Project Report – Decreasing Prehospital Time for Accident Victims
Introduction
Two of the NAE grand challenges are centred around health; engineer better medicines and advance health informatics (Engineeringchallenges.org, 2018). Using data collected from 2016, around 181,384 casualties are reported to the police each year, with more than 660,000 road accidents occurring nationwide (Assets.publishing.service.gov.uk, 2018). With the number of vehicles on the road increasing, ensuring drivers are safe is a pressing issue that we should address. A study done using EMS Patient Care Reports and police crash reports for the state of Alabama (Gonzalez et al., 2009) show a clear correlation between increased time passed between the accident and the patient reaching the hospital, and increased mortality rate. Using the data from rural areas and excluding any patients dead on scene, the mean response time for mortalities is over two minutes longer than for those patients who survive.
In my project I have decided to try and decrease the time taking between the accident occurring and the emergency services reaching the hospital by implementing a system that automatically turns traffic lights green as an ambulance approaches. I would like to produce detailed research on the theory behind this idea as well as why it is necessary, and a simulation in multisim to demonstrate how the traffic lights are coded using assembly language.
Accident Research
Reducing the time between the crash and help being provided by professionals with sufficient equipment (known as prehospital time) is the most important thing in reducing mortalities. By ensuring all lights are green as an ambulance approaches, even saving a few seconds could make the difference between a patient who survives and one who doesn’t. This technology will mostly be used in urban areas where more traffic lights are found and around 67% of accidents occur (Rospa.com, 2018). In a study done to determine how much time drivers lose because of traffic lights (Levinson, 1998) is it discovered that it is around 20% of their journey time. This will vary significantly depending on urban/rural location and time of day, however it is clear that a crucial amount of time could be saved if this technology is implemented. As traffic light delays affect the ambulance on the way from and to the hospital, this technology could make a considerable difference to the prehospital time, especially for longer journeys.
Preventing Another Accident
Another important factor is preventing another accident involving the ambulance itself. The rules for normal drivers about what to do at a traffic light intersection is vague when an ambulance is going the other way. We are told to allow ambulances through, and this is common sense as well because we don’t want to hinder their journey, so with another driver waiting at a green light, the ambulance can be able to pass through a red. However the car driver completely has the right to go through the green light and force the ambulance to wait at the red light. This confusion can cause the two vehicles concerned to not know what the other is doing, and may cause a collision. Between 1993 and 2010, the National EMS Memorial Service reported around 97 technician fatalities (Maguire, 2011) due to ambulance collisions. Another telling statistic is that the road-accident rate for those working with the emergency services is 2.5-4.8 times higher that for those in all other occupations (Maguire, Hunting, Smith, & Levick, 2002). The other side of this is the civilians involved in these collisions, as generally they are not in the wrong. By ensuring the traffic light that the ambulance is approaching is changed to green, the other car will be forced to stop and it will become a normal junction where the risk of an accident is not increased.
Detecting The Ambulance
It is necessary to detect when the ambulance is approaching the traffic lights in order to be able to turn the lights green. To do this, all the ambulances in the city must be connected to the same cloud network as all the traffic light signal boxes. Then radio frequency identification (RFID) can be used by the traffic light to detect the tagged ambulance and therefore run the code to change the light sequence.
RFID is a process used to track consumer products all around the world. Originally it was used as a way to track and identify cattle for farmers but is now the new technology replacing bar codes in many shops as it has many benefits. Active tags contain a battery or other power source and passive tags can collect energy from the radio waves being emitted from a nearby RFID reader and contain 96-bits of electronically-stored data. This is accessed automatically using electromagnetic fields.
Simulation
I am aiming to simulate how each traffic light is programmed in its normal setting using a software called multisim. It starts as red, and then after a set amount of time goes green. After a delay, the light turns to amber and then to red. To simulate the traffic light response, a microcontroller is needed. A microcontroller is a a small computer that has one or more processors, memory, timers and input/output peripherals that can be programmed in a variety of languages including assembly. They are now used in a large variety of situations from children’s toys to medical devices.
