Keywords

1 Introduction

With the evolution of quantified-self tools, smart devices and mobile applications, we are now entering a new era which can be described as that of ‘Modern Wellbeing’. Modern wellbeing pertains to the extensive adoption of new technologies that track different facets of our lives and activities over time, resulting in varied impacts on our bodies, minds, our environment and our communities [40]. The abundance of data that such technologies generate can serve a variety of purposes and fusing such data can provide new and often unexpected insights.

By combining a variety of all the data that we gather as humans in a digital world, the possibility emerges of creating a ‘Digital Twin’. A Digital Twin refers to a digital replica of potential and actual physical assets (physical twin), processes, people, places, systems and devices that can be used for various purposes [12, 19]. A Digital Twin could hold information on different biomarkers, cognitive information, lifestyle and environmental data would give the ability to look at an individual’s well-being in a different way. Such a synthesized artefact opens up the possibility for predictive analyses and early detection of anomalies that occur during the lifecycle of humans.

When creating the Digital Twin, we can map a medical layer and lifestyle layer of individuals. In some ways, we already have such information on a micro and on a macro level. On a micro level, lots of our medical information today is already digitized (MRI’s, radiographies, results of breast cancer examination and so forth). Such information is used to learn and understand the data collected during examinations, to show them to patients and to explain their condition. Such data can also be given to third parties for providing personalized solutions and services, e.g., it can be shared with a manufacturer in case a tailor-made prosthesis needs to be made for example. But Digital Twins can also be more commonplace and mundane than this example might suggest. More familiar and popularized is self-tracking with mobile applications and wearable devices, which is quite pronounced in relation to the whole Quantified Self phenomenon. Even on a macro level, we can conceive Facebook as a coarse grain Digital Twin, capturing parts on what we do, who we are. Considering systems supporting a Digital Twin applies also for several other applications that are available in the social media space and used extensively [44].

Digital Twins can be used to serve a variety of purposes resulting in valuable societal benefits but could lead to negative consequences as well. In the health domain the potential application of Digital Twins for predicting health conditions could result in substantial cost savings for the healthcare system and improving the effectiveness of health interventions. For patients this could lead to improved quality of life, e.g., by keeping patients longer in their own environment, avoiding premature hospitalization, especially since smart devices and mobile applications getting more and more financially affordable.

The smart home today looks very different from the smart homes from years ago. With the introduction of Internet of Things (IoT) these ‘smart devices’ or ‘smart objects or things’ can be equipped with Natural User Interfaces (NUI), which makes them more accessible and easier to use. Interacting with these ‘smart things’ can combine voice, gesture, motion or touch; these new ways of interacting with smart objects come very natural to humans to use. It also broadens the discussion of the embodiment and the social relation humans develop with these new digital technologies [27].

Discussing the opportunities this technological trend offers is one thing, but equally imported are the possible negative aspects, the socio-political impact it has on the individual and society as a whole. One of the consequences of Digital Twin concepts is that it could lead to surveillance resulting in social sorting of a population, changing policies based on the social sorting and the data that is gathered by individuals, resulting in inequality in certain populations [28, 30, 32]. On an individual or patient level, it can create empowerment for the patient but at the same time disempower them. Self-tracking asks for self-discipline, self-examination and as we will see further, individuals have to have the means and the knowledge to engage in managing one’s health through assistive digital technologies [25, 48]. In this paper, we would focus our research on the affordance [15] of these technologies and how these technologies are appropriated. We aim to get insight into how older adults make sense of the new technologies in their everyday life [27] and to answer the following research questions:

  1. 1.

    To which extent do technologies such as wearable device and mobile applications, leading towards a ‘Digital Twin’ concept within preventive and predictive healthcare give human enhancement towards personal healthcare?

  2. 2.

    How do elderly users handle or think about the data they (might) gather?

  3. 3.

    How do they give meaning to their gathered data?

  4. 4.

    How will different stakeholders within the healthcare and care giving organizations be organized around the concept of a Digital Twin.

The research methods we will use are first a literature review on related work and in depth-interviews with 8 individuals, more specifically boomers (1946–1964), 60+ and 70+, mixed gender and mixed education, but predominately higher educated boomers living in Belgium. In addition, we interview 3 stakeholders in the care cycle of elderly people, a general practitioner, CEO of a caregiver’s platform and an MRI radiologist.

2 Related Work

2.1 From Data Selves to Digital Twins

In 2007 Gary Wolf and Kevin Kelly founded the Quantified Self Movement, with the stated aim to explore what these new self-tracking tools could mean on a human level. Today self-tracking has become mainstream and is entering in different areas of our lives. Self-tracking is very promising for preventive healthcare solutions and healthcare in general. Furthermore, with the rise of ‘smart objects’ or ‘smart things’ internet of things in general, we can evolve to a connected self. In these environments, humans are gathering and measuring a mass of data for themselves but also for others. These technologies could enhance human lives as we surround ourselves with the new knowledge about our bodies but also in a broader sense, as the way we live, our lifestyle and our surroundings are mapped and digitally modelled.

