PRE2017 4 Groep8

Group members

• Isabelle Cooijmans | 1014516 | i.h.m.cooijmans@student.tue.nl
• Ramon Hameleers | 0998964 | r.j.e.hameleers@student.tue.nl
• Angelique Husson | 0956648 | a.c.e.husson@student.tue.nl
• Marrit Jen Hong Li | 0963568 | m.i.jen.hong.li@student.tue.nl
• Dana de Vreede | 1020836 | d.d.vreede@student.tue.nl

Previous idea

Our Previous Idea can be found on this page.

Introduction

Problem statement

Elderly suffering from dementia often have problems managing their daily activities and independent living can become difficult. The decline in memory forms a big problem and an interactive reminder system could help these people to create a daily routine based on certain events.

Objective

Our goal is to help elderly in the early stages of dementia. They will be helped in the form of an interactive system primarily focussed on letting the patient water its plants at specific times and let the plant be a reminder for certain periodical things, like eating and medicine. Firstly, by creating this repeated event, elderly will create a stronger daily routine. Such a routine provides consistency and a predictable time slot, in which to return to valued occupations . Secondly, our objective is to research whether the shape of such a system contributes to the functionality of it.

Thus the main objective can be split into two sub-objectives:

• A system that creates a routine for the patient.
• Investigating the impact of shape on functionality.

These sub-objectives will be explained in more detail further in this wiki page.

Users

The users of the technology formulate certain requirements or wishes for the functioning of the technology. The users are a diverse group and therefore they will be split up into three kind of users: primary, secondary and tertiary users. The primary users are the users that come directly into contact with the technology and directly benefit from it. Secondary users will use the technology infrequently or not directly. Tertiary users are the users who are affected by the technology or make decisions about its purchase.

The primary users are:

• Elderly in the beginning stages of dementia

The secondary users are:

• The care takers
• The family, friends and loved ones
• The government

The tertiary users are:

• The technicians

Requirements

The three different types of users described in the previous section all have requirements. These requirements are listed below. Requirements of primary users:

• The elderly with a decline in memory need a system that will help them remember specific tasks
• The elderly need a daily routine to improve their well-being

The specific tasks that the elderly can be remembered of are tasks such as:

• A reminder to water the plants
• A reminder to take in medicine
• A reminder to have a meal

Requirements of the secondary users:

• The secondary users need their elderly to be healthy
• The secondary users need their elderly to be helped to remember basic tasks

Requirements of the tertiary users:

• The tertiary users need a system that is easy to install and easy to maintain.
• The tertiary users need a system that gives a notification in case of an error or when it needs maintenance.

Approach, milestones and deliverables

Having something to care for, keeps people busy and makes life more enjoyable. For example, having a plant and hence the responsibility to take care of that plant can serve as occupational therapy and ease the mind. Taking care of a plant could have a positive impact on someone’s life, especially when they feel lonely. Imagine that this plant is no ordinary plant but a robot plant, that can speak or give signals to the owner. This plant can give forgetful elderly people something they can nurture, but can also give the owner reminders of basic tasks. This robotic plant could for example remind the owner that the plant needs water to stimulate the nurturing aspect and compliment the owner when he or she does a great job caring for the plant. The plant can also give the owner a reminder at a specific time of the day in which the plant asks if the owner has already taken their medicine or to ask if the owner has already eaten. The owner can then respond by pressing a button. In return, the plant can then again complement the owner or stimulate the owner to do their daily activity and so the owner will create a daily routine. The plant is meant as a playful device from which the elderly will benefit, namely, increase their well-being and which they will also enjoy.

Our goal is to deliver a prototype of a robotic plant that will be tested with the involvement of the users and is capable of the following actions:

• The robotic plant notifies the user that the plant needs care
• The robotic plant gives positive signals when it is properly nurtured, or stimulates the user to nurture when it is not cared for
• The robotic plant can remind the owner of small specific tasks
• The robotic plant is able to interact with the owner

Other deliverables are:

• A presentation which will be given in the last week of this quartile. In this presentation, we will present our prototype of the robotic plant, discuss our findings and show our progress.
• A finished wiki page which will include all our findings and progress made during this project. This will be extensively discussed.

Other milestones and deliverables can be seen in the planning.

