Pump Ergnmics Research Phase 1 Final Reprt Deniz ARIK MSc. Student, Faculty f Industrial Design Technical University f Delft, Netherlands arikdeniz@yah.cm +(31) 61 8765 704
2 Ergnmic Prblems In Diabetes Therapy with Insulin Pump
3 Abstract In rder t determine ergnmics related usage aspects Insulin Pumps Therapy ( i.e. Cntinuus Subcutaneus insulin infusin, CSII), 100 participants, all members f a Diabetic insulin pump therapy mailing list, were asked t fill in an nline survey that investigated different dmains related t the ergnmics f the prduct, frm physical t cgnitive including user psychlgy and experience. The survey cnsisted f quantitative as well as pen ended qualitative questins. The quantitative part f the data is statistically analyzed in Matlab. The qualitative answers were separately analyzed and tgether sme highly design relevant cnclusins were drawn that might be useful fr the design f future generatins f pumps.
4 Index Page Title.... 2 Abstract... 3 Index... 4 Intrductin 5 Methd.... 6 Analysis... 10 Cnclusin, Discussin & Recmmendatins.. 20 Appendix.... 22
5 Intrductin Prblematic and Cntext The Insulin pump therapy, als knwn as CSII (Cntinuus Subcutaneus Insulin Infusin), is cnsidered in the medical wrld as the mst effective way f cntrlling bld glucse in Diabetes Mellitus (Type 1 Diabetes) patients. The high effectivity, in turn, helps the patient reduce lng-term cmplicatin risks f Diabetes and alleviates the csts f Scial Health Insurance System related t lng-term Diabetes Cmplicatins. Prperly used, Insulin pumps als help increase the flexibility and therefre quality f life fr a diabetic persn. On the ther hand, because the device has relatively recently been technically pssible and cmmercially available and that the matter is f utmst medical imprtance, the ergnmics f the prducts available in the market tday still need further refinement, an issue cnsidered luxurius until recently. Nwadays the users cntinue t experience sme prblems related t the ergnmics and the use experience f the prduct. New effrts t imprve the design are taken by manufacturers while the prduct gets mre and mre cmmnly used. Tday the device is nt recmmended fr patients with lw educatin because it demands cmplex interactin/care and the severity f the result due t a prbable errr is very high.
6 Methd We have surveyed 100 pump users with prepared qualitative as well as quantitative questins that were published in a cmmercial nline survey site. The participant grup f the research cnsists f Diabetes Patients administering CSII Therapy. The vlunteered participants were all members f an nline insulin pumpers cmmunity, majrity f which are USA natinals. The participant grup is demgraphically very diverse, cvering bth sexes, a wide spectrum f ages and (althugh nt sptted by the research, but prbably) diverse incme levels. The educatin level is frm upper average t high. The relatively large vlume f data helped us draw cnclusins based n statistics. The age distributin f the 100 participants was as fllws:
7 The gender distributin f the participants: What is yur gender? 38 38% 62 62% Female Male The educatin level: Please indicate the highest level f Educatin yu have attained. 0 0% 4 4% 24 25% 16 17% Elementary Schl Year 12 (End f High Schl) Graduate Schl (Bachelrs degree, University) Pst Graduate Degree (Masters, PhD) N Frmal Educatin r Schling 52 54%
8 Pump brands: Sme ther relevant data characterizing the participants are as fllws: Hw lng have yu been n pump therapy fr? 9 9% 8 8% 11 11% Less than 6 mnths 6-12 mnths 1-3 years Mre than 3 years 70 72%
9 Hw lng have yu been diabetic fr? 0 0% 8 8% 7 7% Less than 1 year 1-4 years 5-10 years Mre than 10 years 83 85% The (quantitative part f) raw data can be fund in the appendix. Fr statistical analysis sme mdificatin was dne ver the raw data befre analysis: The unanswered questins (empty matrix entries, see appendix) were filled up with 3= Neutral answers. Fr the last questin, the 0=n pinin answers were replaced by 3=Neutral answers. Fr better visualizatin, the abslute values f the crrelatin cefficients were pltted. Therefre the directin f crrelatins disappeared in the crrelatin graphs in appendix.