Such data might allow us to have more detailed self-knowledge and allow for optimization of a variety aspects of our human existence and experiences. We can have at easy reach information about our health status, our physical activity, our mental well-being, our environments we live in, in fact we have the opportunity to create a better self of ourselves with the help of these assistive digital technologies. Today scholars discuss the emergence of humans akin to ‘walking sensory platforms’ [47] or ‘data selves’ [31], referring to networked humans, the ‘networked self’, it extends the discussion of self-tracking humans. As humans today are engaging with digital technologies in different ways on a variety of platforms, mobile applications and lately with ‘smart objects’ and ‘smart things’. The discussion extends on the level of embodiment and the social relation humans have with these digital technologies, on a micro and macro level. These scenarios are leading towards the idea or the notion of a ‘Digital Twin’ of ourselves. The concept of a Digital Twin refers to a digital replica of potential and actual physical assets (physical twin), processes, people, places, systems and devices that can be used for various purposes. The data is a live, it is ‘lively data’ [29], we could look at this as human-data assemblages, which goes beyond quantifying ourselves. Human-data-assemblages according to Lupton, are created through the interaction and encounters humans have during their life cycle with software, digital platforms, devices and other humans in time and space. In the next topic we will look what a possible Digital Twin could mean for seniors and aging in place. Further in our research methods we use a cultural probe (Fig. 2) to illustrate a possible example of a Digital Twin concept.

2.2 Aging in Place

In the ‘city of people’ project a ‘Hello Jenny’ living lab research project was launched in Ghent. Twelve seniors received a ‘smart speaker’ and a sensor to monitor how frequently the front door goes open and closed to check how many visitors seniors have during the day. When it is detected that the door hasn’t been opened a lot, Hello Jenny, the smart speaker gets a signal. The speaker will ask if the senior wants to have a visit to have a little conversation or to do a walk, to play some cards or other socializing events or activity. The senior can then push a button ‘yes or no’. A buddy gets a message through messenger in the pilot project, the buddy types when is a good moment to come over for a visit, the sentences are converted to speech and the senior gets the message through the smart speaker. The senior can then again push yes or no, and the visit is confirmed [22] (Fig. 1).

Fig. 1.
figure 1

Hello Jenny, prototype © Michiel Devijver [22]

Fig. 2.
figure 2

Digital Twin notion

As aging in place [51] today is an important evolution in our society today [52] mainly because elderly want to stay at their home longer and postpone the transfer to a care home, but also because care homes want to postpone the entrance of elderly people to cut costs [18]. The ecosystem of care services is changing and is preparing for the elderly aging in place. To fulfill the promise of aging in place, it is important that elderly people can rely on the community they live in and the necessary resources to live independently. Resources for aging in place have been researched in recent years by scholars on different levels. A large body of research has been done on smart homes [20, 36], but also for the daily domestic tasks, new digital technologies arise [5], doing groceries today can be organized online and delivery at home is already a widespread practice. Furthermore quantified-self tools are also entering the aging population, the emergence of ‘quantified aging’ [33].

Several living labs and experiments done in quadruple helix models, stimulate that process in investigating how technologies possibly could facilitate aging in place [22, 23, 26 48]. In addition, research is showing that the adoption of new digital technologies within the older population is growing, especially with the baby boomers [41]. Given enough time, these assistive digital technologies will become more popular as user-interfaces will get more user-friendly and more intuitive like we already see in the Natural User Interface of today. Humans can be expected to interact with newer digital technologies by voice, gesture, motion and touch. Furthermore, as all these ‘smart devices’ and ‘smart things’ are connected to each other, overviews can be aggregated into dashboards or in Digital Twins. The usage of assistive digital technologies can give overviews on a daily, weekly or monthly basis or when needed. Data logs can help the caregivers who work and service the elderly population in getting deeper insights of the day to day activities of the elderly. Below we return to the notion of the Digital Twin and look at the different aspects on how a Digital Twin could be built, what the possible motivation could be for feeding the digital twin with data and how this could affect the future caregiver and healthcare eco systems in general. We also consider whether one or more Digital Twins should be supported.

