TissueDB/Simulators/Tourniquet Simulator

The Tourniquet Simulator is a low-cost trainer built from locally available wood, PVC pipe and hardware for practising tourniquet application in extremity haemorrhage control. It is the Simple Version of the CrashSavers DIY trainer.^[2] Its wood frame supports two PVC half-pipes around a spring-loaded mechanism. Tightening a tourniquet compresses a latex hose and stops water flowing from a hand pump into a collection bottle, providing visible feedback. The Simple Version can be used alongside the mobile app’s self-assessment checklist; it has no direct electronic connection to the app.^[1] The parts, dimensions, original priced shopping list and illustrated assembly below follow the CrashSavers construction manual. Later spring-selection and calibration guidance is distinguished in the setup section.^[3]

The construction manual prices 14 shopping-list items at a total of US$41.45. It lists super glue, epoxy and plastic ties without prices. The three separately cited retail packs add US$13.65, giving US$55.10 before tools, calibration equipment and a tourniquet. These pack prices are purchasing benchmarks, not measured consumption costs.

Parts Reference

• Source PDF: Simple Tourniquet Simulator — Step by Step Building Manual
• Wood cutting diagrams: Wood Diagrams (external link) or see Section 4.1.1 of the PDF above.

For complete tools list, see the Step-by-Step Building Manual (PDF).

The W-4 drawing shows a 40 mm width in one view and 20 mm in the other, while stating a 10 mm thickness. Confirm the intended cross-section with the authors before cutting W-4.

Cut sizes and hardware specifications

• Blood vessel: 1 × Latex plastic hose, 5 mm (3/16 in) diameter, 1 m (39 in) length.
• Limb: 2 × PVC pipe, 10 cm (4 in) diameter.
• Frame long sides (W-1): 4 (300 × 20 × 10 mm / 12 × 0.8 × 0.4 in). The original drawing shows a longitudinal slot/groove 200 mm long and 2 mm wide, beginning 50 mm from the end, and Ø5 mm holes in both illustrated face views. The 10 mm side view positions its two holes 20 mm from each end and 5 mm across the face. Confirm the slot depth or through-cut requirement and any unlabelled hole positioning with the authors before machining.
• Frame short sides (W-2): 4 (150 × 20 × 10 mm / 6 × 0.8 × 0.4 in; 5 holes Ø5.0 mm per source diagram).
• Compression crosspiece (W-3): 1 (240 × 20 × 10 mm / 9.5 × 0.8 × 0.4 in; 3 holes Ø6.0 mm for the vertical S-3 posts and 2 holes Ø5.0 mm to the frame, per source diagram).
• Horizontal base beams (W-4): 2 (500 mm / about 20 in long; 10 mm thick; 2 holes Ø5.0 mm in each illustrated view; width discrepancy described below).
• Upright supports (W-5): 4 (175 × 20 × 10 mm / 6.9 × 0.8 × 0.4 in; 2 holes Ø5.0 mm per source diagram).
• Base board (W-6): 1 (600 × 400 × 10 mm / 23.5 × 15.75 × 0.4 in; four mounting positions per source diagram).
• Transverse brace (W-7): 1 (240 × 20 × 10 mm / 9.5 × 0.8 × 0.4 in; 2 holes Ø5.0 mm per source diagram).
• Frame assembly screws (S-1): 16 × Screws 3.0 mm × 4.5 cm (1/8 × 1-3/4 in).
• Spring assembly screws (S-2): 4 × Screws 3.0 mm × 8.0 cm (1/8 × 3 in).
• Centerline post fasteners (S-3): 3 × Screws 4.0 mm × 8.0 cm (5/32 × 3 in).
• Base and upright mounting screws (FS-1): 8 × Flat head screws 3.0 mm × 8.0 cm (1/8 × 3 in).
• Small fastener nuts: 36 × Nuts 3.0 mm (1/8 in).
• Large fastener nuts: 6 × Nuts 4.0 mm (5/32 in).
• Compression springs (R-1): 4 (4.0 mm × 4.0 cm / 5/32 × 1.6 in each, cut from one 30 cm / 12 in spring).

Safety note: The construction manual specifies safety glasses, a gown and safety gloves when preparing the wood. Follow the operating instructions for the tools being used.

Step 1: Prepare the wood pieces using the Structural Parts table and the cutting diagrams for dimensions and mounting positions. Check the W-4 discrepancy above before cutting that part. Sand cut edges smooth with the listed sandpaper.

Step 2: Drill the holes at the positions shown in the diagrams: W-1, the Ø5.0 mm holes in both face views; W-2, 5 × Ø5.0 mm; W-3, 3 × Ø6.0 mm and 2 × Ø5.0 mm; W-4, the Ø5.0 mm holes in its two views; W-5 and W-7, 2 × Ø5.0 mm each. The W-6 drawing marks four mounting positions. For W-1, follow both face views and the 200 × 2 mm slot/groove dimensions on page 23; its depth or through-cut requirement is not stated in the drawing.

Step 3: Prepare the PVC half-pipes: The original parts list calls for two half-pipes cut from 4 in (about 10 cm) diameter PVC pipe. Split the pipe lengthwise and smooth the cut edges. The diameter is not the cut length; the construction manual does not give a pipe length.

