Computer aided medical method and medical system for medical prediction

A computer aided medical method include following steps. An initial symptom is collected through an interaction interface. A representative prediction model is selected from plural candidate prediction models according to the initial symptom. The candidate prediction models are trained by a machine learning algorithm according to clinical data. A series of sequential actions is generated according to the representative prediction model and the initial symptom. The sequential actions are selected from plural candidate actions in the representative prediction model. The candidate actions include plural inquiry actions and plural disease prediction actions. Each of the sequential actions is one of the inquiry actions or the disease prediction actions. The series of sequential actions is displayed on the interaction interface.

BACKGROUND

Field of Invention

The disclosure relates to a computer aided medical method. More particularly, the disclosure relates to a computer aided medical method for generating a medical prediction.

Description of Related Art

Recently the concept of computer-aided medical system has emerged in order to facilitate self-diagnosis for patients. The computer aided medical system may request patients to provide some information, and then the computer aided medical system may provide a diagnosis of the potential diseases based on the interactions with those patients.

SUMMARY

The disclosure provides a computer aided medical method. The computer aided medical method includes the following steps. An initial symptom is collected through an interaction interface. A representative prediction model is selected from plural candidate prediction models according to the initial symptom. The candidate prediction models are trained by a machine learning algorithm according to clinical data. A series of sequential actions is generated according to the representative prediction model and the initial symptom. The sequential actions are selected from plural candidate actions in the representative prediction model. The candidate actions include plural inquiry actions and plural disease prediction actions. Each of the sequential actions is one of the inquiry actions or the disease prediction actions. The series of sequential actions is displayed on the interaction interface.

The disclosure also provides a non-transitory computer readable storage medium with a computer program. The computer program is configured to execute aforesaid computer aided medical method.

The disclosure also provides a medical system. The medical system includes an interaction interface and a control circuit. The interaction interface is configured for collecting an initial symptom. The control circuit communicates with the interaction interface. The control circuit is operable to select a representative prediction model from plural candidate prediction models according to the initial symptom. The control circuit is further operable to generate a series of sequential actions according to the representative prediction model and the initial symptom. The sequential actions are selected from plural candidate actions in the representative prediction model. The candidate actions include plural inquiry actions and plural disease prediction actions. Each of the sequential actions is one of the inquiry actions or the disease prediction actions.

It is to be understood that both the foregoing general description and the following detailed description are demonstrated by examples, and are intended to provide further explanation of the invention as claimed.

DETAILED DESCRIPTION

Reference is made toFIG. 1, which is a schematic diagram illustrating a medical system100according to an embodiment of the disclosure. The medical system100includes a control circuit120, an interaction interface140and a storage unit160.

In some embodiments, the control circuit120communicate with the interaction interface140. The medical system100is configured to interact with the user U1through the interaction interface140(e.g. collecting an initial symptom from the user U1, providing some symptom inquiries to the user U1and/or collecting corresponding symptom responses from the user U1). Based on aforesaid interaction history, the medical system100is able to analyze, diagnose or predict a potential disease occurring to the user U1. The medical system100is trained with a machine learning algorithm, such that the medical system100is capable inquiring and diagnosing based on limited patient data. In some embodiments, the medical system100adopts a reinforcement learning (RL) framework to formulate inquiry and diagnosis policies (e.g., Markov decision processes).

In some embodiments, the medical system100is established with a computer, a server or a processing center. The control circuit120can be implemented by a processor, a central processing unit or a computation unit. The interaction interface140can include an output interface (e.g., a display panel for display information) and an input device (e.g., a touch panel, a keyboard, a microphone, a scanner or a flash memory reader) for user to type text commands, to give voice commands or to upload some related data (e.g., images, medical records, or personal examination reports).

In some other embodiments, at least a part of the medical system100is established with a distribution system. For example, the control circuit120is established by a cloud computing system. In this case, the interaction interface140can be a smart phone, which communicates with the control circuit120by wirelessly. The output interface of the interaction interface140can be a display panel on the smart phone. The input device of the interaction interface140can be a touch panel, a keyboard and/or a microphone on the smart phone.

As shown inFIG. 1, the storage unit160is coupled with the control circuit140. In some embodiments, the storage unit160can be implemented by a memory, a flash memory, a ROM, a hard drive or any equivalent storage component.

