Too long for a comment.

First: how awful for you and your husband.

Is there someone in your department who knows about your medical situation or who you would be comfortably revealing it to who can help? Someone who could arrange a postponement, or quietly let the examiners know enough about the problem so that it would not influence their judgment.

In many universities the viva is really just a formality. Your advisor and your committee know what's in your dissertation and have approved it.

Good luck.

Too long for a comment.

First: how awful for you and your husband.

Is there someone in your department who knows about your medical situation or who you would be comfortable revealing it to who can help? Someone who could arrange a postponement, or quietly let the examiners know enough about the problem so that it would not influence their judgment.

In many universities the viva is really just a formality. Your advisor and your committee know what's in your dissertation and have approved it.

Good luck.