The 67-year-old rocker - real name Ian Fraser Kilmister - was warned by doctors he had to have the device fitted if he ever wanted to tour again after being diagnosed with an irregular heartbeat, brought on by years of drink and drug abuse.
The band were forced to postpone their latest European tour until February after Lemmy was diagnosed with a haematoma blood problem.
Motorhead Guitarist Phil Campbell, 52, told WalesOnline.co.uk: ''His ticker [heart] is fine now and he's made sufficient changes to his lifestyle and diet in order to combat the diabetes.
''He's like the John Wayne of rock, always soldiering on.''
Lemmy also has Type 2 diabetes but is said to be building his fitness back up.
The 'Ace of Spades' rocker said: ''When I go I want to go doing what I do best.''
The iconic frontman was dismissive about his health problems recently, telling Classic Rock magazine: ''It was nothing; I'm over it.''
However, drummer Mikkey Dee, 50, thinks Lemmy needs a reality check and to stop drinking.
He said: ''I think after all he's been through, I'd say this: 'Lem, when are you going to get sick and tired of feeling sick and tired? It's time you started to take care of yourself.' ''
Lemmy said it was a ''tough decision'' to postpone the tour because he didn't want to disappoint his fans.
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