There will be a pedestrian button in the circuit, activated by pressing the space bar in the simulation to change the lights from red to green or vice versa. It represents a pedestrian button at a crossing, where it is pressed to turn the light red and force the cars to stop to allow people to cross the road. In real life, they would change for a set amount of time before automatically stopping the pedestrians and allowing the cars to continue, however in my simulation the button must be pressed every time you want the lights to change sequence.
Coding
Multisim uses an interactive schematic to allow the user to design and simulate a circuit with a very large selection of varied components, including the microprocessor I am using and a traffic light simulator that demonstrates which colour light or lights are illuminated. The microprocessor is coded using Assembly language but this is one of many options. This is a low-level programming language that usually has one statement for each machine instruction. The source code must then be assembled.
A code written in assembly has three sections: data, bss and text (www.tutorialspoint.com, 2018).
The data section is where data and constants are initialised. These can’t be changed during the runtime. The syntax used is section.data.
In the bss section, variables are declared with the syntax section.bss.
The main section of the code all occurs in the text section. The syntax used is:
section.text
global_start
_start:
Comments are sections of text to tell the user what is happening in the code and they each begin with a semicolon (;).
Assembly language statements are written in a basic format of –
label mnemonic operands ;comment
where only the mnemonic is essential and the other parts can be omitted.
I will be using an 8052 microcontroller with four I/O ports that each has 8 pins. Each pin can be configured as input or output pins by applying logic 1 or logic 0 to the I/O port bit respectively. It has three 16-bit timers needed to implement the delays into this circuit, as well as 256 bytes of internal RAM. The timers’ interrupt ability are vital in this project to be able to interrupt the sequence when the pedestrian button is pressed.
Each pin within the ports has a specific use, some of which I have outlined below:
Port 1 (pins 1-8) and port 3 (pins 10-17) can all be configured as input or output pins depending on the logic state applied.
Port 2 (pins 21-28) and port 0 (32-39) are similar, however if external memory is used, port B works as a high order address bus and port 0 works as a low order address bus.
Pin 9 is used as a reset pin when logic state 1 is applied.
Pin 20 is connected to ground.
Pin 14 and 15 are used to connect the clock counter.
Pin 40 is the VCC pin used to supply power to the microcontroller.
Circuit Design
The requirements of the circuit are to run through the different stages of light combinations with varying delay times for each one. When the pedestrian button is pressed the traffic light on green will change to red, and the red one will change to green to allow them to cross the road.
Lights sequence:
Red
Green
Amber
Red
This code runs the main sequence of traffic lights. At each step it waits a second, clears the lights and sets the next stage.Main section of code:
MAIN:
CALL CLEAR_ALL ;Calling function
SETB RRED ;Setting lights
SETB LGREEN
MOV R0,#06H ;Delay before lights change
LOOP1: LCALL ONESEC ;Loop clears lights and runs sequence
DJNZ R0,LOOP1
CALL CLEAR_ALL
SETB RRED
SETB LYELLOW
LCALL ONESEC
CALL CLEAR_ALL
SETB LRED
SETB RRED
LCALL ONESEC
CALL CLEAR_ALL
SETB LRED
SETB RGREEN
MOV R0,#06H ;1 second delay before lights change
LOOP2: LCALL ONESEC
DJNZ R0,LOOP2
CALL CLEAR_ALL
SETB LRED
SETB RYELLOW
LCALL ONESEC ;1 second delay before changing to red
CALL CLEAR_ALL
SETB LRED
SETB RRED
LCALL ONESEC
JMP MAIN
This is a diagram of the microcontroller and it’s connections from each pin. I am using the 8052 microcontroller available in multisim. Pins 1- 6 are connected through buffers to a bus that then connects them to the traffic light control box. The buffer contains diodes to ensure that current only flows forwards in the correct direction.