Step 4: Prepare four R-1 compression springs. The original construction drawing specifies four pieces, each 4 cm long and 4 mm in diameter, purchased as 30 cm stock. Cut to the specified piece length rather than dividing the stock equally; unused stock need not be consumed. The later calibration guide changes these dimensions, so review the spring-selection section before preparing the springs.

Step 1: Start the first rectangular frame. Join one W-1 long side to one W-2 short side at a right angle with an S-1 screw and the illustrated 3.0 mm nuts.

Step 2: Complete the first frame with the second W-1 and W-2 pieces, fastening the remaining corners with S-1 screws. This frame contains two W-1 and two W-2 pieces.

Step 3: Attach W-3 across the first frame using S-1 screws at its ends, as shown in the illustration.

Step 4: Install the three S-3 posts through W-3. Insert the 4.0 mm × 8.0 cm screws into the three Ø6.0 mm holes and secure them with the six 4.0 mm nuts, one on each side of the crosspiece at each post, as drawn.

Step 5: Start the second rectangular frame using another W-1 and W-2 pair and S-1 screws.

Step 6: Complete the second frame with the remaining W-1 and W-2 pieces. It has the same long-side and short-side dimensions as the first frame and remains separate at this stage.

Step 7: Attach W-7 across the second frame using S-1 screws at its ends, as illustrated.

Step 8: Join the frames with the spring assemblies. Align the matching W-2 holes and fit four S-2 screws through the two frames, each with an R-1 spring between the frames. Fit the nuts in the illustrated positions. The original shopping list recommends washers with the S-2 screws; it does not give their quantity, size or price.^[3] The springs separate the frames and allow them to move together under tourniquet pressure; do not fasten the two frames into a rigid stack.

Step 9: Place the PVC half-pipes on the outside faces of the spring-loaded frame, one above and one below as illustrated. These form the limb surface around which the tourniquet is applied.

Step 10: Assemble the support base. Mount the two W-4 horizontal rails on the W-6 base board and attach the four W-5 uprights to the rails using FS-1 screws, following the illustrated positions. W-5 supports the simulator; it is not a set of spring-compression plates.

Step 11: Mount the simulator assembly on the four W-5 uprights using S-1 screws at the positions shown. Check that the assembly is supported and that the two frames can compress against their springs. Complete the fluid system and calibration before practice.

Fluid System Components and Tools

Step 1: Insert one end of the latex hose (5 mm (3/16 in) diameter) into the fumigator (pump sprayer) nozzle. Wrap the connection with Teflon tape to create a watertight seal.

TEST: Pump water through the system before continuing to verify the seal holds. Fix any leaks before proceeding.

Step 2: Thread the latex hose through the middle of the mechanical system, running it lengthwise through the compression zone beneath/between the PVC half-pipes. The hose must sit in the path where spring compression will squeeze it when a tourniquet is applied.

Step 3: Use plastic cable ties to secure the hose at 3 points along the mechanical frame. Caution: Do not overtighten — the ties should hold the hose in position without restricting fluid flow when no tourniquet is applied.

Step 4: Place the outlet end of the hose into the collection bottle as illustrated, using Teflon tape at the connection. The source specifies a bottle larger than 32 oz (about 1 L). Water is supplied by the pump reservoir and collected in this bottle after passing through the simulator.

The authors’ documents give different spring specifications. The original construction manual lists four R-1 springs of 4 mm diameter and 4 cm length. The later How to Use Guide recommends helical compression springs 7–15 mm in diameter (8 mm preferred), specifies a 5 cm cut length, and starts calibration with 4 cm between the upper and lower platforms. The 4 cm platform gap is a different measurement from the spring’s uncompressed length. Confirm which spring specification applies to the build before treating it as calibrated.^[4]

The later guide also recommends checking the spring’s wire thickness against a large paper clip: the spring wire should be no thicker than the clip wire. This is a separate measurement from the overall spring diameter.^[4]

For the later guide’s procedure, have a blood-pressure cuff, string, ruler, tape, a large paper clip and a tourniquet available. Set the platform gap to 4 cm at all four corners. Wrap the cuff around the PVC surface and inflate it to 20 mmHg. Loop the string around the cuff, marking the overlap without adding compression. Apply the tourniquet until the cuff reads 80–100 mmHg, then mark the new overlap and measure the clear distance from the end of the first tape mark to the beginning of the second, as shown in the guide. Compare that distance with the guide’s spring table: 11 cm for 7 mm springs; 8 cm for 8 mm springs; 6 cm for 11 mm springs; and 3 cm for 15 mm springs. These are the authors’ simulator-calibration readings, not patient treatment targets. The guide does not give a calibration-table entry for the original 4 mm spring.

The 2024 study notes that variation in locally obtained springs and tubing can affect calibration and the pressure required to stop flow. Check water flow and the compression response before practice rather than assuming that any substituted spring or hose reproduces the study model.^[2]

The 2024 study reports content, construct and training validation of the CrashSavers simulator.^[2] A later study of the full CrashSavers self-training course enrolled 64 first-responder firefighters in Guatemala City. Time to stop a simulated bleed fell from 58.5 s to 39.2 s (P < 0.003); assessment 18 months after training found retained confidence and tourniquet-placement psychomotor skill. These findings concern the combined didactics, virtual-reality cases and simulator course.^[5]