MIPS system: interview with the company

The yellow superstructure typical of the first generation of MIPS devices has now become part of the essential devices in a helmet. But where does it come from?

Does our brain have its own structure that helps absorb impacts?

The brain is surrounded by skull bones, which give it a protective shell. Between the skull and the brain is a fluid called cerebrospinal fluid which makes it possible for the brain to move relative to the brain itself (see answers below on the brain, rotational motion, and relative motion). However, all tissue, such as skull bones, brain tissue, and blood vessels, has a limit of strength.

What happens to the brain during a fall where the head is hit?

We usually talk about straight falls and oblique falls. Straight fall is considered in most helmet test standards. Through this, one can see how the head falls straight towards the ground considering only the vertical speed. An oblique impact is when you impact against an angle. For example, when riding a bicycle and hitting an object, you have a vertical velocity towards the ground and a forward velocity while falling. Therefore, the impact with the ground is oblique.

In addition to the difference in the fall, there are the properties of the brain. The brain can be seen as a gel with a high water content. Therefore, the properties are similar to those of water. If you move a glass of water sideways not much happens, but if you rotate the glass there is more deformation of the water. This is also what the brain experiences: if you have a vertical impact, the brain tissue doesn't deform much because the rotation of the head is minimal. However, when the impact is oblique, the head and brain rotate and the brain tissue deforms more.

An oblique impact is much more common in a crash than a completely vertical impact, which is quite rare.

What are the forces expressed in kg that our brain undergoes during a fall?

This obviously depends on the impact situation. However, the head experiences a force of approx 750 kg during impact.

Given that the protection of the skull is important for everyone, how much can a head injury affect a young person of developmental age?

The anatomy of the head changes over time, especially in younger individuals who have softer skull bone with sutures and fontanelles, which makes rapid brain growth possible. Thus, the skull bone of young children may be more sensitive to shock than in adults.

Unfortunately, we still see cyclists who do not use helmets, what is the difference for our brain between an impact with or without a helmet?

Epidemiological studies, experiments and simulations have shown that the helmet protects the head. A greater decrease in the number of fractures is observed compared to some brain injuries. This is probably influenced by the fact that the helmet design was more optimized for skull fracture, since only straight-line impacts were evaluated in the standard. However, studies have shown that helmets have a positive effect for both skull fractures and brain injuries. But wearing or not wearing a helmet can be a matter of life and death.

What was your input into the initial design of the MIPS system? Where did the idea of ​​creating this structure, which is proving to be revolutionary for the protection of the skull, come from?

The idea of ​​Mips technology comes from the anatomy of the human head. The brain is surrounded by the "shell" of the skull and between the brain and the skull there is a fluid which makes possible the movement of the brain relative to the skull. The basis of Mips technology is relative movement.

Apparently the MIPS system would seem simple and we don't always fully perceive what happens to our brain during a fall with a helmet with or without MIPS, could you briefly explain the physiological differences?

The purpose of MIPS technology is to help redirect some of the rotational motion away from the brain and instead transform it into linear motion in certain impacts.

There are helmets on the market with different types of MIPS, what are the differences between the various technologies?

The principle is the same, with relative motion between the head and the helmet aiming to help redirect some of the rotational motion in certain impacts. Beyond that, the design features are different and one system may be better suited to a more ventilated helmet and another to a fully covered helmet. But all are designed to do the same thing.

They all start from a single project or have had an autonomous development?

We started with one system and the others have evolved over the years to be even more integrated into the helmet.

Observing the first MIPS, the first reflection was the following: how is it possible that such a light structure could have strategic importance for the health of my head? So my question is: "how many tests have been done to reach the first model of MIPS, which was effective and robust at the same time at the right point?"

The first prototype was designed during the late 90s but the first finished product hit the market in 2007 so a lot of tests have been done in the meantime. To date we have performed over 67.000 tests in our test laboratory.

To objectively verify the robustness of a helmet, did you also have to invent a machine that simulated different types of rotational impact?

The simulated impact test is the oblique one, which we use in our test laboratory to evaluate our technology and which has been performed in different ways over the years. We started using a test method that others have already used, where the helmet and head are dropped against a moving impact surface. With the plate in motion, a horizontal velocity is applied to the helmet upon impact, in addition to the vertical velocity due to the vertical drop. Today, a test method is used in which the helmet is dropped against an angled surface, which also provides a horizontal and vertical velocity component. This test method is now also used in some motorcycle helmet test standards, such as the ECE 22.06 standard.

How did you manage to measure the degree of absorption of rotational impacts to translate it into a number that was understandable even by a simple enthusiast like me?

Each helmet sold with Mips technology is evaluated in our test laboratory before carrying out what we call the homologation test. We perform three different impact tests against an angled surface where the impact location is different. These tests are performed with and without Mips technology. The measured kinematics of head shape during impact are then applied to a computer model of the head and brain. The extent of stretching of brain tissue, called deformation, is studied. Then we can compare the model with Mips technology and the one without Mips technology. The helmet with Mips technology must significantly reduce the deformation to pass the homologation test.

On average, how often a helmet should be replaced even if it hasn't been hit?

It's a rather difficult question to answer, it could depend on the use of the helmet. The expansive materials used in helmets can change their properties over time, for example due to UV rays. However, a study has been published that collected used helmets and tested them again in the laboratory. Small differences were found between the newer and older helmets in terms of impact attenuation. It should be remembered, however, that these tests were limited to straight impacts and not oblique ones. In general it is therefore advisable to replace the helmet immediately after the impact.

What projects are you currently working on??

We're working on many different things right now, but to name a few we're developing new products, working with our partners to equip more helmets with MIPS, and delivering on our all-important sustainability agenda.