When the pedestrian button is is pressed, the code jumps out of main and runs another loop:
; COUNT FOR ONE SECOND
ONESEC:
MOV R1,#14H ; COUNTER USED TO LOOP 20 TIMES, WHICH IS EQUIVALENT TO 1 SEC
SEC_LOOP:
MOV TH0,#00H ; CLEAR TIMER 0
MOV TL0,#00H
CLR TF0 ; CLEAR OVERFLOW BIT
SETB TR0 ; START TIMER 0
JNB TF0,$ ; WAIT FOR OVERFLOW FLAG
CLR TR0 ; STOP TIMER 0
JNZ BTN_PRESSED ;Pedestrian button pressed, break loop
DJNZ R1,SEC_LOOP
The main loop then continues to run but the lights are reversed to that the traffic light that was green last time is now red, and vice versa. This will run in an infinite loop until the user quits the program.
The other three connections to the microcontroller are the VCC set to 5V, the pedestrian button and the ground connection. All the pins that aren’t needed can just be left unconnected. There are also other sections of code that I haven’t shown here but are necessary for the code to run.
Discussion
This simulation shows clearly how traffic lights can be programmed simply using assembly code, and how a trigger can change the sequence and jump out of the main loop of code. In this situation the trigger was the pressing of the pedestrian button however when implementing the RFID technology to detect the ambulance, the trigger would be when the ambulance is approaching the light.
In order to implement this technology in real life to its maximum capacity, more experiments would need to be conducted. When a vehicle is approaching traffic lights, even if they are green, there is often still traffic waiting to accelerate back up to maximum speed. To reduce any delay at the lights, I would need to look at exactly how far away the ambulance should be from the lights when they turn green to ensure it doesn’t have to slow down in the traffic. This would require many surveys with varying amounts of traffic at the lights to find an optimum time to break the loop in the code.
It would also be necessary to look at the situation when the light would be green anyway to ensure that the code doesn’t automatically turn it red. This would require looking at the coding and detecting the traffic light states as the ambulance approaches. Also if the ambulance approaches just as the light has turned red and immediately it turns green again the traffic going the other way might get confused. This should be prevented by watching the ambulance as it approaches the lights and checking to see if they should be changing, and if so is there enough time.
In order to use the RFID system, all the ambulances must be fitted with an electronic tag and all the traffic light control boxes must be fitted with a detector. This could cost between several thousand to several hundred thousand pounds (Chai, 2018), so upfront, it is an expensive initiative. However overall I believe that it would save more money than is spent as everything would become more efficient. A lot of local ambulance services have already implemented RFID technology to track the expensive and critical equipment that is kept on the ambulances. The East Midlands Ambulance Service started using this in 2014 (Journal, 2018). There are passive tags on all the important machines and medicines which are read using a handheld reader and the data is transferred to their secure server. This wouldn’t cost much to expand into tracking the whole ambulance rather than just the equipment.
Once this technology becomes a possibility it would definitely be possible to apply it to the other emergency vehicles (police cars and fire engines). It would help them in the same way, by allowing them to get to emergencies faster and preventing many accidents involving other vehicles at intersections.
Conclusion
In my project my aim was to design and simulate a system that automatically turns traffic lights green as an ambulance approaches to reduce the response time of the emergency services. I have done research into how the ambulances could be detected and have decided that RFID is a simple, effective and relatively cheap way to do this. I then created a simulation that showed how the traffic lights run through their pattern automatically until a trigger causes it to jump out the code and allow whatever light the ambulance is approaching to be set to green.
I think the NAE grand challenges are a really important way at looking at vital projects that could make major differences in the current world we live in (Engineeringchallenges.org, 2018). ‘Advancing Health Informatics’ is simply about making the way we collect, manage and use all the medical data from patients and studies. We still use a lot of old systems that are not very efficient and optimising them could make a massive effect on the NHS in this country. Another side of health informatics is looking at dealing with and ideally preventing the future biological and chemical warfare attacks. As technology develops, there are more ways for terrorists to attack, but monitoring air and soil systems could help deal with this.
