PowerPoint Presentation

Designing a Weight-Sensitive Car Seat Sensor to Reduce the Risk of Whiplash InjuriesPhilip YanSchool of Kinesiology

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-Introduce myself-Introduce my project

Hello, my name is Philip. I hope everyone is enjoying the conference so far and thank you for being here. I have been working on a project at the Sensorimotor Physiology lab for a couple months now and am excited to share what I have learned. My project is entitled Designing a weight sensitive car seat sensor to reduce risk of whiplash injuries. The thing I love most about this is that it really is multidisciplinary. Although it is more of an applied science design project, its basis and applications are grounded in human kinetics and physiology.1

2Numbers Game4,610,000Population260,000Crashes85,000Injuries59,000Whiplash Injuries~ 1% of the Population in British ColumbiaOver $850 Million AnnuallyICBC, 2013

-Why is whiplash research important?

Im usually not a person whos great working with numbers, but I feel like this is a great example that puts into perspective why this research project is so important.

The population of BC is approximately 4.6 million people. In 2013, there were 260,000 reported car crashes and 85,000 reported injuries. ICBC states that whiplash accounts for ~70% of all automobile injuries which means that there were just under 60,000 whiplash injuries in 2013 in BC. Indeed this is a lot of people; however, when looking at the big picture, this is just 1% of the population of BC, and this small population is costing the province over $850 million each year in settlement costs and lost wages.2

What is Whiplash?3

-Define whiplash and symptoms

What is whiplash exactly? Soft tissue damage in the back of the neck resulting from a sudden extension and flexion of the head relative to the torso. The most common symptoms experienced after whiplash include neck pain and headaches which may persist for weeks, months, or even years depending on severity and treatment of the injury.

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The Current Market

Volvo Whiplash Protection SystemGM High Retention Seat4

-Introduce Anti-whiplash devices-aim-2 examples

To prevent whiplash, current car manufacturers have come up with structures termed anti-whiplash devices such as the Volvo Whiplash Protection System and the GM high retention seat. The aim of all these devices are to prevent a whipping motion of the head during a collision by transferring the energy from the occupants head and body onto the seat.

The Whiplash Protection System works by rotating the seat backwards as the occupant gets pushed back into it, and the high retention seat works by utilizing a stiff frame in conjunction with a distensible seatback material so it acts like a baseball mitt to absorb energy and catch the occupant.4

Overall objectiveDifferences in likelihood to suffer whiplash injury based on weight, height, etc.(Mang, 2010)

Currently, no seat design takes into account weight of occupant to reduce whiplash

Create a car seat that can assess mass of person and adapt accordingly in a crash setting

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However, even with these devices, research shows that different populations have variable risk of whiplash injuries. For example, women are still approximately 2 times more likely to suffer from whiplash injuries than men after a collision. This difference has been hypothesized to be attributed to the optimization of anti-whiplash devices for the height and weight of an average male occupant.

The end objective of the entire research project is to develop an adaptive seat that can use occupant weight information to personalize the seatback response during a crash. This means that it will use motors to rotate the seatback at a specified speed and distance for people of different weights.For example, the seat will distend more and decelerate over a longer period of time for a heavier person compared to a lighter person.

The picture that you see on the right side is a rendering of the actual seat frame that was made. 5

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Next we have a video showing the setup that was built in the lab to simulate car crashes. This particular trial was simulating a 12km/hr rear end collision using a crash test dummy on a traditional car seat.6

Design and create a sensor that will measure and classify an occupants weight into a weight category

Objective of my project

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-Current occupant weighing systems-Describe pictures-Aim of my project

The aim of my project is to design and develop a sensor prototype that will measure an occupants weight and classify him into one of 7 weight categories. When completed, this will be mounted onto the car seat and will feed information to the seatback motors7

Circuit boardForce plateLoad cell calibrationDummy testing*Human testing

8Overview of project

This is the overview of my project and well go more in depth about each of these steps.8

Circuit Board9Design

To start the project we first needed to make a circuit board that receives the input information from the load cells and outputs it to a computer software.

