Pneumatic Thoracostomy Sim Trainer EMS Med Ed

A functional, active pneumothorax trainer that installs inside a standard CPR mannequin. Supports both needle decompression and finger thoracostomy with real air-puff feedback via embedded solenoids, FSR sensors, and an ESP32 controller.

This trainer was designed for EMS and medical education programs that need an inexpensive but realistic, repeatable platform for teaching tension pneumothorax interventions. It installs inside a standard CPR mannequin and provides active haptic feedback. When a learner successfully inserts at the correct location with adequate force, the system releases a puff of pressurized air simulating decompression. Please see our GitHub Repository (https://github.com/kardioversion1/ThoracostomyTrainer) for the most up-to-date PDF.

What it simulates:

• Needle thoracostomy at the 2nd intercostal space, lateral approach
• Finger thoracostomy at the 4th–5th intercostal space, lateral approach
• Tactile resistance through a replaceable latex skin insert
• Audible and tactile air-puff feedback on successful decompression
• Visual confirmation via OLED display (procedure counters, pressure bar, zone status)

How it works: A PETG box houses a 500cc IV bag bladder pressurized by a small DC air pump. Force-sensitive resistors (FSRs) sit beneath each insertion zone inside the TPU lung. When sufficient insertion force is detected, the corresponding solenoid valve opens briefly, venting air. The pump then automatically recharges the system. The ESP32 microcontroller allows for customizaiton of everything: sensor thresholds, solenoid timing, pump sequencing, and a full OLED menu with adjustable sensitivity and session counters.

Designed for training environments:

• Resets automatically between learners (typically 15–30 seconds)
• Replaceable latex skin inserts — consumable per session or per day depending on use
• Portable, battery-powered (2× 18650 cells, USB-C charging via TP4056)
• No external power required during training

A companion PDF with full build instructions, electronics wiring, firmware flashing guide, and facilitator training manual is in our GitHub Repository (https://github.com/kardioversion1/ThoracostomyTrainer).

PRINT INFORMATION

TPU Lung: Bambu TPU 90A

     2 walls, 3% gyroid infill

Electronics Enclosure: PLA or PETG

     3 walls, 15% infill, supports if needed

Ribs: PETG for strength (could experiment with firm TPU and multiple walls to prevent fracture)

     3 walls, 20% infill

TPU notes: Print slow (20–25mm/s outer wall). Bambu 90A at default profile works well. 85A is too floppy; 95A is too stiff.

Estimated total print time: ~14–18 hours across all parts

BUILD INFORMATION

Assembly requires basic electronics skills (soldering, wire management) and a few off-the-shelf components.

Required non-printed components (full BOM in PDF). Amazon links are associate links

• ESP32 WROOM-32 dev board
• SH1106 128×64 OLED display
• Rotary encoder with push button
• 2× Force Sensitive Resistors (FSR): https://amzn.to/4e0ekFq
• 2× FaO520D solenoid valves: https://amzn.to/4cBQyyB
• Small 5V DC air pump: https://amzn.to/4tZgfi5
• 3× IRLZ44N N-channel MOSFETs: https://amzn.to/42tsB6k
• XL6009 boost converter module: https://amzn.to/4d1aPO0
• TP4056 USB-C charger module: https://amzn.to/4vN4mOa
• 2× 18650 lithium cells
• 500cc IV bag or air bladder/BP cuff bladder
• Latex skin inserts (sourced via AliExpress 'Tattoo Skin'— see PDF)

Estimated build cost: ~$80–130 USD depending on sourcing

Skill level: Intermediate — comfortable with soldering, basic wiring, and flashing Arduino firmware via USB

ELECTRONICS 

The electronics system runs on an ESP32 with custom Arduino firmware (provided as a .ino file in the companion PDF package). Key features:

• Dual independent FSR zones with per-zone sensitivity adjustment (Low / Medium / High), saved to non-volatile flash
• Dominant-sensor logic prevents cross-zone false triggers
• Dual solenoid control with independent timing
• Pump auto-sequences after solenoid closes; optional pump pause delay
• OLED UI: live pressure bar, threshold tick marks, countdown timers, procedure counters
• Full settings menu via rotary encoder
• USB-C charging; no modification to the mannequin's exterior required

Firmware: Available in the companion PDF package. Flash via Arduino IDE or PlatformIO. All dependencies documented.

Wiring diagram and GPIO table are included in the build PDF.

Build GitHub and PDF with BOM

Please see our GitHub Repository (https://github.com/kardioversion1/ThoracostomyTrainer) for the most up-to-date PDF. For more information, visit www.myKPEC.com or email me at evan@mykpec!

medical, simulation, training, EMS, ESP32, TPU, functional, thoracostomy needle-decompression pneumothorax, anatomy, education.