I really enjoyed looking at this topic for my project. I think it is a really interesting use for this technology that we will hopefully see implemented in ambulances as well as other emergency vehicles in the near future. It was really interesting to look at all the different aspects of research that have to be done before something like this could go from theory to being used practically. The economic viability is a major factor that has to be looked at further before this would ever be considered, however the RFID technology is reasonably priced for the benefits that could be seen.
References
Assets.publishing.service.gov.uk. (2018). [online] Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/648081/rrcgb2016-01.pdf [Accessed 1 Nov. 2018].
Chai, B. (2018). RFID implementation of an ambulance inventory system. [online] Repository.ntu.edu.sg. Available at: https://repository.ntu.edu.sg/handle/10356/59141 [Accessed 28 Nov. 2018].
Duffy, J. (2001). I-CAR professional automotive collision repair. Albany: Delmar Thomson Learning.
Gonzalez, R., Cummings, G., Phelan, H., Mulekar, M. and Rodning, C. (2009). Does increased emergency medical services prehospital time affect patient mortality in rural motor vehicle crashes? A statewide analysis. The American Journal of Surgery, [online] 197(1), pp.30-34. Available at: https://www.sciencedirect.com/science/article/pii/S0002961008002699 [Accessed 4 Nov. 2018].
Engineeringchallenges.org. (2018). Grand Challenges – 14 Grand Challenges for Engineering. [online] Available at: http://www.engineeringchallenges.org/challenges.aspx [Accessed 4 Nov. 2018].
Journal, R. (2018). East Midlands Ambulance Service Uses RFID to Track Equipment Quickly – 2014-07-02 – Page 1 – RFID Journal. [online] Rfidjournal.com. Available at: https://www.rfidjournal.com/articles/view?11948 [Accessed 28 Nov. 2018].
Levinson, D. (1998). Speed and Delay on Signalised Arterials. Journal of Transportation Engineering, 124(3), pp.258-263.
Maguire, B. J. (2011) “Transportation-Related Injuries and Fatalities among Emergency Medical Technicians and Paramedics,” Prehospital and Disaster Medicine. Cambridge University Press, 26(5), pp. 346–352. doi: 10.1017/S1049023X11006601.
Maguire, B. J., Hunting, K. L., Smith, G. S., Levick, N. R. (2002). Occupational fatalities in emergency medical services: A hidden crisis. Annals of Emergency Medicine, 40, 625–632. [online] Available at https://www.sciencedirect.com/science/article/pii/S0196064402006613 [Accessed 14 Nov. 2018].
Rospa.com. (2018). Rural Road Safety – RoSPA. [online] Available at: https://www.rospa.com/road-safety/advice/road-users/rural/ [Accessed 16 Nov. 2018].
www.tutorialspoint.com. (2018). Assembly Basic Syntax. [online] Available at: https://www.tutorialspoint.com/assembly_programming/assembly_basic_syntax.htm [Accessed 17 Nov. 2018].
Technical targets:
My aim for this project and report is to produce a fully working simulation of a traffic light with automated light changes including the code for the microcontroller written in assembly language. I also will do detailed research into how the ambulance approaching the intersection would be detected in theory, and how it can be economically implemented in real life situations as the best way to see if it would reduce ambulance journey time is to undertake a practical survey over a long period of time.
This requires me to become more confident using the Multisim software especially the more complicated components needed in this circuit such as the microcontroller, bus pins and traffic light simulator. I will also have to link my code to the program, which is something I haven’t used before. I also need to learn assembly code and how to write the basic commands I need for the simulation. This language is completely new to me as I will be starting from scratch, however I know we use it next term so this should help me.
I also hope to learn some background knowledge of microcontrollers and how they are connected into circuits. These are essential for use in electronic engineering and we do a module next term on them using the Assembly language, so hopefully this project will allow me to have a good understanding of how they work before then.
Other targets:
Writing long reports with correct grammar and punctuation is not something I have had much practice in so I’m hoping to use this project to get more experience with it. Also the research side of the report is something I would like to improve. I would like to make sure that I take data from lots of different sources including journals and books from the library rather than just websites. These all must be correctly referenced using the Harvard referencing style with in-text and bibliography citations so this is a good chance for me to ensure I am confident with this style of referencing. By using data from these sources to review and back up my points made I can ensure the theory is correct and the project will be a viable idea.
