Keywords

1 Introduction

Recently, depression has caused serious problems and attracted extensive attention in our society. According to WHO statistics, the number of suicide deaths per year is estimated 1 million due to depression. By 2020, depression might become the second largest disease after heart disease.

Traditional depression diagnosis methods are based on the scale examination [1], blood biochemical examination [2] and imaging examination [3]. In addition, many experts developed the software of the Beating the Blues (BTB) for diagnosis and treatment of depression. Although the used methods have been helpful, they have some fundamental problems, such as stigma, arbitrariness and distraction. Whereas the VR technology could provide patients an immersed experience and improve the accuracy of interrogation.

In the aspect of psychological disease treatment, psychologists use VR scenes to trigger the emotion of the patients, such as claustrophobia [4], acrophobia [5], flying phobia [6], spatial neglect disease [7], eating disorders [8], post-traumatic stress disorder [9], male sexual dysfunction [10], relieve pain [11], schizophrenia [12]. In cross research area, “computational psychiatry” had grown up, which could use some new technologies like artificial intelligence, virtual reality and deep learning techniques to treat mental disease [13]. However, the current research mainly focuses on the process of mental treatment, and explores the physiological and psychological mechanisms of disease. However, the VR depression diagnosis has not yet been carried out, as well as the mechanism research.

In conclusion, according to the related research at home and abroad, the research of depression diagnosis based on virtual reality technology is less concerned. In this study, we design the personalized VR depression scene and interactive diagnosis models which can early identify the patients’ disease and improve the efficiency of diagnosis.

2 VR Scene Design Element Analysis

The elements of VR scene design, which are both conventional and personalized, are critical for the success of this study. They are symbols of emotions and meanings. So a reasonable design of content and form is of particularly importance, which directly influences the level of user experience and affect whether user can answer questions objectively and easily. Therefore, in the design of VR scene, we should follow the design principle of user experiences and balance the relationship between aesthetics and function in order to achieve good diagnosis results. In terms of design of VR scene for depression diagnosis, this paper first conducted a literature research, then analyzed on space design, role design and interactive technique.

2.1 Space Design

Space Decoration.

Pressly and Heesacker [14] suggested that it was important to make environment more appealing and comfortable by decoration. The appealing environment can allude to counselors’ personality and character, and can increase feelings of ownership for patients. Designers should consider surrounding the counselors with accessories that are visually pleasing to patients (e.g. family pictures, artwork and objects that are meaningful and attractive). Research also indicated that plant could have a positive effect on some patients who were sick or old, because it symbolizes vitality, growth and regeneration.

Gass et al. [15] found that the first impression of counselors’ attire and seating was highly related to the willingness of the patients. The scene of consultants with casual clothes in the room without any desk would be attractive to patients. In contrast, consultants sitting behind the desk with formal clothes always be perceived as experts. But females would give a lower score to consultants sitting behind desk.

Space Color.

In psychological counseling space, consultants were advised to choose different design rooms for subjects based on age and gender [16]. The research shows that bright colors are accompanied by positive emotional expression for children and young people, while dark colors are accompanied by negative emotional expression. Therefore, it is recommended to use pink wall colors instead of dark ones, and the colorful walls and highly bright ceilings are more suitable for children. Blue is one of the most popular colors for young people and elderly. Next is green and red in turn.

Space Light.

Comparing with bright light, dim light is easier to make the counselees relaxed in the psychological counseling room, and more favorable to expose themselves. The research on psychophysics and environmental psychology have evaluated the relationship between light intensity and task productivity, revealing the personal perception of light and their views on the environment. For instance, the researchers have found that participants held more positive perceptions for a task and reported decreased boredom in a room with windows than that without windows.

2.2 Role Design

Gender Setting.

The role of psychological consultant needs to be more genial with subjects. The famous feminism psychologist Gilligan suggested that females have often been a caregiver that put the relationship and the care of others on the significant position. Compared to male, female is more suitable to be a psychological consultant. A research about the attitude of college freshmen towards psychological consultation indicated that the female is more favored than the male by the respondents [17].

Suits Setting.

Heitmeyer and Goldsmith [18] found that the requirement for consultants clothing style was between formal and casual. Hubble and Gelso [19] noticed that counselees prefer the consultants with formal clothes. Kerr and Dell [20] suggested that professional attire would help the consultants make a professional judgment; if not, it would take an attraction judgment on it. The research indicated that the professional comment on counselors were not only influenced by clothing but also by role. Bailey-Hamptom [21] investigated more precisely the influence of clothing. He noticed that the subject’s evaluation of the consultant in education, knowledge, experience and compassion presented of the following order: “traditional attire > informal attire > casual wear”.

2.3 Interactive Technology

Besides visual interaction, we mainly apply voice interaction. Voice interaction is the core of the depression diagnosis system. The diagnosis questions can be transformed into voice information and delivered to counselees. The elements of voices include volume, tone, speed and timbre.

