Computerized medical diagnostic system including re-enter function and sensitivity factors

What is claimed is:

1. In an automated medical advice system including a computer, and input and output devices, a method of re-entering a diagnosis of a patient's medical problem, comprising the steps of:

performing an initial diagnostic consultation with the patient, thereby collecting patient information;

identifying a situation wherein the patient is to consult the system again wherein an indicator associated with programmed re-enter criteria is set in the computer;

automatically instructing the patient to consult the system at a predetermined time in the future based upon the identified situation;

performing one or more additional diagnostic consultations with the patient, thereby collecting and storing additional patient information, wherein the execution path of the additional diagnostic consultation is responsive to the stored patient information and the indicator of satisified re-enter criteria; and

formulating a diagnosis from said collected patient information during a one of the diagnostic consultations.

2. The method defined in claim 1, wherein the step for identifying the situation provides for monitoring the symptoms of the patient over time.

3. The method defined in claim 1, wherein the step for identifying the situation makes an identification when the system fails to make a diagnosis based on the available patient information.

4. The method defined in claim 1, additionally comprising the step of assessing the severity of the problem during at least one of the consultations.

5. The method defined in claim 1, additionally comprising the step of identifying a person consulting the system after the initial consultation as a re-enter patient.

6. The method defined in claim 1, additionally comprising the step of determining that the initial consultation and each additional diagnostic consultation provides patient information for only one medical problem.

7. The method defined in claim 1, wherein the step of performing additional consultations results in adding the additional information to a medical record of the patient.

8. The method defined in claim 1, additionally comprising the step of identifying a patient needing immediate medical attention during any one of the additional diagnostic consultations.

9. The method defined in claim 1, additionally comprising the step of confirming a diagnosis made during one of the consultations based on the additional patient information.

10. The method defined in claim 9, additionally comprising the step of informing the patient when a change in treatment is available for the confirmed diagnosis.

11. The method defined in claim 1, additionally comprising the step of referring the patient to a physician if a diagnosis made during one of the consultations cannot be confirmed based upon any one succeeding consultation.

12. The method defined in claim 1, additionally comprising the step of automatically contacting the patient at preselected times so as to monitor the condition of the patient.

13. In an automated medical advice system including a computer, and input and output devices, a method of symptom severity analysis, comprising the steps of:

performing a first diagnostic consultation with a patient for a problem by a diagnostic process, thereby collecting patient information;

quantizing a severity of a symptom of the patient based upon the first consultation;

identifying a situation wherein the patient is to consult the system again wherein, if a programmed re-enter criteria is satisified, an indicator associated with the programmed re-enter criteria is set in the computer;

automatically instructing the patient to consult the system at a predetermined time in the future based upon the identified situation;

performing a second diagnostic consultation with the patient for the problem by the diagnostic process;

quantizing the severity of the symptom of the patient based upon the second consultation;

analyzing changes in a level of severity and rate of change of severity over time based upon the quantized severities and

providing instructions to the patient based on the analysis of changes in a level of severity and rate of change of severity over time.

14. The method defined in claim 13, additionally comprising the step of providing selected medical advice if the rate of change of severity exceeds a preselected threshold.

15. The method defined in claim 13, additionally comprising the step of requesting the patient to consult with the system at a predetermined later time if the rate of change of severity does not achieve a preselected threshold.

16. The method defined in claim 13, additionally comprising the steps of:

performing a third diagnostic consultation with the patient for the problem by the diagnostic process; and

quantizing the severity of the symptom of the patient based upon the third consultation.

17. The method defined in claim 16, additionally comprising the steps of:

analyzing any change in the rate of change of severity over time; and

providing medical advice if the change of rate of change of severity exceeds a preselected threshold.

18. In an automated medical advice system including a computer, input and output devices, and a set of medical algorithms, a method of modifying sensitivity so as to change the advice of the system, comprising the steps of:

receiving through at least one of said input devices data indicative of physical symptoms of a patient;

establishing a sensitivity factor representative of relative importance of a selective field of interest having a cost/benefit tradeoff recognized by a healthcare organization in at least one medical algorithm;

changing a threshold value in at least one of the medical algorithms by use of the sensitivity factor, wherein the new threshold value affects a branching decision in the medical algorithm and wherein the medical algorithm uses physical symptoms of the patient to generate a diagnosis;

communicating the diagnosis through the output device; and

changing the sensitivity factor over time to affect the sensitivity of the system thereby improving the advice given by the system.

19. The method defined in claim 18, wherein the sensitivity factor comprises a system-wide sensitivity factor affecting all threshold calculations throughout the system.

20. The method defined in claim 18, additionally comprising the steps of:

establishing a problem sensitivity factor; and

changing threshold calculations in a selected one of the medical algorithms by use of the problem sensitivity factor.

21. The method defined in claim 18, wherein the sensitivity factor is selected from the following sensitivity factors: system-wide, anatomic system, cause, problem, question, organization, or patient, or combinations thereof.

22. The method defined in claim 21, wherein the step of changing the sensitivity factor over time includes changing any combination of the sensitivity factors.

