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    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>IVAMED: Intelligent Virtual Assistant for Medical Diagnosis</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Dana Gallent-Iglesias</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Santiago Serantes-Raposo</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Iñigo López-Riobóo-Botana</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Sonia Gonzalez-Vázquez</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Pablo Manuel Fernandez-Graña</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Instituto Tecnológico de Galicia - ITG - Centro Tecnológico Nacional</institution>
          ,
          <addr-line>Cantón Grande 9, Planta 2, 15003, A Coruña</addr-line>
          ,
          <country>España</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>The recent advancements in deep learning have led to a myriad of approaches for medical diagnosis and assistance. Some topics such as data labelling, data curation, human-in-the-loop, explainability or privacy-preserving methodologies are hot topics for applied machine learning in the healthcare context. In this domain, we normally expect a three-way interaction (doctor-system-patient), so that interfaces play a crucial role. Remotely managed VR (Virtual Reality) systems help us to enhance communication and feedback between doctors and patients in situations where in-person assistance is not feasible. Moreover, the recent breakthroughs with LLMs (Large Language Models) enable us to use natural language as additional interface, considering NLU (Natural Language Understanding) for intent recognition, ASR (Automatic Speech Recognition) and TTS (Text-To-Speech). In the context of the CEL.IA network, we present IVAMED (Intelligent Virtual Assistant for MEdical Diagnosis), a chatbot-oriented application in a VR environment for remote medical assistance. We tackle the situation in which face-to-face assistance is not possible. We provide the tools for remote interaction and guided diagnosis. We propose the evaluation of the MoCA (Montreal Cognitive Assessment) test for early detection of MCI (Mild Cognitive Impairment) and the BDI (Beck Depression Inventory) test for measuring characteristic attitudes and symptoms of depression.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;IVA</kwd>
        <kwd>VR</kwd>
        <kwd>chatbot</kwd>
        <kwd>Rasa</kwd>
        <kwd>medical diagnosis</kwd>
        <kwd>healthcare</kwd>
        <kwd>BDI test</kwd>
        <kwd>MoCA test</kwd>
        <kwd>NLU</kwd>
        <kwd>ASR</kwd>
        <kwd>TTS</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>cedures and preventive measures, which can empower
patients to take better care of themselves [9, 10]. Chatbots
In recent years, there has been a significant rise in the can also assist healthcare professionals by automating
use of chatbots in the healthcare industry [1, 2, 3, 4]. administrative tasks, such as scheduling appointments
Healthcare chatbots ofer a convenient and eficient way and managing patient records, allowing them to focus on
to interact with patients, providing them with person- providing quality care. The healthcare industry has seen
alised and immediate attention. These chatbots can be significant benefits from chatbots, including reduced wait
integrated into websites or mobile applications, provid- times, improved patient outcomes, and reduced costs.
ing round-the-clock assistance to patients. Additionally, There are several standardised cognitive assessment
the recent advancements in NLP (Natural Language Pro- tools used in healthcare, such as the MoCA (Montreal
cessing) have led to the development of LLMs (Large Cognitive Assessment) [11] test and the BDI (Beck
DeLanguage Models), which can understand the nuances of pression Inventory) [12] test. These tests are used to
human language and generate responses that are contex- evaluate cognitive and emotional functions, which can
tually appropriate. aid in diagnosing and treating various conditions. MoCA</p>
      <p>Healthcare chatbots [5, 6] can be used for tasks such is a widely used cognitive screening tool that assesses
as symptom assessment or medication reminders [7, 8]. various cognitive domains, such as attention, memory,
They can also provide information on healthcare pro- language, visuospatial abilities, and executive functions.
