ED an ar unr gnfcan ED managmn conrol. Th hroughpu proc ar h man focu of h rarch, an hu ar furhr cu hroughou h h. Th oupu, or am, charg, an ranfr DT proc, al wh rlang pan from h ED, hr o hr hom, o on of h ED war, or o anohr clncal facly. Oupu proc ar furhr cu n Scon Fgur 1: Schmac vw of h man ED proc In h followng con, w furhr cu h npu, oupu, an hroughpu proc an hr rlaon o h varou yp of ED gn. 7

16 2.2.1 Th ED rrval Proc Th ED arrval proc al wh all apc of pan arrval. Th man arrval proc facor h ra by whch pan arrv a h ED. ypcal ED arrval ra chang gnfcanly accorng o h m of ay. Th phnomnon mporan whn analyzng ED opraon an whn ryng o conrol hm. W wll furhr rfr o h phnomnon n chapr 6, 7, an 8 n cung h ral-m ED conrol mol. Ohr rlvan arrval proc facor ar pan' clncal vry an complxy. Pan vry can b monor n varou way, uch a hrough h ourc of arrval. Pan arrvng va ambulanc ar uually n mor rou clncal conon han pan arrvng on hr own. I mporan o no ha a gnfcan fracon of pan ha arrv o h ED o no rqur mma acu ramn. Tramn o h pan can b lay, vn up o a fw hour, wh no gnfcan clncal conqunc. Inrnal Surgcal an Orhopc Fgur 2: Hourly arrval ra pr pan yp avrag ovr 4 yar Fgur 2 prn hourly arrval ra o h Rambam ED, collc an avrag ovr 4 yar [ 44]. Th lf of h fgur how arrval o h Inrnal con of h ED, whl h rgh of h fgur how avrag arrval o h urgcal an orhopc ED con. hown, h arrval ra ha wo pak, h fr ju bfor noon an h con n h arly vnng. nohr mporan obrvaon ha arrval ra rop o narly zro urng mo la ngh hour. gnfcan amoun of rarch ha bn vo o vlopng ED arrval ra forcang mho. For a rfrnc on forcang an molng ED arrval an rla lraur, [ 23]. Bng abl o forca ED arrval nabl ED managmn o prpar for ovrcrow uaon,.g., by hfng ky pronnl. n nrng rarch quon rla o h from of choc pan hav whl approachng an ED. In ohr wor, o wha gr can pan' con affc h ypcal arrval ra parn,.g., by poponng hr v for a fw hour? Th quon no whn h cop of h rarch. In 8

17 Iral, mo arrval o ED rqur a rfrral from a communy phycan, makng up abou 6% of h v n 29 [ 19]. Thu, ral-m communcaon bwn h communy car facl.., h four major Halh Mannanc Organzaon n Iral ha h ponal o ramacally mprov h ED arrval ra forca. nohr nrng apc of an ED ral-m monorng ym ably o prov onln, ral-m upa au of h nrnal loa whn a pcfc ED, allowng pan o mak auonomc con a o whch ED o approach. Such ral-m vw no h nrnal ED au wll cra a ngav fback loop ha ha h ponal o balanc h ED opraonal uaon. llowng pan o nofy an ED abou hr plann arrval,.g., hrough a ca marphon applcaon, offr furhr mprovmn o h arrval forcang mho. Th quon, an h mplcaon of pobl arrval-ra forcang mprovmn approach, ar byon h cop of h rarch. For our purpo w wll aum ha h arrval ra prov o h monorng an conrol ym a an npu ha canno b chang Th ED Trag Proc On of h challng n rang pan a h ED o rmn hr rgh lvl of clncal urgncy. Such lvl allow h agnng of ramn pror for pan. gnng clncal pror mo mporan for pan ju arrvng o h ED, who prn h mo uncran clncal uaon, an hnc mu a phycan a arly a pobl. Th rag proc, orgna an fr formalz n Worl War I by Frnch ocor [ 13], a proc of prorzng pan ba on h vry of hr conon. In fac, ragng u o b augh wh an mpha on h p of h funcon, rahr han h accuracy of h oucom. Trag manly a roung proc, allowng ED managmn o rou h arrvng pan no h mo uabl ED con. Th rag combn clncal an opraonal n. Th rag proc n wh wo complmnary rul: h pan g a rag cor, whch an ncaon a o h vry of hr clncal conon an h pan rou o a uabl ED con, ba on h rag cor an ohr clncal conon. Thu, ng h rag cor, uch a ho ba on h uralaan Trag Scal TS, allow cargvr o ranform clncal urgnc no opraonal pror [ 41]. Th rag h fr nracon bwn h car pronnl an h pan who ju arrv a h ED. Thu, prov a clar paraon bwn h ED arrval proc an h ED nrnal proc, a llura n Fgur 1. No all ED u an xplc rag proc an no all pan ar agn rag cor. Nvrhl, h rag proc can b vw a h fr clncal-opraonal proc prov for nw pan ju arrvng o h ED. Trag uually prform by an xprnc nur [ 28]. 9

18 mpl work an rarch hav bn conuc for hlpng agn h appropra rag cagor o pan. Th rlaonhp bwn h cagor an h ED phycal rucur an rourc ulzaon of gra mporanc. For xampl, n [ 42], S. Mahapara propo a mho ha u h acu cagor rag cagor 1 an 2 n opmzng pan ramn chulng, an h lghr cagor cagor 3, 4, an 5 for prcng rourc u. gnng a rag cor o a nwly-arrv pan ll no uffcn for allowng phycan o prorz pan an o c whch pan o ra nx. In raly, h am phycan n o boh agno nwly-arrv pan an ra pan alray n proc. Thu, wo compng group of pan mu b prorz accorngly. Th ED Elcronc Halh Rcor EHR ym may prov much mor al clncal nformaon abou pan alray n proc an can b u for furhr opmzaon. For xampl, uppo ha an xprnc cargvr abl o accuraly prc f a pan o b charg or o b hopalz. Th woul nabl h rucon of h ovrall avrag lngh of ay LOS, for xampl, of charg pan, by gvng hm prcnc ovr pan ha ar abou o b hopalz. Such opmzaon an conrol furhr cu n h ubqun chapr Th ED Inrnal Proc Th nrnal proc conu h man par of h n-o-n ED pan flow. n ovrall vw of h ED nrnal proc acv prov n Fgur 3 [ 44]. pc n h fgur, h pan flow proc can b mol a a job hop proc [ 22], [ 49], [ 61]. I nvolv vral procng-aon n clo phycal proxmy, hrough whch job ar ravlng whl complng work. pplyng ha mol o an ED ng, w corrla: aon wh locaon n h flow proc whr car pronnl gv clncal ramn o pan an job wh h pan hmlv or wh aonal work, uch a X-Ray nrpraon, n o b on by cargvr no ncarly n fron of a pan. 1

19 Fgur 3: Inrnal proc acvy char., B, an C nca alrnav opraon. Th r o nca h mrgng pon of all alrnav opraon. Thr no anar ED ng. Thu, h ED can b vw a a compoon of h followng aon from vral yp, l n an arbrary orr Fgur 4 [ 44]: Th arrval aon h fr aon a pan ncounr afr arrvng a h ED. mon work prform a h aon. If a rag proc x, prform n an mma ubqun aon. Th nurng aon a aon a whch nur gv ramn o pan an prform rla work. ngl ED may conan mulpl nurng aon. ha aon, nur maur val gn, gv mcaon, an ak lab, c. In om uaon, pan mu wa afr rcvng ramn for o ak affc bfor hy can connu on o ohr aon. 11

20 Th phycan aon a aon a whch phycan ra pan. n ED gnrally ha mulpl phycan aon. Phycan aon may hav a yp,.., for h ffrn pcal phycan uch a nrn, urgon, or orhop. Th conulan aon a aon a whch a phycan from ou of h ED ra pan. Unlk h phycan aon, h conulan aon uually unoccup. If a pan n o a conulan, h wll probably n o wa for hr arrval o h ED. Pan ar occaonally n o h rlvan war o a conulan rahr han wang for h conulan o com o h ED. Th magng aon a aon a whch X-Ray, CT, Ulraoun, MRI, an ohr mlar ar prform. Som ED hav an ngral magng aon, whl ohr u on n h man par of h hopal. Pan uually n o quu up for h magng aon. Th aon' rvc compo of wo ub-rvc proc: fr, an mag akn, an con, a raolog nrpr h mag an n h rul back o h rfrrng phycan aon. Th pan only n o b phycally prn urng h fr rvc par. Thu, a pan may v ohr aon whl a raolog nrpr hr mag. 12

21 Th lab aon a aon a whch laboraory ar prform. Uually, a nur conuc h lab a h nurng aon an hn n h ampl o h lab aon. Th lab aon n back lab rul o h ED afr a gnfcan pro of m uually up o half an hour or longr. Pan ar abl o go o ohr aon urng ha m, aumng ha h ohr aon can prform hr work whou rqurng h lab rul. Fgur 4: Inrnal proc aon.., rourc char., B, C, an D alrnav opraon; Rourc quu n r; ynchronzaon quu n grn. 13

22 Fgur 5 [ 44] llura h combn acvy-aon flow. I hu prov a hgh-lvl mpla for pobl pan rou whn an ED. Fgur 5: Th nrnal proc combn acvyaon char. a, pan flow hrough h ED aon wh ju a paral orr. Pan may v ach aon mor han onc, or no a all. Thu, h man goal of a pan flow monorng an conrol ym o monor h pan flow proc an pobly conrol for mprov an prhap opmal pan roung. chvng h goal h cor focu of our rarch. Thu, w xnvly cu h u n h ubqun chapr Rachng a Dcon Th ED nrnal proc rul n h con whhr o: am a pan o on of h hopal war, charg a pan hom, or ranfr a pan o anohr car lvry organzaon. Thu, rachng an am, charg, ranfr DT con nca h paraon bwn h ED nrnal proc an h DT xcuon proc. Rachng an accura DT con n a mly mannr on of h mo mporan ED goal. ED rv o oban an accura DT con a fa a pobl. Th con proc lf manly clncal, hough om opraonal apc ar ll nvolv n. Th acual con uually ma by h phycan ha ha h man 14

