Patent Publication Number: US-2022237774-A1

Title: Medical information processing apparatus, medical information processing method, and non-transitory computer-readable medium

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2021-011465, filed on Jan. 27, 2021; the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to a medical information processing apparatus, a medical information processing method, and a non-transitory computer-readable medium. 
     BACKGROUND 
     A problem to be solved by the embodiments described in the present disclosure and the drawings is to present information that makes it possible to experience a feeling of a subject. However, the problems to be solved by the embodiments described in the present disclosure and the drawings are not limited to the abovementioned problem. It is also possible to consider the problems corresponding to advantageous effects achieved by the configurations presented in the embodiments described below, as other problems. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating an exemplary configuration of a medical information processing apparatus according to a first embodiment; 
         FIG. 2  is an explanatory drawing for explaining an overview of a visual decoder; 
         FIG. 3  is an explanatory drawing for explaining an overview of a feeling decoder of a first feeling estimating function; 
         FIG. 4  is an explanatory drawing for explaining an overview of a feeling decoder of a second feeling estimating function; 
         FIG. 5  is a diagram illustrating an example of a vector space having vectors of input and output words; 
         FIG. 6  is a flowchart illustrating an example of an examination process performed by the medical information processing apparatus according to the first embodiment; 
         FIG. 7  is a flowchart illustrating an example of a subject feeling estimating process performed by the medical information processing apparatus according to the first embodiment; 
         FIG. 8  is a flowchart illustrating an example of an evaluator feeling estimating process performed by the medical information processing apparatus according to the first embodiment; 
         FIG. 9  is a flowchart illustrating an example of a tuning process performed by the medical information processing apparatus according to the first embodiment; 
         FIG. 10  is a flowchart illustrating an example of a searching process performed by the medical information processing apparatus according to the first embodiment; 
         FIG. 11  is a block diagram illustrating an exemplary configuration of a medical information processing apparatus according to a second embodiment; and 
         FIG. 12  is drawing illustrating an example of a two-dimensional distribution diagram of onomatopoeia. 
     
    
    
     DETAILED DESCRIPTION 
     The following will describe a medical information processing apparatus, a medical information processing method, and a non-transitory computer-readable medium according to the present embodiments, with reference to the accompanying drawings. In the following embodiments, some of the elements referred to by using the same reference characters are assumed to perform the same operation, and duplicate explanations thereof will be omitted as appropriate. 
     First Embodiment 
       FIG. 1  is a block diagram illustrating an exemplary configuration of a medical information processing apparatus  1  according to a first embodiment. The medical information processing apparatus  1  is configured to obtain first nerve activity information and second nerve activity information of a subject such as a patient, from a measuring device that implements functional Magnetic Resonance Imaging (fMRI) or is realized with an electroencephalogram (EEG). The first nerve activity information is information having recorded electrical activities of the brain and nerves of the subject. For example, the first nerve activity information is brain activity information having recorded activities of the brain such as the frontal lobe relevant to feelings of the subject. The second nerve activity information is information being different from the first nerve activity information and having recorded electrical activities of the brain and nerves of the subject. For example, the second nerve activity information is brain activity information having recorded activities of the brain such as the visual cortex relevant to visual sensation of the subject. Further, instead of a device implementing functional Magnetic Resonance Imaging or an electroencephalogram (EEG), the measuring device may be realized by using other types of devices. 
     Further, on the basis of the second nerve activity information, the medical information processing apparatus  1  is configured to generate visual information indicating the visual sensation of the subject. In other words, the medical information processing apparatus  1  is configured to generate image data indicating the visual sensation experienced by the subject while in the state indicated by the second nerve activity information. 
     Further, the medical information processing apparatus  1  is configured to generate first feeling information by estimating the type of feeling and a degree of the feeling experienced by the subject, on the basis of the first nerve activity information. Examples of the type of feeling include, joy, adoration, terror, amazement, grief, disgust, rage, and vigilance. The degree of the feeling is expressed as one of the levels such as Level  1 , Level  2 , Level  3 , and the like. 
     Further, the medical information processing apparatus  1  is configured to obtain, from a measuring device, third nerve activity information of an evaluator corresponding to a time when presentation information is presented. The presentation information is information presented to the evaluator so that the feeling of the subject can be experienced. For example, the presentation information is image data of the visual information or the like. Alternatively, the presentation information may be image data found in a search so that the feeling of the subject can be experienced. The evaluator is a person such as a medical doctor or a clinical psychologist who evaluates feelings of the subject. The third nerve activity information is information having recorded electrical activities of the brain and nerves of the evaluator. For example, the third nerve activity information is brain activity information having recorded activities of the brain such as the frontal lobe relevant to feelings of the evaluator. 
