The left receiver of the pacer does not work.
The left side of the diaphragm 
The left lung does not breathe.

Leoparents write an email to the producer.*
They get an answer in half an hour.
They arrange a phone conversation with the Representative of the company.

- It's about Leo, right? Yes, I have been present at his operation! Of course I remember him. Everything worked fine.
And I know Leo from the film...- said the Representative.

Leodad talks with the Representative for more than an hour.
Representative first asks many detailed questions and then, she gives an instruction, how to perform the tests.
It's impossible, that the mechanism inside Leo broke.

In the evening Leoparents act as instructed. They test the device.

The result is unequivocal.
The right side of the pacer works fine.
The left side is dead.
The impossible becomes possible.

JAVIER PÉREZ Metamorfosis

* It's still a mystery, how is it possible that no one from the Home Ventilation at Children’s Memorial Health Institute managed to get in touch with the producer of the pacer during the last 2 months, despite of initial agreement to take care of Leo pacer after its implementation ;-/