A poem first published more than a century ago, in 1910, but still topical given the ongoing debate on assisted dying, and the recent decision of our MPs that cats and dogs may be put out of their misery but human beings must, like Shakespeare’s Gloucester, be tied to the stake and stand the course.
How Annandale Went Out
‘They called it Annandale – and I was there
To flourish, to find words, and to attend:
Liar, physician, hypocrite, and friend,
I watched him; and the sight was not so fair
As one or two that I have seen elsewhere:
An apparatus not for me to mend –
A wreck, with hell between him and the end,
Remained of Annandale; and I was there.
I knew the ruin as I knew the man;
So put the two together, if you can,
Remembering the worst you know of me.
Now view yourself, as I was, on the spot –
With a slight kind of engine. Do you see?
Like this?… You wouldn’t hang me? I thought not’.
Edwin Arlington Robinson
David Sutton 
Annandale is “An apparatus not for me to mend” – he’s terminally ill? He’s not really a human being any more, hence “it” in the first line? “a slight kind of engine” – a hypodermic needle?
Yes, terminally ill, and note how the word ‘apparatus’ reduces the human being to the status of an irretrievably broken machine. I too take ‘a slight kind of engine’ to be a hypodermic needle that the doctor uses to inject probably a morphine overdose.