     Further, on the basis of the third nerve activity information, the medical information processing apparatus  1  is configured to generate second feeling information by estimating the type of feeling and a degree of the feeling experienced by the evaluator. 
     Further, the medical information processing apparatus  1  is configured to judge whether or not a degree of similarity between the first feeling information and the second feeling information is equal to or higher than a threshold value. When the degree of similarity is lower than the threshold value, the medical information processing apparatus  1  is configured to search for presentation information that makes the degree of similarity equal to or higher than the threshold value. In other words, the medical information processing apparatus  1  is configured to search for the presentation information that enables the evaluator to experience the feeling of the subject. For example, the medical information processing apparatus  1  may search for the presentation information such as image data that enables the evaluator to feel terror that is substantially equivalent to terror felt by the subject. 
     Further, when the degree of similarity between the first feeling information of the subject and the second feeling information of the evaluator becomes equal to or higher than the threshold value, the medical information processing apparatus  1  is configured to issue a notification. In this manner, the medical information processing apparatus  1  is configured to present the presentation information that makes it possible to experience the feeling of the subject. 
     Next, a configuration of the medical information processing apparatus  1  will be explained. The medical information processing apparatus  1  includes a Network (NW) interface circuitry  11 , an input interface circuitry  12 , a display  13 , a memory  14 , and a processing circuitry  15 . 
     The NW interface circuitry  11  is connected to the processing circuitry  15  and is configured to control transfer of various types of data and communication performed with apparatuses and devices connected via a network. For example, the NW interface circuitry  11  is realized by using a network card, a network adaptor, a Network Interface Controller (NIC), or the like. 
     The input interface circuitry  12  is connected to the processing circuitry  15  and is configured to convert an input operation received from an operator (a medical worker) into an electrical signal and to output the electrical signal to the processing circuitry  15 . More specifically, the input interface circuitry  12  is configured to convert the input operation received from the operator into the electrical signal and to output the electrical signal to the processing circuitry  15 . For example, the input interface circuitry  12  is realized by using a trackball, a switch button, a mouse, a keyboard, a touchpad on which input operations can be performed by touching an operation surface thereof, a touch screen in which a display screen and a touchpad are integrally formed, a contactless input circuitry using an optical sensor, an audio input circuitry and/or the like. Further, in the present disclosure, the input interface circuitry  12  does not necessarily have to include physical operation component parts such as a mouse, a keyboard, and/or the like. For instance, possible examples of the input interface circuitry  12  include an electrical signal processing circuitry configured to receive an electrical signal corresponding to an input operation from an external input device provided separately from the apparatus and to output the electrical signal to a controlling circuit. 
     The display  13  is connected to the processing circuitry  15  and to display various types of information and various types of image data output from the processing circuitry  15 . For example, the display  13  is realized by using a liquid crystal display device, a Cathode Ray Tube (CRT) display device, an organic Electroluminescence (EL) display device, a plasma display device, a touch panel, or the like. 
     The memory  14  is connected to the processing circuitry  15  and is configured to store therein various types of data. Further, the memory  14  is configured to store therein various types of programs that are read and executed by the processing circuitry  15  to realize various types of functions. For example, the memory  14  is realized by using a semiconductor memory element such as a Random Access Memory (RAM) or a flash memory, or a hard disk, an optical disk, or the like. 
     The processing circuitry  15  is configured to control operations of the entirety of the medical information processing apparatus  1 . As for the processing circuitry  15 , for example, processing functions implemented by a nerve activity information obtaining function  151 , a visual information generating function  152 , a first feeling estimating function  153 , a third nerve activity information obtaining function  154 , a second feeling estimating function  155 , a searching function  156 , a presenting function  157 , and a notifying function  158  are stored in the memory  14  in the form of computer-executable programs. The processing circuitry  15  is a processor configured to realize the functions corresponding to the programs by reading and executing the programs from the memory  14 . In other words, the processing circuitry  15  that has read the programs has the functions illustrated within the processing circuitry  15  in  FIG. 1 . For example, the memory  14  is an example of a storage medium that is a non-transitory computer-readable medium and includes instructions which a computer is caused to execute. 
     With reference to  FIG. 1 , the example was explained in which the single processer realizes the nerve activity information obtaining function  151 , the visual information generating function  152 , the first feeling estimating function  153 , the third nerve activity information obtaining function  154 , the second feeling estimating function  155 , the searching function  156 , the presenting function  157 , and the notifying function  158 ; however, it is also acceptable to structure the processing circuitry  15  by combining together a plurality of independent processors, so that the functions are realized as a result of the processors executing the programs. Further, although the example was explained with reference to  FIG. 1  in which the single storage circuitry (e.g., the memory  14 ) stores therein the programs corresponding to the processing functions, it is also acceptable to arrange a plurality of storage circuits in a distributed manner, so that the processing circuitry  15  reads a corresponding program from each of the individual storage circuits. 