About some of the topic that is discussed before only a little research has been done as can be seen later in the literature study. Therefore some things will be tested using hypothesis tests. A hypothesis will be stated and this hypothesis will then be tested for example by taking the robotic plant to nursing homes and then conducting some questionnaires. This will be explained further in the following section called ‘Research’.

Research

What are our hypotheses?

The first hypothesis is that the user will be more interactive with a robot which has the shape of a plant than a robot shaped like a box. In the literature part, the effect of the caring character of PARO, the robotic seal, is that people with dementia started talking to the robot. A box does not have a caring character, but a plant does. So taking a robot shaped as a plant would probably be prefered over a box-shaped robot.

The second hypothesis is that a daily routine would have the same effect on men as it will have on woman. As F.M. Ludwig had shown is that a daily routine will have a positive impact on women. However, this test never was executed on men, thus our second hypothesis is that this effect will be similar.

Test plan

This project is about testing two things. Namely, whether the elderly get an improved quality of life when using the robot, and secondly whether there the shape of the robot plays a roll in how the patients interact / react to it.

How should this project be implemented in real life?

In the following part, the effect of the robotic plant in real life is discussed. The statements that are made are our personal expectations and ideas of the robotic plant in real life.

General setup

The effect of the plant and the impact of its shape can be tested and analysed by actually using the robot. Before the elderly will be in touch with the robot, the state of their well-being and health will be determined, using similar methods as used by F.M. Ludwig. This means that first some conversations will be held with the patients in which not only direct questions will be asked to gather knowledge and understanding of the situation, but also long conversations will be held. During the longer conversations one can get a better impression of how the patient feels, its capability of focussing on one conversation for an extended amount of time and how the patient feels about its own well-being. Beside this conversation, a questionairre will be created for the patient to fill in every month. Such a questionnaire should give us all the necessary information about the patients health. Over the period in which the robot is tested, every month another conversation will be held and the patient can fill in the questionaire again. Based on the outcomes of our own findings from the conversations and the results of the questionairre, changes in the patient's well being can be found.

How would primary users interact with the device?

The primary users are woman above 70 with early dementia who live at a nursing home. The robotic plant will be set somewhere in their room close to a window, where there is sunlight since the living plants next to the robotic plant should get sunlight to grow.

During the usual day of the user, the robotic plant will ask the user to give it water and possibly remind the user of their medication. The robot plant will do this via a microphone. It will then politely ask whether the primary user will water him. After the user gives water to the plant, the plant will give a positive feedback in the form of lighting. For the medication reminders, the robotic plant will ask the user whether the user has already taken her medication. This will be asked at the exact time that the medication should have been

The interaction of the user with the plant will be heavily dependent on how the user feels about the plant. In many cases, the user will find it hard to accept a 'talking plant' and possibly reject it. However, the majority will accept the plant into their home. In case the user will have no intention of accepting the plant, it will be of little use. During the primary interview questions will be asked to the user about how it feels toward such a 'strange' object to prevent a waste of time.

Expectations

In the following section the expected outcomes and effects will be discussed.

Expected effect on primary users

Our expectations of the effect that the robotic plant has on primary users are the following:

Using the robot will take a significant amount of time to be useful. However, towards the end of the testing period the user will have a more structured day due to the routine that the robot provides. This results into not only the user forgetting to do certain activities, such as taking medication or eating at regular time instances. But the robot will also give the user a better sense of time. When the user hears the second 'alarm', he/she becomes more aware of what activities could have been done at that time, and thus will be more aware of its productivity and planning. In the ideal case of an actual improvement of productivity, the user will have more time to relax, play or be active, which is an essential element for maintaining health

Another scenario is that the plant will stimulate the primary user to care for the plant, as without care the plants next to the robotic plant will die. Such a feeling of responsibility usually means that the user's mind still is very clear and the feeling of responsibility will stimulate that even more.

How would secondary users interact with the device?

The secondary users are the family of the primary user and the people working at the nursing home of the primary user and doctors and the primary user’s general practitioner. These primary users both interact the same with the device. Because of privacy reasons, the secondary users should be the ones who install the medication reminders. Information about medication is confidential and only the secondary users and the primary users know about this information. There should be a way possible to set and update these reminders. This can be done via a website or an app, which means that it can be updated from far away. This is necessary since the secondary users are not always there to implement new medication reminders or know about new medication on time to set a timer. The primary user will get new medication prescribed to them by a doctor at the hospital or by their general practitioner. These people would then be the best fit to keep track of their medication reminders. The people who work in the nursing home normally should check whether medication is taken, but now the robotic plant does this for them. If the patient did not take their medicine, an alarm should be given to the nurses, such that they can still give the medicine.