As shown inFIG. 1, the interaction interface140can be manipulated by a user U1. The user U1can see the information displayed on the interaction interface140and the user U1can enter his/her inputs on the interaction interface140. In an embodiment, the interaction interface140will display a notification to ask the user U1about his/her symptoms. The first symptom inputted by the user U1will be regarded as an initial symptom Sini. The interaction interface140is configured for collecting the initial symptom Sini according to the user's manipulation. The interaction interface140transmits the initial symptom Sini to the control circuit120.

The control circuit120is configured for generating symptom inquiries Sqry to be displayed on the interaction interface140according to the initial symptom Sini. The symptom inquiries Sqry are displayed on the interaction interface140sequentially, and the user U1can answer the symptom inquiries Sqry through the interaction interface140. The interaction interface140is configured for receiving symptom responses Sans corresponding to the symptom inquiries Sqry. When the control circuit120collects enough information to make a decision, the control circuit120is configured to generate a result prediction, such as at least one disease prediction (e.g., a disease name or a list of disease names ranked by their probabilities) or/and at least one medical department suggestion matching the possible disease according to the initial symptom Sini and the responses Sans. The control circuit120will decide optimal questions (i.e., the symptom inquiries Sqry) to ask the user U1according to the initial symptom Sini and all previous responses Sans (before the current question). The optimal questions are selected according to a prediction model utilized by the control circuit120in order to increase efficiency (e.g., the result prediction can be decided faster or in fewer inquiries) and the correctness (e.g., the result prediction can be more accurate) of the result prediction.

Reference is further made toFIG. 2, which is a flow chart illustrating a computer aided medical method200according to an embodiment of the disclosure. The computer aided medical method200can be performed by the medical system100inFIG. 1.

As shown inFIG. 1andFIG. 2, operation S210is performed to collect the initial symptom Sini through the interaction interface140. For example, the interaction interface140may show a text notification read as “How do you feel today? If you don't feel well, can you describe your feeling in a few words?” The user U1may reply the question by typing (or inputting by voice recognition) an input as “I suffer severe headache right now.” In this example, the initial symptom Sini (e.g., headache) can be recognized in the input from the user U1.

In some cases, some computer aided medical system will establish a monolithic prediction model to analyze inputs from patients and generate the prediction. However, it takes a lot of computations to establish the monolithic prediction model because the monolithic prediction model should cover all kinds of diseases and symptoms. The monolithic prediction model may take a long time to make the prediction, and the prediction made by the monolithic prediction model may not be accurate some of the time. In addition, it is difficult to train the monolithic prediction model because there are too many diseases and symptoms should be considered by the monolithic prediction model. Even in a hospital, there are many doctors specialized in different medical departments. It is hard for one doctor to diagnose all kinds of symptoms and diseases with high efficiency and high accuracy.

To mimic real doctors in different hospital departments, the medical system100utilizes multiple candidate prediction models trained by a machine learning algorithm according to clinical data. Reference is further made to FIG.3, which is a schematic diagram illustrating different candidate prediction models MD1, MD2and MD3established according to an embodiment of the disclosure. In some embodiments, the candidate prediction models MD1, MD2and MD3are trained independently corresponding to different anatomical parts of a human body. In some other embodiments, the candidate prediction models MD1, MD2and MD3are trained independently corresponding to different functional parts (e.g., respiratory system, digestive system, nervous system, endocrine system) of a human body. Each one of the candidate prediction models MD1, MD2and MD3is not required to cover all diseases and symptoms over the human body. The combination of the candidate prediction models MD1, MD2and MD3shall be able to cover all diseases and symptoms on different anatomical parts or different functional parts over the human body.

Each of the candidate prediction models MD1, MD2and MD3is trained according to clinical data related to one anatomical part of the human body. The clinical data includes clinical records from some medical databases, such as data and information from the Centers for Disease Control and Prevention (www.cdc.gov/datastatistics/index.html). Each clinical record describes a relationship between a diagnosed disease and corresponding symptoms of the diagnosed disease. For example, a patient who has the disease of venous insufficiency may have the symptoms of skin lesion, leg swelling and leg pain; another patient who has the disease of fracture of arm may have the symptoms of arm pain, wrist swelling, elbow stiffness or tightness; and, still another patient who has the disease of chronic constipation may have the symptoms of sharp abdominal pain, pain of the anus and stomach bloating. The clinical records about different diseases and symptoms are grouped into different anatomical parts (or different functional parts).

