My DIY pressure pulse sensor build

More
3 years 8 months ago #41673 by ctautotech
Hey all, been a subscriber since back in the winter sometime, done a ton of reading here but this is my first post. After watching the recent series of pressure pulse sensor videos, I decided to try my hand at building one since I have plenty of random parts and supplies kicking around, and I love making my own tools when I can. This is my result.

I scavenged the piezo element from an old smoke/CO detector unit - it's about 1" diameter and mounted inside a small plastic housing. In my search for an enclosure for my sensor, I came across a large aluminum electrical cable strain relief. The threaded end is 1/2" NPT male and 3/8" NPT female, so already easy to hook up adapters/hoses. The large end was almost a perfect fit for the piezo, but I did have to throw it in the lathe and bore it out about .060 and create a shoulder for the piezo to be held against by the cap. I used an old 10' RCA video cable for the lead, simply because it was available and I do have adapters for it for both BNC and banana jack scopes (I have a Hantek 6074 at home, and just this week got a Zeus for my own at work).

As for the second pic, it was late at night when I finished the build last week, but I wanted to see just how sensitive it was, so I hooked it up to the Hantek using the Hscope app on my phone. My voice created a good signal, but on a whim I decided to unscrew the barb fitting and adapter, and held the housing itself right up to the carotid artery in my neck. Lo and behold it produced a clean 14mV signal from my own pulse that even my lowly Hantek scope could pick up just fine. I was astounded. Still haven't gotten around to using it on a vehicle to see how useful it is at much higher frequencies / sample rates, but I think this is promising.

Anyway, just thought some folks might find it interesting. Cheers :)
Attachments:
The following user(s) said Thank You: Noah, Da Beginner

Please Log in or Create an account to join the conversation.

  • Noah
  • Noah's Avatar
  • Offline
  • Moderator
  • Moderator
  • Give code definitions with numbers!
More
3 years 8 months ago #41679 by Noah
Quite the cardiogram you've captured there.

Thanks for sharing your build with the community. Be sure to update us with more captures when you get to use it on a car.

And congratulations on the Zeus!

"Ground cannot be checked with a 10mm socket"

Please Log in or Create an account to join the conversation.

More
3 years 8 months ago #41682 by Tyler
The test results are in, and the EKG confirms it... You're a scope nerd. It's terminal. :silly:

Please Log in or Create an account to join the conversation.

Time to create page: 0.230 seconds