Expected effect on secondary users

The family of the primary user will be less worried about their elder, since the robotic plant will make sure that medication is taken and the wellbeing of their elder increases.

The people working in the nursing home will have less work to do since they do not have to make sure that medication is taken by the elder, which would give them more time to do other things that are needed for a longer time period. Of course they still have to check whether the elderly have really taken their medicine, but if the elderly has already done this it would reduce the people of the nursing home some time. Hence this will increase the quality of the nursing home. Moreover, they will know when the elder did not take his/her medicine and hence they know when to step in and help the elder to take his/her medication. The doctors and the general practitioners will be given a little more work, however this can be automated in the action of writing prescriptions. This would give more time to people working in the medical field then it would cost. Since this all helps the nursing homes and the elderly, this would be beneficial for the government.

How would tertiary users interact with the device?

The tertiary users are the technicians. These users only interact with the device when there is a need for maintenance or failure.

Expected effect on tertiary users

The introduction of the robot will have little impact on the tertiary users

Literature Study

In order to obtain more insight about the topic a literature study about the state of the art will be conducted. ...

General literature study about dementia therapy

Ageing and exercise: building body capital in old age.

In this article the effect of participating in group exercise is analysed. The test group, 70 year old women, corresponds to our users. The effect of being involved in group exercise is that despite their age, the women maintained bodily health and vitality, making them better able to live independently and improving their overall health. Thus being involved in group activity contributes to solving the initial problem by making the women more indepent.

Horticultural therapy in dementia care: a literature review.

This article about horticultural therapy in dementia care combines 15 research articles together and gives a review about their findings. These research articles conducted studies about how dementia therapy affects the quality of life. Horticultural means the art and science of growing plants. The article has several findings about emotional health, self-identity and engagement. . Findings of this article are for example that gardening in groups has a positive effect as the elderly can socialize and talk about the gardening. Elderly suffering from dementia often have anxiety, agitation and depression symptoms that can lead to depression. This can have a significant effect on the quality of life. Several of these 15 studies have shown that horticultural therapy has a positive effect on these health symptoms. Since not all studies support this statement, the therapy does not support guaranteed sustained wellbeing or reducing the distress for all people. However, it represents a means by which carers can encourage elderly living with dementia to engage in meaningful activity. The main conclusion of the article is that horticultural therapy can benefit elderly suffering from dementia in several ways.

Robots that help elderly with cognitive problems

Paro

Apathy, agitation, loneliness and depression are common behavioral and psychological symptoms of dementia. These symptoms can make life distressing for the person with dementia and can also make it challenging for care staff to meet the needs of the person. In recent years, social robots have been used as a means to reduce this. Both animalistic robots, such as Paro, or robotic toys make the patients enjoy their time more and thus improve their well-being. Such an effect can also be created using plants or other systems the elder has to take care of.

Robots who take care of plants

The Pet Plant: Developing an inanimate emotionally interactive tool for the Elderly

The effect of pets on the health of elderly is widely known and this effect can also be summoned by robot pets. Another alternative is to use

Low cost colour sensors for monitoring plant growth

A relatively new area of research is that of non-destructive methods to measure the health status of plants. Such as looking at subtle changes in the colour of the leaves. This paper mainly focuses on low cost colour sensor for monitoring leaf colour of plant tissues.

To implement this system a autonomous robotic arm containing RGB colour, environmental and proximity sensors are used, as well as a camera. The robotic arm uses five stepper motors controlled through a motor controller and a micro-step driver. Their system was either compatible with the ColorPAI or the TCS 3200 colour sensor and both were controlled with a Basic Stamp microcontroller. The ColorPai uses a RGB LED light source and records the quantity of light reflected back from the object to determine the color. The TCS3200 illuminates the object with two white LEDs and interprets the colour of the object by producing a square wave with a frequency proportional to the light reflected by the object. A completely different way of determing plant leaf colour is by using an image captured by the camera and determining through software the colour of each pixel. This may however lead to false colour. For example when shadows from overlapping leaves are misinterpreted as colours of the leaves itself.