23. The method defined in claim 18, wherein the value of the sensitivity factor is initially set to one.

24. The method defined in claim 18, wherein the changing threshold calculations step includes a multiplication of the sensitivity factor times a threshold value.

25. In an automated medical advice system including a computer, and input and output devices, a method of re-entering a diagnosis of a patient's medical problem, comprising the steps of:

performing an initial diagnostic consultation with the patient, thereby collecting patient information;

identifying a situation wherein the patient is to consult the system again, wherein, if a programmed re-enter criteria is satisfied, an indicator associated with the programmed re-enter criteria is set in the computer;

automatically instructing the patient to consult the system at a predetermined time in the future based upon the identified situation;

performing one or more additional diagnostic consultations in response to the indicator of satisfied re-enter criteria such that additional information collected from the patient is associated with one medical problem; and

formulating a diagnosis from said collected patient information during a one of the diagnostic consultations.

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MICROFICHE APPENDIX

A Microfiche Appendix containing computer source code is attached. The Microfiche Appendix comprises 9 sheets of microfiche having 454 frames, including one title frame.

The Microfiche Appendix contains material which is subject to copyright protection. The copyright owner has no objection to the reproduction of such material, as it appears in the files of the Patent and Trademark Office, but otherwise reserves all copyright rights whatsoever.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to medical knowledge systems and, more particularly, to systems for giving medical advice to the general public over a telephone network.

2. Description of the Related Technology

Health care costs currently represent 14% of the United States Gross National Product and are rising faster than any other component of the Consumer Price Index. Moreover, usually because of an inability to pay for medical services, many people are deprived of access to even the most basic medical care and information.

Many people delay in obtaining, or are prevented from seeking, medical attention because of cost, time constraints, or inconvenience. If the public had universal, unrestricted and easy access to medical information, many diseases could be prevented. Likewise, the early detection and treatment of numerous diseases could keep many patients from reaching the advanced stages of illness, the treatment of which is a significant part of the financial burden attributed to our nation's health care system. It is obvious that the United States is facing health-related issues of enormous proportions and that present solutions are not robust.

One prior attempt at a solution to the health care problem is called Ask-A-Nurse, wherein a group of nurses provide health information by telephone around-the-clock. A person with a medical problem calls an 800 number and describes the problem to the nurse. The nurse uses a computer for general or diagnostic information on the ailment or complaint mentioned by the caller. The nurse may then refer the caller to a doctor from a computerized referral list for a contracting hospital or group of hospitals. Client hospitals contract with Ask-A-Nurse to provide patient referrals. A managed care option called Personal Health Advisor is similar and adds the capability for the caller to hear prerecorded messages on health topics 24 hours a day. Several problems exist with these prior medical advice systems. First, these systems have high costs associated with having a nurse answer each telephone call. Second, the caller may have to belong to a participating health plan to utilize the service. Third, if for some reason all nurses on a particular shift happen to be busy and the caller has an emergency condition (that is not known by the caller to be an emergency), precious time in getting emergency services may be lost during the delay.

Another prior health system was developed by InterPractice Systems which provides a computerized service that answers health care questions and advises people in their homes. A health maintenance organization (HMO) may provide this service to its members in a particular geographic area. To get advice at home, an HMO member connects a toaster-sized box to a telephone and calls a toll-free 800 number. Using a keyboard that is part of the box, the user answers questions displayed on a screen of the box relating to the user's symptoms. Depending on the answers, the user might be told to try a home remedy, be called by a nurse or doctor, or be given an appointment to be examined. A limitation of this system is the additional expense of the electronics box, which could either be purchased by the user for approximately $300 or purchased by the health organization with the expense to be passed on to the users. Another limitation is that this service is directed to members of a particular contracting health organization, such as an HMO. What is desired is a system that does not require additional hardware for the basic service, but that utilizes the existing communication network. The desired system should be available for use by any person, not just members of a certain organization.

A prior attempt at a health care solution for a limited set of conditions is described in U.S. Pat. No. 4,712,562. A patient's blood pressure and heart rate are measured and the measurements are sent via telephone to a remote central computer for storage and analysis. Reports are generated for submission to a physician or the patient. U.S. Pat. No. 4,531,527 describes a similar system, wherein the receiving office unit automatically communicates with the physician under predetermined emergency circumstances.

U.S. Pat. No. 4,838,275 discloses a device for a patient to lay on or sit in having electronics to measure multiple parameters related to a patient's health. These parameters are electronically transmitted to a central surveillance and control office where a highly trained observer interacts with the patient. The observer conducts routine diagnostic sessions except when an emergency is noted or from a patient-initiated communication. The observer determines if a nonroutine therapeutic response is required, and if so facilitates such a response. As previously mentioned, highly trained people are needed by this system along with the special measurement apparatus (embedded in a bed or chair).

Other prior attempts at a health care solution are typified by U.S. Pat. No. 5,012,411 which describes a portable self-contained apparatus for measuring, storing and transmitting detected physiological information to a remote location over a communication system. The information is evaluated by a physician or other health professional. As before, highly trained people are necessary to utilize such an apparatus.

