El Medallo User Guide (v1) - Humanos3D/ElMedalloBionicArm GitHub Wiki

What to Give the patient:

If you are delivering an El Medallo bionic arm to someone make sure to give them the following.

  • Their Arm
  • A physical copy of this user guide in their native language (you can download the PDF here)
  • 2 Spare 18650 Batteries (Strongly Recommended)
  • An 18650 Battery Charger
  • Your contact information so they can contact you if they have problems or questions.

Overview

The El Medallo Bionic Arm is an EMG controlled motorised prosthetic. It is controlled by 2 EMG sensors mounted on the arm residual which link to a custom electronics board powered 2 motors inside the forearm. It is powered by 2 long-lasting lithium-ion batteries that can be removed after each day of use for overnight charging. There is a custom socket inside to ensure comfort while wearing the arm over the course of the day.

The El Medallo has 2 switches on it, the switch next to the battery opening is the power switch, this must be on for the arm to function. The other switch is the freeze switch, when this is activated the arm will hold its current position, this is useful if you are holding something for a long time and you do not want to arm to accidentally trigger.

How to Put on your Bionic Arm

Put on your provided prosthetic sock and then simply place your arm into the socket. Rotate the upper arm cuff into place and secure everything with velcro straps.

Installing Batteries and Turning On

Place the 2 18650 batteries into their case then insert the case into the arm. It should fit snugly in place, make sure that the case does not crush the wires, there is a channel in battery entrance for the wires to travel through.

Once the batteries are inside simply push on the lid. To turn on your bionic arm activate the switch next to the battery lid and your arm will turn on. It takes about 30 seconds for the EMG sensors to calibrate and begin to work properly; the bionic arm may activate in this time.

How to Control your Bionic Arm

There will be 1-2 EMG sensors attached to your residual limb that will activate the arm. If you have 2 different sensors then you will be able to use the 2 different grips, a pinch grip and a power grip. Simply flex the muscle where the EMG sensor is placed and you will activate the arm!

You can rotate the wrist 90 degree in either direction by firmly grabbing the hand and rotating it around the wrist.

There is a switch on the top of the arm, this is the freeze switch. When this is activated the arm will hold its current position, this is useful if you are holding something for a long time and you do not want to arm to accidentally trigger.

How to Care for your Bionic Arm

The El Medallo has been designed with strength in mind, however, this does not mean it is indestructible. Treat your prosthetic in the same way you would treat your own limbs. Impacts, excessive force, abrasion as well as lengthy, repeated exposure to sunlight will reduce the lifespan of your El Medallo.

Do not attempt to life more than 5kg with your El Medallo as this will strain the motors reducing their strength and lifespan. The El Medallo can resist light splashes of water but it is not waterproof, do not expose it to rain or submerge it in water as this will permanently damage the electronics.

Safety

The batteries powering your El Medallo are 18650 Lithium Ion batteries which are safe to use but if mistreated, can be dangerous. If mistreated the batteries in the El Medallo could release excessive heat, catch fire or explode. Safety Precautions to follow:

  • Never submerge the batteries in water
  • Avoid exposing the batteries to high temperature
  • Do not leave the batteries in direct sunlight
  • Do not puncture the battery
  • Do not bend or deform the battery
  • If the battery is leaking, do not touch it with your bare hands, the chemicals inside lithium ion batteries are corrosive
  • Do not use the batteries if they have visible damage
  • Do not mix with other batteries
  • Do not charge the batteries while they are hot
  • Do not dispose of your batteries in household rubbish, recycle it
  • When not in use store the batteries in a non conductive container by themselves
  • Only use the supplied charger or another charger rated explicitly for 18650 batteries

If the battery is heating up rapidly or swelling, remove the battery safely from your El Medallo and place it away from people for an hour. After this time dispose of the battery safely and contact your bionic arm supplier.

If you are not going to use the batteries for a long time fully charge them before storing and make sure they are charged then discharged at least once a year. Lithium Ion batteries naturally become less effective over time, if you notice that the arm is not performing for an entire day anymore contact your El Medallo supplier. They will be able to provide you with new batteries.

Replacing your Bionic Arm

If your bionic arm become uncomfortable as your residual arm grows and changes contact the organisation you received your arm from. It is likely that you will need to re-measured and re-fit with an arm. Don't worry, this will be a relatively easy process compared to assembling a whole arm!

Feedback

If your El Medallo breaks during normal use, makes unusual noises or behaves abnormally please contact Humanos3D at [email protected] or the chapter that delivered you your prosthetic.