     The term “processor” used in the above explanations denotes, for example, a Central Processing Unit (CPU), a Graphical Processing Unit (GPU), or a circuit such as an Application Specific Integrated Circuit (ASIC) or a programmable logic device (e.g., a Simple Programmable Logic Device [SPLD], a Complex Programmable Logic Device [CPLD], or a Field Programmable Gate Array [FPGA]). One or more processors are configured to realize the functions by reading and executing the programs saved in the memory  14 . Further, instead of saving the programs in the memory  14 , it is also acceptable to directly incorporate the programs into the circuits of the one or more processors. In that situation, the one or more processors realize the functions by reading and executing the programs incorporated in the circuits thereof. 
     The nerve activity information obtaining function  151  is configured to obtain the first nerve activity information indicating the activities of the nerves of the subject. Further, the nerve activity information obtaining function  151  is configured to obtain the second nerve activity information indicating the activities of the nerves relevant to the visual sensation of the subject. The nerve activity information obtaining function  151  is an example of an obtaining unit. More specifically, the nerve activity information obtaining function  151  is configured to obtain the first nerve activity information and the second nerve activity information from the measuring device that implements functional magnetic resonance imaging or is realized with an electroencephalogram. Also, the nerve activity information obtaining function  151  may obtain the first nerve activity information and the second nerve activity information of a designated part of the subject. For example, the nerve activity information obtaining function  151  may obtain the first nerve activity information of the frontal lobe in the brain of the subject. Further, the nerve activity information obtaining function  151  may obtain the second nerve activity information of the visual cortex in the brain of the subject. 
     The visual information generating function  152  is configured to generate visual information reproducing visual sensation experienced by the subject while in the state indicated by the first nerve activity information. The visual information is image data reproducing the visual sensation of the subject. 
     More specifically, the visual information generating function  152  is configured to generate the visual information from the second nerve activity information by using a visual decoder. In other words, the visual information generating function  152  is configured to generate the image data on the basis of the visual decoder that has learned, through machine learning, a correspondence relationship between the second nerve activity information indicating activities of nerves relevant to visual sensation and image data. In relation to this,  FIG. 2  an explanatory drawing for explaining an overview of the visual decoder. As illustrated in  FIG. 2 , when the second nerve activity information is input thereto, the visual decoder is configured to generate the visual information corresponding to the second nerve activity information. 
     For example, the visual decoder is realized by using a trained model generated through the machine learning. More specifically, the visual decoder is generated through supervised learning in which second nerve activity information is input as training data on the input side of the trained model, whereas visual information corresponding to the second nerve activity information is input as training data on the output side. 
     For example, the visual decoder is generated through the supervised learning in which second nerve activity information of the vision cortex is input as the training data on the input side, whereas image data viewed at the time of obtaining the second nerve activity information is input as the training data on the output side. Further, although it is possible to obtain the second nerve activity information serving as the training data used for generating the visual decoder from any person, it is desirable when the person is an able-bodied person having no mental disorder. 
     The first feeling estimating function  153  is configured to generate the first feeling information by estimating the feeling experienced by the subject, on the basis of the first nerve activity information. In other words, the first feeling estimating function  153  is configured to estimate the first feeling information indicating the feeling experienced by the subject, on the basis of the first nerve activity information. The first feeling estimating function  153  is an example of a first estimating unit. More specifically, the first feeling estimating function  153  is configured to estimate the first feeling information on the basis of a feeling decoder that has learned, through machine learning, a correspondence relationship between the first nerve activity information and the first feeling information. The first feeling information is information that indicating a feeling related to the five senses and degrees of the five senses of the subject. 
     In relation to the above,  FIG. 3  is an explanatory drawing for explaining an overview of the feeling decoder of the first feeling estimating function  153 . As illustrated in  FIG. 3 , when the first nerve activity information and the visual information corresponding to the first nerve activity information are input thereto, the feeling decoder is configured to generate the first feeling information corresponding to the first nerve activity information and the visual information. In other words, the feeling decoder is configured to estimate the first feeling information, on the basis of the first nerve activity information and the image data corresponding to the first nerve activity information. For example, the feeling decoder is realized by using a trained model generated through machine learning. More specifically, the feeling decoder is generated through supervised learning in which first nerve activity information and visual information are input as training data on the input side of the trained model, whereas first feeling information corresponding to the first nerve activity information and the visual information are input as training data on the output side. 
     The visual information is input to the feeling decoder illustrated in  FIG. 3 . However, it is acceptable even when no visual information is input to the feeling decoder. In other words, the feeling decoder may be configured, when the first nerve activity information is input thereto, to generate first feeling information corresponding to the first nerve activity information. In that situation, the feeling decoder is generated through supervised learning in which first nerve activity information is input as training data on the input side of the trained model, whereas first feeling information corresponding to the first nerve activity information is input as training data on the output side. 