23 rponbly for h pcfc pan' ca. In om uaon, no clar who h rponbl phycan an u ha may cau much lay n rachng a con. Dlay omm alo occur n uaon n whch a con clncally ffcul o mak, hu rqurng conulaon from an xpr phycan. Thr ar vn uaon n whch phycan n o lay clncally ffcul con, hopng ha hng bcom clarr wh m. Infyng h uaon an alrng upon hm wll ponally mprov ED opraon, bu ar byon h cop of h rarch Th DT Proc Th DT proc ar afr h DT con ma. Th charg proc manly opraonal. Durng our rarch, w ma vral obrvaon rla o h proc ha ponally mprov ED opraon. Opmally, pan houl lav h ED mmaly afr h con ma, hr o go hom, o chck n o on of h hopal war, or o ranfr o anohr car lvry organzaon. Th o no happn for a gnfcan fracon of h ca u o vral raon, mo of hm no unr ED managmn conrol. Th mo gnfcan cau for lay h amng proc. Th amng proc ofn lay bcau war ar, uually, hghly occup, nng o lay h amon of nw pan. Varou proc an a [ 57] ar offr for acclrang an mprovng h proc. Ohr lay occur n uaon n whch h con ma o charg pan back hom, bu only afr om aonal clncal ramn. a rul, pan rman n h ED for vral hour, conumng h ED rourc an affcng h ED maur prformanc. In ohr wor, n cran uaon phycan lay h charg con, knowng ha pan n o ay n h ED for a fw mor hour anyway. Bng abl o accuraly monor h DT proc ugg nrng conrol opon. Knowng n avanc whch pan ar abou o b charg back hom whou furhr lay woul allow o gv hm om opraonal prory ovr pan ha ar abou o b am or n aonal ramn. Th prorzng woul nabl on o horn h ovrall m h pan pn a h ED. W cu uch u furhr n h followng chapr. 2.3 ED Opraonal Effcncy Thr ar many apc of ED opraonal ffcncy an many opraonal proc affcng hm. Opraonal proc can affc opraonal ffcncy along hr m cal cagor ragc, accal, an ral-m. Th ragc cagory nclu opraonal proc ha affc ffcncy n a yar m cal. Such proc ar, for xampl, h phycal plannng an ng of h ED, capacy, an h ovrall rourc uch a room, b, phycan, an nur alloca o. Th accal cagory nclu proc ha affc ffcncy n an hour-o-ay m cal,.g., 15

24 forcang ED arrval ra, ng h affng lvl a a pcfc ay, an ohr rla hor-rm ED polc. Th ral-m cagory nclu proc ha affc ffcncy n a mnu-o-hour m cal,.g., monorng currn ED loa an cng whch pan o ra nx or whr pan houl go nx. Our rarch focu on unranng u rla o h ral-m cagory of opraonal proc. Nvrhl, n h nx con, w prov a hor ovrvw of varou opraonal ffcncy apc rla o opraonal proc from h ohr wo cagor ED Sragc Opraon Cagory Th rm ED ragc opraon rfr o opraonal proc n h ragc cagory, namly ho proc ha rla o h way h ED gn an o opra. Svral gn of ED opraon hav volv ovr h yar o b uppor opraonal ffcncy whl akng clncal apc no accoun. Th followng l rprn h mo common gn an brfly crb h man pro an con of ach. Trag an ED gn n whch an xprnc car gvr,.g., an xprnc nur, xamn nwly-arrv pan an agn hm a clncal vry rag cor. Th agn cor hn u for ng pror among h pan who wa for ramn. Th rag cor alo u for ng aln for fr pan-phycan ncounr. Th cor ypcally no u byon h fr ncounr, a h clncal au aum o b parally-known onc h phycan xamn h pan. Th rag proc obvouly mprov pan roung an h ably o aoca bwn opraonal apc, uch a aln, an clncal vry. Th own of rag ha rqur an aonal rourc. Th rourc ruc from h ovrall car rourc. Trag alo a a aon, wh a pobl quu prcng, pobly ang o h ovrall lngh of ay whn h ED a wll a o h m ll fr ncounr. Fa rack FT an ED gn n whch prory bng gvn o pan who rqur mnmal ED clncal rourc. Two yp of pan may bnf from h FT ng acu pan, for whom hopalzaon obvouly ncary an hu h amng con can b ma mmaly, an pan wh ml conon, for whom h charg con can alo b ma mmaly. Th fa rack m o b h mo aracv ED ng. Th FT challng o nfy ho cana pan who wll ponally bnf from h fa rack an hn gv hm h appropra prcnc. Thu, FT go han-n-han wh rag. n ffcn rag proc upon pan arrval may rul n a much mor ffcn opraon n boh gn. Walkng acu an ED gn n whch h ED v no wo man con: for rang acu pan who ar no abl o roam abou h ED on hr own, an for pan who ar abl o walk by hmlv from on aon o anohr. In om ng, a hr rauma con x. Thr ar gnfcan ffrnc n h phycal 16

25 ng of h con. Th acu con much largr an conan a b for vry pan, whl h walkng con up lk a clnc. In h acu con, phycan walk from on pan o anohr, whl n h walkng con, pan wa ou o b call no h phycan' offc. gnng pan o con uually on by ang h way hy arrv o h ED f hy arrv by hmlv,.., walk n, hy ar n o h walkng con. If hy arrv va ambulanc or on a rchr, hy ar uually n o h acu con. Dvng h ED no acu an walkng con allow ED managmn o gnfcanly ncra h ED ac capacy: walkng pan rqur l pac hn pan n b. ng a formal rag proc upon pan arrval may ruc rror n pan placmn no con. Illn ba an ED gn n whch h ED v no con accorng o phycan pcaly. Thr m o b no avanag o h yp of ED ng from an opraonal prpcv, a manly follow clncal n. n nrng obrvaon [ 15] rulng from h gn h n o ran phycan o pcalz n mrgncy mcn. Such phycan profcncy may ramacally ruc h ED rourc n for rang pan, a all phycan wll hav h am profcncy an wll b abl o har room an ra mo pan. n mrgncy mcn phycan abl o gv nal clncal ramn o mo pan arrvng o h ED. For pan wh clncal conon ha ar byon h rach, an mrgncy mcn phycan may conul an xpr phycan hrough h conulancy proocol, a alray bng on n h currn ED ng ED Taccal Opraon Cagory Th rm ED accal opraon rfr o opraonal proc ha affc opraonal ffcncy on a aly ba. Iu rlang o h anar lvl of rourc.g., phycan, nur an lf-avng qupmn; h fnon of rol an paraon of u among phycan, nur, an amnrav aff fall whn h accal opraon cagory. Probably h mo nrng quon n h accal cagory aff chulng, pcfcally, how o agn h rgh ED affng lvl for mng ED goal. Much work [ 64], [ 29], [ 25] ha bn vo o ED chulng an affng. ED chulng an affng an h ohr apc of accal opraon ar byon h cop of h rarch an hu wll no b furhr conr ED Ral-m Opraon Cagory Th rm ED ral-m opraon rfr o opraonal proc ha affc opraonal ffcncy on a mnu-o-hour m cal. Th proc ar h focu of our rarch. Spcfcally, w ar nr n u rla o monorng h ral-m ED opraon an n conrollng. In h ubqun con, w furhr analyz an 17

26 xamn h proc n al, focung on wo complmnary u monorng h ovrall ED loa an conrollng h ral-m pan flow whn. 2.4 Monorng an Conrol Mhoology "Monorng an conrol ym" a common rm n h nural nvronmn [ 56]. Monorng an conrol ym ar u for conrollng manufacurng proc o nur aqua hroughpu an qualy lvl. Wh h prolfraon of gal ym for proc coornaon an ocumnaon an wh avanc n wrl communcaon an rackng chnqu, ha bcom praccal o prov monorng an conrol ym n rvc-ba nvronmn uch a hm park, bank branch, lcom rvc cnr, an hopal [ 27], [ 5]. vancmn an progr n hopal IT hav ma pobl o collc an accura vw of h currn a vn n hcc an ynamc nvronmn uch a h ED. Th mhoology llura n Fgur 6 can b follow whl nroucng a monorng an conrol ym no an ED. Fgur 6: Monorng an conrol mhoology Monorng an conrol mhoology con of four man ag. In h fr ag, ED managmn an ohr rlvan akholr fn h l of rlvan ky ncaor wh h xpc prformanc of ach. In h con ag, a ym wh monor-anmaur capabl nrouc no h nvronmn. Th monorng ym prov an accura vw of h rack ncaor. In h hr ag, an analy-anunran proc ak plac o br unran maurmn rul. La, a rul from h hr ag, ED managmn may c o pu n conrol o nflunc h prformanc ncaor. lrnavly, akholr may c o aap an mofy h prformanc ncaor, o ha hy br rflc h nvronmnal n, rqurmn, an pobl achvmn. Th r of h ocumn follow h abovmnon mhoology. W cu ky prformanc ncaor KPI fnon n Chapr 3, n whch w urvy h mo mporan ED KPI whl gvng pcal anon o ncaor ha affc h ED loa. In Chapr 5, w propo an nnovav way o monor an maur h ED 18

27 nvronmn. In Chapr 6, w analyz an nrpr a pcfc ED opraon quon, namly "Whch pan houl a phycan ra nx?" an prn a hurc conrol ha ar. In chapr 7 an 8, w furhr analyz h propo conrol hrough mulaon an mahmacal analy. Th back arrow n Fgur 6, namly ho ha ugg a mofcaon o h KPI, an h maurmn of h nflunc of a nw conrol on h opraon, rqur ploymn of a ym whn a ral ED an hu ar no ar furhr n h h. 19