2.3 Digital Twins, a Connected Self

This is not a Black Mirror episode but let’s look at the Digital Twin as a connected self, a sidekick of yourself. As humans move around, do different activities, travel, are active in different work settings and live different lifestyles, one can imagine Digital Twins to have different categories in the Digital Twin that are in relation with each other. For example, a medical layer, a lifestyle layer, a home and a workplace layer. A Digital Twin could potentially simulate health risks on a longer term, help athletes to get more insights in their training schedules, risk management at work, get more insights on performance and productivity and all this on a micro but also on macro scale, on society as a whole [44]. One would get also more insight in the aging process and how to facilitate this process towards ‘dignified’ aging. Or creating or working towards ‘a better you’. One of the interviewees mentioned: ‘it would be great to have a view on an ideal Digital Twin of oneself and get advice on how you would be able to get there’, considering the abilities of the individual. As we will see in our findings, security will be very important if we evolve towards a Digital Twin. Briggs worked on the notion of a Biometric Daemon, authentication system through an electronic pet. The electronic pet not only provides possible secure ways to authentication, but at the same time can develop a relationship with its owner. The more the biometric daemon is nurtured by means of the behavior (conversation, familiar behavior, idiosyncratic movements) of the owner who is identified with the Biometric Daemon, the more they will bond with each other and develop an intimate relationship. Briggs also suggest that the Biometric Daemon will be unhappy when it is separated from its owner and eventually will die if separated to long from its owner. ‘Daemons have a number of interesting properties. They are animal in form but share an identity with their owner – and exhibit an intimacy based upon seamless communication of a shared emotional state. Any separation between daemon and owner will result in the death of the daemon’ [4]. The Biometric Damon is a dynamic object, capable of adapting. This means that overtime the Biometric Daemon can adapt based on the owners behavior, it becomes a digital companion, a sidekick of yourself with the capability to become a personal coach, a companion in a secure way, because of its biometric features of identification and authentication, a Digital Twin could be born.

The notion that a Digital Twin could be materialized as a social robot, like the example of a biometric daemon we discuss here, brings us also to research that has been done on how older adults perceive social robots as companions. Most of this research has been done in controlled environments like care centers [6, 24, 35]. These studies show a positive outcome in general, however it is still early days in the field of social robots.

If we think further about these robotic technologies and the empathy they give to older adults in this case is maybe also worrying. While these technologies know what our preferences are after a while, what we like to eat, what physical activity we like, what our daily habits and routines are, do they also know what they mean? Can we actually have a dialogue that goes further than the coded dialogues, even when AI is deployed? If one relates this back to the quantified self, the feedback we get from those technologies are very blunt and don’t show any empathy at all. They just report facts and figures [43]. They will never ask the question ‘why you haven’t run for a week’ or even considering context around ‘the why you haven’t run for a week’.

Turkle, speaks of ‘pretended empathy’ as robots don’t really have a past or lived a life, it is all programmed and coded, they don’t have real empathy nor feelings. “What is the value of interaction that does not contain shared life experiences and contributes nothing to a shared story of human-meaning-and indeed may devalue it” [50]? Social robots will challenge us and should make one think about the commitment we can give to the older adults or those who need care in general. One should look at these technologies as enablers and facilitators to create a balance between human commitment and the help of social robots and/or quantified self-tools, in making ‘aging in place’ still human, enabled, facilitated by technology and humans. Let’s explore further the notion of a Digital Twin, what motivates individuals to nurture a Digital Twin.

2.4 Motivation for Feeding a Digital Twin

A Digital Twin needs to be fed or nurtured with data, such as medical data, archived in a hospital, data gathered by approved medical devices, data from lifestyle wearable devices or data from domestic smart devices, individuals have in their home. In the Biometric Daemon example, researchers speak about imprinting and nurturing. Imprinting ‘when it becomes exposed to the identify information of an individual but simultaneously bonds to that individual’. Nurturing is a process where the daemon learns about the individual by conversation, touch and behavior of the owner [4]. The motivation to do this could be found in the reasons for which humans are tracking themselves with wearable devices and other tools that are available today. Within the quantified self-domain, lots of research has been done on the motivations and the reasons why humans are tracking themselves, as well as the negative aspects [9, 10, 12, 45]. The main reasons that individuals track themselves are curiosity, leisure and health. In addition, research shows that there is a lot of drop out with self-trackers, among the main reasons are failure of technologies, individuals track themselves when things are going well, the data is always the same and the effort and time it requires to reflect on the results. If we look further into motivation for health reasons, Gimpel et al. [17] provides a framework of five motivational factors that motivate humans to track themselves.

  • Factor 1: Self-entertainment: motivation because of the pleasure it brings to the self-tracker, this motivation lies into the aspect that the user has fun and enjoyment in using these digital devices.

  • Factor 2: Self-association: the prospect of being associated within a community, ‘community citizenship’. This is less about one’s self, but more ‘how one relates to a community or understanding her or his individualization within a certain environment, self-individualizing aspects within the community. The idea that a self-tracker needs a counterpart to understand him or herself mainly by comparison’.

  • Factor 3: Self-design: motivation by the possibilities of self-optimization. Self-trackers are interested in controlling and optimizing their life, whether they track mood, physical activity or other tracking aspects of their daily life.

  • Factor 4: Self-discipline: motivation due to self-gratification. The self-tracker is more motivated by the prospect of achieving certain goals, getting rewarded, or not being penalized and avoiding negative consequences.