Sausure, the father of modern language, in his book: Cours de linguistique générale, recorded the psychological attributes of voice, and pointed out the concept of “sound image”, that is the psychological feeling of voice. The psychological attributes of voice mainly are reflected in the two basic psychological processes of voices delivery and voices perception. The measurement of speed is the number of syllables per second. Different consulting speed would result in different time pressure, lead to a diverse counseling effect. Bass music reduces θ wave activity and increases α wave activity, which is good for relaxation and concentration. High volume helps activate arousal levels, but may lead to distraction. Low speed is more conducive to network consultancy than high speed [22]. According to [23], the network interrogation had a better effect on reducing the subjects’ anxiety by using 60 dB and low speed 160 words/minute than using high speed and high volume.

3 Development of Virtual Reality Diagnosis Scene

3.1 Scene Development Process

The development of virtual diagnosis scene is divided into three parts: material design, interaction design and the output, as shown in Fig. 1. Main components of the development process are detailed as follows:

Fig. 1.
figure 1

Schematics of VR scene development process.

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3.2 Doctor Material Design

There are mainly two methods of doctor material design. The first method is role model after investigation of a doctor’s countenance and behavior at the hospital. The advantage is that the character’s style can be freely defined by designers. But the character design requires a good aesthetics basic, which takes a long time to complete the sketches, map design, texture, character dubbing and mouth shape design etc. The second method is shooting the human characters, then importing it into the VR engine. The role of the character is similar to real diagnosis environment with a higher shooting efficiency. But the role image, language and gesture are defined, which requires coordination with the virtual scene. In this paper, we adopted the role shooting method and specific requirements are shown in Table 1 and Fig. 2.

Table 1. Role requirements.
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Fig. 2.
figure 2

Postures of questioning (a) and recording (b) of the doctor.

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3.3 Diagnosis Space Design

Space design can be divided into two methods. The first method is simulating the virtual scene according to the design requirements of the actual diagnosis room. The advantage is that the size, light and ornaments of the diagnosis room can be designed freely. But the design needs good aesthetic skill during the sketch design, effect diagram design, mapping, baking design and other design steps. The second method is utilizing existing 360° spatial material provided by the engine store of Unity 3D (Unity is the ultimate game development platform developed by Unity Technologies). In this paper, we use 360° spatial material complemented by 3D plants to adjust the spatial extent of the brightness so as to fit our requirements for the diagnosis environment. Specific requirements are shown in Table 2 and Fig. 3.

Table 2. Space design requirements.
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Fig. 3.
figure 3

Snapshot of the designed scene.

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3.4 Audio Material Design

Audio material includes the following aspects: starting sound, sound in resting state, sound in diagnosis, special sound for encouragement, and ending sound. Specific contents are shown in Table 3.

Table 3. Audio material.
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3.5 Interface Design

Before we began interface design, we established the flow chart of the diagnosis system as shown in Fig. 4. Then we have established a VR system based on the DPVR (give company name related to this device) device and Unity engine for the purpose of depression assessment, which is described as follows. In the Welcome scene (Fig. 5a), a cursor is indicated which will rotate with the head’s rotation in order to enhance user interaction. Then it will go to the Resting scene (Fig. 5b) where a green grove shows up. At the same time, low volume music Sound Of Silence will be played to lead users to a relaxation state before real test. After that, it goes to a Test Reminding scene (Fig. 5c) and fades away into a Q&A Demo scene (Fig. 5d), where a demonstration is shown to the tested subject on how to answer questions. The place is a quiet and comfortable room with a large sofa placed in a half rectangle and bookshelf full of colorful books and bright windows in the background. After the Demo section is finished, the real testing session (Fig. 5e) starts where a female doctor of 25 years old appears at a position on the golden section of the left side. On the right side it is the text part including questions and answers. After a question is played, the subject need to answer in his/her own voice. This answer is automatically recognized by natural language processing embedded in the VR device. Then the chosen answer is partially flashed to attract the attention of the subject. After all the questions are answered, the scene goes to the End stage (Fig. 5f) with a title of thanks shown to the subject for his/her participation in the study.

Fig. 4.
figure 4

Flow chart of the diagnosis system.

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Fig. 5.
figure 5

The designed VR interface showing different stages in the assessment of depression (see text for the detailed description of different sub-figures)

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4 Experiment and Results

4.1 Experiment

We designed a survey to test user experience of the designed VR scene. 10 subjects (5 males and 5 females, age: 21–37 years) were recruited for a questionnaire test.

We set up a user experience questionnaire containing 8 topics, including the effectiveness, efficiency, attractiveness, ease of learning and human-computer interaction of VR scene design. A No from 1 to 5 is given to indicate the user’s satisfaction to each item with 3 meaning general, 1 meaning dissatisfaction and 5 meaning satisfaction. The subject was asked to fill the user experience questionnaire after a test was conducted using the design VR depression diagnosis system.

4.2 The Result

Table 4 illustrates the content of the questionnaire and score obtained from each tested subjects.

Table 4. The content of the questionnaire and score.
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The experimental results show that the user experience was generally quite good. The score of satisfaction is over 3 points. The visibility of doctor’s position obtains the highest score. The lowest is naturalness of the scene, mainly affected by the coordination between the human doctor and the virtual scene.

5 Conclusion

In this study, we have successfully designed interactive scenes for depression assessment in VR environment, following a specific route of design element analysis. Preliminary normal user assessment confirmed good user experience. In future work, a clinical trial will be conducted to verify the effectiveness of the system with targeted subject population, and long term research is needed to investigate the emotional interaction design and graphical visualization in order to improve its user experience in patient test.