Dialysis Machine Alarm

CUSTOM ADAPTATION PURPOSE: To enable an individual with renal failure and a hearing disability to recognize and respond to an alarm when overnight dialysis treatment is disrupted. An individual with renal failure who is hard of hearing needed to be able to recognize and respond to an alarm if treatment was disrupted due to accidental disconnection of tubing or blocking of tubing. The audible alarm on the machine was of a frequency that the user could not hear. Four metal blocks were used to raise the machine above the surface on which it was sitting, providing access to the alarm speaker. A metal box containing a microphone and a two-stage amplifier was placed beneath the machine near the speaker and fixed in place with Velcro strips. The microphone picks up the sound of the alarm. The amplifier works a relay that locks closed to power a motor in a plastic box the size of a computermouse attached to the main box by a wire. An extra piece of metal screwed to the shaft of the motor causes it to run out of balance, which in turn causes the plastic box to vibrate.The user tapes the box to his or her body and the vibration awakens the user when the alarm sounds.TITLE: Dialysis Machine Alarm. JOURNAL: TAD Journal. REF: Vol 23 no 2, Winter 2003: p.12. PAGES (including cover): 2 2003.