A computation time for training one of the candidate prediction models MD1, MD2or MD3will be much shorter than a computation time for training the monolithic prediction model, because the one of the candidate prediction models MD1, MD2or MD3shall consider diseases and symptoms related to one anatomical part (or one functional part). In addition, the candidate prediction models MD1, MD2and MD3can be trained individually in parallel computing, such that it will be faster to establish the candidate prediction models MD1, MD2and MD3than to establish the monolithic prediction model.

Each of the candidate prediction models MD1, MD2and MD3is trained with the clinical data related to one anatomical part (or one functional part). For example, the candidate prediction model MD1is trained with the clinical data related to head; the candidate prediction model MD2is trained with the clinical data related to chest; and, the candidate prediction model MD3is trained with the clinical data related to arm. The candidate prediction models utilized in the medical system100and the computer aided medical method200are not limited to three models as shown inFIG. 2. For brevity,FIG. 2is a demonstrational example to illustrate three candidate prediction models MD1, MD2and MD3. The candidate prediction models utilized in the medical system100and the computer aided medical method200can be two or more different models.

In an embodiment, the human body can be classified into eleven different groups (respectively corresponding to different anatomical parts), such as head, neck, arm, chest, abdomen, back, pelvis, buttock, leg, skin, and general area on the human body. The group of “general area” corresponds to diseases and symptoms that do not just affect one anatomical part on the human body. In this embodiment, the medical system100and the computer aided medical method200will train eleven candidate prediction models corresponding to these eleven groups. For brevity, the following paragraphs are explained with the embodiment including three candidate prediction models MD1, MD2and MD3as shown inFIG. 3.

In another embodiment, the human body can be classified into different groups (respectively corresponding to functional parts), such as respiratory system, digestive system, nervous system, endocrine system, musculoskeletal system, circulatory system, urinary system, reproductive system and general function (which means the symptom does not occur to one particular functional part) on the human body.

The initial symptom Sini is collected through the interaction interface140. The initial symptom Sini will provide an important clue about how the user U1feels. The control circuit120is able to determine which one of the candidate prediction models MD1, MD2and MD3is suitable to predict the situation of the user U1. As shown inFIG. 1andFIG. 2, operation S220is performed to select a representative prediction model from the candidate prediction models MD1-MD3according to the initial symptom Sini.

For example, if the initial symptom Sini is “headache”, the candidate prediction model MD1(corresponding to the head) can be selected from the candidate prediction models MD1-MD3as the representative prediction model. On the other hand, if the initial symptom Sini is “short breathing”, the candidate prediction model MD2(corresponding to the chest) can be selected from the candidate prediction models MD1-MD3as the representative prediction model.

As shown inFIG. 1andFIG. 2, operation S230is performed to generate a series of sequential actions according to the representative prediction model and the initial symptom Sini. The sequential actions are selected from a plurality of candidate actions in the representative prediction model.

As shown inFIG. 3, if the candidate prediction model MD1is selected as the representative prediction model, the candidate prediction model MD1includes several candidate actions Acand. Two types of candidate actions Acand in the candidate prediction model MD1include inquiry actions INQ1, INQ2, INQ3, INQ4, INQ5and INQ6and disease prediction actions PRED1, PRED2and PRED3. Two types of candidate actions Acand in the candidate prediction model MD2include inquiry actions INQ1, INQ5, INQ7, INQ8, INQ9, INQ10and INQ11and disease prediction actions PRED3and PRED4. Two types of candidate actions Acand in the candidate prediction model MD3include inquiry actions INQ3, INQ10, INQ12, INQ13, INQ14and disease prediction actions PRED2, PRED5and PRED7. Each of the sequential actions is one of the inquiry actions INQ1-INQ14or the disease prediction actions PRED1-PRED7. In some embodiments, the sequential actions are displayed on the interaction interface140.