10 Analysis Validity f survey: The validity f the verall research can be checked by the crrelatins between the answers f sme validatin questins. We have seen, fr instance, that the answers t the questins Intrducing the pump t ther peple is highly crrelated t the answer f the questin scial reactins. The answer t questin Need t learn pumping thery is highly crrelated t the answers f Need t have extra truble trubleshting skills. Overall feeling f security is als highly crrelated t verall feeling f everything being under yur cntrl Analysis f averages fr the entire ppulatin: Average scres fr each questin are shwn in appendix. These averages give a brad view abut very general aspects f the pumps withut taking int cnsideratin any subgrup particularity. The lwest ranking average scres, (indicating the aspects with lwest satisfactin) were in the fllwing dmains: -Trying the clths n while shpping -On the sea side (swimming, sunbathing) -Unexpected impacts n the infusin site -Tube being caught by bjects and pulled -Lsening f adhesive due t sweating -Wrry abut infectins arund the infusin site
11 The highest ranking average scres (indicating the aspects with highest satisfactin) were in the fllwing dmains: -Intrduce the pump t ther peple -Ease f access t desired inf/functin -Temprarily discnnecting the pump -Ability t temprarily mdify basal rates fr different situatins -Knwledge and ability t use all functins f the pump -Perceptin f increased wellbeing -Overall feeling f security -Overall feeling f everything being under user s cntrl -Imprved HbA1C results -Flexibility in fd types & quantity -Flexibility in scheduling meal & sleep times A high level f disagreement was scred fr the fllwing tw statements: I wuld readily want t cnvert back t my previus diabetes management methd if my pump didn t imprve my glucse levels I feel mre diabetic with my pump
12 Analysis f averages f subgrups / deviatin f subgrup averages frm entire ppulatin averages : T have a deeper insight int the scres, sme subgrups that culd pssibly shw sme particularities were created. The cmplete list f subgrups can be fund in appendix alng with number f participants in each subgrup. We have illustrated the average scres f particular grups as well as their deviatin frm the whle ppulatin. (See graph is appendix.) Taking the tw graphs as reference, the fllwing relevant findings were btained: The change f averages thrugh the fllwing 4 subgrups were particularly crucial in that it demnstrates the adaptatin f the user t his/her pump. The subgrups fcused are: -Pump users since 6 mnths r less (n=9) -Pump users since 6 t 12 mnths (n=7) -Pump users since 1 t 3 years (n=15) -Pump users since 3 years r mre (n=69) The agreement with the statement I feel mre diabetic with my pump drps frm 3 t 2.5 in the 2 nd grup and frm the 3 rd grup n t 2. The satisfactin frm flexibility in fd types & quantity (initially scring 3.5) and flexibility in scheduling meal & sleep times (initially scring 4) bth mark a visible increase finally reaching 5.
13 We als ntice a decrease in agreement with the statement I am very wrried abut infectins arund the infusin site first scring 3,5 and finally scring 2,5. Anther statement that receives less agreement as time ges by is I wuld readily want t cnvert back t my ld diabetes management methd if my pump therapy did nt change my glucse levels scring initially 2.5, very clse t neutral, but finally 1.5, a strng disagreement. There is a slight ameliratin (each 0.5 in average) in the fllwing aspects as well: Perceptin f increased well being Sense f being cnnected t a machine Overall perceptin f increased freedm with pump Overall pinin abut yur pump The scres f satisfactin abut Sleeping at night increases frm 2.5 t a final f 3.5 marking anther aspect f adaptatin f pump users t initially cnfrnted prblems. There is n significantly deterirating satisfactin scre in these subgrups marking the passage f time and gain f experience with insulin pump.
