# Android QuestionDeveloping a Navigation System for a Complex Facility

#### carlos7000

##### Well-Known Member
Longtime User
I have been asked to create an application to solve the following problem.

Many patients and new staff members miss appointments and exams due to the complexity of a clinic. Although there is staff and signs that indicate the way to different departments, it is not possible to have a guide at every corner or hallway, nor to place a sign on every wall. Recently, an elderly lady missed an appointment because it took her an hour to reach the cardiology office. The hospital complex is quite large, composed of several buildings spread across 2 blocks. Sometimes, to go from one place to another, it is necessary to cross the street. There is a bridge connecting two buildings or an underground tunnel linking two buildings separated by the street. Some buildings are connected by an underground tunnel that goes through the basement of the parking lot. In addition, the height of the buildings varies: one has 3 floors, others have 5, and one has 10 floors. For now, the exact details are not very important.

Within the hospital complex, we find parking lots, offices, consultation rooms, hallways, elevators, stairs, restaurants, rooms, intensive care units, operating rooms, warehouses, a kitchen, waiting rooms, laundry facilities, and much more. It is a true maze. I have thought about creating a graph (network of nodes) where each office, room, etc., is a node, and using an algorithm like Dijkstra's to solve the problem. However, I have very limited knowledge about graphs. I am not looking for the most efficient, fastest, or resource-efficient algorithm, just the one that is easiest to implement in B4A.

I would like to hear your ideas on how to approach this problem using B4A.

#### Andrew (Digitwell)

##### Well-Known Member
Longtime User
As I see it you are only looking at half the problem. The route.
There is a question before that which is, "Where am I?"

This is not easy to solve inside as GPS does not work very well indoors. There are solutions which use beacons or Wifi.
See this post which discusses indoor beacons in B4X

#### William Lancee

##### Well-Known Member
Longtime User
Cost of equipment and maintenance to hospital and possibly to patients should be minimized.
Beacons would be required all through the hospital complex - far too costly - and a maintenance nightmare.

Apparently (untested) four LoRa transceiver stations within a kilometer area would allow positioning,
but then the patient would need a LoRa receiver attached to their device - impractical.

One approach that might be feasible is to use QR GuideMe stations (a cheap non-electronic image on the wall).
The patient would need nothing beyond their device and the GuideMe app.
Each scan would let the GuideMe app to instruct the patient how to get from that QR station to the target.

#### AnandGupta

##### Expert
Longtime User
Although there is staff and signs that indicate the way to different departments, it is not possible to have a guide at every corner or hallway, nor to place a sign on every wall.

Put Sign boards at strategic places showing a marker like "BLOCK - AA AREA - 2C", a phone number in big font and also qr code of the same. Have the phone number with multiple channel. Put few desk person to handle the phone and guide the patient to required place. The guide can ask to what the board says, "Block" and "Area" and know where the patient is now. Then it becomes easier to guide him/her to the correct block and area.

The qr code of the phone is for tech savvy to quickly dial the number without punching the numbers itself.

#### carlos7000

##### Well-Known Member
Longtime User
As I see it you are only looking at half the problem. The route.
There is a question before that which is, "Where am I?"

This is not easy to solve inside as GPS does not work very well indoors. There are solutions which use beacons or Wifi.
See this post which discusses indoor beacons in B4X

What I came up with is to give each node a unique name and place a QR code with the code underneath, as seen at the beginning of this video.

It is formed as follows: Let's assume a patient is in the respiratory therapy department, in the pulmonology division, in Building H, on the 3rd floor. Each entrance to the complex has a QR code, just like each node in the complex (each office, etc.). Internally, that location would be identified with a code like 'HP3NEUTR' which stands for Building H, 3rd Floor, Pulmonology, Respiratory Therapy. There is a code like at that specific place.

By scanning the code, the application already knows which node the patient is at. Then, in the application, the department and subdepartment are selected. The application calculates the route from that node to the selected node

As I see it you are only looking at half the problem. The route.
There is a question before that which is, "Where am I?"

This is not easy to solve inside as GPS does not work very well indoors. There are solutions which use beacons or Wifi.
See this post which discusses indoor beacons in B4X

#### carlos7000

##### Well-Known Member
Longtime User
Cost of equipment and maintenance to hospital and possibly to patients should be minimized.
Beacons would be required all through the hospital complex - far too costly - and a maintenance nightmare.

Apparently (untested) four LoRa transceiver stations within a kilometer area would allow positioning,
but then the patient would need a LoRa receiver attached to their device - impractical.

One approach that might be feasible is to use QR GuideMe stations (a cheap non-electronic image on the wall).
The patient would need nothing beyond their device and the GuideMe app.
Each scan would let the GuideMe app to instruct the patient how to get from that QR station to the target.

Yes, I think the simplest and most economical is with qr codes.

#### Andrew (Digitwell)

##### Well-Known Member
Longtime User
It is formed as follows: Let's assume a patient is in the respiratory therapy department, in the pulmonology division, in Building H, on the 3rd floor. Each entrance to the complex has a QR code, just like each node in the complex (each office, etc.). Internally, that location would be identified with a code like 'HP3NEUTR' which stands for Building H, 3rd Floor, Pulmonology, Respiratory Therapy. There is a code like at that specific place.

By scanning the code, the application already knows which node the patient is at. Then, in the application, the department and subdepartment are selected. The application calculates the route from that node to the selected node

it is not possible to have a guide at every corner or hallway, nor to place a sign on every wall.
I thought you weren't able to put up many signs.