They only tested the TCS3200 and calibrated it across a broad range of green and yellow colours. In the end it had an average error around the 4% when determining an RGB color in the range of green and yellow colours.

Effect of gardens on the mood of the elderly heart

A research done on the impact of different garden design on the mood and functioning of an elderly's heart. Organised and structured gardens benefit the health of the elderly. This means that a structured placement of plants throughout a house or elderly home will also improve the health of the patient.

Garden greenery and the health of older people in residential care facilities

In this article, the relation between greenery gardens in elderly homes and the self-perceived health of the patients is examined. This was done by a vast amount of questionnaires for the residents of many elderly homes. Also elderly were asked to report on their personal health and garden visits. Both tests showed a positive and strong relationship between patient well-being and the accessibility of a garden. Visiting such a garden gives a sense of being away and even wondering about them gives a positive impact on the patients health. This information shows the importance of accessible greenery in elderly homes

Plant growth monitoring system, with dynamic user-interface

The paper develops a prototype for an efficient plant growth monitoring system. It provides data about the environmental parameters surrounding the plant and maps the changes in plant growth to the inputs given by person caring for the plants, such as the quantity of water or fertilizers. It can also measure the plants height.

The system consists of a Raspberry Pi which analysis the output of multiple sensors and sends this data via Bluetooth to someone's phone. They also developed a user-friendly app which displays all this data. The system does not take care of the plants itself, it only monitors a variety of environmental parameters

Robotics in protected cultivation

Right now there is a lot of research to increase automation in protected cultivation. Production of high-value plants is facing an increase in problems such as increased costs for employees and decrease in skills. Robotics can help decrease these problems. The problems can be sorted into different groups. For seeding, grafting and cutting there are already products which can do this just as there are for transporting, sorting, packaging and cleaning. However, there is still a lot to win in the department of weeding, thinning, leaf picking, protection and harvesting. The technical challenges in robotics are the fact that technologies have to deal with complex environments. There are two solutions which can be used in this case, advancing technology or modifying the environment.

Thermostats and measurements of oxygen(state of the house)

NeoFox Oxygen:

This oxygen sensor shows oxygen sensing using two methods. First of all, by making an electrochemical compound that will conduct current based on oxygen levels in the material. This is a relatively easy method and gives linear dependency between the oxygen level and the current created, but will also consume the oxygen. Secondly, by using a fluorescent material that will react to oxygen, different sorts of light will be radiated. Based on the frequency, amplitude, and phase of this emission, the amount of oxygen can be determined. This second method may be faster and more reliable, but also more difficult to produce.

PhO2: Smartphone-based Blood Oxygen Level Measurement Systems using Near-IR and RED Wave-guided Light

Measuring a patient's blood oxygen level plays a critical role in healthcare practices. In the paper, they develop a phone-based oxygen level estimation system which uses the camera and flashlight functions of a smartphone. Since the camera and the flashlight of a smartphone aren't made for this purpose, they encountered many challenges in using them for this purpose.

Blood oxygen level is often indicated by oxygen saturation measurement (SpO2). Accurately measuring SpO2 with a high frequency is critical in monitoring the well being of key organs and also to provide warning signs of abnormalities. One of the most common ways to measure SpO2 is by using a pulse oximetry system. This system comprises dedicated hardware and software. It works by project light beams at specific wavelengths deep into the users' finger, toe, earlobe, or other location. This light hits dedicated photoelectrodes and the intensity of the light received carries information that can be used to determine the users' SpO2. This way of measuring SpO2 is very reliable but it requires the user to purchase one and to carry it with them during the day. Patients often forget to take the device with them or forget to charge it. Also, different patients have very different finger and earlobe sizes and the devices are thus not always a good fit.

There are already many applications for smartphone out there that use the flashlight and camera to determine various blood properties. However, none have the ability to accurately estimate SpO2. This low accuracy is a result of the fundamental challenges when one tries to repurpose the camera and flashlight for SpO2 measurements. Examples of these challenges are:

• One needs an IR wavelength
• One needs to work around the varying movement, pressure, contacting area of the users' finger

In the paper, they develop a hardware add-on (PhO2) designed to be snapped on the phone as a phone case which has optical filters of different wavelengths. The add-on helps stabilize the users' finger. Due to the limitations of the phone's hardware, the reflected light captured by the PhO2 is further processed by dedicated algorithms.