14 Analysis f crrelatins between questin scres: The crrelatin f answers t each ther (pair-wise) is shwn in the table (see appendix) Fr the sake f a mre cmprehensible graph, the directin f crrelatin is discarded by taking the abslute value f the resulting cefficient. Weak crrelatins, (i.e. belw 0.3) are discarded as well. Sme very high crrelatins, almst equaling 1, are grabbing the attentin at the first sight. These high crrelatins (that are generally relatively clser t the diagnal line) are the crrelatins between similar questins. The high crrelatin cefficients are a gd mark f validity f the results, as discussed previusly in the validatin part. Ignring thse validating nes, sme ther high crrelatins becme apparent. The age is mderately (and inversely) crrelated t the scres f agreements fr the fllwing statements I wuld enjy a mre playful, custmizable pump with a better style and fun add-ns and I wuld prefer an mp3 player / mbile phne like pump T put it in anther way, this finding makes it clear, nt surprisingly, that yunger pump users prefer their pump t be mre fun and less medical, incrprating ther functins than slely medical nes. Anther weaker, nevertheless relevant crrelatin is between the gender and the scre f cmfrt manifested in questin Lsening f adhesive due t sweating. Als visible frm
15 subgrup averages, we can say that male users are suffering mre because f their sweat lsening the adhesive f the infusin set than female pump users. A very imprtant chain f crrelatins is visible in the rw f Wearing the pump. Amng many thers the mst imprtant nes are the crrelatins with Perceptin f increased well being, Sense f being cnnected t a machine, Overall feeling f security, Overall feeling f everything being under yur cntrl, Overall perceptin f increased freedm with pump and Overall pinin abut yur pump. Supprting this fact is the mderately high negative crrelatin with agreement fr the statement I wuld readily want t cnvert back t my ld diabetes management methd if my pump therapy did nt change my glucse levels These findings makes it clear that wearability f the pump is ne f the key stnes fr building an imprved quality f life. Anther interesting finding is the crrelatin between Overall pinin abut yur pump and Hyperglycemia ccurrence which is significantly higher than the ne with Hypglycemia ccurrence
16 Analysis f qualitative questins & cmments by participants The fllwing 3 pen-ended and qualitative questins were asked t the participants cnsecutively in rder t get their cmments: The ultimate gal in insulin pump research& develpment is t achieve an artificial pancreas capable f delivering insulin autmatically accrding t the bld glucse values, withut the interventin f the patient. Tday s pumps are nt smart. Please answer the fllwing tw questins a. and b. Please feel free t ffer an answer even thugh yu think it is technically unachievable. a. Regardless f technical impssibilities, and in exceptin f making yur pump smart, if yu were given the chance f eliminating ne negative aspect, what aspect wuld yu chse t eliminate in the pump f yur dreams? Please give brief details. b. Regardless f technical impssibilities, and in exceptin f making yur pump smart, if yu were given the chance f adding ne psitive aspect, what aspect wuld yu chse t add in the pump f yur dreams? Please give brief details. Please feel free t add yur cmments abut any pump therapy aspect that was nt cvered in this survey. The answers were revealing mre particularities at the expense f quantifiability.
17 Sme f the answers belw are ne ffs prpsed by nly ne participant but having substantial design relevant cntent. Sme ther answers are just representatives fr many similar nes prpsed very frequently by participants. Frequently prpsed: The warning alerts system is nt very lud and isn't adjustable - WHY?(my hearing is perfect, but ften my pump is tucked away in my clthes) custmizable fd database incrprated in the pump 'Make it "wireless" - fr example, I like the idea f the Omnipd (which has n tubing), but the part attached t the bdy is t large t cnsider seriusly using.' 'A lt f factry settings can't be easily custmized by the user (duratin f time t screensaver, prgramming certain aspects f bluses and temp rates, etc.) Easily custmizable settings either frm attached sftware thrugh desktp cmputer r thrugh pump menus wuld be great.' 'screen. Glssy screen and nt enugh cntrast between lettering and backgrund make it difficult t read the screen in sme situatins.' 'I hate having t fill the reservir with insulin. Insulin pens have been n the market fr years - why can't the pump have a pre-filled reservir'' 'bigger reservir and lnger battery life' 'The 3 day limit fr infusin sites.' 'Entirely WATERPROOF 'n physical insertin f catheters/sensrs'