#### carlos7000

##### Well-Known Member
Longtime User

Put Sign boards at strategic places showing a marker like "BLOCK - AA AREA - 2C", a phone number in big font and also qr code of the same. Have the phone number with multiple channel. Put few desk person to handle the phone and guide the patient to required place. The guide can ask to what the board says, "Block" and "Area" and know where the patient is now. Then it becomes easier to guide him/her to the correct block and area.

The qr code of the phone is for tech savvy to quickly dial the number without punching the numbers itself.

The idea is very good. they have staff in a few locations to help guide people. When you ask any of them, even while on the spot, sometimes the instructions are confusing, sometimes wrong. So they are looking for something less prone to those errors.

#### William Lancee

##### Well-Known Member
Longtime User
People to help guide patients could use the same app on their own phone.
I have met many people who want to help but need help themselves. The QR solution in the video could do that.

#### AnandGupta

##### Expert
Longtime User
When you ask any of them, even while on the spot, sometimes the instructions are confusing, sometimes wrong. So they are looking for something less prone to those errors.
I just imagined my self as the elderly lady,
an elderly lady missed an appointment because it took her an hour to reach the cardiology office.
and I said to myself "Damm it. These youngsters busy with their phones, do not have time for old people". "If only some one had guided me today, I would have met my doctor", "Now again I have to come tomorrow. Aaah!"

And there I saw the need for non-tech use for old persons like me.

#### carlos7000

##### Well-Known Member
Longtime User
I just imagined my self as the elderly lady,

and I said to myself "Damm it. These youngsters busy with their phones, do not have time for old people". "If only some one had guided me today, I would have met my doctor", "Now again I have to come tomorrow. Aaah!"

And there I saw the need for non-tech use for old persons like me.
imagine. If with assistants, sometimes the instructions, sometimes they send you elsewhere, imagine on the phone asking for help.

Sure. It would be very good if a guide had accompanied her to the doctor's office where she had the appointment.

The problem is that here in Colombia, if a medical appointment is missed, they reschedule it for another 3 or 6 months.

Hence the importance of reducing these cases or preventing them from happening again.

#### William Lancee

##### Well-Known Member
Longtime User
The person still needs to get to the hospital on time. Not so easy!
(Unless you're Miss Daisy)

Grandma can still miss her appointment. The cost of failure is too high!
There should be some accommodation for those who have mobility and/or memory problems.
I hope there are Social Workers who help in such situations.

#### carlos7000

##### Well-Known Member
Longtime User
I thought you weren't able to put up many signs.
The posters that are now are about 2 meters high by 1 wide. Although they probably won't be removed, if the app works as expected, the number of posters may be able to be reduced. The ideal would be to remove them. But not everyone has a smartphone. In addition, there will be people who prefer to be guided by the posters or with the help of the advisers at the information stands. The request they made to me is: Will it be possible to make an application that helps users navigate the facilities in a faster and more efficient way, at a low cost?

The codes would look something like this. They are not very invasive.

#### William Lancee

##### Well-Known Member
Longtime User
One of the nice things about this approach is that it will be easy to prototype and test.
And of course the B4X app (as developed by you) will make it possible to do it in record time.

BTW, I like the design of the signs themselves.
(It must be the light reflection, but this one looks like someone took pot shots at it.)
There is no need to remove them, except, as the symbiotics guy says, they lie! For example, if hematology is somewhere else.

Questions:
1. Can the phone decode the QR from that distance?
2. Are there enough signs so that at least one is visible at all times (or at least around the corner)?

#### carlos7000

##### Well-Known Member
Longtime User
One of the nice things about this approach is that it will be easy to prototype and test.
And of course the B4X app (as developed by you) will make it possible to do it in record time.

BTW, I like the design of the signs themselves.
(It must be the light reflection, but this one looks like someone took pot shots at it.)
There is no need to remove them, except, as the symbiotics guy says, they lie! For example, if hematology is somewhere else.

Questions:
1. Can the phone decode the QR from that distance?
2. Are there enough signs so that at least one is visible at all times (or at least around the corner)?
Hello,
1. The codes of different sizes trying to ensure that the size is neither too small nor too large. proportional to each space. For example, for an office, a qr code of about 7cms x 7cms will be placed. if it is for a corridor it could be 10cms x 10cms and for an apartment, it could be about 15cms x 15cms, or a little more. When one is close to an office, the code is not required to be very large, as seen in the image. In the corridors, elevators, hallways, etc., it could be a little bigger so that you don't have to get so close and for a dependency, you could put a sign with the name of the departments, the code, and other information.
2. Yes of course. Every office, every corridor, every elevator, etc. must have a code.

#### MicroDrie

##### Well-Known Member
I will give another tip in case the QR codes become a big success. A QR code is still able to read an image with a relatively high error margin. If there are several Q codes next to each other, the question arises which one is the right one. Put an icon in the center of a QR code that says what the QR code stands for to make choosing the right QR code easier. Furthermore, you should not choose too small dimensions for the QR code during printing in order to be able to choose sharp (and therefore with fewer errors).

#### carlos7000

##### Well-Known Member
Longtime User
I will give another tip in case the QR codes become a big success. A QR code is still able to read an image with a relatively high error margin. If there are several Q codes next to each other, the question arises which one is the right one. Put an icon in the center of a QR code that says what the QR code stands for to make choosing the right QR code easier. Furthermore, you should not choose too small dimensions for the QR code during printing in order to be able to choose sharp (and therefore with fewer errors).

Yeah. We have already done some tests and it seems to us that the minimum size should be between 5 and 7 cm in length and height of the code. It will be of that size to put it next to the door of an office. For an apartment, which encompasses several offices, the qr code should be 15 cm long and high. For the entrances of each floor, the qr code can be even larger so that it can be read from a greater distance

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