Smart device for gas range

This is a smart device, which knows when the gas is on and whether the stove is left unattended. In case of an unattended stove, the device will send a message to the user, which can shut off the gas supply or call for relevant party's immediate attention remotely. When sending the message fails or when there is no response, the device will automatically shut off the gas supply.

Iot-Based Intelligent Modeling of Smart Home Environment for Fire Prevention and Safety

Fire detection has become an issue since it caused severe damage including the loss of human lives. To reduce property damage and save lives, early detection of a fire event is very effective. The installation of a fire alarm system is the most convenient way to detect a fire early and avoid losses.

In the paper, they propose an efficient, IoT-based intelligent home fire prevention system using multiple sensors, which each uses its own mechanism for detection.

In the paper, problems and challenges related to the current approaches are identified, GSM communication is used to alert the user at early stages, star topology is used for the deployment of sensors and communication between sensors and main home sink and the system concerning energy consumption is evaluated.

Design and Development of a Low-Cost, Portable Monitoring Device for Indoor Environment Quality

In this article, the design and development of a low-cost, portable monitoring system for indoor environment quality(IEQ) is described. A prototype is made with commercially available low-cost sensors and a do-it-yourself approach is provided. The designed system monitors temperature, humidity, PM2.5, PM10, TVOC(x3), CO2, CO, IAQ, illuminance, and sound levels. The biggest advantage of this design is the low cost, since it provides a comprehensive, portable, and real-time monitoring solution, for less than 200 dollars.

A cheap and third-age-friendly home device for monitoring indoor air quality

This article proposes a new methodology to analyze indoor air quality with a cheap and third-age-dedicated device. The researchers developed a prototype, which they called HOPES, Home Pollution Embedded System. This prototype gives simple and understandable information, also comprehensible for people with cognitive problems or that are not familiar with new technologies. The prototype gathers data about pollutants and displays the different air pollutants concentrations to the user. These air pollutants concentrations are from toxics gasses up to explosives. Furthermore, in the paper, an overall air quality index is elaborated and displayed by HOPES with lights and numerical information. HOPES is an internet of things device. Hopes works in real time and can be connected to a geographic information system platform and the web to add spatial information about each pollutant. The results highlighted how it is possible to get useful air quality information with a cheap device.

Medication reminders

Smart Home medication reminder system

Many elderly people need assistance from nurses, housekeeping, and visitors that remind them to take their pills. New technologies can provide a medication reminder system. This article mainly focuses on the Open Home Automation Bus (openHAB). This is a software that integrates and thus combines different home technologies together. There are several smart technologies that help elderly people and this software can combine them and make it easy to use.

A WSN smart medication system

It is very important that patients or elderly people take in their medicine correctly. However, for elderly, it often becomes difficult to remember whether or not they have already taken their medicine. Also when these people have lots of different pills it can become hard to remember which to take and when to take them. A wireless sensing network (WSN) system have been invented which can remind patients to take their medicine. The system consists of a master panel (MP) and portable smart pill-boxes (SPB). Magnetic sensors are used to detect whether or not there are pills in the (SPB). If not pill has been taken. This paper describes the three-state pill sensing mechanism and all other aspects of the wireless sensing network.

Medicine Reminder and Monitoring System for Secure Health Using IOT

Elderly people sometimes tend to forget doing basic things among daily routine. This can lead to them forgetting to take their medicine at the right time of forgetting it entirely. Using the Internet of Things (IoT) network low-cost medical sensing can be produced. There have been multiple tests with technologies to find a way to decrease this problem. A monitoring system and sensor can send information using a wireless module. The information can be shared using IoT, however, since health information can be very personal an encryption or decryption purpose is recommended.

MESSAGE INA BOTTLE

Medication reminders in the form of pill bottles are already available. The bottle can notify patients when they need to take their medication or missed a dose as well as seeing that the pills are almost out and notifying a pharmacy. This technology can not only increase the effectiveness of certain drugs but also reduce the readmission rates at hospitals. The pill bottle uses a sensor to detect opening and closing of the lit and compare its content. This is then sent to the startups server which can analyze the data. Using different colors of light the user is given an indication of when taking medication is necessary.