In contrast, BDI is a self-reported questionnaire used to
measure the severity of depression symptoms.</p>
      <p>VR (Virtual Reality) has been used in healthcare to
improve patient outcomes [13], including pain management
and rehabilitation [14, 15]. VR can provide a realistic and
immersive environment for patients to distract them from
their pain and facilitate relaxation. It can also provide a
safe and controlled environment for rehabilitation
exercises. Chatbots can be integrated with VR technology to
provide personalized assistance during their VR sessions.</p>
      <p>In Section 1.1, we present our motivation to carry out
this project. In Section 1.2 we enumerate our main
contributions. In Section 2, we depict the architecture and
methodology followed for this project, describing our
results in Section 3. Finally, we conclude with some
limitations in Section 4 and future work in Section 5.</p>
      <sec id="sec-1-1">
        <title>1.1. Motivation</title>
        <sec id="sec-1-1-1">
          <title>For domain-specific sensitive contexts like healthcare,</title>
          <p>we need to adjust and control the chatbot output
thoroughly. The chatbot-oriented LLMs fit in AGI (Artificial
General Intelligence) contexts and they can be somewhat
“fine-tuned” with prompt engineering [ 16, 17], but this is
not enough for guided and ad hoc ADI (Artificial Domain
Intelligence) systems. Another important point of our
project is the contribution in the development of remote
medical diagnosis tools with VR integration. This enables
us to enhance communication and feedback between
doctors and patients in situations where in-person assistance
is not feasible.</p>
          <p>In the context of the CEL.IA network1, we propose
an IVA (Intelligent Virtual Assistant) integrated in a VR
environment for remote medical diagnosis. We mixed
the concepts of NLU using the Rasa chatbot framework
with both ASR and TTS modules. All these components
are part of the VR system, which enables the users to
perform the BDI and the MoCA tests. In this paper, we
describe our first demo version, including the dialogue
system in a chatbot-oriented application.</p>
        </sec>
      </sec>
      <sec id="sec-1-2">
        <title>1.2. Contributions</title>
        <p>For this IVA project, our contributions are as follows:
• We integrated a chatbot-oriented application
for remote medical diagnosis in a VR
environment, providing visual interaction with
selection and manipulation strategies to perform
the medical tests (MoCA and BDI).
• We implemented a domain-specific IVA
system with Rasa framework for NLU and
dialogue management.
• We provide both voice and text interfaces to
better communicate with the chatbot, so that
we can use spoken language in Spanish (ASR), as
well as listen to the answers (TTS).</p>
      </sec>
    </sec>
    <sec id="sec-2">
      <title>2. Methodology</title>
      <p>
        We designed and implemented the following modules:
• NLU subsystem: In charge of the intent
recognition NLP task. Rasa projects follow a data-driven
approach, providing several files with text
samples for each intent and configuration files to
adjust the pipelines for model training.
1https://www.redcelia.es/
• Dialogue module: Relies on a combination of a
rule-based system and a “user stories” mechanism
to infer the next action in the conversation. These
actions can be (
        <xref ref-type="bibr" rid="ref1">1</xref>
        ) direct chatbot responses or (
        <xref ref-type="bibr" rid="ref2">2</xref>
        )
delegations in the SDK action server.
• ASR module: We have integrated a speech
recognition module, which allows us to convert from
audio to text and transmit it back to the chatbot.
The text is then analysed by the NLU module and
a response is generated by the Rasa dialogue
system. We leverage the Spanish stt_es_citrinet_512
model from the NVIDIA NeMo toolkit2.
• TTS module: After receiving the response from
the chatbot, we convert the text output back to
human voice, making it convenient to engage
with the IVA system. We made use of the
Spanish glow-speak:es_tux model from the OpenTTS
framework3.
      </p>
      <sec id="sec-2-1">
        <title>The general diagram of the IVA system is depicted in Figure 1. In Section 2.1, we study in more detail the NLU training pipeline for the chatbot and in Section 2.2, we summarise the VR system integration.</title>
        <sec id="sec-2-1-1">
          <title>2.1. NLU pipeline</title>
          <p>We used some of the Rasa components to train the model
[18]. We configured diferent pipelines, replacing the
feature extractor component and preserving intact
the rest of them:
1. Tokenizer: Rasa component in charge of
splitting each sentence into tokens or words. We used
the simple WhiteSpaceTokenizer to get the tokens
splitting using white spaces.