The components of the circuit board allows us to do 2 things:-turn the force plate on and off-adjust the signal amplification of each load cell so that we can accurately read what were measuring9

Force plate: Aluminum plate on metal frame

Design10

To make the force plate, we took 4 load cells from an electronic bathroom scale and made an aluminum base for them. In addition, notches were cut to hold the load cells in place. The advantage of having an aluminum base plate is that it will not deform no matter how many times it gets sat on, as compared to, say, a sheet of force sensitive resistors that also detect force but might bend over time and give an inaccurate force reading.10

11Calibration results

89.78 lb/v25.19 lb/v32.06 lb/v30.71 lb/v

Because the load cells only record information in voltages, we needed to find out the force:voltage ratio of each individual load cell. We have just finished this step and to do that, we used a force gauge, as shown here. It works by telling us exactly how many pounds of force we are exerting as we press down on the load sensor with the gauge. At the same time, the load cells record the same information, except in voltages. Using the voltage data from load cells and force information from the force gauge, we created the graphs that we have here. The red lines indicate pounds of force, and the blue lines indicate voltage that the load cells recorded.

For example, load cell 3 recorded approximately 2 volts when we exerted 60 pounds of force on it.

From these graphs, we determined the force:voltage ratio of each load cell as displayed by the numbers above the graphs. Load cell 3 will record 1 volt for every 32 pounds of force.

Knowing this information, we can standardize weight readings across all 4 load cells.11

12Future steps

Over here, we have our car seat frame that lies underneath the foam that you sit on. Our next step is to attach our sensor prototype to the metal frame of the seat base, as shown by the red rectangle.12

BIORID II crash test dummy

Labview

Future steps13

In the next few weeks we plan to test our sensor for reliability and functionality by placing a crash test dummy onto the car seat. Our force plate should classify the dummy into the same weight category every trial, within a wide margin of variation in the positioning of the dummy.

To classify weight of the occupant, we use a computer software called Labview. This program that weve created categorizes occupant weight through a series of yes/no or true/false statements.13

70% are whiplash related = ~60,000 whiplash injuries in a year

~1 person every 10 minutes

Conclusions14

If you remember the statistics from the beginning of the presentation, there were 60,000 whiplash injuries in 2013. This actually means that 1 person receives a whiplash injury every 10 minutes. From the beginning of this presentation until the end, there will be another person who has suffered whiplash.

By developing a weight sensor that allows for unique seatback responses, we may be able to decrease the incidence of whiplash injury and subsequently, the social and economic burden it places on our society.

In conclusion, I would like to stress that my project to build a weight sensitive car seat sensor is an important area of research that incorporates different disciplines and is applicable to all of us.14

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British Columbia Government EBook Collection, & Insurance Corporation of British Columbia. (2013). Quick statistics. North Vancouver, B.C.: ICBC.

Harder, S., Veilleux, M. and Suissa, S. (1998). The effect of socio-demographic and crash-related factors on the prognosis of whiplash. J Clin Epidemiol 51(5): 377-84.

ICBC (2000). Annual Report. British Columbia, Insurance Company of British Columbia.

Mang, D. (2010). Using acoustic stimuli to inhibit the startle response triggered by whiplash collisions : Implications for injury prevention

16References

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Todman, D. H. (2007). Whiplash injuries: A historical review. The Internet Journal of Neurology 8(2).

Y. Sterner and B. Gerdle, "Acute and Chronic Whiplash Disorders - A Review," J Rehabil Med, vol. 36, pp. 193-210, 2004.

17References

Problems encountered

What materials to useFSR sheet

Calibration of circuit board

18Questions

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This project is really unique because it will be the first to create a seat that can automatically adapt its crash response according to the weight of its passenger.21Questions