Personal & toysShows up, but not every week
Blood-pressure monitor
Also called BP cuff, automatic sphygmomanometer.
A small air pump, a bleed valve, and a pressure sensor, already on one board. Useful if you are doing pneumatics at cuff pressure and not useful as a medical device afterwards.
A donor is the dead machine. The parts below are what is still worth removing from it. “Leave it” is a part that is physically in there and should stay in there: too dangerous, too worn, or only useful as part of a repair you are not doing.
A scrapped machine is a box of parts that failed at different times. The reason it was thrown out is often one bad piece. The motor, the cord, the supply, and the screws are frequently still good. This index says which is which.
Why it is in the trash while the parts are not
Erratic readings, which may be the sensor or a leaky cuff. The pump often still runs.
Before you open it
Do this while it is still unplugged, cool, and not leaking. Cells out.
Where the dead machine usually is
- Bathroom — In the house
- Thrift store — Retail
- Bulk trash day — Curb
Thrift stores. Do not return it to medical use after you have been inside it.
How it comes apart
The case screws. The pump and the valve are obvious. Do not lose the small O-rings.
Tools: Phillips, Meter.
What to take
The table is the short version. The notes under it describe that part inside this machine, not only the general description.
| Part | Call | How many | How often | Where to look |
|---|---|---|---|---|
| Small pump | Prize | 1 | usually | Inside. |
| Solenoid | Worth pulling | 1 | usually | The bleed valve. |
| Pressure sensor | Worth pulling | 1 | usually | On the board, with a port. |
| LCD panel | Leave it | 1 | usually | The display. |
| Battery clip and holder | Bonus | 1 | usually | AAA bay. |
Prize
A 3–6 V diaphragm pump for air.
Inside.
Keep the tubing.
Good.
Worth pulling
A small valve that dumps pressure.
The bleed valve.
With the pump.
Good.
Analog, cuff range. Calibrate it.
On the board, with a port.
Keep it on the board.
May be the fault.
Bonus
A holder.
AAA bay.
Clean it.
Good.
Leave it
Bare glass.
The display.
Leave it.
Not a module.