  • Factor 5: Self-healing: motivation by the possibilities of self-healing. The self-tracker doesn’t have a lot of trust in the current health system, carrying some sort of rebellion attitude towards healthcare systems. They want to have a certain independence from traditional healthcare systems. Further research will give more insight why elderly might be motivated to feed their Digital Twin with data.

2.5 Digital Twin and the Environment

As mentioned before, a large body of research has been done on smart homes for aging in place and on Ambient Assistive Living (AAL). However today, IoT (Internet of Things) technologies are entering homes bringing closer the prospect of a smart home, also making it relatively affordable financially and acceptable in terms of usability and user-experience.

Smart homes can be monitored in a detailed way. The smart home can be managed locally but also remotely; it has the potential to detect ‘red flags’, having an alarming function and service providers can be integrated in the whole process, in viewing and controlling their patients from a far. As mentioned before these IoT based systems can be supported by natural user interfaces and the underlying technology can be transparent to end users [11].

The IoT environment is connecting ‘humans to things’, as mentioned before in the human data assemblage [31], ‘things to things’, smart devices talk to each other and there could be an interoperability between them. IoT is also connecting ‘humans to humans’ [22]. One could state that IoT is fulfilling the needs of AAL (Ambient Assisted Living), namely:

  • Monitoring health status of a human in the smart home environment to provide peace of mind for the owner but possibly also for the family, trusted friends and caregivers.

  • The ability to live independently and therefore stay longer in place.

  • Giving a sense of security/safety and the ability to maintain the social network of the elderly, giving the possibility to engage with their community remotely but also in real life [11, 21, 48].

  • Exploring different scenarios with the gathered data, to change or alter data to make simulations, to predict the future in a way with ‘the what if…’ or ‘if this then this…’ scenarios so to speak. In the next chapter we can examine how this could work.

2.6 Digital Twins Integrated in a Healthcare System

Mr. P is 61 years old is in good health and trains regularly and likes to run a marathon at least once a year. His health, sports and physical activity are monitored by his sports doctor on a regular basis. Based on his heart rate (cardiovascular screening), acidification of muscles (musculoskeletal screening) and performance screening, Mr. P gets a forecast of what his performance will be and what kind of sensitivities may arise in his next marathon season. Mr. P relies on the input and output of data to adjust his lifestyle and behavior towards a successful marathon season without injuries.

Mr. D, is a general practitioner, is a type 1 diabetes patient and sports person. He switched towards a glucose system (patch) that gives real time data on his glucose level. Mr. D now has much more insights on his glucose, more accurate. Furthermore, he gets insights on trends of his glucose status. Mr. D now feels more insecure than before. Because he has real insights on his status, his life experience has become different, he has more peace of mind, but at the same time also feels insecure. Mr. D uses these patches for already two or three years as an early adaptor.

Miss C. is 75 years old and has recently suffered a stroke. Today she is surrounded by care givers helping her in her domestic tasks and her revalidation process. This is all scheduled very precisely. Miss C. has a strong community around her, the neighbors, friends and medical care, since one of her family members is a specialist in a hospital. Miss C. sees potential in the Digital Twin concept. She thinks that it could have given her and her surroundings more insight in her bio-medical data, which could have helped her maybe prevent the stroke. In addition, she thinks that she could enjoy more control if the Digital Twin would be easy to use and help her to organize her life, especially with caregivers visiting her today.

These are scenarios derived from real situations that came up during interviews using the thematic analysis method [3] in the first scenario (P1 from the stakeholders participants) bikes on regular basis with his friend and observed him when his friend made the switch from a traditional glucose measuring system towards the new patch system, where his friend now gets real-time data in. The second and the third scenario, were testimonials from the participants P1 and P6, which we will discuss further in our research results. When thinking about Digital Twins, one tends to think immediately about the medical impact it could have. To get more insights on the self through a lens of a ‘virtual self’. As the Digital Twin is a data-driven approach, the power not only lies in the one-person, personalized medicine, but also in the scale of data or big data and give a ‘high resolution’ view on what is the ‘normal or healthy state’ today in a given population.

We’ve been looking in this paper at digital assistive technologies that could give the ability, considering the enablement and constraints or advantages and disadvantages for an aging population to stay longer in place. The notion of Digital Twin looks more at how we can predictively look at an individual and a society as a whole to explore human enhancements or human life extension [7] combining data information on biomedical data information but also lifestyle and behavior data information.

‘…whereas the means used to achieve life extensionfood, physical activityclearly fall into the field of natural remedies, the broader process of scientific acquisition of data and of (social) design of which they are part may turn the process into a form of engineering, and therefore, arguably, of human enhancement. In fact, if the same group of people would obtain the same life extension effect, but this time because they have the financial means to access some complex biotechnological interventions, intuition would probably lead us to classify this as enhancement’ [7], p7.