When writing the different sections of the report I want to ensure that I stick to the report marking criteria as well as trying to include the most relevant facts and information, as this will make sure I achieve the best grade possible. I want to put in enough detail that someone from a non-science background would be able to understand all my theory behind the idea and how it would translate to real life. Hopefully this project will allow me to develop these skills and improve my report writing, as this becomes a very important task as I start undertaking more projects and practical tasks in order to accurately and clearly put my points across.
Technical skills learnt:
In order to help teach myself about the microcontroller and assembly programming language I made use of my tutor’s knowledge on this topic as well as other lecturers from the university who have more experience with this technology. They were all very helpful and gave me hints about where to start my research into each section as well as a brief overview of how microcontrollers worked. I will now be more happy to ask for help and advice from anyone who has more knowledge on a topic I am trying to understand to help further my learning.
I have also learnt about RFID, the technology used to detect when the ambulance is approaching the lights. I hadn’t heard of this use for radio waves before, and wasn’t aware that it is such a widely used technology in all sectors from tracking cows and other animals in farming, to helping sell clothes and food items in retail.
I am also much more competent using multisim with the 8052 Microcontroller as this runs slightly differently to normal. As the code is required to run the simulation, a separate program checks it and compiles the code to ensure it runs correctly before running the simulation. This is something that I will now feel much happier using in future modules and projects. I also enjoyed using the traffic light simulation and this shows visually that the program is running correctly, something I will try to implement more in the future.
Other skills learnt:
I very much enjoyed undertaking the research behind this project. It was fascinating to read some of the journals that I have used as references and to see what type of projects people have done. I learnt much more about how to read and understand these and will definitely use this more in the future, as opposed to just websites that briefly explain the theory.
I also learnt that when thinking about ideas for a project I need to be more conscious of the time and resources available to me as well as my knowledge of the topic and how much I can realistically learn in the time specified. This project is a slightly different and simplified project of what I originally intended to do as some of the resources I needed weren’t available to me and I wasn’t going to be able to complete my project to the standard I wanted to if it was too complicated.
Finally I learnt a lot about time management and how to undertake such a big project. It is vital that you try and stick to your Gantt chart as much as possible as it is only going to make everything easier in the long run. We are mostly used to having pieces of coursework that can be completed in a few hours if necessary, but this project, like most projects when working in industry, needed a lot more time focused on it over a few months.
Project Management
My original idea for my project was to design and simulate an integrated circuit with a microcontroller that would detect a car accident and automatically contact the ambulance with the GPS services of the car. I did some research into this and found, however, that it would be too much work for the amount of time we were meant to spent on the project. The other issue was that the simulation was proving difficult as multisim and other simulation programs have no way of simulating the GSM module within the program which is needed to find the GPS coordinates and contact the emergency services.nTherefore I decided to stick with the same grand challenges and keep the focus around reducing prehospital approach but simplify the project so I could complete it in enough detail in the time allowed.
As the original Gantt chart I wrote was aimed at my first project idea it had to be altered to fit this project, and therefore started at a later date. In general I stuck to my modified Gantt chart, however when writing one again I will consider more carefully other deadlines and non-academic commitments. Sometimes I had a lot of work to do with my project and also lots of other deadlines and activities, and then other times I had only a few things to do on this project and no other commitments. I will also consider more carefully how long each test will take in comparison to others, as some of the tasks took longer than expected, and vice versa.
In the future I would try and find people doing similar projects to me, and see if there is any research they had done that would help my project. For example if I had stuck with my original project aimed at detection of a crash and contacting the ambulance I might have been able to do it if I focused on part of it and someone else did another part.
Overall I enjoyed most of the aspects of the project. It was nice to work through it all by myself, from the background research to the simulation and linking theory to practice to see how it would work in real life. I’m looking forward to the project next year when hopefully I will go back to my original idea and try to produce a working prototype.