2. Feature extractor: Rasa component in charge of
feature engineering to transform the
corresponding tokens into numerical vector representations.
We made use of several feature extractors. We
provide all the details in the experimental Section
3.
3. Intent classifier : Rasa component in charge of
the intent recognition NLP task. We used the
DIET classifier from the Rasa framework authors
[19]. DIET is a multi-task modular transformer
architecture that handles both intent
classification and entity recognition together. It provides
the ability to plug and play various pre-trained
embeddings like BERT (and variants), GloVe,
ConveRT, among others [20].
4. Fallback classifier : This Rasa component is in
charge of triggering the default intent when the</p>
        </sec>
      </sec>
      <sec id="sec-2-2">
        <title>2https://catalog.ngc.nvidia.com/orgs/nvidia/teams/nemo/</title>
        <p>models/stt_es_citrinet_512
3https://github.com/synesthesiam/opentts#voices
intent prediction from the DIET classifier does not
have a confidence above a pre-specified
threshold. If so, the default intent will diverge from the
regular conversation, following a custom action
for managing the unexpected input.</p>
        <p>Nowadays, the most amount of NLP approaches are
end-to-end and avoid the feature extraction step
[21]. However, we are following a more classical
approach since we do not have enough data for an
end-toend fine-tuning process with transformer models.
Moreover, relying on multilingual deep word embeddings as
the input features for the DIET classifier has some
advantages, considering that this model outperforms fine-tuned
BERT and is about six times faster [20].</p>
        <sec id="sec-2-2-1">
          <title>2.2. Immersive interface</title>
          <p>We can highlight the following two main features:
1. VR environment for medical diagnosis and
cognitive tests: The interface for the cognitive
tests (MoCA and BDI tests), as well as the other
generic UI (User Interface) elements, make full
use of the Babylon.js framework, which provides
support for the WebXR standard to develop
immersive web experiences, deployable on
dedicated immersive hardware or web standard. The
majority of the UI elements have been
implemented as virtual objects within a 3D
environment running inside an HTML canvas on the
web page. This approach facilitates the switch
between a traditional 3D web application with
WebGL and an immersive environment with WebXR.
Additionally, the scene includes the avatar for
the IVA system with a recording button through
which audio can be sent to communicate with the
conversational IVA and answer to the cognitive
test questions (see Figure 2).
2. Remote assistance service: The diagnosis
system integrates a service that the healthcare
professionals can remotely control to evaluate the
cognitive tests the patient is carrying out. This
service has been built on the Colyseus
framework4, an open source project that provides tools
for the implementation of multi-user online
experiences. This functionality allows the
healthcare professional to create a shared online
environment, where a 3D scene of a virtual clinic is
loaded. From this virtual space, the doctor has
access to a menu where he/she can select the
cognitive test to be loaded on the scene and to be
performed by the patient. Then, the professional
can use this virtual space to visualise patient’s
progress within each test in real-time. For
instance, when the patient is asked to draw a clock,
the doctor can observe the drawing’s progression
in real-time (see Figure 3).</p>
        </sec>
      </sec>
      <sec id="sec-2-3">
        <title>4https://www.colyseus.io/colyseus</title>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>3. Results</title>
      <sec id="sec-3-1">
        <title>We trained a text classification model for intent recognition to carry out the BDI and MoCA cognitive tests, and so we did for assistance generating a medical report, the three functionalities included in the health demonstrator.</title>
        <p>
          We conducted tests with diferent configurations
for feature extraction in the NLU pipeline, following
two diferent approaches:
1. Traditional feature extractors: We made use
of (
          <xref ref-type="bibr" rid="ref1">1</xref>
          ) lexical/semantic-based feature extractors
to generate shallow feature vectors, (
          <xref ref-type="bibr" rid="ref2">2</xref>
          ) regex
and pattern-based feature extractors to
generate binary vectors according to the pattern being
present or not and (
          <xref ref-type="bibr" rid="ref3">3</xref>
          ) Bag-of-words vectors
with 1-grams words and 4-grams characters [22].