28 CHPTER 3: ED KEY PERFORMNCE INDICTORS prformanc ncaor or ky prformanc ncaor KPI a maur of prformanc. Such maur ar commonly u o hlp an organzaon fn an valua how uccful, ypcally n rm of makng progr owar long-rm organzaonal goal [ 11]. Thu, prformanc ncaor prov h founaon of h monorng-an-conrol ym. Dfnng h KPI of mo mporanc nabl akholr o maur hm an hn o rv o mprov hm n a mhoologcal an conn mannr. Th ac of monorng KPI n ral m known a bun acvy monorng BM [ 1]. common pracc for mplmnng BM ym o u complx vn procng CEP archcur [ 3], [ 53]. CEP-ba BM ym gnra oupu from collcng an analyzng ram of vn. par of h prn rarch, w vlop ERhyhm, a ral-m CEP-ba BM ym. Th man goal of ERhyhm o monor h ED nvronmn an o gnra h rqur KPI. W crb h ky concp an cor componn of h ERhyhm monorng an conrol ym n Chapr 4. Th ED a complx nvronmn n whch a w vary of ncaor houl b conr. Monorng h whol of ncaor a manng an complx ak. Incaor can b claf no varou cagor. Som ncaor may conrac on anohr. Som prn ffrn lvl of granulary an ar maur ung ffrn un. In h followng con, w crb om of h mo mporan KPI u for maurng an conrollng h ED. In Scon 3.2, w nrouc h ED loa KPI, a complx KPI ha prn ffcul n rm of monorng an maurmn a wll a n analy an nrpraon. In Chapr 5, w offr an orgnal approach for alng wh ED loa monorng an maurmn. 3.1 Rfrr Ky Prformanc Incaor par of h rarch, w vlop h ERhyhm monorng an conrol prooyp. In Chapr 4, w crb ERhyhm n al. ERhyhm gn o monor an maur a w vary of KPI. In h followng con, w urvy om of h mo mporan KPI gnra by ERhyhm. Obvouly, ach KPI ha a pcfc manng. Th ERhyhm ym calcula ach KPI from a of low-lvl vn collc from h monor nvronmn. ERhyhm hn gnra h oupu KPI o b prn o ED managmn, aff, an ohr akholr. W crb blow ach KPI ung hr lmn: cor manng, h of npu vn from whch bng calcula, an h acual oupu ha crb. W conr aonal nformaon an ral-m alr ha h ERhyhm ym abl o 2

29 gnra ba on h cor npu vn. W prov a compl l of npu vn an oupu KPI n ppnx Tm Tll Fr Encounr TTFE Th Tm Tll Fr Encounr TTFE ncaor maur h m from a pan' arrval a h ED unl h m h pan fr n by a phycan. Th ncaor on of h mo mporan ncaor for ED managmn, a maur an opraonal ncaor,.., m, wh rong clncal apc. Noably, h acual pan' clncal conon no known unl h fr phycan' xamnaon; hu, layng a phycan' xamnaon may rul n clncal roraon. Conqunly, h conrol of h ncaor on of h man goal of h rarch. Inpu vn Th TTFE KPI ba on wo npu aa vn, namly h pan rgraon an h ar of h fr ncounr vn. Oupu vn Th ym gnra a TTFE oupu vn for ach pan upon h bgnnng of h fr ncounr wh a phycan. n oponal hrhol vn avalabl for h ym o rpor only h m ha xc h hrhol. Oponal aon an alr Informaon rv from TTFE oupu vn can b u o bnf h conrol an con uppor par of h ERhyhm n wo mporan way: Prov an alr f pan wang m hghr by om prfn prcnag han h avrag ramn m, an ramn ha no y bgun. Such an alr wll warn ED managmn n avanc of uaon n whch h TTFE aln abou o b vola. Compar avrag TTFE for h la pro wh h avrag TTFE of om horcal pro.., an avrag of h am m on h am ay urng h la yar pro. Th may rqur aonal nformaon comng from a aaba. Such an alr may rv a aonal npu for h ovrall ED loa KPI Toal Lngh-of-Say Th lngh-of-ay LOS ncaor maur h ovrall m from a pan' arrval o h ED unl amon or charg. Th LOS calcula for ach pan. ggrgav vw for varou cagor may b prov a a rvav oupu vn. Th KPI on of h mo mporan ncaor owar mprovng ED prformanc. Th LOS KPI nca ED clncal, opraonal, an rvc qualy lvl. Much work 21

30 ha bn vo o monorng an conrol of h KPI [ 26], [ 39]. ypcal ED a pcfc LOS hrhol,.g., four hour, an am on kpng h LOS blow ha hrhol for h majory of h pan. Th LOS can b vw a a complx KPI calcula from vral lowr-lvl KPI ha maur h varou pha of h car proc. Thu, h TTFE crb n h prvou con maur h fr clncal proc ag. Smlarly, a m from con o rla KPI may b gnra for maurng h m from rachng an DT con, unl h m a pan acually lav h ED. Inrngly, an nhrn raoff x bwn h LOS an h TTFE KPI. Conrollng h LOS ncaor an balancng wh h TTFE ncaor ar among h man goal of our rarch an ar ar n grar al n h followng con. Inpu vn Th LOS KPI ba on wo npu aa vn, namly h pan rgraon vn an h pan lf vn. Oupu vn Sym gnra LOS oupu vn for ach pan who charg hom from h ED or am o on of h hopal war. n oponal hrhol vn avalabl for h ym o rpor only ho pan wh an LOS ha xc h hrhol. Oponal aon an alr Gnra an alr whn h avrag LOS xc a cran prfn confguraon lvl. Th may nca ha h ovrall ED loa ncrang abov h r hrhol Pan Ulzaon Rao Th pan ulzaon rao PUR ncaor maur h rao bwn ramn m an h ovrall LOS for ach pan. Th KPI calcula for vry prconfgur m pro. Upon pan charg, a ramn rao ummary vn gnra. ggrgav vw may b prov a a rvav KPI oupu vn PUR Inpu Evn Th PUR ba on mulpl npu vn. In aon o pan rgraon an pan lf vn, h PUR monor all ar an op ramn vn gnra a h varou aon. PUR Oupu Evn Tramn pro h cumulav m pro n whch a pan acually unr ramn by car pronnl. 22

31 Toal lngh-of-ay h amoun of m a pan pn n h ED from rgraon o charg. Th maurmn akn from h LOS KPI. Oponal aon an alr Gnra an alr f h avrag ramn rao cra blow a gvn hrhol. Th may nca ha h ovrall ED loa ncrang. Gnra an alr f h ramn rao for a gvn pan cra blow a gvn hrhol. Varou hrhol may b for varou pan vry lvl. Th alr may nca ha a pcfc pan rcv low qualy rvc, from boh h clncal an opraonal prpcv Car Pronnl Ulzaon Rao Th car pronnl ulzaon raon CPUR ncaor maur h rao bwn work m an h um of work m wh l m for ach car pronnl yp. Th ncaor calcula for vry prconfgur m pro. h n of ach hf, a work-rao ummary vn gnra. n nvual CPUR ncaor can b gnra for a pcfc nvual a rqur by ED managmn. Th ED car pronnl may objc o uch an ncaor, an hu, carful anon rqur a o mplmnaon. Howvr, h u ar byon h cop of h rarch an wll no b furhr ar. Inpu vn Th CPUR ba on mulpl npu vn. Th CPUR monor all ar an op ramn vn by a car pronnl group or by a pcfc nvual. Th vn covr boh vn aoca wh h acual pan ramn a wll a vn aoca wh h aonal work prform by car pronnl. Oupu vn Work rao h amoun of m cargvr acually gv ramn o pan urng a gvn calculaon pro, nclung aonal work no prform n fron of a pcfc pan. Oponal aon an alr Gnra an alr f h avrag work rao ncra abov a gvn hrhol. Th alr may nca ha h ED loa xcng om cran r lvl Phycal Occupancy Th phycal occupancy PHO ncaor maur h numbr of pan n ach ED room or con a prconfgur pon n m. 23

32 Inpu vn To calcula PHO, h ERhyhm ym rack n/ou locaon vn an coun h numbr of pan currnly n h monor room or con. Oupu vn Occupancy lvl gnra an occupancy lvl rpor for ach room, con, an for h ovrall ED, for ach prconfgur m pro. Oponal aon an alr Prov alr f room capacy xc. Th alr may nca ha h ED loa xcng om cran r lvl. n accura locaon rackng mchanm may prov many valuabl alr an conrol byon bac capacy monorng. Som of h capabl ar: Monor all popl n a room.g. famly mmbr an alr cury for ponal ovrcrowng or cor rul volaon. Prov aonal nformaon abou a pan ha agn o a room bu no phycally loca whn h room. For xampl, a pan ha n o b n h raology con for a CT xam bu ll wang for ranfr n h man ED con. 3.2 Th ED Loa KPI: Complx KPI ED loa cranly on of h mo gnfcan an nrng KPI o monor an conrol [ 24], [ 54]. Rucng h ED loa a major ay-o-ay ED managmn challng. Hgh ED loa la o xcv wang m an an unplaan nvronmn, whch n urn cau: poor rvc qualy from boh clncal an opraonal prpcv; unncary pan an anxy for pan; ngav moon n pan an cor ha omm coul vn la o volnc agan aff; v ncra rk of clncal roraon; v ambulanc vron; v pan lavng whou bng n; v nfla aff workloa; an mor [ 58]. Maurng ED loa rv mulpl purpo an may prov o b uful from varou apc. Th mo common n foun n h lraur, for knowng h acual ED loa, o allow ED managmn o rmn h uaon ha call for ambulanc vron [ 21], [ 35]. Tha, ED managmn houl b abl o nfy uaon n whch an ED n o b clo u o ovrcrowng, an ambulanc mu b rrc o ohr hopal. In aon, conn maurmn of ED loa may nabl ED managmn o nfy rn n loa an o aju an aap h ED opraon accorngly. Dplayng a ral-m napho of h ED loa allow managr 24

