You’ve just had a crash. You think you hit your head in the process, but how hard? Hard enough to break the helmet? Hard enough to give yourself a concussion or the chance of a TBI(Traumatic Brain Injury)? Those are the questions that the Tozuda Head Impact Sensors aim to answer. There have been impact sensors before them, but Tozuda wanted to come up with an answer that was simple, easy to see, and required zero electronic parts.

Tozuda Helmet Impact Sensors turn red if a concussion is probable

Tozuda Helmet Impact Sensors turn red if a concussion is probable

The small capsule is completely mechanical and contains a liquid and a red dye. If the helmet and the sensor experience an impact of 85Gs or greater, the sensor will turn red almost instantly and clearly indicate that you should be checked for a head injury. According to Tozuda, at 85Gs, an adult has a 60% likelihood of concussion based on research from Brown University.

Designed to be small and light enough to use on any helmet, the sensors are 15mm x 15mm x 40mm and weigh in at 8g.

Obviously, there are a number of uses beyond cycling – like high impact sports including football and hockey. Essentially, if you wear a helmet, you could stick a sensor to it – though Tozuda only shows the sensors on helmets with a hard plastic ABS shell. Over the years, we’ve heard mixed advice about sticking any kind of device to the outside of a helmet for fear that impacting the helmet at that same point could potentially change the way the helmet would protect your head in the event of a crash (we’ve reached out to Tozuda about this for comment and will report back). It seems that this might be more probable if you put the Tozuda sensor on a super light cycling helmet. Keep that in mind if you decide to pledge for their Kickstarter where sensors start at $20 a piece for their early bird deal. All sensors will be made in Philadelphia, and will ship in September.


  1. deanaaargh on

    Seems like someone should integrate this into their helmet design.

    …if not for purely cynical reasons to sell replacement helmets that have been knocked

    • typevertigo on

      Agreed. Something like the G-indicator stickers that “Mythbusters” used to use would be great in terms of size reduction, but this is good too.

  2. Dylan on

    Maybe they could make it a replaceable part in the helmet design similar to the pads inside of a football, lacrosse, and hockey helmet. That way they could just sell a lot of these $20 small parts (instead of expensive ($150+) helmets each time an event occurs. In terms of other sports of course, you should always get a new bike helmet when you hit the ground with one.

    • goliath on

      Dylan – I am not sure that helmet manufacturers would be willing to accept the liability associated with a built-in concussion indicator, which the general user base would assume to be a flawless and accurate system.

  3. Bogey on

    Someone should tell them that this technically is an indicator and not a sensor.

    What really bothers me though is that it won’t react the same to hits from various angles or to glancing blows. Even though these types of impacts are dangerous, this unit may not indicate that a hard hit has happened.

    It is a step in the right direction but isn’t quite there yet because people will rely on it.

    • Crash Bandicoot on

      I think it’s a step in the right direction. I hate to say this but the costs of going to the emergency room, checked out, CT scans, and other imaging combined with HDHCP’s have deterred me from going in every time I’ve cracked a helmet which is quite scary in hindsight. Therein lies the problem in countries with nationalized healthcare this is less of an issue because you’d be stupid not to go in and get checked out. I can definitely see this helping folks in the good ol US of A where an ER visit can end up costing 10 grand +

      • German Healthcare Fanboy on

        Had a crash with my bike. Landed on my head. Had it checked for zero bucks! Why would someone not want this???


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