2. Pre-trained language models feature
extractors: Based on the transformer architecture for
obtaining deep word embeddings. We considered
the models BERT (Spanish monolingual version)
[23], DistilBERT (multilingual version) [24],
XMLRoBERTa (multilingual version) [25] and GPT-2
(Spanish monolingual version) [26].
        </p>
      </sec>
      <sec id="sec-3-2">
        <title>For the intent classification task, we used the DIET clas</title>
        <p>sifier [ 20]. We compared the results obtained following
the two aforementioned feature extraction approaches,
defining 5 diferent configurations: BERT, DistilBERT,
GPT-2 and XLM-RoBERTa for the pre-trained language
models feature extractors and the “No model”
approximation for the traditional feature extractors. We followed
a 4-fold cross-validation. We computed the macro
average for the f1-score, which summarises the recall and
precision metrics of the intent classifier.</p>
        <p>Intuitively, feature extraction using transformers and
their deep word embeddings should be better. However,
looking at the Figure 4, this is not the case. The highest
macro f1-score value was achieved by the “No model”
approach, which uses the traditional feature extractors. The
classic feature extractors behave better with short and
simple sentences, where the global context is not relevant
and the vocabulary is limited (MoCA and BDI tests for
medical diagnosis). Among the transformer-based
extractors, the worst results were achieved by GPT-2, since this
is a decoder-only transformer model optimised for NLG
(Natural Language Generation) tasks rather than for NLU
classification tasks. It is worth mentioning that the best
transformer approach was DistilBERT, the light-weight
encoder-only model needing less computing resources,
even outperforming the XLM-RoBERTa model for feature
extraction.</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4. Limitations</title>
      <p>Some problems could arise when using our chatbot
implementation:
• Rasa Knowledge base: Due to the data-driven
nature of Rasa, any new example must be
manually added to the knowledge base and,
consequently, it is required to retrain a new model
including the changes in the NLU pipeline.
• Traditional feature extraction vs deep word
embeddings: As it was exposed in the Section
3, the simplicity of the sentences expected by
our chatbot favours traditional feature extractors
over transformers and deep embeddings. Using a
language model limits the chatbot performance if
we are not considering an end-to-end approach
with a fine-tuned model for the NLU task [21].
• Similar intent classification : Although this
limitation was mitigated implementing
similarity scores (in order to match each user input to
the most reasonable answer for each medical test
slot), the chatbot still occasionally struggles with
classifying intents when the sentence is almost
identical to an example from another intent.</p>
    </sec>
    <sec id="sec-5">
      <title>5. Conclusion and future work</title>
      <sec id="sec-5-1">
        <title>In this work, we present IVAMED, a chatbot-oriented</title>
        <p>IVA application for medical diagnosis in a VR
environment with ASR, TTS and web interfaces. We included a
dialogue system capable of guiding the user to perform
each of the medical tests and get a result. We made use of
the Rasa framework and proposed several NLU pipelines
for intent classification.</p>
        <p>In the near future, we want to explore some NLU
improvements following an end-to-end approach with
a fine-tuned intent classifier based on
transformerencoders. In this way, we will avoid the current feature
extraction step in the NLU pipelines. We are also
exploring data augmentation techniques to increase the
number of samples for each intent, leveraging LLMs and
cross-language translation models.</p>
      </sec>
    </sec>
    <sec id="sec-6">
      <title>Acknowledgments</title>
      <p>This project belongs to the CEL.IA network initiative5,
which is supported by the Ministerio de Ciencia e
Innovación through the CDTI (Centro para el Desarrollo
Tecnológico Industrial) (grant CER-20211022).</p>
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