33 an aff o ac n xrm uaon by makng promp con,.g., n ca of hgh or xrm loa pak. Ral-m ED loa maurmn urn ou o b a challngng, mulmnonal ak. Fr, on mu c whch paramr conrbu o h loa. Scon, on mu fn how o calcula loa on h varou paramr.., rourc. Thr, on mu agn a lvl of conrbuon o ach of h paramr whl ngrang all maurmn no a ngl loa cor. Th fac ha no "Sanar ED" x a o h loa maurmn complxy. No on phycal ED ng can b nf a anar. ED ar var from on anohr n many mnon, uch a phycal z, h populaon hy rv, affng lvl, an clncal an opraonal proocol. In aon, ED nvolv varou n,.g., phycan, nur, pan, managr; ach of whom may fn h loa funcon ffrnly, an may rqur procally ajung h loa fnon o accommoa chang ha occur ovr m. a rul, ED Loa fn a an ngrav KPI, h calculaon of whch ba on an xnv of low-lvl aa vn collc from h monor nvronmn. Hgh ED loa pn on a w vary of clncal an opraonal paramr. Som of h paramr ar alray bng monor an play a an-alon KPI, a crb n prvou con. Ohr may rv purly a npu paramr for calculang an monorng h ED Loa ncaor Connu Loa Paramr Clafcaon W foun h connu loa paramr clafcaon CLPC, ugg by Solbrg al. [ 55], mo uful for rvng a a baln for h ERhyhm loa monorng an conrol funconaly. Th CLPC wa fn by a panl of 74 naonal xpr who a 113 maur an cho 38 hrough a cuon an rang proc. Th CLPC follow h Inpu-Throughpu-Oupu opraonal mol nrouc n Scon 2.2. Th mol prm mo nf loa paramr o b group no on of hr ag: Inpu or rrval ag 15 paramr nclu facor uch a h volum of ll an njur popl n h communy an h capably of h r of h halh car ym o ar h n of nvual no rqurng mrgncy car. Throughpu or Inrnal ag 9 paramr nclu facor ha affc h ffcncy of an ED o cop wh npu, rangng from ED b an affng o h ffcncy of ancllary rvc an conulan acc. Oupu or DT ag 14 paramr nclu facor ha affc h ably of h npan ym o am pan rqurng hopal car, an of h ambulaory car ym o prov mly po-charg car. 25

34 To clarfy hr purpo, w hav furhr group h paramr whn ach ag by h man concp hy rprn: Pan man 6 m rfr o h volum of pan arrvng o h ED for rcvng mcal car. Pan complxy 3 m rfr o pan' clncal facor, uch a h urgncy an ponal roun of h prn complan, h ably of h clncal conon, an h baln mcal an pychoocal burn of lln. ED capacy 5 m rfr o h ably of h ED o prov mly car for h lvl of pan man, accorng o h aquacy of phycal pac, qupmn, pronnl, an h organzaonal ym. ED workloa 6 m rfr o h man an complxy of pan car ha unrakn by h ED whn a gvn pro. ED ffcncy 4 m rfr o h ably of h ED o prov mly, hghqualy mrgncy car, whl lmng wa of qupmn, uppl, an ffor. Hopal capacy 6 m rfr o h ably of h hopal o prov mly npan car for ED pan who rqur hopalzaon, accorng o h aquacy of phycal pac, qupmn, pronnl, an h organzaonal ym. Hopal ffcncy 8 m rfr o h ably of h hopal o prov mly, hgh-qualy npan car whl lmng wa of qupmn, uppl, an ffor. Th l of all 38 paramr prov n ppnx B. In h nx chapr, w cu h cor concp of h ERhyhm ym. In Chapr 5, w crb how ral-m bun acvy monorng ym, uch a ERhyhm, can b u o ar h ED loa monorng challng n an nnovav way. 26

35 CHPTER 4: REL TIME ED MONITORING In h prvou chapr, w crb h KPI' rol whn a ral-m bun acvymonorng nvronmn an urvy om of h mo mporan ED KPI. Nx, w wll crb h ky concp of an ED ral-m monorng-an-conrol ym; how uch a ym bng u for monorng an maurng h ED nvronmn an for gnrang, hrough calculaon, h rqur KPI. ypcal ED monorng-an-conrol ym compr hr major layr: h collcon layr, whch prov h npu o h ym, h logc layr, an h play layr, whch prn ym oupu o ur. Fgur 7 prn h hgh-lvl rucur of a ypcal monorng-an-conrol ym. No ha h fgur llura a comprhnv vw. No all componn ar manaory for vry oluon. Fgur 7: Typcal ED monorng-an-conrol componn rucur 4.1 ERhyhm: Ral-m Monorng-an-Conrol Sym Durng our rarch, w vlop ERhyhm, a prooyp ral-m monorng-anconrol ym. ERhyhm ha hr man layr: h npu layr, h logc layr, an h oupu layr. Th ERhyhm npu an oupu layr ar mplmn a an vn procng nwork EPN [ 3], [ 4]. Implmnaon on n SramBa V6.2 [ 12]. Th ERhyhm logc layr xn h EPN wh cuom-ma logc an analyc componn. 27

36 Th npu layr,.., h aa collcon layr, connc o h aa ourc an rcv h aa vn hrough h conncon. Nx, w crb h varou aa ourc ypcally foun whn an ED nvronmn. W hn follow by crbng h hr layr of h ERhyhm prooyp ym. 4.2 Th Daa Sourc an h Daa Collcon Layr Th aa collcon layr prov h npu o h ym. Th collcon layr u varou communcaon man o ranfr raw vn from gnrang ourc no h ym. Compur nwork bcom prvav an varou nwork yp can b foun n vry morn ED. Mo commonly, a TCP/IP-ba nwork u by mo nformaon chnology applcaon. In rcn yar, a prolfraon of wrl nwork ha acclra h u of mobl compur an han-hl vc. Mo rcnly, RFID chnolog hav bn nrouc, makng accuraly locang popl an objc pobl. ll uch nwork allow h xnv collcon of vn from h monor nvronmn an h ranmon of h vn no h logc an analy layr of h monorng-an-conrol ym. In h ubqun con, w prov mor al on om of h applcaon an chnolog, mphazng h ffrnc bwn clncal an opraonal ym. W ar h way n whch boh yp conrbu o ED ral-m monorng Clncal pplcaon a Opraonal Daa Sourc Hopal nvronmn ulz IT ym a an vr-growng pac. ypcal hopal manag hunr of IT applcaon. mong h man applcaon, on can uually coun h am-charg-ranfr DT ym, h lcronc halh rcor EHR ym, h pcur archv an communcaon PCS ym, an h lab nformaon managmn ym LIMS. Th ym mprov h clncal proc by rcorng an ocumnng, an by provng nan acc o pan' clncal nformaon. uch, h ym prov a rch ourc of crucal clncal nformaon, ang ED pronnl n prformng ay-o-ay ak. Concnally, h ym can b u a an nrc ourc of nformaon rgarng h opraonal uaon n h ED. Spcfcally, Th EHR ym h major managmn nformaon ym MIS u whn hopal for ocumnng clncal ramn of pan. Mo hopal ar n h proc of rplacng hr papr-ba ocumnaon ym wh compur-ba EHR. Hopal' ED howvr, ar l u for ployng an aapng EHR ym, u o h urgncy an mobl naur of h work whn hm. Nvrhl, rcn xprnc hav hown ha hopal ar xnng h rach of EHR ym an ployng hm whn ED a wll [ 52]. On uch EHR can b foun n h Rambam Mcal Cnr' ED. Rambam' ED managmn, oghr wh Rambam' IT am, c urng 29 o xn EHR funconaly no h ED. Currnly, Rambam' EHR fully funconng an prov h n nformaon o nur, phycan, an 28

37 managmn whn h ED. EHR alo prov uful nformaon abou clncal apc of pan' ramn. Through EHR, a phycan abl o ocumn agno an rqu furhr ramn, uch a prcrbng a pcfc rug or akng for xpr conulaon on an unrolv ca. Th EHR ym gn o uppor an ocumn clncal proc. uch, o no prov h ou-of-h-box, rqur vw on h opraonal au of h ED. Fgur 8: Informaon gnra an collc urng h clncal proc Sll, a hown n Fgur 8, many opraonal vn can b gnra by EHR a wll a by ohr MIS,.g., by monorng h m phycan ak o nr pcfc clncal orr for a pan. In h followng con, w cu IT ym ha ar gn o collc opraonal vn from h monor nvronmn Opraonal Daa Sourc Complmnary o h clncal applcaon, opraonal applcaon ar gn o a n managng h opraonal nvronmn. Inoor locaon rackng ILT [ 9], [ 32], [ 33], [ 48] a pcfc cla of opraonal applcaon ha nabl rackng h xac locaon of pan an pronnl whn h ED an accuraly nf h ar an n of pan/car pronnl nracon. Rcnly, h global poonng ym GPS ha bcom h -faco anar for ouoor rackng, an rv a h founaon for many locaon-rackng applcaon [ 8]. In paralll, gnfcan ffor 29

38 hav bn vo o vlop an ffcn an accura ILT ym. Howvr, a y, no opmal, anar chnology x ha uabl for noor locaon rackng. ILT ym ar alo rfrr o a RFID ym, afr h chnology of rao frquncy nfcaon. RFID chnology ha rcnly bcom wpra, u o many mr. Bacally, RFID prov unqu nfcaon o objc; hnc, can b u a h founaon for rackng, monorng, an conrollng objc movmn [ 32], [ 33]. RFID ha raonally bn u for rackng objc uch a conumr-packag goo, mcaon, an mcal qupmn. Y h am chnology can b u for unquly nfyng human,.g., pan an car pronnl n hopal. pplyng RFID for noor-locaon rackng rqur an aonal layr o aoca h RFID ag wh a pcfc locaon. Th aocaon can b mplmn va wo concpually ffrn approach: Cll-ba locaon rackng locaon nf hrough h locaon of h rar of h RFID ag. Trangulaon locaon calcula from rao frqunc, u n h communcaon bwn h RFID ag an car RFID rar. Exnv rarch bng vo o br unran h pro an con of ach approach an hr varou apc; hu, w wll no ar h apc furhr whn our rarch Locaon Monorng of ED En Ung RFID or a mlar chnology allow a monorng-an-conrol ym o collc ral-m locaon nformaon of rlvan n whn h ED. Ral-m nylocaon monorng nabl h ral m maurmn an calculaon of mo rqur KPI: Spcfcally, h followng n play a gnfcan rol whn h ED proc flow; om n ar furhr group no ny yp. Pan: Each pan nf by a unqu ID. Pan ar furhr group by clncal conon. Phycan: Phycan ar group no vral yp by profcncy. Each profcncy yp ha a unqu nfr. lm numbr of phycan from ach profcncy yp ar n h ED a any gvn pon n m. Nur: Nur ar group no vral yp accorng o hr pcfc rol. Each rol yp ha a unqu nfr. lm numbr of nur from ach yp ar n h ED a any gvn pon n m. 3