With the Digital Twin comes new responsibility pertaining to maintaining data integrity, ensuring appropriate access and use of the information it encodes. Achieving these goals raises several questions such as: Where will the Digital Twin reside? Who will have access to it? What are legitimate uses of this information? What are suitable mechanisms for providing consent? Who is accountable for decisions made based on the Digital Twin? Such discussions will inevitably accompany the emergence of the Digital Twin. As mentioned before there are ethical questions to be resolved, among the lines of data privacy, transparency, patient autonomy (human agency and oversight). Governance is needed in the whole discussion to make it transparent, considering accountability as well, to be able to become a trustworthy human oriented technology [2, 8, 46, 49].

3 Research Methods

Our research methods consist in a literature review on ‘Aging in Place’ [51, 52] combined with ‘Digital Twin’ theory in healthcare. In addition, we conducted in-depth interviews with eight boomers (1946–1964), 60+ and 70+, and three stakeholders in the care cycle of elderly people, a general practitioner, the CEO of a caregiver platform and an MRI radiologist.

During the in-depth qualitative interviews’ cultural props [34] in the form of images were used as a conversation starter to explain what a Digital Twin is, without influencing the interviewees too much. The interviews were in verbatim style transcribed, and then analyzed through thematic networks to analyze the patterns [34].

4 Research Results

In-depth qualitative interviews were conducted with a purposive sample, recruited from the Dutch speaking part of Belgium (5 participants) and from the Netherlands (3 participants). The subjects were all 60+ in a healthy condition. However, two of them have had some severe incidents in the past. One of the subjects had a minor stroke in 2018 and another subject could avoid a stroke because of early detection of a blood clot behind the eye. Another subject survived breast cancer. Subjects enjoyed a higher education in general, worked or are still working in a cultural setting and in higher education. In addition, we conducted a stakeholder sample, recruited in Belgium, which contained three stakeholders, one radiologist, specialized in Magnetic Resonance Imaging (MRI) and active in a hospital, one general practitioner and one CEO of a caregiver platform. We used images to start the conversation and to explain the concept of a Digital Twin as none of the interviewees were knowledgeable in the domain of Digital Twin concepts, especially the boomers. Even though some of them gather quite some data for several purposes, they were not really aware of the emergence of the Digital Twin concept in a medical or preventive healthcare environment. We transcribed the interviews in a verbatim style and then used the thematic analysis and thematic network methods [3, 33] to analyze the patterns that occurred in the interviews.

Two sets of questions were conducted, one set for the boomers and one set for the professionals active in healthcare. With the questions we explore how boomers would perceive a Digital Twin and what it could mean for them and what would motivate them to feed a Digital Twin. Furthermore, we also had questions about the preparation for the end-of-life care, considering the presence of the Digital Twin embedded in the life cycle of boomers.

4.1 The Boomers (1946–1964) 60+ and 70+

The Boomers and Motivation for Feeding a Digital Twin

In the in-dept interviews, all of the subjects agreed on the usefulness of feeding a Digital Twin with their medical data and other data if it would help them to get more insights, to adjust lifestyles if needed. Such as eating and physical activity were the most important ones. One subject is already working together with his sports doctor to optimize his results in the marathons and other smaller running events he is running. Together they analyze the possibility for injuries, what his performance could be during a marathon and the diets he needs to follow. One subject was more motivated to do this out of curiosity and at the same time to see how the children possibly could be affected. If their health conditions would be genetically transferred or if it would be more behavior related.

The motivation aspects are in line with the framework of Gimpel [17], more specifically on the factors of ‘Self-design’ and ‘Self-discipline’, as subjects are willing to control and optimize their lives if it helps them and achieve certain goals to get rewarded in a sense of positive influence on their quality of life and not to get penalized or get negative consequences from certain behaviors. Within this perspective is also a self-gratification factor.

A sub question we asked was, if there should be a need to cheat in the data, for example on your diet, drinking or smoking habits. However, none of the subjects were interested to cheat on the Digital Twin, they all agreed it would have no sense to do so. One subject (P2) says ‘no, the Digital Twin is my ‘higher conscious’ as it were. So, if I say that I drink only one glass of wine and I had two glasses, the twin would say you had two glasses’.

Forecasting Diagnoses and Life Expectations

None of the subjects were interested in their life expectations in terms of when they are going to die. One subject (P5) said ‘if I have a severe bicycle accident I could die too, this is all very relative’. One subject (P6) would find it creepy to know about his life expectations through DNA samples for example. Another subject (P2) would find it interesting if there would be a diagnosis of cancer for example, in this case it would be interesting to know whether it is possible to survive it or how many months you still have with a certain cancer diagnosis, this is something that is possible today, but maybe more accurate in the future, considering the possibility of a holistic view through a Digital Twin.

Getting forecasts on certain diagnosis would have an added value for the subjects. All of them would find that very helpful to adjust behavior if necessary and to know what they need to watch in order to keep a good health. For example, to know cholesterol levels or sugar levels would be helpful. Which they already do when they have a yearly check-up, but then it would be more frequently. On the other hand, one subject (P6) mentioned that too much information could lead to inducing behavior, leading towards a restricted life somehow, not a naturel and spontaneous life anymore. Feeling controlled by personal surveillance.