18 One ff s : 'Insertin sites need t be able t be purchased separately - as sites and as tubing.' 'My daughter wuld like it t have "cl games". Wuld be nice if it was slimmer with runded edges. Tubing cil up when nt needed.' 'infusin sets shuld have retractable tubing.' 'Smaller insertin set withut a bulky attachment t the tubing.' 'Making my pump Mac cmpatible - I knw it is pssible t d lts f dwnlads and data management, but all sftware is fr PC users.' 'Create an autmatic insertin device fr infusin sets that g in at an angle' 'Pumps are becming TOO ver-featured. Things like alarm clcks are cute,but NOT necessary fr insulin pumps, and just add a ptential fr things t g wrng -- n smething as critical as an insulin pump, "Keep It simple' 'clred tubing. :-)' 'I wuld find it useful t have a cannula alert that reminded me t change the insertin set - I frget when I put it in and tend t nly change it when it gets itchy r I pull it ut by mistake - I'm sure that 'a lt f users wuld find this useful.' 'I feel mre secure with the additin f the "Blus Wizard" which lessens my anxiety abut hypglycemia events. And I like the Aut Off feature, t.' 'risk the battery running ut and having t change it. This is particularly true if I'm in public r in class. I'd rather just sneak myself a sht under the table than risk my pump beeping and having t dig in my purse fr the batteries.' 'I hate all the extra baggage I need t carry arund with me separate BG meter, strip, backup meter and strips, backup syringe and vial f' insulin, backup infusin set and reservir, spare batteries fr all devices. The mre all f this that can fit int ne device that I wear the mre happy I wuld be.' I wuld make it easier t dwnlad int a cmputer - r increase the memry fr stred events s that I culd check back mre easily this 'is prbably mre relevant t wmen as hrmnal changes during menstruatin make a mnthly adjustment necessary and it wuld be useful t see what the pattern is rather than relying n memry. 'as I aged and my bsm went Suth I lst accessible infusin sites at the waist. Finding gd sites after 53 years f diabetes is a majr prblem, as is decreased ability t twist and turn t insert.' stretchable tubing, s the length is adjustable
19 A read thrugh the cmments abve gives very imprtant design hints fr ameliratin f the pumps. Sme amng thers are: The ergnmic aspects related t legibility f the screen and audibility f the alerts are aspects that are mst cmplained abut. The tubing is perceived frequently as ne f the mst annying parts f the pumps. The tubeless pump, Omnipd, is nt widely accepted mainly because f the bulkiness f the apparatus situated n the infusin site. Sme users suggest making the tube retractable which might be a gd design slutin fr the tubing prblem. The reservirs are very frequently cmplained abut because f the fact that they generally dn t cme pre-filled. The cmplaints are ranging frm general incnvenience f additinal effrt fr filling them t difficulty experienced when remving air bubbles trapped inside the reservir. A preference twards devices that culd pssibly be ttally waterprf is manifested.
20 Cnclusins, Discussin & Recmmendatins This was a research abut ergnmic aspects f insulin pumps. The research was administered nline t 100 vlunteering participants. It invlved pen-ended qualitative and quantitative questins enabling a cmbined use f qualitative techniques that prvided mre insight int aspects as well as statistical techniques that helped t cme up with findings n numerical basis. Sme very imprtant, highly design related issues have been discvered and discussed in the related sectins. A general cnclusin wuld be that the physical ergnmics f the prducts available in the market require substantial imprvement. Sme imprvements are technically feasible tday whereas sme ther might cme true nly with imprvements in the technlgy frm shrt t lng-term. Sme ther ergnmic prblems are inherent t pump therapy and are very unlikely t be slved. The cgnitive ergnmics aspects related t the pumps seemed nt t be a majr issue in the research. But this shuld be interpreted with cautin since the research ppulatin is highly educated. On the ther hand the fact that pumping therapy requires high intellectual and cgnitive skills is a cgnitive ergnmics prblem by itself. There has been sme weak pints in the research. The crrelatins that are analyzed are pair-wise and any multiple dimensinal crrelatins (invlving the relatin between mre than 2 variables) are nt studied in this research. Sme pssible crrelatins might have nt manifested themselves because f sme highly invariable participant characteristics, such as, high educatin level, lng diabetes histry and such. Thse characteristics, being mre r less cnstant
21 thrughut the research ppulatin are, as ne wuld expect, weakly crrelated t ther variable if at all. A better dwn sampling f the entire participant ppulatin t artificially create variance in thse aspects might be cnsidered at the expense f dwnsizing the ppulatin and reducing the significance f any statistical cnclusin that will be drawn. 5 unknwn matrix entries in the raw data matrix (5 ut f 600) are unintentinally mdified and the riginal infrmatin as well as the lcatin is lst irrecverably. But the cnservative apprach during analysis helped reducing the risk f any false finding. Almst all participants agreed t be cntacted nce mre and added their cntact details in the database. This gives the pssibility f mre detailed analysis n certain aspects that require further attentin.