39 Room: Each room n h ED monor. Room may hav lm capacy,.g., f rvng acu pan, or unlm capacy for rvng ambulaory pan. B: Each b ha a unqu ID. room' capacy for acu pan monor by h numbr of b conan. combnaon of clncal an opraonal monorng aa ourc prov uffcn nfrarucur for a ral-m ED monorng-an-conrol ym. For h ak of h rarch, h raw clncal an opraonal aa vn ar prov by h ED Smulaor [ 43]. Th ED Smulaor gnra vn mlar o ho xpc o b gnra from clncal an opraonal IT ym n a ypcal ED. Rambam ED managmn an ohr ubjc mar xpr vala h parn an rbuon of nformaon gnra by h ED Smulaor an foun hm mlar o ho ha ar ypcally foun n a ral ED opraonal nvronmn. Th mulaor gnra abou 1 ffrn vn yp. Mo vn ar rla o h opraonal proc an pan flow whn h ED. comprhnv vn l can b foun n ppnx. 4.3 Th ERhyhm Inpu Layr Th ERhyhm npu layr mplmn ung SramBa Inpu Conncor. Th Inpu Conncor cln gn o b mb whn h clncal an opraonal aa ourc ha ar avalabl n a pcfc ED. Smlarly, h Inpu Conncor cln mb whn h ED Smulaor co an prov h man EPN' vn channl bwn h aa ourc an h ERhyhm. On arup, h ED Smulaor connc o h EPN ung h SramBa SB nrnal proocol, whch mplmn on op of TCP/IP. Ung ha proocol, h Inpu Cln n vn o h logc layr, whch mplmn a an EPN whn SB. Th ED Smulaor u wo paralll channl ovr whch n wo yp of vn, aa vn an clock vn. Th currn vron of h ED Smulaor gnra ju opraonal aa vn. Th n o conr clncal aa vn an h xac aa pc ar crb n chapr 6 an 7. To ovrcom h ffculy, w a clncal aa arbu o h ERhyhm logc rcly, bypang h ERhyhm npu layr Th Inpu Evn Thr ar hr man npu vn yp n h ERhyhm: aa vn, conrol vn, an clock vn. Each vn yp furhr crb blow. Daa Evn Each aa vn ha an vn-id fl ha nco h manng of h vn. l of all pobl npu aa vn prov n ppnx. 31

40 Each aa vn conan h followng arbu: Evn ID Unqu nfr for h vn. Rourc Typ Can b a room.g., n whch a CT can bng akn, a b, or a lab. Rourc ID a unqu rourc nfr. Car Gvr Typ.g., phycan, nur, conulan, c. Car Gvr ID unqu car gvr nfr. Pan Typ.g., orhopc, urgcal, or rauma. Pan ID a unqu pan ID. Tm a m amp n whch an vn wa gnra. Conrol Evn Svral conrol vn ar u o varou hrhol an calcula m pro an ohr confguraon paramr whn h EP. Conrol vn ar confguraonpnn. Only mnmal conrol vn funconaly currnly mplmn n h ERhyhm. Th mo mporan mplmn conrol vn h m ll fr ncounr TTFE uraon. TTFE an ED-pnn paramr, ba on h rag cagor an hr aoca aln, a fn by h ED managmn. Clock Evn EPN u clock vn o xcu logc ha no rggr by pcfc vn. Th clock vn prov h granulary lvl of h ERhyhm KPI calculaon an play. Th granulary lvl pn on h ypcal proc pac, h ra an accuracy of h npu aa vn, an h monorng-an-conrol granulary lvl rqur by ED managmn. In aon, ffrn KPI may rqur ffrn granulary lvl. Th mnu cal foun o b an appropra lvl of granulary for ral-m monorng of ED nvronmn. Th mulaon-ba ERhyhm ym rqur ynchronzaon bwn h mulaor clock an h ral-worl clock u by h EPN. Th calculaon pro of h EPN can b confgur an currnly o on-mnu nrval. Th nrnal ED mulaor u on-con nrval bwn uccv ck. Hnc, h clock vn gnra by h ED mulaor vry mnu of mulaon m,.g., vry 6 mulaon ck. 4.4 Th ERhyhm Logc Layr Th ERhyhm logc layr prov h cor KPI monorng an maurmn funconaly. Each ncaor rcv h rlvan npu vn an gnra a uabl 32

41 oupu vn o b play on h ERhyhm ahboar. Incaor can b aly a o h EPN. Each vn procng agn EP mplmn a pcfc ncaor or a mall group of rla ncaor. Mo ncaor ar calcula pr pro,.., a a a a-m. Fw ncaor ar calcula for ach vn,.. a an vn-a-a-m. Each EP rl on a ca aa rucur. Som lmnary aa rucur.g., ulzaon counr can b ru bwn varou EP. Each EP u own aa rucur for avng a. No nrnal communcaon ak plac among EP, an ach EP ac a a an-alon componn. Th archcural con rul n ubopmal prformanc, bu much ar o manan an xn. Fgur 9: Th ERhyhm EPN mplmn by ung SramBa 6.2 Fgur 9 prn h hgh-lvl vw of h EPN mplmn n SB. Thr mnmal u of h ray-ma SramBa opraor,.g., o flr ou vn ha ar no rlvan o a pcfc agn, or o convrg mlar vn no on. Th manly bcau w vlop a Java co ha mplmn h EP logc. Thu, mbng h opraor rcly no h EP logc na of mananng hm a para n bcom rval n mo ca. No ha ang nw ncaor mpl an raghforwar, a hr ar no pnnc among h EP Th ERhyhm Oupu Layr Th man purpo of h ERhyhm oupu layr o communca h calcula KPI o h uaon ahboar. Th ERhyhm oupu layr mplmn by ung h SramBa oupu conncor. Th oupu conncor cln mb whn h ED 33

42 ahboar. On arup, h ED ahboar connc o h EPN, ung SramBa SB proocol, whch mplmn on op of HTTP. Ung ha proocol, h SB Flx oupu cln rcv h oupu vn ram from h logc layr an pa o h Flx-ba ED ahboar applcaon. Th ED ahboar rcv numrou oupu ram. Each mplmn by ung a ca SB Flx conncor. Each oupu ram gn o hanl a pcfc oupu vn yp ha aoca wh a pcfc KPI. Thu, oupu vn hav no unf rucur. ll rqur vn aapaon an mofcaon ar on whn h ERhyhm logc layr. Each oupu vn alor-ma o b prn on h ED ahboar whou furhr analy an ranformaon. 4.5 Monorng Dahboar Monorng ahboar rv a h ur nrfac UI componn of ral-m monorng-an-conrol ym [ 4]. Through ahboar, ur ralz h whol nvronmnal uaon a wll a h uaon of pcfc n whn ha nvronmn. Publc ahboar ar mplmn ung larg lcronc play. Tchnology for crang larg lcronc play ha bcom prvav. Such play ar currnly bng u n many rvc-ba nvronmn, uch a arpor, bank branch, lcom rvc cnr, an hopal. Th mo gnfcan avanag of bg ahboar l whn hr ably o rv mulpl ur concurrnly. flgh arrval boar a h arpor gn o rv all pangr. No nvual-pcfc nformaon play on uch publc boar. Monorng an conrollng pan flow whn ED rqur managng nvual' pcfc nformaon. Thu, ym mu conr pan prvacy whl playng nvual pcfc nformaon on publc ahboar. Morovr, a arg aunc of ED publc ahboar can b roughly cagorz no wo group, pan an famly cor an car an managmn pronnl. Each of h group rqur ffrn nformaon from h monorng-an-conrol ym. Whl gnng a ahboar-ba UI, carful anon mu b pa o h varou ur group an hr ffrn n. UI capabl an h u of ahboar n a publc nvronmn, uch a an ED, ar ubjc for a para rarch [ 16]. In our rarch, w only mnmally nvga h b nformaon aa rqur by pan for ffcn pan flow conrol. W furhr vlop a proof of concp ED ahboar for playng h varou KPI ha h ERhyhm gnra. 34

43 4.5.1 Th ED Dahboar Th ED ahboar prov h ED ur pan, car pronnl, an managmn wh a graphcal nrfac o h of ncaor calcula an monor by h ERhyhm. Th man purpo of h ED ahboar o monra ERhyhm capabl an o play h varou KPI h ahboar monor. Th ED ahboar mplmn ung Flx chnology [ 2]. Flx allow fa vlopmn of rch an profonal ahboar. Ung Flx, h ahboar can b vw from anywhr va mo commrcal Inrn browr. W ulz xng Flx wg an componn an ngra hm no h ED ahboar. Fgur 1 an Fgur 11blow how wo napho of h ED ahboar. Fgur 1: Th Occupancy lvl ncaor play ung vral Flx wg 35

44 Fgur 1 monra varou play opon for h phycal occupancy KPI. Th op vw how h occupancy lvl for h currn ay; h lf mr vw how nan occupancy lvl, an h rgh vw how avrag aly occupancy lvl, maur annually. Fgur 11: rrval an aff ulzaon nclung forcang Fgur 11 llura h prcv capabl an con uppor funconaly ha mgh b ncorpora no h ED ahboar. Th op-lf graph how h pan arrval ra, a monor by h ERhyhm ll 17: for ha ay. Th op-rgh graph how h prc arrval ra from 17: unl 23: for ha ay. Such prcv capably, crb n [ 3], can b ncorpora no h ERhyhm. Th acual phycan ulzaon KPI, whch par of h pronnl ulzaon KPI, can hn b prn, along h prc ulzaon, ba on h xpc arrval ra an h numbr of phycan ha ar xpc o b prn a h ED. Such a prcon a ED managmn o aju phycan' numbr for accommoang mma ED rqurmn an for mng h rqur KPI. No ha prcv chnqu an capabl ar byon h cop of h rarch an ar prov hr ju o compl h pcur of ED ahboar capabl Fuur Rarch no ED Suaon Dahboar Exnv rarch ll rqur an unrway o nfy h varou ED ahboar ur rol an h pcfc of rqurmn of ach rol. Such rarch wll prov anwr o crucal quon, uch a: 36