Ethics and Privacy Implications with a Digital Twin

With this question we wanted to explore how the subjects felt about collecting their data as an individual, but furthermore if one looks at a bigger scale on society level or even a certain population, how it could enable social sorting, or even discriminate and exclude a certain population [1, 28].

Most of the subjects are worried about their data privacy on an individual level. If the medical data would stay secured within a hospital or general practitioner, they would not worry but if this would not be the case, it would be a big worry. One subject said (P5) ‘not personally, I have a good job, if I retire I will need downsize a bit, so I’m privileged in a sense. I would not really be worried as long as people stick to the rules’. Another subject (P2) ‘I would not take a Digital Twin if the law on privacy is not in place’. Yet, another one said (P1), I’m am who I am, so no I’m not worried. Then another one was thinking more ahead (P3) ‘I think today it is a general worry how we evolve as a society. You are going to be punished on your behavior and on what you say, it is already happening in some cultures and I see it in ours as well’.

With Whom Would We Share the Digital Twin and Who Owns It?

This question is getting more deeper on how humans in general could or would prepare for the end-of-life. Whom they would trust to hand things over when they are not conscious or not able anymore to decide for themselves. Forms of dementia that might emerge or other critical situation where the subjects cannot decide themselves anymore. Is there a role for the Digital Twin, or who would have access to Digital Twin besides the medical staff?

Most of the subjects see themselves having ownership of the data they produce through the Digital Twin. For some it might be a layered relationship and ownership, where the user gives consent to certain aspects of the Digital Twin. All of them would share the information or give consent to the medical staff where they are in treatment in order to get professional feedback. They would not necessarily share their information with their family when they are in a healthy state but appoint them as trustees in the case they cannot decide anymore for themselves. One of the subjects said (P5) ‘I don’t know if I would trust a Digital Twin that far to make decisions, it is best to have still humans involved in the process and have the ability to discuss things’.

The Concept of the Digital Twin or the Materialization of a Digital Twin

Most of the subjects see the Digital Twin as database combined with an algorithm. There are some variations, subjects see it also as an object, that could be installed at home, some kind of a robot, a social companion maybe that helps you. Others see it as a dashboard on their computer where they have an overview. In some ways it is already available in hospitals in Belgium when you had examinations, but you need to ask for access at the moment.

Another subject finds it difficult to conceptualize it. The subject said (P4) ‘I find it difficult to grasp this. I don’t think I would like a database telling me or nudge me to do things. If I can use a metaphor, for me life is a conversation not a database’. In general, the subjects don’t see the need of having multiple twins, two subjects (P3), (P6) argued that it could be useful if used as a test environment, referring to the control and test groups that were or are being used in research methods today.

Could a Digital Twin help in ‘Aging in Place’?

There was a general positive agreement that the evolution of today’s assistive digital technologies would most probably work for the subjects to stay longer at home. However, this agreement was conditional upon it being user friendly and privacy respecting. One subject argued (P2) ‘Information would be extremely important, how to use it what it holds. I need to be fully informed. I know exactly what is for and how it is used. What I get out of it. So, I don’t want to have surprises. And not that there are some hidden elements, like the hospital can automatically download your data. Or the government can say, people over 80 in a certain region should live there or so and so. That should be absolutely to be avoided’.

Another discussion that came up was: (P6) ‘What does it mean ‘aging in place?’ Maybe we need to go to new ways of living, co-living, what is home? Maybe a new environment, where the soup man comes by to deliver soup, like we had in the old days, or the milkman and the bakery’, a more personal approach.

What Happens with the Digital Twin When You Die?

Today when people die, the access to their medical file is closed and will come to an end, and the relationship with caregivers and medical staff will be ended. However, the medical data stored in hospitals is archived for 30 years according to Belgian law. In this research all subjects would prefer that their Digital Twin dies with them. Either a symbolic burning or a lock down. Some would donate their data for medical purposes on an anonymous basis. In all cases medical data would be archived as the law foresees it today.

The Extra Comments on This Questionnaire

A few subjects made extra comments. Most of them found it an interesting debate really worthwhile investigating this. The concerns they had was on the usability of the Digital Twin concept. How it would unfold and how they could access it. For all of them this was a new way of thinking. One of the subjects said (P4): ‘this is not about data systems but about social systems.’ It is a question of democracy. The question is what is the nature of our society. And the question is what we are going to do about it. These are political debates. Furthermore, the question is what do we do about these oligarchies that run and ruining our lives and rule the world’.

4.2 The Stakeholders

As mentioned before the stakeholders are participants working in a medical environment. Participants are active as CEO of caregiving platform, as a radiologist, specialized in Magnetic Resonance Imaging (MRI) and active in a hospital and a general practitioner.