Each of the inquiry actions INQ1-INQ14is to ask a question about whether the user suffers a specific symptom (e.g., “Do you cough?”, “Do you have fever?”, “Can you sleep well?” and “Do you suffer short breathing”). When the user U1provides answers (e.g., the answers can be simply a yes/no responses) to the inquiry actions INQ1-INQ14, the control circuit120will acknowledge more information about the user U1. When the information about the user U1is enough to make a prediction, the control circuit120will select one disease prediction action according to the initial symptom Sini, all previous inquiry actions and all symptom responses Sans prior to the prediction. In some embodiments, each of the disease prediction actions PRED1-PRED7corresponds to one disease.

If the candidate prediction model MD1is selected as the representative prediction model, the candidate prediction model MD1is utilized by the control circuit120to select one of the candidate actions Acand according to a current state STAT, and the one of the candidate action is selected to be the current action Acurt. When one of the inquiry actions INQ1-INQ6is selected as the current action Acurt, the medical system100and the computer aided medical method200will perform the selected one of the inquiry actions INQ1-INQ6. When one of the disease prediction actions PRED1, PRED2and PRED3is selected as the current action Acurt, the medical system100and the computer aided medical method200will perform the selected one of the disease prediction actions PRED1, PRED2and PRED3.

Reference is further made toFIG. 4, which is a flow chart illustrating further steps performed in the step S220inFIG. 2. As the embodiment shown inFIG. 4, the step S220can further include steps S221-S226.

The computer aided medical method200performs the step S221, by the control circuit120, to map the initial symptom Sini to at least one anatomical part of the human body. In some cases, the initial symptom Sini may occur to only one anatomical part (e.g., the headache is related to the head portion). In some other cases, the initial symptom Sini may occur to two or more anatomical parts (e.g., the open wound due to trauma can be related to arm, chest, leg and other parts; the night sweats can be related to skin, head, back and other parts). Step S222is performed to determine whether the initial symptom Sini is mapped to at least two anatomical parts or mapped to one anatomical part.

If a disease in the clinical data is related to at least two of the anatomical parts of the human body, related clinical records corresponding to aforesaid disease are utilized to test accuracies of at least two of the candidate prediction models. As shown inFIG. 3, different candidate prediction models MD1and MD2may have the same inquiry actions INQ1and INQ5, and the same disease prediction action PRED4. Similarly, different candidate prediction models MD2and MD3may have the same inquiry action INQ10. Also, different candidate prediction models MD1and MD3may have the same inquiry action INQ3and the same disease prediction action PRED2.

When the initial symptom Sini is mapped to one anatomical part, Step S223is performed one of the candidate prediction models MD1-MD3matching with the one anatomical part is selected as the representative prediction model. For example, if the initial symptom Sini only happens to the head, or if the initial symptom Sini matches with the inquiry action INQ2only existed in the candidate prediction model MD1, the candidate prediction model MD1can be selected as the representative prediction model. If the initial symptom Sini only happens to the arm, or if the initial symptom Sini matches with the inquiry action INQ12only existed in the candidate prediction model MD3, the candidate prediction model MD3can be selected as the representative prediction model.

On the other hands, if the initial symptom Sini are mapped to at least two anatomical parts, step S224is performed, by the control circuit120, to select a set of the candidate prediction models relative to the at least two of the anatomical parts. If the initial symptom Sini happens to the head and also the arm, or if the initial symptom Sini matches with the inquiry action INQ3existed in the candidate prediction models MD1and MD3, the candidate prediction models MD1and MD3can be assigned in the set. In this case, step S225is performed, by the control circuit120, to test a training accuracy for each of the candidate prediction models in the set (MD1and MD3). Step S226is performed, by the control circuit120, to choose one of the candidate prediction models in the set with the highest training accuracy as the representative prediction model. In this case, one candidate prediction model (MD1or MD3) with a higher training accuracy will be the representative prediction model.

In some embodiments, the training accuracy for each of the candidate prediction models can be tested as follows: Firstly, the control circuit120can hide the diagnosed diseases in the clinical records. The control circuit120inputs the clinical records including descriptions of symptoms to the candidate prediction model MD1and the candidate prediction model MD3respectively. The control circuit120makes predictions according to the candidate prediction model MD1and the candidate prediction model MD3respectively. The control circuit120verifies the predictions generated by the candidate prediction model MD1and the candidate prediction model MD3respectively with the original diagnosed diseases in the clinical records.