45 Whch ncaor houl b monor? n a wha nrval? How much aa houl b prn n ach crn? How houl navga bwn crn work? Wha hrhol ar n for alrng for h varou KPI? I a rll own n? n f o, o wha lvl an by whom? How houl h ahboar prov ED aff wh ral-m conrol capabl? How houl h ahboar prov "wha-f" analy an con uppor? How can prvacy b proc? n many mor In h nx chapr, w furhr crb mho an fnng for monorng h complx ED loa KPI. In chapr 6, 7 an 8, w hn follow wh a p analy an ugg con uppor for h quon "Whch pan o ra nx?", kng an appropra clncal an opraonal balanc bwn h TTFE an h LOS KPI. 37

46 CHPTER 5: REL-TIME ED LOD MONITORING ND MESUREMENT In prvou chapr, w crb h complxy of h ED nvronmn, cu varou nrng KPI o monor an maur, an prn h ky concp bhn h ED ral-m monorng-an-conrol ym. On of h man prom of an ED ral-m monorng rgarng ably o maur h ral-m ED loa. In Scon 3.2, w prn h ED loa-monorng an maurmn challng. Durng h rarch, w vlop an nnovav approach for ral-m ED loa monorng an maurmn. W hn mplmn h approach an monra ung h ERhyhm ym, a crb n h prvou chapr. Our approach nabl h maurmn an calculaon of ur-un loa, ba on a w pcrum of npu aa vn an varou prfn loa funcon. Bng awar of pcfc ur n mak h ym ur-pcfc,.., rulng n a loa cor ha rflc h rlvancy of h low-lvl uaonal vn o h ubjcv loa xprnc of a pcfc ur. Our approach, whch ba on arfcal nural nwork [ 31], nabl h followng: a ac mchanm for h fnon of an xplc loa funcon an a ynamc larnng mchanm ha aap h loa calculaon o ur prcpon by ovrrng h xplc ac loa funcon fnon. Th ynamc larnng mchanm ha wo man avanag. Fr, nabl mpl aapaon of h loa funcon no any ED ng, bypang h n o nforc a rg loa funcon fnon for non-anar ED ng. Scon, allow for h calculaon of ffrn loa valu for h am objcv uaon. Th parcularly uful for capurng h opraonal loa prcpon ffrnc of varou ur group. Thu, by acrfcng rg fnon for hgh flxbly, our approach allow ur o compar varou uaon an o rach nform con rgarng h appropra p o ak o ruc h ED loa, by clarng an ambulanc vron uaon, for xampl. 5.1 Dynamc ED Loa Funcon Th fr p n calculang h ED loa o fn h loa funcon. For ha, w n o fn h xac of npu paramr an h rlav conrbuon of ach paramr o h ovrall loa cor. Va rarch ha bn vo o h fnon of a canoncal an anar ED loa funcon [ 2], [ 51], [ 55], [ 62]. Th man goal of uch rarch o com up wh a unf loa cor. unf loa cor wll nabl ED comparon an wll acclra h vlopmn of gnrc mho for opmzng h ED opraon. Unforunaly, unl now, a connu ha no bn rach on a unf 38

47 ED loa cor. Morovr, uch a connu may nvr b rach, u o h gnfcan ffrnc n ED yp an ng. Th obrvaon la u o vlop an aapv loa funcon ha calcula h loa cor ba on a ynamc l of low-lvl npu paramr. Th xac of npu paramr ha ar rlvan o a pcfc ED ng chon from an xnv of paramr ha wr nf n h lraur [ 55] a ponal conrbuor o h ovrall ED loa. Incorporang a ynamc an aapv loa funcon whn h ERhyhm ym allow o prov a manngful an valuabl loa cor n a w vary of ED ng. Confgurng an aapng h loa funcon no a pcfc ED ng can b on n wo way acally,.., by xplcly fnng h rlav conrbuon of ach of h npu paramr o h ovrall loa an ynamcally,.., by ung larnng chnqu for agnng h rlav conrbuon lvl hrough a fback mchanm. In h nx con w prov mor al on h mchanm an h way n whch hy ar mplmn. 5.2 Nural Nwork-Ba Loa Funcon W cho o u arfcal nural nwork for mplmnng h ED ynamc-loafuncon-nablng mchanm. Nural nwork NN-ba funcon ar flxbl for compoon, aapv ovr m, manngful for h ur, an nabl h fnon of complx rlaonhp.g., nonlnar bwn npu an oupu Nural Nwork Thorcal Backgroun rfcal nural nwork [ 31] ar graphcal rprnaon of complx mahmacal funcon. Thy ar compo of un call prcpron Fgur 12a an arrang a a mul-layr f-forwar nwork Fgur 12b, n whch h oupu of on layr ar h npu of h nx layr. Th yp of rucur wa npr by h bran rucur. Nural nwork ar uccfully u n many applcaon uch a parn clafcaon, mnonaly rucon, an funcon approxmaon [ 34], [ 36], [ 38]. Bcau of h orgn of h nwork gn, h no n uch nwork ar ofn call nuron. NN gra avanag, n comparon o ohr machn larnng chnqu, hr mplcy, boh n rprnaon an n larnng. In aon, h numbr of rqur ranng xampl rlav o h nwork rucur no hgh compar o ohr machn larnng oluon. 39

48 Fgur 12: a ngl prcpron; b mullayr nwork Each prcpron compo of n npu x 1, x 2,, x n ; n wgh w 1, w 2,, w n ; an an acvaon funcon φ. Th oupu of h un vx, wφx T, w, whr x1, x 1, x 2,, x n, wb, w 1, w 2,, w n. Exampl of acvaon funcon ar gn φugnu, lnar funcon φuu, an logc funcon φu1/1 -u. Th yp of acvaon funcon affc h ably of h nwork o larn an applcaonpnn. Th un n ffrn layr ar connc n a f-forwar yl o rmn h nwork rucur Fgur 12b. Th xac rucur alo applcaon-pnn, an n many ca oman knowlg can hlp o rmn h rucur. Gvn an M lmn ranng of h form x, y, n whch X n R h npu o h nwork an y R h xpc oupu or arg funcon of h nwork, h back propagaon algorhm [ 31] can b u o fn a of wgh ha mnmz h man quar rror MSE bwn h prov oupu an h currn calcula oupu. Two yp of larnng can occur offln or bach larnng an onln larnng. In offln larnng, h nr ranng gvn n avanc. ach raon of h back propagaon algorhm, all of h xampl ar akn no accoun whn upang h wgh. In onln larnng, h xampl ar gvn on afr anohr, an ach larnng raon pn on h currn xampl only. Onln larnng ypcally u whn h nvronmn chang ovr m, an whn h nwork ran o f ho chang. 5.3 Ung Nural Nwork o Calcula ED Loa To monra h avanag of our mhoology, w bul a nural nwork ha u a w rang of loa npu paramr. W ablh h nal nwork rucur an h of nvual paramr conrbuon ba on h xhauv rucur-l an ncaor ugg n h loa paramr rvw papr [ 55]. W u h nal rucur crb n Fgur 13 a our bac nwork for h loa calculaon. 4

49 Fgur 13: ED nural nwork vw. Th rangl a oal nuron, hxagon ar h ag nuron, rcangl ar h concp nuron, an amon ar prmv npu ncaor nuron. Th hrarchy n h nwork con of four man layr: Incaor Layr Th layr can ak any numbr of low-lvl npu paramr. Our nal mplmnaon follow h of ncaor ugg n h rvw papr [ 55]. W mofy om of h ncaor o hy br rflc h ypcal ED nvronmn ugg by [ 44]. For xampl, ncaor ED Throughpu m wa plc no wo no on for am pan an on for charg pan. Th aapaon allow u o agn ffrn conrbuon wgh o ach of h wo mor bac ncaor. Concp Layr Th bac ncaor from h fr layr ar connc o x concp no: pan man, pan complxy, ED capacy, ED ffcncy, ED workloa, an hopal ffcncy. In our bac ng, ach ncaor connc o a ngl concp. Th hopal capacy concp wa om from h concr mplmnaon u o h lack of appropra aa. Th ED ffcncy concp wa v no wo ub-concp rvng h npu an h hroughpu paraly. Th mofcaon wa ma o kp h r-lk rucur of h nwork. Opraonal Sag Layr Th vn concp from h con ag ar connc o hr opraonal ag, npu, hroughpu, an oupu, followng h ED concpual mol crb n Scon 2.2. Loa Scor Layr Th layr conan a ngl oupu no rprnng h oal ED loa cor. 41

50 5.4 Th ED Loa Larnng Mchanm Th arfcal nural nwork larnng mchanm can b mplmn ung hr bach or onln mho. Boh approach rqur knowlg of h "ru" ED loa valu gvn a of npu paramr vcor. On way o g h of ED loa valu o prn ach npu vcor o h xpr ur an ak hm/hr o prov h ED loa valu n rurn. Howvr, h mho no praccal for wo man raon. Fr, npu vcor ar ofn oo long for human prcpon an mbng. Scon, h r valu of h arg funcon canno b xplcly calcula. In ohr wor, hr no uch hng a a "ru" ED loa valu ha h ur abl o prov for a gvn npu paramr vcor. Thu, w choo a ffrn approach, whch rl on h ERhyhm uaon ahboar an h ur' ubjcv uaon prcpon. Ina of prnng h npu vcor lf, w prn h currn ED uaon ung h ERhyhm uaonal ahboar Fgur 14. Th ERhyhm ahboar prn h currn calcula ED loa cor maur n prcnag of h loa baln oghr wh aonal nformaon abou h au of h ED. Fgur 14: Dahboar napho; loa valu black ln calcula a h prcn of h avrag grn ln By lookng a h ahboar, an by phycally xprncng h ED' currn uaon, h ur gan ngh no h accuracy of h calcula ED loa. Th ngh mrly ubjcv an ba on a comparon of h currn uaon o prvou uaon a xprnc by h ur. Ung h rlav fback buon, h ur hn prov fback abou h crpancy bwn h ym' calcula loa an hr ubjcv loa xprnc. Th nural nwork larn from h prov fback an aju loa funcon accorngly. For xampl, f h ur fl ha h rprn loa far 42

