HEARTS (Hospital Evaluation Assistant for Rapid Transplant Screening) is a knowledge based system (KBS) which conducts initial screening to determine if patients with coronary artery disease may be placed on the waiting list for a heart transplant. Given the critical shortage of donor organs, the medical community can only place patients who are likely to benefit from an organ transplant on the waiting list. Unfortunately, the process for screening patients is lengthy, approximately 4 months. During this time a donor organ may become available, but those patients still being screened cannot be considered as a possible match. We describe the development, testing, and user response to HEARTS. HEARTS benefits patients by speeding the screening process and placing them on the waiting list more quickly. Members of a transplant committee benefit by being freed from conducting the initial screening to focus on more critical issues

Ball, Debra

Lawson, Susan

Shaft, Teresa

English

AIS Electronic Library (AISeL)

Association for Information SystemsAIS Electronic Library (AISeL)AMCIS 1998 Proceedings Americas Conference on Information Systems(AMCIS)December 1998HEARTS: A Knowledge-Based System for InitialScreening of Heart Transplant PatientsDebra BallUniversity of TulsaTeresa ShaftUniversity of TulsaSusan LawsonUniversity of TulsaFollow this and additional works at: http://aisel.aisnet.org/amcis1998This material is brought to you by the Americas Conference on Information Systems (AMCIS) at AIS Electronic Library (AISeL). It has been acceptedfor inclusion in AMCIS 1998 Proceedings by an authorized administrator of AIS Electronic Library (AISeL). For more information, please contactelibrary@aisnet.org.Recommended CitationBall, Debra; Shaft, Teresa; and Lawson, Susan, "HEARTS: A Knowledge-Based System for Initial Screening of Heart TransplantPatients" (1998). AMCIS 1998 Proceedings. 47.http://aisel.aisnet.org/amcis1998/47-131-HEARTS: A Knowledge-Based System for Initial Screening ofHeart Transplant PatientsDebra J. BallWilliamsSusan LawsonWilliamsTeresa M. ShaftUniversity of TulsaAbstractHEARTS (Hospital Evaluation Assistant for Rapid Transplant Screening) is a knowledge based system (KBS)which conducts initial screening to determine if patients with coronary artery disease may be placed on thewaiting list for a heart transplant.  Given the critical shortage of donor organs, the medical community canonly place patients who are likely to benefit from an organ transplant on the waiting list.  Unfortunately, theprocess for screening patients is lengthy, approximately 4 months.  During this time a donor organ maybecome available, but those patients still being screened cannot be considered as a possible match.  Wedescribe the development, testing, and user response to HEARTS.  HEARTS benefits patients by speeding thescreening process and placing them on the waiting list more quickly.  Members of a transplant committeebenefit by being freed from conducting the initial screening to focus on more critical issues. IntroductionThe shortage of organs for transplantation is widely acknowledged and the situation is not expected to improve. “Transplantation, with its extreme scarcity of resources, imposes some of the most critical and difficult choices in health care”(Penchas and Roll, 1996: 2347).  In response to this shortage, information technology based initiatives such as XPEDITE (Beard,Klein, Daily, and Kauffman, 1997) to speed the matching of donor organs to a recipient have been undertaken.  However,technology has not been as widely utilized to assist physicians with the task of screening candidates for transplantation.Specifically, not all patients are appropriate candidates for an organ transplant.  Given the shortage of donor organs, it isimportant that only those patients who are most likely to benefit from a transplant be placed on the waiting list for transplantableorgans.  For example, if a patient suffers from a myriad of health problems such that they are unlikely to survive surgery or theirgeneral physical condition is likely to deteriorate even with a transplant, a patient will not be placed on a waiting list until theirother health problems are treated or stabilized.  Heart transplant facilities have specific criteria that a patient must meet to be considered for a transplant.  “Choices reflectpriorities when determining transplantation procedure.  If choices must be made, then one would tend to think that one wouldbe better off if these priorities were established according to a pre-researched and established plan or system.  After all, thechoices (priorities) are repetitive.  It would be wasteful to go through the same long and costly analytical process da capo eachtime” (Penchas and Roll, 1996, p. 2345).  Currently, the decision to place a patient on a waiting list for a donor organ is a multi-step process that requires the input of a twelve person committee whose members include cardiologists, other physicians,registered nurses, social workers, and the chief of staff.  