     The third nerve activity information obtaining function  154  is configured to obtain the third nerve activity information indicating the activities of the nerves of the evaluator corresponding to the time when the presentation information is presented. More specifically, the third nerve activity information obtaining function  154  is configured to obtain the third nerve activity information from a measuring device that implements functional magnetic resonance imaging or is realized with an electroencephalogram. Further, the third nerve activity information obtaining function  154  may obtain the third nerve activity information of a designated part of the evaluator. For example, the third nerve activity information obtaining function  154  may obtain the third nerve activity information of the frontal lobe relevant to feelings of the evaluator. 
     The second feeling estimating function  155  is configured to generate the second feeling information by estimating the feeling experienced by the evaluator, on the basis of the third nerve activity information. More specifically, the second feeling estimating function  155  is configured to generate the second feeling information from the third nerve activity information by using a feeling decoder. The second feeling information is information that indicating a feeling related to the five senses and degrees of the five senses of the evaluator. 
       FIG. 4  is an explanatory drawing for explaining an overview of the feeling decoder of the second feeling estimating function  155 . As illustrated in  FIG. 4 , the evaluator views the visual information of the subject. In other words, the evaluator views the presentation information. When the third nerve activity information at the time of viewing the visual information or the presentation information and the visual information or the presentation information corresponding to the third nerve activity information are input thereto, the feeling decoder is configured to generate the second feeling information corresponding to the third nerve activity information and the visual information. In other words, the second feeling estimating function  155  is configured to estimate the second feeling information indicating the feeling experienced by the evaluator, on the basis of the third nerve activity information indicating the activities of the nerves of the evaluator and the image data generated by the visual decoder. Further, the second feeling estimating function  155  may use the same feeling decoder as the one used by the first feeling estimating function  153  or may use a feeling decoder that is exclusively generated. 
     The visual information is input to the feeling decoder illustrated in  FIG. 4 . However, similarly to the first feeling estimating function  153 , it is acceptable even when no visual information is input to the feeling decoder. In other words, when the first feeling estimating function  153  has input the first nerve activity information and the visual information to the feeling decoder, the second feeling estimating function  155  inputs the first nerve activity information and the visual information to the feeling decoder. In contrast, when the first feeling estimating function  153  has input the first nerve activity information to the feeling decoder, the second feeling estimating function  155  inputs the first nerve activity information to the feeling decoder. 
     The searching function  156  is configured to search for the presentation information to enable the evaluator to experience the feeling of the subject. More specifically, when the degree of similarity between the first feeling information indicating the feeling of the subject and the second feeling information indicating the feeling of the evaluator is lower than the threshold value, the searching function  156  is configured to search for the presentation information that makes the degree of similarity between the feelings equal to or higher than the threshold value. Further, on the basis of the first feeling information, the searching function  156  is configured to determine the presentation information to enable the evaluator to experience the feeling of the subject. The searching function  156  is an example of a determining unit. 
     For example, the searching function  156  is configured to calculate the degree of similarity between the first feeling information and the second feeling information. The searching function  156  is configured to calculate a degree of similarity between the type of feeling of the first feeling information and the type of feeling of the second feeling information. Further, the searching function  156  is configured to calculate a degree of similarity between the degree of the feeling indicated by the first feeling information and the degree of the feeling indicated by the second feeling information. As a result, the searching function  156  calculates the degree of similarity between the feelings. In other words, the searching function  156  is configured to determine the presentation information for the evaluator on the basis of the first feeling information of the subject and the second feeling information of the evaluator. In this situation, the first feeling information and the second feeling information are generated from the first nerve activity information and from the third nerve activity information, respectively. Accordingly, instead of from the first feeling information and the second feeling information, the searching function  156  may calculate a degree of similarity from the first nerve activity information and the third nerve activity information. Further, the searching function  156  may calculate a degree of similarity between the feelings by using other methods. In other words, the searching function  156  is configured to determine the presentation information so that the degree of similarity between the first nerve activity information of the subject and the third nerve activity information of the evaluator is equal to or higher than the threshold value. 
     Next, a method for searching for the presentation information will be explained. Upon viewing the image data represented by the visual information, different evaluators experience different feelings depending on temperaments and cultural backgrounds thereof. For example, upon viewing of image data depicting a spider, feelings experienced by the evaluators vary among the evaluators. For this reason, the searching function  156  is configured to repeatedly perform the process of searching for the presentation information that makes the degree of similarity between the feelings equal to or higher than the threshold value. 