51 blow h r valu, h clck on h largr buon, ncang ha h loa cor houl b ncra by approxmaly 1%. mlar upa proc 1%, -1%, -1% xcu for h ohr hr rlav fback buon. Lng ur prov fback ovr long nough m pro rul n havng a loa funcon ha accuraly rflc h ED loa. fr complng h larnng proc, h ym abl o prn a ralm loa cor a a prcnag of h loa baln, a can b n n Fgur Trackng Loa on Inrnal Rourc On ky avanag of a nural nwork l n ably o rflc a complx phycal rucur,.., by allowng vry nuron o hav an xplc opraonal manng. For ha, our nural nwork gn kp h r-lk nuron hrarchy na of h uual all-o-all conncon. Th allow ach nuron o prrv opraonal manng urng h larnng proc. Conrvng h r-lk rucur allow h ur o rack h currn loa back no h nvronmn an o gan a pr unranng of h currn loa au Fgur 4. Morovr, w can g an alr from any hrarchy lvl n h ym f a cran nuron bcom ovrloa. For xampl, n om uaon h ovrall ED loa only 4% of h baln, bu h CT room ovrcrow u o lack of pronnl. In h ca, h appropra nuron au wll rach h hgh mark an h ym wll hu n an alr o h uaon ahboar, prov h nuron wa prconfgur accorngly. a rul, h ED managr mgh rac by nng l vr pan o h Hopal' CT room na of o h ED' CT room, for xampl. Fgur 15: Tracng loa. Grn ln nca oal loa, orang ln nca hroughpu; h r n h oal loa wa clarly cau by ncrang h hroughpu nuron; w can rac furhr an uc ha h pak n hroughpu wa cau by lvaon of h ED workloa concp nuron. 43

52 5.6 Mulpl Vw of ED Loa ky avanag of our framwork ably o allow ynamc larnng ba on fback from ffrn ur group. Thu, w can calcula an prn vral ffrn loa cor for h am objcv uaon. Th ably allow u o aap h loa valu o a vary of ED ng. Th only concr rqurmn for provng manngful valu o g conn ur fback. Th can only b achv f fback wll b connly prov by h am ur. Suaon mgh occur n whch w can xn h group of ur ha prov fback, aumng hr fback omwha conn wh h loa uaon. For xampl, maurng h currn ED loa a prcv by ocor, nur, an pan, or vn by a ngl nvual uch a h ED managr, coul hav an nrng applcaon. Rarch [ 44] how ha ach rol group n h ED connly xprnc varyng loa u o frqun nvronmnal chang hroughou ach ay. Thu, h ably o ablh a ubjcv loa funcon ha b rflc h acual loa xprnc by a gvn ur group coul b a uful ool for managng h ay-o-ay ED loa. To nabl h ERhyhm ym o rflc a group ubjcv loa, w fr n o fn h group' profl. Each group' profl rflc opraonal loa a bng xprnc by a gvn group. Group profl can b acally fn by fxng wgh o rlvan nuron, or by ynamcally larnng hm, whch prfrabl. Dynamc larnng nvolv capurng fback from a pcfc ur group aoca wh a pcfc profl. 44

53 To monra h ym' ably o rflc varou loa valu for varou ur group, w nf hr pobl group yp nur, ocor, an pan. Each group ha an agn group profl an a rlvan arg loa funcon. Nur an ocor arg loa funcon wr fn a h avrag occupaon rao urng a cran m pro. Pan arg loa funcon wa fn a h rao of a pan wang m o h pan oal ayng m n h ED. Fgur 16 how a ypcal ay loa curv for h hr ur group. Fgur 16: Smula nur, ocor, an pan profl bhavor, whn 1% h avrag aly loa Fgur 17 ummarz avrag loa valu for h hr xamn ur group: nur, ocor, an pan. Each profl compr h wgh of major rlvan nuron monor by h ym. Fgur 17: Ur profl compo of major raw ncaor wgh larn by h ym 45

54 W can ha all hr profl how raonabl bhavor whn comparng m of ay an whn comparng h profl o on anohr. Whn h ym ovrloa, all ur fl. Howvr, h loa xprnc ffrn for ach group. For xampl, ocor mu ay lar han nur a h n of h ay o clo all opn ca. Thu, h loa on hm cra lar han o for nur. On h ohr han, rag, rv by nur, h fr aon n h pan flow. Hnc, h nur opraonal loa ar arlr. Th xampl monra ha ffrn wgh o n x on h nuron, mphazng h n for ubjcv loa cor for h am objcv ED a. 46

55 CHPTER 6: ED PTIENT FLOW CONTROL In h prvou chapr, w monra h bnf of ployng a ral-m monorng an conrol ym for h monorng an maurmn of ED loa. Th conrol par of h ral-m monorng-an-conrol ym al wh h ably o nflunc pan flow whn h ED n ral m o mprov h ED ky prformanc ncaor KPI. To o o, w fr n o gan a p unranng of varou apc Fgur 6. In h chapr, w xamn pcfc ED opraonal apc, analyz hm, an ugg ponal opmzaon approach. W hn follow wh om mulaon rul n Chapr 7, hn connu, n Chapr 8, wh a mahmacal analy of h problm' ylz mol. For h analy, w n a of mahmacal ool. Quung nwork a naural choc for analyzng h ED nvronmn an for ganng a p ngh no KPI. crb n Chapr 2, h ED nrnal opraonal proc can b analyz ung a quung nwork mol. Th procng rvr mol h varou ED aon an h job mol h pan ha rqur rvc a on of h ED aon. Th ED uually opra n hgh loa, hu mo aon uually hav wang quu whr pan wa for rvc. Conr h comprhnv ED acvy an rourc quung mol crb n Fgur 5. Th complxy of uch mol rnr hm nracabl for mahmacal analy an unuabl for ganng ngh no rvc polc an opmal conrol. Thu w connu our analy by brakng no mallr quung mol an analyzng hm a f hy wr an-alon mol. Spcfcally, w nfy wo complmnary vw whl molng h ED a a quung nwork h pan' vw an h car pronnl vw. W hn ranla h wo vw no wo rla quung mol, ach wh own con problm. From h pan' vw, w confron a roung problm,.., cng o whch aon h pan mu go nx; whl from h car pronnl' vw.., h aon' vw, w confron a chulng problm,..,, cng whch pan houl b ra nx. W furhr mplfy our mol a rqur, by ang aonal conran,.g., ovr h arrval proc, o mak mahmacally racabl. Furhrmor, w u complmnary chnqu, uch a mulaon, an nrvw wh ED managr, for ganng aonal ngh no h opraonal bhavor of h analyz conrol polcy n uaon a clo a pobl o ho xpc o b foun n h ay-o-ay ED raly. In h followng con, w fr brfly ar h flow conrol roung problm from h pan' prpcv, pcfcally, "Whr houl h pan go nx?". W hn connu wh a al analy of h flow conrol chulng problm from h aon' vw "Whch pan houl h phycan ra nx?". 47

56 6.1 Whch Saon o V Nx? Th xac aon-qunc for a nw pan arrvng o h ED unknown upon arrval an rmn a ramn progr. Th ramn proc no qunal an pan ofn rurn o h am aon mulpl m. Noc, hough, ha h nx aon n a pan' rou whn h ED alway known. Uually, afr complng ramn a om aon, a phycan prov ncaon abou h rqur ubqun aon. Th phycan may nca h n o v mor han a ngl aon,.g., for orrng laboraory, for conulng a pcal uch a gyncolog, an for ung an ulraoun. In om uaon, phycan rqu paral orrng ovr h aon qunc. For xampl, a gyncolog may n o h pan only afr an ulraoun compl. In ohr uaon, ramn n ffrn aon can b xcu n a oally arbrary orr. For xampl, lab mu b akn pror o a fnal con bu npnn of a gyncolog' conulaon. Fgur 18: ylz quung mol for h "Whch aon o v nx?" problm. Thu, h ynamc, flxbl, an unprc ED nvronmn offr h ponal for gnfcan roung opmzaon. Fgur 18 crb a ylz mol for h "Whch aon o v nx?" con problm. Such mol wr mahmacally analyz by. Zvran [ 65] n h conx of Halhcar. In, vn an lmnary ral-m conrol of pan flow woul lkly yl a gnfcan mprovmn of h ED opraonal nvronmn. For xampl, an mma al for flow conrol o rc pan o h aon wh h hor quu. For an mprov conrol, w coul look furhr no h ancpa pan' rou. Such conrol may rqur forcang of h fuur aon on a pan' ramn rou. Our analy o no al wh uch 48

57 opmal roung u. Clarly, howvr, uch con mu play a gnfcan rol n h ovrall opmzaon of h ED pan flow. 6.2 Whch Pan o Tra Nx? Th "Whch pan o ra nx?" PTN con problm an a h cor of our rarch. Th quon mrg a mo nrng whn h ED ay-o-ay opraon. Th ochacally hgh loa unr whch h ED uually opra rul n an opraonal quu of wang pan pror o ach ramn aon. In ohr wor, pan mu ypcally wa for ramn a ach an vry aon along hr ramn rou. Thu, h mprovmn of h ED opraonal prformanc, gan by opmally arng h PTN quon, xpc o b gnfcan. PTN mprovmn may affc h pan' fnal clncal rul, whch h mo mporan ED prformanc maur. Th fnal clncal rul may b complx o maur. Maurng h ffc of PTN opmzaon on ED fnal clncal rul ou of h cop of our rarch an ubjc o fuur work. Nvrhl, an o parally ar h ffculy, w conr mulpl vw whl analyzng h PTN quon, namly h clncal vw, h rvc lvl vw, an h opraonal vw. Toghr, h vw prov a raonabl ma for ovrall ED prformanc wh rpc o h problm a han. Nx, w crb h cor apc of h vw an hr mplcaon on h PTN quon Clncal Vw Th clncal vw h mo mporan vw whl arng h PTN quon. I mporan o kp n mn ha mo pan' clncal apc ar hn o phycan urng h ED car proc. Th man purpo of h ED car proc o rval h pan' clncal uaon an o ac upon hm. Th known clncal apc of h PTN quon ar ncapula whn h rag cor. Th rag cor prn h pan' clncal au a a by h rag nur pror o h fr phycan ncounr. B pracc a mo ED o no rqur phycan o upa h rag cor afr h fr ncounr, nor o hy rqur provng ohr "runnng" clncal cor o pan, vn hough uch a procur may la o furhr mprovmn n anwrng h PTN quon Opraonal Vw Th opraonal vw our man focu whl arng h PTN quon. Our oughafr polcy k o mprov varou ED' opraonal KPI, nclung m ll fr ncounr, ovrall pan lngh-of-ay, pan wang-m o rvc-m rao, an h ovrall numbr of pan whn h ED. By lmng ourlv o opraonal 49