Robots who look at the eating of their users

An Intelligent Food-Intake Monitoring System Using Wearable Sensors.

Researches are looking for accurate methods requiring less user-involvement to assess general food-intake. The paper proposes an intelligent foot-intake monitoring system that can automatically detect eating activities. An in-ear microphone with a miniature camera is combined in a light-weight wearable headset. The sound from the microphone is classified into different eating activities and the camera takes pictures of the food if a chewing activity is detected. The key images of food are then selected sequentially and a dietary assessment log is generated to reflect a user's dietary behaviour. Novelties in this design were:

• Developing a noise-resilient sound activity detection method suitable for daily use
• Introducing food images to improve assessment accuracy
• Selecting key images automatically to minimize the size of the food-intake assessment log

Big fridge is watching you

The smart kitchen is becoming reality. With the enormous increase of technology in everyday things one cannot deny the probability of a smart fridge. This fridge could use information from your wearables, agenda and smart devices to recommend meals. The used data can also be relayed to doctors or caregivers, for instance when an elderly is not eating enough. Furthermore, it can help people who tend to forget what is in the fridge with keeping an inventory and tracking expiration dates. This way an order could be placed for what is needed from the supermarket.

Automatic Dietary Monitoring Using Wearable Accessories

In this article, a lot of research is done on how they modeled a person dietary. However, this is not really relevant to our project. But, later in the article a discussion is given about the state of the art of sensing technologies, integration in accessory-based wearable devices and estimated parameters of different dietary dimensions. After which the researchers explain which challenges must be addressed to make ADM technology viable.

The Billy-Billy robot

Fig. 1: Billy-Billy robot

At the end of our literature study a robot was found that was made using similar ideas as our project.

The robot that we discovered is called the Billy-Billy robot. It is a robot in the shape of a face with a plant growing out of its head. Billy-Billy is a flowerpot that has several unique features. It is an interactive flowerpot who makes the life of elderly people more enjoyable in an interactive way. Billy-Billy has smart sensors that can detect when the herbs or plant growing out of Billy-Billy needs more light or extra water. It can then notify the elderly. Billy-Billy is easy to install and can be used in several minutes and also has plant seeds included when bought. It does require a network connection. This internet connection provides an online platform in which family and friends can see how happy Billy-Billy is. It also allows the family and friends to send text messages to Billy-Billy and in return Billy-Billy can communicate these messages to the elderly. Lastly Billy-Billy has an integrated agenda system which notifies the user to take medicine, notify when a carer arrives or when a family party is planned.

We are very interested in the Billy-Billy robot and contacted the company to ask specific questions about their robot. This robot shows that we as a group are not the only one interested in the subject and that this kind of robot really could help elderly people.

Prototype

Fig. 1: Top side flower

Fig. 2: Under side flower

Fig. 4: Schematic LEDs

Fig. 5: Test LEDs

Fig. 3: Stem

3D-model

The original tulip-model came from thingiverse: https://www.thingiverse.com/thing:1429882. The tulip is made from three elements, the stem, a leaf and the flower itself. The stem and the flower were edited in FreeCAD to make room for the electronics. The inside of the flower was hollowed out to be able to install a speaker and a LED-strip (see figure 1). Four holes are extended even further into the flower to make room for four 5 mm RGB LEDs. A hole was made through the stem of the tulip all the way to the electronics to be able to wire everything (See figure 2 and 3). The rest of the electronics will be installed in the plant tray below the tulip.

The model was printed with transparent plastic. This way the LEDs can make the tulip change colors.

Electronics

There are multiple circuits inside the tulip. Every single one corresponds adds a different functionality to the tulip. All circuits are driven by an Arduino UNO.

LED-strip

For this project a common anode RGB LED-strip is used inside the flower. A schematic overview of the way the LED-strip is connected is depicted in figure 4. The LED-strip is modeled by a four male headers (J1 in the schematic), one corresponding to the 12V input (pin 1 in the schematic) and the other three corresponding to each color. Eight 1.5V batteries power the Arduino and are directly connected to the LED-strip. The maximum current a color in a single LED on the strip draws is 30mA. An I/O-pin of an Arduino delivers a maximum of 40mA which means it can only power one LED on the strip. Transistors are placed after every color on the LED-strip to allow a bigger current to flow. Since the LED-strip has a common anode, we used NPN transistors. Thus current flows from the batteries through the LED-strip, back through all three colors and a corresponding transistor. We used BD139 transistors (view the datasheet here: http://www.redrok.com/NPN_BD135_45V_1.5A_12.5W_Hfe40_TO-126.pdf) and they can handle a maximum of 1.5A. This means enough current flows to power 50 LEDs.