     For example, the searching function  156  may use a natural language processing model that is configured, upon receipt of an input of a word representing a target of visual information and a word representing a type of emotion indicated by emotion information, to output a peripheral word. The peripheral word is a word having a meaning close to that of the input word. For example, the natural language processing model is generated through machine learning. The natural language processing model is a natural language processing algorithm such as “Word2Vec”. The natural language processing model is configured to learn a multi-dimensional vector space that properly expresses semantic relationships among words. The semantic closeness between words is expressed as a distance between corresponding word vectors. When the natural language processing model has output the peripheral word, the searching function  156  is configured to construct a vector space having vectors of the words that were input and output. 
       FIG. 5  is a diagram illustrating an example of the vector space having the vectors of the words that were input and output. The vector space in  FIG. 5  depicts a situation in which two peripheral words were output from the natural language processing model. When having constructed the vector space, the searching function  156  is configured to set the feeling of the evaluator in the vector space. For example, the searching function  156  sets the feeling of the evaluator in a position within the vector space that corresponds to the type of emotion and the meaning of the degree of the emotion indicated by the second feeling information. 
     In the vector space, the searching function  156  is configured to set a goal position in which the degree of similarity between the emotions of the subject and the evaluator is estimated to be equal to or higher than the threshold value. Further, by conducting a search in the vector space, the searching function  156  is configured to specify a word in the goal position. For example, in the vector space, the searching function  156  searches for a word that minimizes a cost function. After that, the searching function  156  is configured to output presentation information specified by the word found in the search. In other words, the searching function  156  is configured to output image data containing the target representing the word. 
     Further, by using the word vectors, the natural language processing model is also capable of performing virtual addition and subtraction on words, such as “king−male+female=queen”. For this reason, with respect to the words structuring the vector space that has already been constructed, the searching function  156  may perform calculations on the words, for the purpose of enabling the evaluator, in post-processing, to share the feeling information of the subject in a context suitable for the evaluator&#39;s temperament or cultural background. Accordingly, the searching function  156  is able to reconstruct the vector space. Furthermore, when a word vector relevant to a feeling (e.g., sound, smell) different from the visual sensation is output, the searching function  156  may append, as additional information, information about the feeling relevant to such a word vector, to the specific presentation information found in the search. 
     Every time the searching function  156  finds presentation information in a search, the presenting function  157  is configured to present the presentation information to the evaluator. More specifically, the presenting function  157  is configured to present the presentation information to the evaluator, by causing the display  13  to display the presentation information. In this situation, instead of using the display  13 , the presenting function  157  may present the presentation information to the evaluator by using a device implementing the virtual space technology such as X Reality (XR). More specifically, the presentation information may be presented to the evaluator, by using a device implementing Augmented Reality (AR), Mixed Reality (MR), Substitutional Reality (SR), Virtual Reality (VR), or the like. 
     When the degree of similarity between the feeling of the subject and the feeling of the evaluator becomes equal to or higher than the threshold value, the notifying function  158  is configured to issue the notification. As a result, the evaluator is able to recognize that his/her feeling is substantially the same as the feeling of the subject. 
     Next, various types of processes performed by the medical information processing apparatus  1  will be explained. 
       FIG. 6  is a flowchart illustrating an example of an examination process performed by the medical information processing apparatus  1  according to the first embodiment. 
     The medical information processing apparatus  1  performs a subject feeling estimating process to estimate a feeling of the subject as illustrated in  FIG. 7  (step S 1 ). 
     The medical information processing apparatus  1  performs an evaluator feeling estimating process to estimate a feeling of the evaluator as illustrated in  FIG. 8  (step S 2 ). 
     The medical information processing apparatus  1  performs a tuning process illustrated in  FIG. 9  (step S 3 ). 
     The medical information processing apparatus  1  thus ends the examination process. 
       FIG. 7  is a flowchart illustrating an example of the subject feeling estimating process performed by the medical information processing apparatus  1  according to the first embodiment. 
     The nerve activity information obtaining function  151  obtains the first nerve activity information and the second nerve activity information, from the measuring device that measures brain waves or the like of the subject (step S 11 ). 
     The visual information generating function  152  generates the visual information from the second nerve activity information, by using the visual decoder (step S 12 ). 
     The first feeling estimating function  153  generates the first feeling information, by estimating the feeling of the subject while using the feeling decoder (step S 13 ). 
     The medical information processing apparatus  1  thus ends the subject feeling estimating process. 
       FIG. 8  is a flowchart illustrating an example of the evaluator feeling estimating process performed by the medical information processing apparatus  1  according to the first embodiment. 
     The third nerve activity information obtaining function  154  obtains the third nerve activity information from the measuring device that measures brain waves or the like of the evaluator who has viewed the presented visual information (step S 21 ). 
     The second feeling estimating function  155  generates the second feeling information from the third nerve activity information by using the feeling decoder (step S 22 ). 
     The medical information processing apparatus  1  thus ends the evaluator feeling estimating process. 
       FIG. 9  is a flowchart illustrating an example of the tuning process performed by the medical information processing apparatus  1  according to the first embodiment. 