22 APPENDIX
23 Quantitative Questins (in rder) & Scring: What is yur age? What is yur gender? 0.Female 1.Male Please indicate the highest level f Educatin yu have attained: 1.Elementary Schl 2.Year 12 (End f High Schl) 3.Graduate Schl (Bachelrs degree, University) 4.Pst Graduate Degree (Masters, PhD) 5.N Frmal Educatin r Schling Hw lng have yu been n pump therapy fr? 1.Less than 6 mnths 2.6-12 mnths 3.1-3 years 4.Mre than 3 years Hw lng have yu been diabetic fr? 1.Less than 1 year 2.1-4 years 3.5-10 years 4.Mre than 10 years Hw cnfident are yu with using varius functins f a: Persnal Cmputer Mbile Phne 1.Nt cnfident at all 2.Nt cnfident 3.Neutral 4.Cnfident 5.Very Cnfident Belw are sme ptentially psitive and negative "Daily Experiences" related t the use f the insulin pump. Please rate the emtin/impressin caused by each f them n a scale frm 1 t 5: 1.Very annying, very disappinting, r very uncmfrtable 2.Annying, disappinted, r uncmfrtable t sme extent 3.Neutral, never thught f it, r n pinin 4.Enjyable, satisfying, r cmfrtable t sme extent 5.Very enjyable, very satisfying r very cmfrtable Eating ut Exercising
24 Wearing the pump Things t d befre leaving huse (daily) Traveling Trying the clths n while shpping On the sea side (swimming, sunbathing) In the shwer Sleeping at night Intrduce the pump t ther peple During sexual intercurse Unexpected impacts n the infusin site (hitting the dr etc.) Tube being caught by bjects and pulled Lsening f adhesive due t sweating Entering secure areas, passing thrugh plice cntrl and magnetic detectrs Adhesive f the set epilating the infusin site while taking the set ff Obtrusiveness f alerts, in exams, meetings, presentatins, cinema, driving Scial reactins Belw are sme ptentially psitive and negative aspects related t yur "Interactin" with the insulin pump. (Please rate the emtin/impressin caused by each f them n a scale frm 1 t 5) 1.Very annying, very disappinting, r very uncmfrtable 2.Annying, disappinting, r uncmfrtable t sme extent 3.Neutral,never thught f it, r n pinin 4.Enjyable, satisfying, r cmfrtable t sme extent 5.Very enjyable, very satisfying r very cmfrtable Inserting the set Pain in the infusin site Filling the reservir Readability f the screen Ease f access t desired inf / functin Audibility f alerts Temprary discnnecting the pump Ability t temprarily mdify basal rates fr different situatins Accidental pressing f buttns Need t learn pumping thery Need t have extra truble-shting skills Remte cntrl Knwledge & Ability t use all functins f the pump
25 Belw are sme ptentially psitive and negative aspects related t the "Emtinal Result" f using an insulin pump. (Please rate the emtin/impressin caused by each f them n a scale frm 1 t 5 1.Very annying, very disappinting, r very uncmfrtable 2.Annying, disappinting, r uncmfrtable t sme extent 3.Neutral, never thught f it, r n pinin 4.Enjyable, satisfying, r cmfrtable t sme extent 5.Very enjyable, very satisfying r very cmfrtable Perceptin f increased well being Sense f being cnnected t a machine Pump clurs, ability t persnalize Overall feeling f security Overall feeling f everything being under yur cntrl Overall perceptin f increased freedm with pump Overall pinin abut yur pump Belw are sme ptentially negative aspects related t the use f insulin pump. (Please rate the adequacy f statements belw n a scale frm 1 t 5) 1.Strngly disagree 2.Disagree t sme extent 3.I am neutral, I have n pinin 4.Agree t sme extent 5.Strngly agree I am very cncerned abut the cst f therapy I am very wrried abut infectins arund the infusin site I am very cncerned abut unexpected / sudden pump prblems Belw are sme ptentially psitive and negative aspects related t the "Perfrmance" f yur insulin pump. Please rate the change after yu started using yur insulin pump 1.Clearly wrse 2.Wrse t sme extent 3.Neutral, never thught f it, r n pinin 4.Better t sme extent 5.Clearly better Imprved HbA1C results Hyperglycemia ccurence Hypglycemia ccurence Ketacidsis ccurrence Flexibility in fd types & quantity Flexibility in scheduling meal & sleep times
26 Belw are sme statements related t the pump therapy. (Please rate the adequacy f the statements n a scale f 1 t 6) 1.Strngly disagree 2.Disagree t sme extent 3.Neutral 4.Agree t sme extent 5.Strngly Agree 0.N pinin I wuld readily want t cnvert back t my ld diabetes management methd if my pump therapy did nt change my glucse levels I wuld enjy a mre playful, custmizable pump with a better style and fun add-ns I wuld prefer an mp3 player / mbile phne like pump I think sme incnveniences f my pump are related t bad design & can be imprved easily with enugh user feedback There are times I use my pump in a way that was nt suggested by the pump cmpany but invented by me r ther pump users I feel mre diabetic with my pump