The base of every transistor is connected to a PWM pin on the Arduino. The three PWM signals control the color of every LED. Three resistors (220Ω) are placed in front of each base to limit the current.

Remaining LEDS

Four RGB LEDs are added in the bottom of the flower. They are also depicted in figure 4. In contrast to the LED-strip, these LEDs have a common cathode. They are directly connected to the Arduino, no external powersource is used. Resistors are placed in front of each color to make sure the desired current will flower. The following datasheet is used as a reference: https://www.arduino.cc/documents/datasheets/LEDRGB-L-154A4SURK.pdf. The voltage drop over the green and blue color is 3.3V, while the voltage drop over the red color will be 1.95V. The I/O-pin of an Arduino delivers 5V. This means there needs to be a voltage drop of 1.8V over the resistors before the green and blue color. There needs to be a voltage drop of 3.05V over the resistor before the red color. The blue and red color need 30mA while the green color needs 25mA, which means the value of the resistors will be:

[math]\displaystyle{ R = \frac{V}{I} = \frac{1.8V}{30\times10^{-3}A} = 60\Omega }[/math]

[math]\displaystyle{ R = \frac{V}{I} = \frac{1.8V}{25\times10^{-3}A} = 72\Omega }[/math]

[math]\displaystyle{ R = \frac{V}{I} = \frac{3.05V}{30\times10^{-3}A} = 101.67\Omega }[/math]

In the E12 resistor series the closest value is 100Ω. These are also the values we used.

Possible extensions of the robot

As there is only limited time for this project, not all our wishes can come true. In this section future extensions, improvements and ideas of the robotic plant will be presented.

Colour testing

The robotic plant designed in this project has been used to test the hypothesis whether the shape of the plant impacts the user. This was tested by comparing a plant with a square box. Another hypothesis that is interesting to test in the future is whether or not colour signals will impact the user. For example the plant gives green coloured lights when it is nurtured properly. It will use other colours to send reminders or to attend the user that it not cared for.

Hearing problems

It can occur that an elderly person does not hear well. And maybe this person is to stubborn to use a hearing aid. This causes the elderly person to not hear the plant properly when it gives reminders. A solution would be to install the option to higher the volume when the user does not hear the plant. The elderly person could press a button when the message has been heard. If the plant does not get a response it could repeat its message, but now with a higher volume. This cycle will be repeated until it gets a response from the user or until it reaches a certain volume level. When a certain volume level is reached it will not repeat the message anymore but will send a notification to the caring staff. However one can object that this might become annoying to the user and causes the elderly to ignore the plant completely.

Size of the plant

Another interesting aspect to test in the future is whether the size of the robotic plant has an impact on the user. Currently the robotic plant is a tulip and is relatively small. Maybe if it would be bigger it would have a different reaction from the user.

Kind of plant

Another aspect which would be interesting to investigate and test is whether the kind of plant matters. For this project a tulip was used, which is a flower. However multiple flowers exist, for example roses or dahlias. Moreover, there exists more plants than just flowers, e.g. a tree or a cactus. Maybe if the robotic plant would look like the plants on the side, it would have a better reaction from the user. Or maybe if the robotic plant would look like the users favourite plant, the user would like it better.

The voice of the plant

The voice of the plant is now the voice of someone on the project team, while this can feel unfamilair to the user. Hence the impact with a familiar voice as the voice of the users child or users wive/husband would be interesting to investigate.

Tracking system

One of the limitqtions of the robotic plant is that it is stationary. The robotic plant has not yet a way of knowing whether the user is present in the same room as the plant or not. So this should be fixed for later use of the plant. This can be done with a tracking device on the user. In this way the plant could keep track of the users location. An other example would be a wearing device which has a certain range of sending signals. So the plant will know when the user is close enough.

Voice recognition and response

It would be interesting to test whether voice recognition with a response would give a better interaction with the robotic plant.