     The searching function  156  calculates the degree of similarity between the feeling of the subject and the feeling of the evaluator (step S 31 ). In other words, the searching function  156  calculates the degree of similarity between the first feeling information and the second feeling information. 
     The searching function  156  judges whether or not the degree of similarity between the feeling of the subject and the feeling of the evaluator is equal to or higher than the threshold value (step S 32 ). 
     When the degree of similarity between the feelings is lower than the threshold value (step S 32 : No), the medical information processing apparatus  1  performs the searching process illustrated in  FIG. 10  (step S 33 ). 
     The presenting function  157  presents the presentation information obtained by performing the searching process (step S 34 ). After that, the medical information processing apparatus  1  proceeds to step S 31 . 
     When the degree of similarity between the feelings is equal to or higher than the threshold value (step S 32 : Yes), the notifying function  158  issues a notification indicating that the feeling of the subject is similar to the feeling of the evaluator (step S 35 ). 
     The medical information processing apparatus  1  thus ends the tuning process. 
       FIG. 10  is a flowchart illustrating an example of the searching process performed by the medical information processing apparatus  1  according to the first embodiment. 
     The searching function  156  specifies a word relevant to the visual information (step S 41 ). In this situation, when the degree of similarity between the feeling of the subject and the feeling of the evaluator to whom the visual information was presented is still not equal to or higher than the threshold value, the searching function  156  specifies a word relevant to the presentation information. 
     The searching function  156  estimates a peripheral word of the word representing the target indicated by the visual information or the presentation information and a word indicating the type of emotion indicated by the second emotion information of the evaluator (step S 42 ). In other words, the searching function  156  inputs, to the natural language processing model, the word representing the target indicated by the image data and the word indicating the type of emotion indicated by the second emotion information of the evaluator. After that, the searching function  156  uses a word output from the natural language processing model, as the peripheral word. 
     The searching function  156  constructs a vector space having vectors of the words input to the natural language processing model and a vector of the peripheral word output from the natural language processing model (step S 43 ). 
     The searching function  156  sets the feeling of the evaluator as an initial position in the vector space (step S 44 ). 
     The searching function  156  sets, in the vector space, a goal position in which the degree of similarity between the emotions of the subject and the evaluator is estimated to be equal to or higher than the threshold value (step S 45 ). 
     The searching function  156  specifies a word corresponding to the goal position, by conducting a search in the vector space (step S 46 ). 
     The searching function  156  obtains presentation information corresponding to the specified word (step S 47 ). In other words, the searching function  156  obtains image data containing the target representing the word. 
     The medical information processing apparatus  1  thus ends the searching process. 
     As explained above, the medical information processing apparatus  1  according to the first embodiment is configured to obtain the first nerve activity information indicating the activities of the nerves of the subject. Also, the medical information processing apparatus  1  is configured to estimate the first feeling information indicating the feeling experienced by the subject, on the basis of the first nerve activity information. Further, the medical information processing apparatus  1  is configured to determine the presentation information to enable the evaluator to experience the feeling of the subject, on the basis of the first feeling information. Accordingly, the evaluator is able to perform a diagnosis process or the like, while experiencing the feeling of the subject. In other words, the medical information processing apparatus  1  is capable of presenting the information that makes it possible to experience the feeling of the subject. 
     First Modification Example 
     The presentation information was described above as being image data; however, instead of being the image data, the presentation information may be auditory information. 
     In this situation, the visual information generating function  152  is configured to generate visual information to be presented to the evaluator. Further, when the degree of similarity between the feelings of the subject and the evaluator is still lower than the threshold value even after presenting the visual information, the searching function  156  is configured to search for image data. When the visual information generating function  152  has generated visual information or the searching function  156  has generated image data, the presenting function  157  is configured to obtain the auditory information corresponding to a target represented by the visual information or the image data. 
     For example, when the target represented by the visual information or the image data is a fire, the presenting function  157  is configured to obtain auditory information including sounds from an actual site having a fire. Further, the presenting function  157  is configured to present the obtained auditory information to the evaluator. In other words, the presenting function  157  is configured to cause a speaker or the like to output the auditory information. 
     In this situation, the presenting function  157  may obtain the auditory information by using any method. For example, the presenting function  157  may obtain the auditory information specified by the target represented by the visual information or the image data, from a database of auditory information. Alternatively, the presenting function  157  may obtain the auditory information, by using a trained model configured, upon receipt of an input of information indicating a target represented by the visual information or the image data, to output auditory information. 
     Alternatively, the medical information processing apparatus  1  may directly obtain the auditory information without the intervention of the visual information or the image data. For example, the medical information processing apparatus  1  may generate the auditory information on the basis of the first nerve activity information obtained from the auditory cortex. 
