In reference to the patent: CA2383173C
Is there any restriction in using this patent in Singapore or New Zeland? Thank you in advance for any reply.
This is a Canadian patent, which does not apply outside of Canada. However, according to WIPO, there appear to be equivalent patents in New Zealand (NZ 517105) and Singapore (SG 2002000131).
IPONZ appears to show that NZ 517105 is still in force.
IPOS appears to show that SG 2002000131 is still in force.
Accordingly, it seems that you are not free to use the claimed subject matter of these patents.