MCKelly – ALS part 2

I have nearly finished the upgrade of one of our MegaCode Kelly’s as referenced here.  Well, that’s not for the faint of heart.  I’ve seen the ResusAnne Simulator SimPad upgrade kit which is very complete.  All of the little bits and pieces (cable ties, anchors, hoses, etc.) which are included in that kit need to be worked out and sourced independently for this upgrade.

This does require a complete tear-down of the manikin.

The main board mounting plate needs to be re-drilled to accommodate the larger main board.  The lower left corner stays in the same place and holes are drilled to match.  The load board moves directly up to clear the main board.

main board drill pattern

Here’s a photo of what it should look like when re-installed in the manikin.  Notice that the load board extends over the edge of the cutout in the manikin.

IMG_20131001_124449

The next big modification is the chest.  The lung occluder servos end in a fitting 13mm OD.  The end of the trachea (just past the bifurcation) is 19mm OD.  The original ALS has a molded adapter tube to join these parts.

IMG_20130925_162124

I made up a stack of flexible PVC hoses (13mm ID, 16mm ID, 19mm ID) to make this transition.  There was also a change in lung design at some point.  I really like the idea of a screw connector to replace the lungs, so kept our old grey lungs for the time being.  Eventually, we’ll switch to the new white style lungs.  I cut a 20mm sprinkler riser in half to make this connection. It screws into the end of the lung occluder assembly and secured to the lung with a cable tie.

IMG_20131001_171207The connection to the pressure sensors uses about 300mm of 3mm ID PVC hose.  This hose also fits the connections on the chest rise bladder and the hose from the thigh tank.  It has a larger OD, but opening out the chest plug with a drill worked OK.

Finally, the thigh tank reservoir.  I couldn’t stand the schraeder valve (bicycle) connection and wanted this to interface with our standard wall air setup.  This required some slight modifications to the thigh tank assembly.

I removed the schraeder valve and the rest of the components temporarily.  Note that this assembly consists of the fill valve, reservoir tank, relief valve, 10 psi regulator, 8 psi regulator and finally a solenoid valve.  I have no idea why Laerdal chose to put in two regulators set so closely together.  I also noted that the locking nuts on the regulators came loose fairly easily and needed to be re-tightened.

IMG_20131001_154646IMG_20131001_154527IMG_20131001_155021IMG_20131001_155827

On the first leg I managed to break the hose barbs off both the inside of the schraeder valve and the Tee fitting that screws into the tank.  Note that the clear hoses are 1/4″ OD and DO NOT fit into 6mm push on-fittings.  Thankfully, 6mm soft poly tubing has the same ID as the original and fits nicely.  The Tee replacement I used was a 6mm x 1/8″ thread tee from SMC pneumatics.  I also installed a check valve in the thigh assembly between the tank Tee and the external fill hose since the QD we’re using doesn’t seal on the plug end.

IMG_20131002_091844IMG_20131002_091907

I drilled a couple holes in the side of the fill penetration for a cable tie to hold the fill hose securely.  The fill hose ends in a KK3-P quick disconnect which I put down the trouser leg for connection to the wall air source.

SMC parts used in this modification included:

  • KQ2T06-01NS (only if you break the original Tee) $5.40
  • KK3P-06H Quick disconnect plug end $6.10
  • KK3P-06S Quick disconnect socket end for the hose that goes to the wall – this is self sealing so you can change manikins easily without disconnecting from the wall. $16.70
  • KCH06-00 AKH06-00 Check valve with 6mm push-on fitting at both ends $13.50
  • KK2F06-01-X2 straight 6mm – female 1/8″ thread to connect to the hose barb which comes out of the wall $4.70
  • From other suppliers: 1/4″ x 1/8″ thread male tailpiece (hose barb), a bit of 1/4″ ID hose and a hospital wall air nut.  The photo below shows a slightly different arrangement of fittings, but does the same job.

IMG_20130618_104909

The compression sensor had to be soldered to the cable end left conveniently in the chest plate.  The hall effect sensors in the head are still a work in progress.  I need to go look at the original again to confirm exact placement and may have to fabricate a mounting plate.

Not particularly difficult, but there’s lots of steps and bits and pieces to sort out and source, so it took some time.  We’ll see how it holds up over time and abuse by medical students.

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One thought on “MCKelly – ALS part 2

  1. Pingback: wrong fitting | True Plastic Surgery

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