     Second Modification Example 
     The presentation information was described above as being image data; however, instead of being the image data, the presentation information may be olfactory information. 
     In this situation, the visual information generating function  152  is configured to generate visual information to be presented to the evaluator. Further, when the degree of similarity between the feelings of the subject and the evaluator is still lower than the threshold value even after presenting the visual information, the searching function  156  is configured to search for image data. 
     When the visual information generating function  152  has generated visual information or the searching function  156  has generated image data, the presenting function  157  is configured to obtain the olfactory information corresponding to a target represented by the visual information or the image data. When the target represented by the visual information or the image data is a fire, the presenting function  157  is configured to obtain olfactory information indicating a component of the smells from an actual site having a fire. Further, the presenting function  157  is configured to present the obtained olfactory information to the evaluator. In other words, the presenting function  157  causes a device configured to generate a smell of a designated component to output the smell of the component indicated by the olfactory information. 
     Further, the presenting function  157  may obtain the olfactory information by using any method. For example, the presenting function  157  may obtain the olfactory information specified by the target represented by the visual information or the image data, from a database of olfactory information. Alternatively, the presenting function  157  may obtain the olfactory information, by using a trained model configured, upon receipt of an input of information indicating a target represented by the visual information or the image data, to output olfactory information. 
     Alternatively, the medical information processing apparatus  1  may directly obtain the olfactory information without the intervention of the olfactory information or the image data. For example, the medical information processing apparatus  1  may generate the olfactory information on the basis of the first nerve activity information obtained from the olfactory cortex. 
     Second Embodiment 
     A medical information processing apparatus  1   a  according to a second embodiment is configured to present tactile information as the presentation information.  FIG. 11  is a block diagram illustrating an exemplary configuration of the medical information processing apparatus  1   a  according to the second embodiment. 
     A nerve activity information obtaining function  151   a  is configured to obtain the second nerve activity information of the subject to whom a tactile stimulation is given by a tactile device such as an Electrical Muscle Stimulation (EMS) system. The second nerve activity information contains nerve electric potential (hereinafter, “nerve potential”; the same applies hereinafter) and muscle potential of the vertebrae or brain activity information such as a brain wave or brain potential of the cerebral cortex. In other words, the second nerve activity information is muscle potential information indicating the activity potential caused when the muscles of the subject contract. 
     A tactile information generating function  159  is configured to generate tactile information from the second nerve activity information. The tactile information is presentation information presented to the evaluator via a tactile device. For example, the tactile device is configured to give a touch stimulation to the evaluator, on the basis of the tactile information. On the basis of the second nerve activity information, the tactile information generating function  159  is configured to generate the tactile information including an intensity, a duration, and the like of the touch stimulation. For example, the tactile information generating function  159  is configured to use the difference between a reference line and a maximum amplitude value as the intensity of the touch stimulation. Further, when normalization is necessary, the tactile information generating function  159  is configured to make a correction by using an average amplitude value on a time scale during which no skin stimulation is given, i.e., without the tactile stimulation. Further, as the duration, the tactile information generating function  159  is configured to use a total of the time periods during which the amplitude value keeps exceeding the reference line by an amount equal to or higher than a threshold value during the measuring period. Further, the tactile information generating function  159  is configured to take noise above the reference line into consideration. When noise in the form of pulses intermittently continues multiple times, the tactile information generating function  159  is configured to calculate the number of times as an index. Further, the tactile information generating function  159  may calculate a sum of the products of the intensity and the duration of the touch stimulation, as an index indicating the intensity of the entire tactile sensation. 
     A first feeling estimating function  153   a  is configured to generate the first feeling information by estimating a feeling experienced by the subject, on the basis of the first nerve activity information obtained from the frontal lobe or the like of the patient. For example the first feeling estimating function  153   a  is configured to generate the first feeling information expressing the feeling experienced by the subject, by using an onomatopoeia. In other words, the first feeling information is information indicating the tactile sensation. 
     In relation to the above,  FIG. 12  is a drawing illustrating an example of a two-dimensional distribution diagram of onomatopoeia. Onomatopoeia is a collective term for words imitating sounds and words imitating manners such as “fukafuka (‘fluffy’ in Japanese)” and “tsurutsuru (‘smooth’ in Japanese)”. Different individuals have different feeling impressions from onomatopoeia. In  FIG. 12 , in the two-dimensional distribution diagram indicating a correspondence relationship among tactile sensations, onomatopoeia such as “fukafuka(‘fluffy’)” and “tsurutsuru (‘smooth’)” expressing impressions of an individual are set. In other words, the two-dimensional distribution diagram of onomatopoeia is generated for each subject and each evaluator. Accordingly, by projecting the feeling specified by the first nerve activity information onto the two-dimensional distribution diagram of the onomatopoeia, the first feeling estimating function  153   a  is able to specify an onomatopoeia suitable for the subject. 