In an embodiment, steps S224to S226are executed in real time to decide the most accurate prediction model for the initial symptom Sini. However, the disclosure is not limited thereto. In another embodiment, all possibilities of the initial symptom Sini can be calculated in advanced (by repeating the steps S221to S226) to find out the most accurate prediction model for each possible initial symptom, and a mapping relationship between all possible initial symptoms and different representative prediction models can be recorded in a lookup table, which can be stored in the storage unit160. When the initial symptom Sini is collected, the control circuit120can refer to the mapping relationship in the lookup table to decide the representative prediction model for the initial symptom Sini.

The medical system100and the computer aided medical method200may improve an accuracy of the prediction and reduce a computation time, because the sequential actions are searched in a relatively smaller database of the candidate prediction models MD1-MD3(compared to a monolithic prediction model covering all diseases and symptoms).

Reference is further made toFIG. 5, which is a flow chart illustrating further steps performed in the step S230inFIG. 2. As the embodiment shown inFIG. 5, the step S230can further include steps S231-S236. The steps S231-S236include further details about how to generate a series of sequential actions according to the representative prediction model and the initial symptom Sini.

Reference is further made toFIG. 6AtoFIG. 6C, which are schematic diagrams illustrating a demonstrational example about how to generate the sequential actions in different stages. It is assumed that the candidate prediction model MD1is selected as the representative prediction model in the demonstrational example shown inFIG. 6AtoFIG. 6C. In other cases, the representative prediction model can be replaced by other candidate prediction models and not limited to the candidate prediction model MD1.

FIG. 6Aillustrates a schematic diagram of the representative prediction model (the candidate prediction model MD1) at a first stage. When a first action of the sequential actions is decided as shown inFIG. 6A, the step S231is performed to collect a current state STAT1inputted to the representative prediction model (i.e., the candidate prediction model MD1). At the first stage, the current state STAT1includes the initial symptom Sini. Step S232is performed to generate state-action values respectively for each of the candidate actions (including the inquiry actions INQ1-INQ6and the disease prediction actions PRED1-PRED3) according to the current state.

In an embodiment, the state-action values of the candidate actions can be respectively evaluated by Q-value function. The state-action Q-value function can be defined as: Qπ(s, a). The outcome of Q-value function can be referred to the expected return of performing an action “a” in a state “s”, along with a policy π. The Q-value can be divided into a current reward and an expected Q-value in the following stages. The expected return is elevated by a reward signal corresponding to performing the action. In some embodiments, the state-action Q-value function is defined as: Qπ(s,a)=E[Rt|st=s, at=a, π], referring to the expected return of performing the action a in the state s, along with the policy π. Since the Q-value can be divided into a current reward and a next-step Q-value using dynamic programming, it can be rewritten into the following recursive definition: Qπ(s,a)=Es′[r+ΥEa′˜π(s′)[Qπ(s′,a′)|]s, a, π]. The optimal Q-value is then defined as Q*(s, a)=maxπQπ(s, a). Also, it can be shown that the optimal Q-value obeys the Bellman equation: Q*(s, a)=Es′[r+Υmaxa′Q*(s′, a′)|s, a]. Lastly, the optimal deterministic policy can be defined by π*(s)=arg maxa∈A, Q*(s, a). In some embodiments, since the state and action spaces are typically high dimensional, a representation of the state-action Q-value function encounters the state explosion problem. To address this problem, a deep Q-network (DQN) architecture is developed as a function approximator for Q-functions. The deep Q-network is essentially a neural network representing Q(s, a; θ) with parameters θ. In some embodiments of this application, the deep Q-network as our model in the medical system100and the computer aided medical method200.

The medical system100and the computer aided medical method200consider the inquiry and diagnosis process as a sequential decision problem of an agent (i.e., the control circuit120based on the representative prediction model) that interacts with a patient. At each stage, the agent inquiries a certain symptom of the patient. The patient then responds with true/false to the representative prediction model indicating whether the patient suffers from symptom. In the meantime, the agent can integrate user responses over time steps to propose subsequent questions. At the end of the process, the agent receives a scalar reward if it can correctly predict the disease with limited number of inquiries (every addition inquiry deduces a penalty from the reward). The goal of the agent is to maximize the reward. In other words, the goal is to correctly predict the patient disease by the end of the diagnosis process with limited number of inquiries.

