Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/jessicarod7/aps490_pfpu2_mini

PFPU2 capstone software
https://github.com/jessicarod7/aps490_pfpu2_mini

aps490 capstone detection embedded rp2040 rust science

Last synced: 3 days ago
JSON representation

PFPU2 capstone software

Awesome Lists containing this project

README 

        
# Automated Brain Detection System



For the Multidisciplinary Capstone Project at the University of Toronto, our team (PFPU2) was tasked

with identifying methods to avoid unintentional brain damage during autopsies. Typically, this is

the result of the varying thickness of cranial bone, which makes it difficult to estimate the

distance to the brain. When combined with the rapid turnaround needed in pathology units, this means

some damage from the autopsy saw is not uncommon.



Our solution was a contact detection system, which measures conductivity by passing a high-frequency

AC signal through the saw blade, and measuring the output to identify fluctuations in the signal. It

is inspired and derived from the SawStop® automatic braking technology used in woodworking.



You can find a copy of our showcase poster [here](./Capstone_Poster_FINAL_-_cmyk_300_dpi.pdf).



## About the code



This pure Rust project was designed for the RP2040 (mainly the Pi Pico board). It generates a 100

kHz signal using PWM and measures the output with the ADC. The current implementation could use some

improvements in analyzing the signal (especially with timing), but was sufficient to identify

contact with highly conductive surfaces, and shows indications of doing the same with capacitance.



If you're building on the design, here are some useful references:



- The schematic for our design can be found in the hardware branch

  of [jessicarod7/aps490_retraction_fsm](https://github.com/jessicarod7/aps490_retraction_fsm/tree/hardware).

  Don't copy the battery charger, instead reference

  the [Pi Pico datasheet §4.5-4.6](https://datasheets.raspberrypi.com/pico/pico-datasheet.pdf#page-21).

- Look at the high/low voltage range of the signal, but also _the voltage itself_. I found it

  increases significantly with proximity (not just contact) with highly conductive surfaces, like

  the capacitive capabilities of the SawStop.

  See [the poster](./Capstone_Poster_FINAL_-_cmyk_300_dpi.pdf) (§5.0, _Detected ΔVavg_)

  for more information.



The [`logs/`](./logs) folder contains some recorded test data used in system validation. It's not

critical to the program.



## About us



We are undergraduate students completing our BASc:



- Zainab Ali, Mechanical Engineering

- Olivia Lotzer, Mechanical Engineering

- Jessica Rodriguez, Computer Engineering

- Tina Sokhanvar, Mechanical Engineering

- Zeynep Tibik, Mechanical Engineering



I'm Jessica, and wrote the software in this repo.



## Acknowledgements



We would like to thank the following individuals:



- Our client, Dr. Christoper Ball, forensic pathologist with the Provincial Forensic Pathology

  Unit (PFPU) in Ontario, Canada

- Our industry advisor, Dr. Fabio Tironi, forensic pathologist

- Our supervisor and APS490 course coordinator, Dr. Kamran Behdinan, professor in Mechanical

  Engineering and UT-IMDI director

- Our TA, Ranjan Mishra, PhD candidate



We would also like to thank our additional contact points, the PFPU, and the entire APS490 course

team for their assistance.



### SawStop



We took inspiration from the SawStop design, covered by the now-expired US patent 7,055,417, and

which may be covered by continuations or international patents. We built our proof-of-concept for

experimental use only, and have no plans to scale. If you intend to build on our design, you should

consult for legal advice, especially if you plan to do so at a larger scale or commercially.



SawStop and all related terms are trademarks or registered trademarks of SawStop, LLC.



## License



Copyright 2024 Jessica Rodriguez



Licensed under the Apache License, Version 2.0 (the "License");

you may not use this file except in compliance with the License.

You may obtain a copy of the License at



http://www.apache.org/licenses/LICENSE-2.0



Unless required by applicable law or agreed to in writing, software

distributed under the License is distributed on an "AS IS" BASIS,

WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

See the License for the specific language governing permissions and

limitations under the License.