     For example, the first feeling estimating function  153   a  is configured to project the feeling specified by the first nerve activity information with the use of the feeling decoder, onto the two-dimensional distribution diagram of the onomatopoeia. As a result, the first feeling estimating function  153   a  is able to specify an onomatopoeia suitable for the subject. After that, the first feeling estimating function  153   a  is configured to generate the first feeling information having the specified onomatopoeia. 
     A third nerve activity information obtaining function  154   a  is configured to obtain the third nerve activity information of the evaluator to whom the tactile stimulation is given by the tactile device. The tactile device is configured to operate on the basis of the tactile information of the subject. In other words, the tactile device is configured to output the tactile stimulation on the basis of the tactile information of the subject. Accordingly, the third nerve activity information obtaining function  154   a  is able to obtain the third nerve activity information of the evaluator corresponding to the time when the feeling experienced by the subject is given. 
     A second feeling estimating function  155   a  is configured to generate the second feeling information by estimating a feeling experienced by the evaluator, on the basis of the third nerve activity information. For example, the second feeling estimating function  155   a  is configured to project the feeling specified by the third nerve activity information with the use of the feeling decoder, onto the two-dimensional distribution diagram of the onomatopoeia. As a result, the second feeling estimating function  155   a  is able to specify an onomatopoeia suitable for the evaluator. After that, the second feeling estimating function  155   a  is configured to generate the second feeling information having the specified onomatopoeia. 
     A searching function  156   a  is configured to search for the presentation information to enable the evaluator to experience the feeling of the subject. More specifically, when the degree of similarity between the feeling of the subject and the feeling of the evaluator is lower than the threshold value, the searching function  156   a  is configured to search for the presentation information that makes the degree of similarity between the feelings equal to or higher than the threshold value. For example, the searching function  156   a  is configured to calculate a degree of similarity between the projection position of the feeling within the two-dimensional distribution diagram that is specified by the onomatopoeia corresponding to the first feeling information and the projection position of the feeling within the two-dimensional distribution diagram that is specified by the onomatopoeia corresponding to the second feeling information. Further, when the degree of similarity between the feelings is lower than the threshold value, the searching function  156   a  is configured to search for the presentation information that makes the degree of similarity between the feelings equal to or higher than the threshold value. In other words, the searching function  156   a  is configured to search for the tactile information to be presented to the evaluator via the tactile device. 
     Every time the searching function  156   a  finds presentation information in a search, a presenting function  157   a  is configured to present tactile information to the evaluator via the tactile device. 
     The notifying function  158  is configured to issue a notification when the degree of similarity between the feeling of the subject and the feeling of the evaluator becomes equal to or higher than the threshold value. As a result, the evaluator is able to recognize that, as for the tactile sensation, his/her feeling is substantially the same as the feeling of the subject. 
     As explained above, the medical information processing apparatus  1   a  according to the second embodiment is configured to obtain the first nerve activity information from the subject to whom the tactile stimulation is given. On the basis of the first nerve activity information, the medical information processing apparatus  1   a  is configured to estimate the first feeling information indicating the tactile sensation experienced by the subject. Further, on the basis of the first feeling information, the medical information processing apparatus  1   a  is configured to determine the presentation information to enable the evaluator to experience the tactile sensation of the subject. Accordingly, the evaluator is able to perform a diagnosis process or the like, while experiencing the tactile stimulation felt by the subject. In other words, the medical information processing apparatus  1   a  is capable of presenting the information that makes it possible to experience the feeling of the subject. 
     Further, instead of the tactile information, the presenting function  157   a  may present the onomatopoeia as the presentation information. The second feeling estimating function  155   a  may project the feeling of the subject onto the two-dimensional distribution diagram of the onomatopoeia of the evaluator, by using the first nerve activity information and the first feeling information. After that, the second feeling estimating function  155   a  may specify an onomatopoeia of the evaluator positioned closest to the projection position of the feeling of the subject in the two-dimensional distribution diagram of the onomatopoeia of the evaluator. As a result, the second feeling estimating function  155   a  is able to replace the onomatopoeia of the subject with the onomatopoeia of the evaluator. Further, the presenting function  157   a  may present the replacing onomatopoeia of the evaluator as the presentation information. In this situation also, the evaluator is able to simulatively experience the feeling of the subject. 
     Further, the onomatopoeia was explained above as an example of a method for quantifying the touch. However, instead of the onomatopoeia, other methods may be used for quantifying the touch. The touch may be quantified by using a Face Rating Scale (FRS) with which the intensity of a pain can be determined on the basis of a facial expression of an individual. Alternatively, the touch may be quantified on the basis of a pain detect sheet, which may be used in medical interviews of individuals. It is also acceptable to quantify the touch by using other methods. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.