Given a state s, the representative prediction model outputs the Q-value of each candidate actions. In our definition, there are two types of candidate actions, which are the inquiry actions INQ1-INQ6and the disease prediction actions PRED1-PRED3. If the maximum Q-value of the outputs corresponds to one of the inquiry actions INQ1-INQ6, then the control circuit120outputs the corresponding symptom inquiry to the user U1, collects a symptom response from the user U1, and proceeds to the next stage.

In the situation shown inFIG. 6A, the current state STAT1including the initial symptom Sini merely provides a little information about the user U1Currently, the information provided by the initial symptom Sini will not be enough to make the disease prediction. The medical system100and the computer aided medical method200will prefer to take an inquiry action rather than make the disease prediction at this stage. As shown inFIG. 6A, the Q-values of the inquiry actions INQ1-INQ6will be relatively higher and the Q-values of the disease prediction actions PRED1-PRED3will be relatively lower at the current stage.

Step S233is performed to selecting one of the candidate actions with a highest one of the state-action values as the current action of the sequential actions. In the embodiment show inFIG. 6A, the inquiry action INQ3has the highest Q-value (Q=0.45). Therefore; the inquiry action INQ3is selected as the current action Acurt1, which is also the first action of the sequential actions.

Step S234is performed to determine whether the current action Acurt1is an inquiry action or not. In this case, the current action Acurt1is the inquiry action INQ3, such that a symptom inquiry corresponding to the inquiry action INQ3can be displayed on the interaction interface140in the step S235.

Reference is further made toFIG. 6B, which illustrates the schematic diagram of the representative prediction model (the candidate prediction model MD1) at a second stage after the first stage shown inFIG. 6A.

The step S231is performed to collect a current state STAT2inputted to the representative prediction model (i.e., the candidate prediction model MD1). At the second stage, the current state STAT2includes the initial symptom Sini, the previous inquiry action INQ3and the symptom response RES3N corresponding to the inquiry action INQ3. In this case, the symptom response RES3N indicates that the user U1does not suffer the symptom mentioned in the inquiry action INQ3. Step S232is performed again to generate state-action values respectively for each of the candidate actions (including the inquiry actions INQ1, INQ2, INQ4-INQ6and the disease prediction actions PRED1-PRED3) according to the current state STAT2. The state-action values of the candidate actions will be updated according to the symptom response RES3N. In this case, because the current state STAT2has been different from the previous state (STAT1shown inFIG. 6A), the state-action values respectively for each of the candidate actions can be re-evaluated by Q-value function. The outcome of Q-value function may be increased or reduced according to the Yes/No answer in the symptom response RES3N. While selecting a target inquiry action (i.e., the inquiry action INQ3in this case) from the candidate actions, one of the inquiry actions capable of inducing significant variations on Q-values of other candidate actions will be selected as the target inquiry action. After the symptom response RES3N is provided to the medical system100and the computer aided medical method200, the Q-values of the inquiry actions INQ1, INQ2, INQ4-INQ6and the disease prediction actions PRED1-PRED3will change in response to the symptom response RES3N.

As the embodiment shown inFIG. 6B, the inquiry action INQ5has the highest Q-value (Q=0.57). Therefore, the inquiry action INQ5is selected as the current action Acurt2, which is also the second action of the sequential actions.

In this case, the current action Acurt2(which is the inquiry action INQ5) next to a previous action (Acurt1shown inFIG. 6A) is generated further according to the symptom response RES3N beside the initial symptom Sini.

Step S234is performed to determine whether the current action Acurt2is an inquiry action or not. In this case, the current action Acurt2is the inquiry action INQ5, such that a symptom inquiry corresponding to the inquiry action INQ5can be displayed on the interaction interface140in the step S235.

Reference is further made toFIG. 6C, which illustrates the schematic diagram of the representative prediction model (the candidate prediction model MD1) at a third stage after the second stage shown inFIG. 6B.