Several services to provide medical or pharmaceutical advice are now available via "1-900" telephone numbers, e.g., "Doctors by Phone." These services are available 24 hours a day and 7 days a week. A group of doctors, including some specialties, is available to answer questions about health care or medical conditions for people anywhere in the United States who call the "1-900" telephone of one of the services. A group of registered pharmacists answers questions about medications for the "1-900" pharmaceutical service.

SUMMARY OF THE INVENTION

The present solution to the health care problem is a computerized medical diagnostic and treatment advice (MDATA) system that is a medical knowledge-based system designed to give medical advice to the general public over the telephone network. The goal of the MDATA system is to provide everyone with equal access to high quality, 100%-consistent medical advice at a reasonable cost. The MDATA system provides callers with extremely fast and virtually unlimited access to health care information, twenty-four hours a day, from any location around the world. Health care advice is made available to an entire spectrum of users, from elderly patients confined to their homes to travelers in a foreign country with telephones in their cars.

The central ideas leading to the development of the MDATA system are based on the following assumptions:

Nearly 90% of all patient complaints are confined to approximately 100 medical problems.

Almost all primary care decisions involved in these 100 problems can be made based upon information learned solely by obtaining a detailed medical history. The results of the physical examination, laboratory, and imaging studies only tend to confirm a diagnosis.

The minimal amount of information that many doctors believe can only be obtained from the physical examination can actually be directly acquired from the patient when given appropriate instructions.

In most cases, a face-to-face interaction between the doctor and patient is not necessary. A detailed and well-constructed history, along with physical findings elicited from the patient, can be obtained over the telephone.

Medicine is basically diagnosis and treatment. Although treatment recommendations change frequently, the fundamental principles of making the diagnosis do not.

There is a significant delay between the time a new therapy is recognized as safe and effective and the time physicians are able to provide it to their patients.

These central ideas are utilized in the implementation of the MDATA system.

A goal of the MDATA system is to give better medical advice than a family practitioner who is unfamiliar with a patient, e.g., an on-call physician. A person seeking medical advice frequently will not be able to see or speak with his or her personal physician in a timely manner. The MDATA system provides medical advice whenever desired by the caller--seven days a week/24 hours a day.

All previous medical algorithms, including those used in the military, are designed for face-to-face interactions. Self-help books generally do not consider age and sex in their algorithms. Furthermore, a book cannot take into account how many times a person has consulted the same algorithm within a short period of time for the same problem. The medical algorithms used by the MDATA system are designed for use in a telecommunications setting and overcome the deficiencies of self-help books.

Previous medical advice systems do not do a time-density analysis for a number of factors with regard to the number of complaints per unit of time. The MDATA system uses "meta" functions to perform these analyses.

Previous medical advice algorithms do not have a way of detecting the consciousness level of the person seeking consultation. The MDATA system invokes a "mental status examination" whenever a complaint or problem has the possibility of an altered level of consciousness. In addition, the MDATA system uses "semantic discrepancy evaluator loops" which allow the system to invoke the mental status exam if there are differences in answers to the parallel threads of thought that are woven or embedded into the system.

Other medical advice systems do not have a "re-enter" feature to monitor a patient's progress or worsening over time. The MDATA system checks for and responds to changing conditions over time.

Prior medical advice systems suffer from the inability to be nearly instantly up-dated as new medical information is made available. The MDATA system regularly and frequently updates the treatment aspect of the system.

The computerized medical diagnostic and treatment advice (MDATA) system is a medical knowledge-based system designed to give medical advice to the general public over the telephone network. Using a new authoring language, interactive voice response and speech recognition technology, the MDATA system encodes a highly useful core of expert and general practitioner diagnostic and treatment knowledge into a computerized system for access by non-medically trained personnel.

The MDATA system does not provide advice for every medical problem, nor does it make an exhaustive study of one vertical cross-section of medicine. Instead, the MDATA system provides up-to-date medical advice for approximately one hundred of the most commonly encountered problems in general practice and emergency medicine. It also provides valuable information to the public on any number of other medical topics.

As another embodiment of the MDATA system, a person desiring medical advice and having access to a personal computer (PC) loads a program into the PC to produce a stand-alone medical diagnostic and treatment advice (SA-MDATA) system. Rather than listening to questions and responding via touch tone keypresses or via voice, the user responds to questions and directions displayed on the computer screen via a computer input device, such as a keyboard or mouse. The diagnosis and/or treatment recommendations provided by the MDATA system are the same as that provided by the SA-MDATA system. The user of the SA-MDATA system can procure updates by contacting the MDATA system sponsor/administrator to obtain the most current treatment table information for a particular diagnosis.

One aspect of the present invention includes, in an automated medical advice system including a computer, and input and output devices, a method of re-entering a diagnosis of a patient's medical problem, comprising the steps of: performing an initial diagnostic consultation with the patient, thereby collecting patient information, identifying a situation wherein the patient is to consult the system again, instructing the patient to consult the system at a predetermined time in the future, and performing one or more additional diagnostic consultations with the patient, thereby collecting additional patient information.

Another aspect of the