Motivation to Feed a Digital Twin from a Medical Staff Perspective

According to the stakeholders, the motivation of patients in feeding a Digital Twin were diverse. According to (P1) in order to get patients on board, simplicity would be a key element. For (P1) simplicity lies in the ease of use of devices or software in general. Software or mobile applications should not need a manual, devices have a simple on or off button and so forth, they are simple. In Fogg’s behavior model [13] there are six simplicity components, one of them is brain cycles, this complies to what (P1) is referring to, do users have to think deeply or hard to use assistive digital technologies. (P1) also is convinced that caregivers can have an import role as trustees of the aging population to make them familiar with assistive digital technologies. Most caregivers enjoy the trust of the individuals they visit they are taking care of on a regular basis. For (P2), the motivation lies the potential a Digital Twin could have as a digital personal coach, which functions as an awareness creator, a digital advisor which also could refer individuals to human coaches, such as dietitian or sleep coaches and so forth. (P2) also pointed out that the lifestyle of humans is important to evaluate the whole process of patients. Combined with the medical data one would get a more holistic view on the individual. (P3) argued that the ability to stay longer at home would be a big motivator for individuals, also to avoid illness, but that is difficult to do. (P3) also mentioned that some individuals would not be able to cope with the thought of getting all that information on themselves and that patients already today say no, they don’t want to know all the details on what possibly could happen to them.

The findings of patients not being able to cope with all the knowledge digital data might give, is something that also rises in the second question we discussed. What would a medical staff see as a worry with all the digital data that could come available for the patient through a Digital Twin. Patients would share the data with the caregivers, but whether they are resilient enough to grasp and deal with the information is another question. This is depending on the personality of the patient.

How Could the Ecosystem Work with a Digital Twin?

All the stakeholder participants were convinced that there is a need to have open and uniform standards of all the systems that are in use or will come in use in the future. This is not an easy task, and this is a responsibility of the government (P1, P2), that hospitals have open standards towards the caregivers and general practitioners, to create interoperability of the systems. Patients have access and can or have to give consent to look at their data if it is someone outside the medical environment. The medical data that comes in, is always discussed with the general practitioner. The general practitioner gives advice, for example, to start a trial for a week to measure their heartrate with a digital application for example, to see when there are critical moments. This was conceived as very helpful. (P2) mentioned again the functionality of a digital personal coach before going to a human coach, the complementarity between the two could be very helpful.

Is There a Need for a Cheating Function with the Digital Twin?

In contrast with the boomers, all three of the stakeholder participants were convinced that it is human to cheat. Humans are always presenting themselves better than they are. (P1) said: ‘If I go to my general practitioner to have a check-up and to have a blood sample, the three days before I will eat differently, drink less, be aware of my behavior, while I shouldn’t do that. I should behave as I normally do, but I don’t’. (P2) said: ‘I don’t believe in objective evaluations by patients’. Take smoking for example, smoking you cannot monitor unless you do it manually and if they are addicted it is even a bigger problem’. (P3) argued that the patient always has the right to say no or to stop for a while in giving data or to monitor themselves.

Who is the Owner of the Digital Twin?

Just as with the boomers, they all agreed that the patient is the owner of his or her Digital Twin. ‘It is a sine qua non’ says (P2).

What Happens When You Die with the Digital Twin?

(P3) Today the data is anonymized, and it is archived for 30 years when patients die, this is defined by the Belgian law. (P2) ‘It would be interesting to have access to the data of a population to see how a certain city or even country is doing health wise. This might be a role for the WHO (World Health Organization)’ But the patient always gives consent what happens with the data. He or she decides, he or she is in control.

How Do We Conceptualize a Digital Twin?

Depending on the personality, maybe people can choose? (P1) says: ‘In my experience it would be a database where we work with algorithms. Although I’m always apprehensive, it is only an algorithm, what is it going to invest and what will it exactly do? (P2): ‘It could be a little robot. Maybe other people prefer something else, maybe there are options. The question is also how the data is entered, who can see the data and where does it stop?’ (P2) sees it possible that a social sorting could be possible. But in Belgian healthcare this would not be possible, he argues. But of course, it can be done. Practice shows that a lower class excels in messing with their health, social sorting would underline that phenomenon. (P3): I think the data would be in the cloud, something like that. The medical data is separated from the other data such as lifestyle data and so forth in terms of accessibility. I think China has probably the most Digital Twins, ‘I saw this documentary, the surveillance that is going on, this is absolutely to be avoided. These applications exist and applied’, (P3) continues ‘I’m always worried about this surveillance, the abuse or misuse of these applications’.

Should It Be a Bottom-Up or Top-Down Initiative?

(P1) thinks it might be bottom-up initiative in forms of living labs, although a lot of living labs die and face the ‘valley of death’. Somehow one should be able to get over that point and try to create a fit-to-market. If it would happen in a top-down scenario, (P1) thinks in that case, there would be a lot of resistance from the potential users to get a Digital Twin.