The step S231is performed to collect a current state STAT3inputted to the representative prediction model (i.e., the candidate prediction model MD1). At the second stage, the current state STAT3includes the initial symptom Sini, the previous inquiry action INQ3, the symptom response RES3N, the previous inquiry action INQ5and the symptom response RES5Y corresponding to the inquiry action INQ5. In this case, the symptom response RES5Y indicates that the user U1suffers the symptom mentioned in the inquiry action INQ5. Step S232is performed again to generate state-action values respectively for each of the candidate actions (including the inquiry actions INQ1, INQ2, INQ4, INQ6and the disease prediction actions PRED1-PRED3) according to the current state STAT3. The state-action values of the candidate actions will be updated according to the symptom response RES3N and the symptom response RES5Y. In this case, because the current state STAT3has been different from the previous state (i.e., STAT2), the state-action values respectively for each of the candidate actions can be re-evaluated by Q-value function. The outcome of Q-value function may be increased or reduced according to the Yes/No answer in the symptom response RES3N and the symptom response RES5Y. While selecting a target inquiry action (i.e., the inquiry action INQ5in this case) from the candidate actions, one of the inquiry actions capable of inducing significant variations on Q-values of other candidate actions will be selected as the target inquiry action. After the symptom response RES5Y is provided to the medical system100and the computer aided medical method200, the Q-values of the inquiry actions INQ1, INQ2, INQ4, INQ6and the disease prediction actions PRED1-PRED3will change in response to the symptom response RES5Y.

As the embodiment shown inFIG. 6C, the disease prediction action PRED2has the highest Q-value (Q=0.83). Therefore, the disease prediction action PRED2is selected as the current action Acurt3, which is also the third action of the sequential actions.

In the situation shown inFIG. 6C, the current state STAT3includes the initial symptom Sini, the previous inquiry action INQ3, the symptom response RES3N, the previous inquiry action INQ5and the symptom response RES5Y. In this case, the current state STAT3may provide sufficient information to make the disease prediction. Therefore, the Q-values of the inquiry actions INQ1, INQ2, INQ4and INQ6will be relatively lower and the Q-values of the target disease prediction action PRED2will be relatively higher at the current stage.

In this case, the current action Acurt3(which is the disease prediction action PRED2) next to a previous action (Acurt2shown inFIG. 6A) is generated further according to the symptom response RES5Y beside the initial symptom Sini and the symptom response RES3N.

Step S234is performed to determine whether the current action Acurt3is an inquiry action or not. In this case, the current action Acurt3is not an inquiry action but the disease prediction action PRED2, such that step S236is performed to output the disease prediction action PRED2. For example, the disease prediction action PRED2can be displayed on the interaction interface140. The user U1can acknowledge the disease prediction action PRED2.

In some embodiments, when the disease prediction action PRED2is selected as the current action Acurt3, the computer aided medical method200further generates a prediction result according to the selected disease prediction action PRED2. In an embodiment, the prediction result can be a disease name. In another embodiment, the prediction result can be a list of disease names ranked by probability. For example, the list of disease can include the disease predictions PRED2, PRED3and PRED1in sequence of their Q-values (0.83, 0.31 and 0.22 in the example shown inFIG. 6C). In another embodiment, the prediction result can be a medical department suggestion.

The sequential actions generated in step S230includes two inquiry actions and one disease prediction as the embodiment shown inFIG. 6AtoFIG. 6C. However, the disclosure is not limited thereto. In the disclosure, the computer aided medical method200is not limited to generate a specific amount of the sequential actions. The amount of the sequential actions is determined dynamically according to the evaluation of the state-action values respectively for each of the candidate actions at each stage. Once a disease prediction is evaluated to have the highest state-action value among all candidate actions, the computer aided medical method200will decide the final result of the disease prediction. In some cases, the sequential actions can include 3-7 inquiry actions or even more. In other words, the timing to generate the disease prediction is dynamically determined by the representative prediction model. The timing to generate the disease prediction is not fixed at a certain amount of the responses. In other words, it is not limited to generate the disease prediction after3responses are collected, or after5responses are collected.

Another embodiment of disclosure includes a non-transitory computer readable storage medium (e.g., the storage unit160shown inFIG. 1) with a computer program to execute aforesaid computer aided medical method200shown inFIG. 2,FIG. 4andFIG. 5.