However, the criteria for initial screening are complex, but set (known).Hence, a KBS could conduct initial screening.  Since patients are excluded from receiving a transplant due to other medicalconditions or lifestyle (i.e., smoking or alcoholism), the sooner a patient can receive feedback, the more quickly they can seektreatment to become eligible for a transplant.  The committee benefits from the KBS as it frees them to focus on more criticalissues such as the later stages of the screening process (which are more subjective), preparing patients for and performingsurgery.  The hospital benefits by knowing that initial screening criteria are applied in consistently.Knowledge AcquisitionThe criteria for screening a patient for transplant surgery are hospital specific. Different hospitals may accept patients withdifferent risk factors depending upon the capabilities and experience of the transplant team.  Therefore, HEARTS could not bedeveloped from generic criteria, but must be specific to a particular hospital.  Despite well-known medically-oriented KBS suchas MYCIN, KBS are not commonly utilized in hospitals.  Therefore, it was necessary to obtain special permission from thehospital’s Heart Transplant Committee and Chief of Staff prior to meeting with two experts (also members of the Heart-132-Transplant Committee).  That it took over three weeks to obtain permission is further evidence of the committee’s workload andthat a KBS that could streamline the screening process would be beneficial.Knowledge acquisition was conducted by two of the authors (who served as knowledge engineers) with two transplantcoordinators (registered nurses and members of the heart transplant committee).  One of the knowledge engineers had completed3 years of nursing school and had 3 years experience working in an emergency room as a nurse technician specialist.  Hermedical knowledge was essential when working with the experts.  During the knowledge acquisition session, it became apparentthat different screening criteria are applied depending upon the specific diagnosis.  It was decided to focus on a single diagnosisand the experts requested Coronary Artery Disease.  Knowledge acquisition was conducting via think-aloud verbal protocolswith both knowledge engineers and experts present.During the knowledge acquisition session, the experts manually evaluated a simulated test case.  They developed ahierarchical diagram of their thought process as they made individual decisions about the case.  The experts verbalized theirthoughts as they proceeded.  The knowledge engineers noted any inconsistencies that occurred.  In addition, the other experthelped validate the process.  Frequently the experts concurred.  At other times they disagreed and discussed the acceptablemanner to determine the correct path.  These discussions reinforced our beliefs that a KBS that consistently applied the criteriawould be beneficial.  At the end of the session the one expert commented that “you don’t realize how many things go into thisin doing it until you write it down.”  Indicating they found some benefit from the knowledge acquisition process.  During thesession the experts generated two cases that were used later for testing.  Development and TestingDiagnostic reasoning and medical diagnosis in particular are well-known domains for KBS.  Further, rule-based knowledgerepresentation schemes have been successfully applied to this type of reasoning.  Since HEARTS is essentially a prototype todemonstrate the capability of KBS to the Heart Transplant Committee, a shell was deemed the best development approach.  VP-Expert, a well known and readily available shell, was selected.The rule-base was developed from the hierarchical diagram created by the experts during knowledge acquisition.  HEARTSqueries the user for information regarding a patients’ medical condition.   Based on the hierarchical diagram, the rules werebroken into 3 major clusters.  The first cluster examines basic information such as the patient’s age, if they were properlyreferred, do they smoke, take non-prescription drugs, etc.  When patients are excluded from the transplant program for thesetypes of reasons, HEARTS recommends the appropriate next step for the patient such as seeking treatment for drug/alcohol abuseor quitting smoking and reapplying after a given time period, or contacting a more appropriate heart transplant program as shownin the rule below:IF Age = Yes ! Age > 65THEN  Medical_Criteria = Not_okDISPLAY "Our hospital Heart Transplant program requires the patient's age to be less than 65.  Thepatient  may consider contacting Stanford's Heart Transplant Program."; Note that all rules include a BECAUSE clause, which allows VP-Expert to respond to WHY queries, but were eliminated fromthese example for space reasons.  