Both (P2) and (P3) are convinced that security is a top priority. In that sense both also argued it should not reside within a government, ‘you never know what regime one will get in the future’. Although both find that regulation is something that should come from the top through privacy commissions or an ‘order of ethics in medicine’.

To conclude, data leaks and security are the biggest concerns in a digital twin concept from a medical point of view but also from the boomer’s perspective.

5 Conclusions, Limitations and Future Research

In this paper we presented a theoretical overview on ‘Aging in Place’ combined with ‘Digital Twin’ theory. To understand the notion of the Digital Twin we also build on the notion of a ‘Biometric Daemon’ [4], this is the notion of an electronic pet researched for authentication and identity recognition, we see possible similarities in this concept for the notion of a Digital Twin. Further in our research we conducted in-depth interviews with eight boomers (1946–1964), 60+ and 70+, and three stakeholders in the care cycle of elderly people to get more insights on following research questions: “To which extent do technologies such as wearable device and mobile applications, leading towards a ‘Digital Twin’ concept within preventive and predictive healthcare give human enhancement towards personal healthcare?” The added value or human enhancement for participants lies in the medical and lifestyle overview participants might get from a Digital Twin. Participants would use it to adjust their behavior when needed, in that sense participants are also convinced it could help them to stay longer at home and have the ability to ‘Aging in Place”. For the stakeholders the latter has a lot of added value as well. They could perform short trials based on the information they get from the patients Digital Twin leading towards personal medicine. On the flip side, participants worry about the privacy and security of the data, although the security side was more a worry on the stakeholder side, but privacy of data is a concern for all, it has to comply with the rules of ‘Privacy by Design [8] and AI Trustworthy guidelines [2]. The discussion that big data could be used for social sorting and stimulating inequality was something participants perceived as a threat in our democracy and is part of the political debate. The next research question we explored in our research was “how do elderly users handle or think about the data they (might) gather?” Our findings show that in general participants would be motivated to nurture a Digital Twin if it would help them to make decisions about certain health issues they might have or health issues that could occur in the future. However most of the participants were not interested in forecasting life expectations through a data-driven approach. Furthermore, some participants argued that today, forecasting on certain diseases or possible injuries is already possible today and possibly more accurate in the future. In addition, participants also stressed on the affordability of assistive digital technologies in terms of usability and user-experience. The ease of use and rules of simplicity should apply [14, 37, 38] no complex brain cycles, no manuals to learn, on and off buttons should be as easy to push the button, see ‘Hello Jenny’ [22]. Related to the previous research question we also want to go deeper on “how the elderly would give meaning to their data”. The participants who already track themselves for several reasons (prepare for marathons or recovering from health issues), mainly track their physical activity, nutrition aspects or other biomarkers such as blood pressure, glucose, are discussing their data with a general practitioner as to understand the data they gather. However the medical stakeholders argued that patients are not always eager to know about their health or the risks they have when they continue their lifestyle and not making any changes. In addition, they also argued that patients are not always honest about their lifestyle they lead either. This was a big contrast, as on the participant’s side they didn’t see any reason to cheat with the Digital Twin. Our last research question was specifically towards the medical stakeholders: “How will different stakeholders within the healthcare and caregiving organizations be organized around the concept of a Digital Twin?” It is clear that the stakeholders active in a medical environment are concerned about the security of the digital data that is gathered through a Digital Twin. On an individual level, data from the patient but also as a whole, the big data phenomenon from today. What it can entail in terms of social sorting and the possibility to evolve to an exclusive society instead of an inclusive society, creating inequality as a norm [39]. Stakeholders argued this is already happening today, but when everything becomes data-driven, the stakes are even higher. For now, digital technologies don’t have empathy, there is no context within the data-driven world today [42]. This is a point of attention; therefore, these assistive digital technologies have to be complementary and have a facilitating function for the medical professionals.

On the other hand, the stakeholders see a lot of positive elements to stimulate awareness and behavior change possibilities when necessary with patients. Furthermore, they see value in starting little trials to help patients whether they need adjustments of medication, going towards more personalized medicine. As a last comment they had, in order to get a full potential out of a Digital Twin, there need to be standards in the systems that are in place today in the hospitals and caregiving organizations, they need to be interoperable in order to look at correlations and to create more context around a certain individual and his or her Digital Twin.

The limitations of this research lies in the fact that the notion of a Digital Twin is an abstract concept for the participants, especially for the boomers. As researchers we paid less focus on the constraints of the notion of a Digital Twin, this is subject for further research.

Future research should give more insight on how we can conceptualize a Digital Twin, will it be an object or just AI software or both. Furthermore, we could explore the design requirements taking in account also the constraints that these assistive digital technologies could induce and considering the affordance for an aging population. In addition, exploring design research on adaptive technologies and adaptive objects.