58 opmzaon, w mu ranla clncal crra no hr opraonal prox. Th on manly by ung h rag cor a a proxy o h pan' clncal au, an by provng co funcon ha ak no accoun paramr wh clncal rlvancy, uch a pan ag, wang m, an h lklhoo of a pan o b am o h war or charg from h hopal Srvc Lvl Vw Th rvc lvl rfr o a pcfc opraonal apc ha focu on h cuomr xprnc urng h ED car proc. Rcn work n rvc cnc, uch a rmony al. [ 14], ugg a grar focu on pan' n whl provng rvc. Improvng rvc lvl, n our conx, man mprovng h rvc xprnc from h pan' pon of vw. W ranla h rvc lvl vw no rucng wang m an h ovrall lngh-of-ay a h ED, whou compromng h lvl of clncal ramn. On nrng opon for rvc lvl mprovmn o agn prory o pan who ar abou o b charg from h hopal ovr pan who ar abou o b am. Snc am pan wll ay a h hopal anyway, hy ar hu mor agnoc o h ovrall lngh-of-ay. Pan who ar abou o b charg back o hr hom ar anxou o lav h ED, an h hopal, a oon a pobl, whch alo clncally afr for hm. Farn a parcularly nrng rvc prformanc ncaor. For xampl, akng pan' ag no accoun whl rmnng whch pan houl b ra nx may conr favorably from h rvc lvl farn prpcv. Fr com fr rv FCFS a wly-u farn polcy a ED, whch mo pan woul accp. Changng h polcy whl ryng o ar a wr KPI may rul n pan apponmn an objcon, namly rvc lvl roraon. Th affc of applyng a rvc polcy ohr han FCFS on pan afacon an on ohr rvc lvl KPI ubjc o fuur rarch. 6.3 Opraonally Opmal PTN Conrol Dcuon wh ED managr l o h followng clncal rqurmn, whl arng h PTN quon pan' lngh-of-ay houl b mnmz an mng rag aln a mu. Furhrmor, h cuon alo ugg ffrnaon n h wang co of ffrn pan cla. Ba on h cuon, w formula a clncally opmal conrol ha yl h followng guln: clncally opmal PTN conrol m rag aln conran wh h la mnmal ffor for nwly arrv N pan. I hn rv n proc IP pan o a o mnmz clncal co. Th co funcon combn clncal, opraonal, an rvc lvl apc,.., by ung wang m, rag cor, pan ag, an DT au a npu paramr. Th xac valu for h paramr pn on a pcfc ED ng 5

59 an ar hu o b prov by h ED managr. Th opmal PTN conrol wh hr aoca apc ar furhr crb n h followng con. 6.4 Th PTN Sylz Quung Mol Th cor of h PTN quon al wh h n o rv vral compng work m,.g., h pan' ncounr, by h am rvr,.g., phycan. Thu, h quon bcom whch work m houl h rvr car o nx. Obvouly, h work m paramr houl b conr. Mappng h PTN no a quung nwork mol la o h followng formalm: Fgur 19: ylz quung mol for h PTN quon. Conr a mulcla ngl aon quung ym wh fback. Each aon compr of a pool of acally ncal rvr phycan. Nwly arrv work m pan arrv o h quu wang ara n a gnrc arrval proc. Srvc m pan-phycan ncounr mol by an npnn an ncally rbu... ranom varabl, wh man E. Srvc ra hu gvn by µ1/e. Th ym ha fback. Tha, afr fnhng rvc, h m pan hr lav h ym charg hom or am o h hopal or connu o a lan m pro,.., a pro a whch bng rv a ohr aon, an rurn o on of h n proc IP quu for aonal rvc. Th ym ha mulpl prory quu. Each m ha a prory nx ba on a vary of paramr. Thu, m ar no ncarly rv by hr arrval orr bu ar ba on hr prory. Th chulng algorhm choo h nx m o proc ba on om rvc polcy ha may ak m' prory no accoun. 51

60 Spcal anon gvn o h ncounr qunc numbr. Im rqurng nal rvc N pan ar ra ffrnly han m alray whn h proc IP pan. 6.5 Quung Thory an Quung Nwork Quung hory h mahmacal uy of wang ln, or quu. Th hory nabl h mahmacal analy of vral rla proc, nclung arrvng a h back of h quu, wang n h quu, an bng rv a h fron of h quu. Th hory prm h rvaon an calculaon of vral prformanc maur, nclung h avrag wang m n h quu or h ym, h xpc numbr wang or rcvng rvc, an h probably of ncounrng h ym n cran a, uch a mpy, full, havng an avalabl rvr, or havng o wa a cran amoun of m o b rv. Nwork of quu ar ym ha conan an arbrary bu fn numbr of quu. Cuomr, omm of ffrn cla, ravl hrough h nwork an ar rv a h no. In opn nwork, cuomr can jon an lav h ym, whra n clo nwork, h oal numbr of cuomr crculang whn h ym rman fx. In quung hory, a quung mol u o approxma a ral quung uaon or ym, o h quung bhavor can b analyz mahmacally. Howvr, h quung mol,.g., h on crb n Fgur 19, ofn urn ou oo complx for xac analy. W can hn ror o approxmaon, a wa on n h ca. Th rfrnc mol wa analyz aympocally n havy raffc, by Huang, Carml an Manlbaum [ 37]. Nx, w prov furhr crpon of vral quung mol concp ha ar rlvan o h ED pan flow Sym Ulzaon an Opraon Rgm Th ym ulzaon, ρ, rmn by h proporon bwn h ym' capacy, µ, an h arrval ra, λ. rrval ra fn a h ra by whch job arrv o h ym. Tm-varyng arrval ra, a foun n h ED nvronmn, rul n a rann nwork. rann nwork characrz by alrnaon bwn low ulzaon an hgh ulzaon [ 45]. In prn rarch of quung ym, varou opraonal rgm hav mrg, whch plac a ffrn focu on rourc ffcncy v. rvc qualy. Morovr, mo of h rarch for quung ym wh many rvr ha opra n ay a an xcpon h work on by Yom-Tov [ 63]; hu, h rarch no rcly rlvan o our nc ED, mol a quung ym, rqur m-varyng analy for mall numbr of rvr. 52

61 W hu furhr focu our rarch on a uaon of rg capacy. W aum ha h ED rourc lvl.g., numbr of rvr fx an arch way for a ral-m mprovmn of ED prformanc unr m-varyng arrval ra by opmzng opraonal apc, uch a h PTN rvc polcy Srvc Polc an Prory Quu Srvc polcy fn a h polcy by whch h rvr car o job ha wa n quu. Th mo raghforwar rvc polcy fr com fr rv FCFS, n whch job ar bng rv by hr arrval orr. No ha n h FCFS, quu arrval m h only paramr ha bng conr for cng upon h nx job o rv. a rul, FCFS can aly b mol a a ngl quu ngl rvr quung ym. Th no h uaon n mo rvc nvronmn, nclung n h ED. mulcla quung ym allow for clafyng job no cla by ung varou job characrc an hn o agn a quu for ach of h cla. Th rvc polcy hn mu rmn whch quu o rv nx. W aum job whn ach quu ar bng rv along h FCFS polcy. In our mol, w hu n o c upon h characrc o conr whl clafyng job no cla. Spcfcally, whn clncal nvronmn, w conr clncal characrc, uch a pan ag an rag cor, along wh opraonal characrc, uch a h rag aln an h xpc DT au. Nx, w crb vral known mulcla rvc polc Co-ba Srvc Polcy an h Gnralz Cµ Rul co-ba polcy aoca a co funcon wh ach quu. Spcfcally, followng [ 59], w conr a gnral ngl-rvr mulcla quung ym ha ncur a lay co a ra C k k for ach cla k job ha r k un of m n h ym. W no h margnal lay co an nananou rvc ra funcon of cla k by c k C' k an µ k, an w l a k b h "ag" or m ha h ol cla k job ha bn wang a m. W call h rvc polcy ha a m rv h ol wang job of ha cla k wh h hgh nx µ k c k a k, h Gnralz cµ gcµ Rul. Van Mghm furhr how ha, wh non-crang convx-lay co, h gcµ rul aympocally opmal f h ym opra n havy raffc. Th gcµ rul ugg an aracv polcy for rvng IP-pan gvn ha uabl co funcon ar prov. Th co-ba polcy m l uabl, a la rcly, for mng h aln rqurmn of N-pan. 53

62 6.5.4 Daln-conran Srvc Polcy m lm or aln a narrow nrval of m, or parcular pon n m, by whch an objcv or ak mu b accomplh. Daln ar yp of opraonal conran prov by opraon managmn a a conrol man. alnconran rvc polcy, whn a mulcla, ngl-aon quung ym, rv o rv any cla k job arrvng a m by aln k. hown by [ 6], h aln-conran rvc polcy can b approxma by qunc of convxncrang lay co funcon. Th formulaon ruc h nracabl opmal chulng problm no on for whch h gcµ chulng rul known o b aympocally opmal. Morovr, uch an approach allow ranlang a alnconran rvc polcy no a co rvc polcy. 6.6 Mulpl Dcon ng h PTN clncal rqurmn rval ha h PTN con proc can b vw a a con r n whch mulpl con ar rqur a mulpl lvl, a hown n Fgur 2. Fgur 2: Th PTN concpual con r. Fr on mu c whhr o choo from h N-pan quu or from h IPpan quu. Th fr con rv from h ffrn clncal rqurmn aoca wh h ffrn pan yp. Tha, N pan houl b rv by hr aln, whl IP pan houl b rv ba on hr ovrall lngh-of-ay. Th con con o mak, onc a pan yp chon, whch xac quu o rv whn ha yp. Laly, ffrn polc ar ncary for uaon n whch h rag aln can b m an for uaon n whch canno. 54