The second rule cluster queries about additional health problems that might make the patientineligible for a transplant at this hospital.  Conditions such as peptic ulcers, vascular disease, active infections, or irreversablehepatic, renal or pulmonary disease.  Each condition is evaluated a separate rule, if none of these conditions are found, the rulesthat comprise the third cluster are evaluated.  This cluster evaluates more complex conditions including the status of patients withdiabetes, hypertension, cancer, etc.  Below are three rules used to evaluate hypertension:IF Systolic >= 160 !Evaluate for hypertensionAND Diastolic < 100 THEN   Hypertension = Yes; IF Hypertension = Yes And Medication = No !Is the patient taking medication for hypertension?THEN Medical_Criteria_2 = Not_ok DISPLAY "This patient needs to be evaluated for medical treatment for hypertension.  This patientcan be re-evaluated after hypertension  is managed by medical therapy.";IF Hypertension = Yes  AND Medication = Yes !Hypertension medication is not workingTHEN Medical_Criteria_2 = Not_ok DISPLAY "This patient's medical therapy is not controlling the hypertension within acceptableboundaries.  Re-evaluate when the patient's hypertension is under control with medical therapy.";If, based on HEARTS’ evaluation, a patient meets all criteria, further laboratory work is conducted and utilized by the committeeto conduct the final stage of screening. -133-Two test cases developed by the experts and a third created by the knowledge engineers were used to determine if HEARTSwas giving accurate recommendations.  During testing, HEARTS sometimes failed and it was difficult to pin-point the step inthe query causing the failure.  The failed case was re-executed using the VP-Expert’s auto-query function which enabled thesystem to request the information necessary to complete the case.  By doing so, it became apparent that a gap (Gamble and Shaft,1996) existed in the rule-base.  Specifically, the initial and final portions of the necessary rule-chain were in place, but the rulesin the initial portions of the rule-chain were not instantiating all the variables necessary to fire the appropriate rule in the finalportion of the rule chain.  Although the gap would have been detected and corrected manually, auto-query speeded the debuggingprocess and subsequently was used to test all rule combinations.User Feedback and Future PlansFollowing testing, HEARTS was demonstrated to the experts by executing the test cases.  The experts then used HEARTSto run other cases on their own.  Their response was positive and they felt that HEARTS would save time when screeningpatients and they planned show HEARTS to the other members of the Heart Transplant committee and the Chief of Staff.Depending on their responses,  the experts will propose development of full-scale version of HEARTS.  In addition to beinguseful in the Heart Transplant department, the experts believe that other areas of the hospital could benefit from KBS and intendto introduce HEARTS to the Congestive Heart Failure clinic.  In the future, a second phase of development may be conductedto expand HEARTS’ rule-base to conduct later steps in the screening process.  These additional steps consider laboratory testresults and other medical procedures before recommending a patient be placed on the waiting list. ConclusionAmazing technological advances have been achieved in medicine, such as a robot that performs surgery (seehttp://www.musculographics.com/krs.com).  However, when an entire medical procedure is examined it is apparent thattechnology is almost non-existent in initial diagnosis.  HEARTS demonstrates the ability for KBS to conduct routine diagnosticactivities which could enable the medical community to  better allocate scarce resources.ReferencesBeard, J. W, Klien, D. H., Daily, O. P., and Kauffman, M. “Applying Information Technology Management Capabilities toSupport Organ Procurement and Transplantation.”  Proceedings of the Sixth International Conference on Management ofTechnology (MOT’97), The Creation of Prosperity, Business and Work Opportunities Through Technology Management,H. Mueller, J. G. Persson, and K. P. Lumsden (Eds.) pp. 386-377.  Stockholm, Sweden: The Swedish Society of MechanicalEngineers, Naval Architects and Aeronautical Engineers, 386-377, June 1997.Gamble, R. F. and Shaft, T. M. “Eliminating Redundancy, Conflict, and Incompleteness from Knowledge-Based Systems.”International Journal of Software Engineering and Knowledge Engineering, 6(4), 1996, 673-697.Penchas, S. and Roll, M. “Organ Transplantation: Evolving a National Transplantation Policy and Methodology in Israel.”Transplantation Proceedings, 28(4) August, 1996, 2345-2348.

HEARTS: A Knowledge-Based System for Initial Screening of Heart Transplant Patients

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HEARTS: A Knowledge-Based System for Initial Screening of Heart Transplant Patients

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