August 28, 2009 Steve Singer Hansen Medical, Inc.

Exhibit 10.45

August 28, 2009

Xxxxx Xxxxxx

Xxxxxx Medical, Inc.

000 Xxxxx Xxxxxxxx Xxxxxx

Xxxxxxxx Xxxx, XX 00000

Re: Extension of Purchase Agreement (the “Agreement”)

Agreement No. SS02AUG2007

Dated: September 21, 2007

Dear Xxxxx:

As you may know, the Purchase Agreement, which is the basis of our manufacturing relationship, is set to expire on September 21, 2009, per section 1 of the Agreement. The Agreement permits the parties to extend the relationship by mutual agreement. Therefore, as our manufacturing relationship is set to continue, we need to extend the terms of this Agreement, which is the purpose of this letter.

As such, the parties to the Agreement agree to extend the terms of the Agreement for an additional twenty-four (24) months or until September 21, 2011. If Xxxxxx agrees to this extension, please have the appropriate person sign both original letters and return one to us.

We look forward to continuing a strong relationship.

/s/ Xxxx Xxxxxx

Xxxx Xxxxxx

Xx Vice President Customer Services

Plexus Corp.

I, Xxxxx Xxxxxxxx, Xx. , on behalf of Xxxxxx Medical, Inc., represent that I have authority to bind the company and so agree to the terms and conditions set forth in this letter.

/s/ Xxxxx Xxxxxxxx, Xx.

Signature

Xxxxx Xxxxxxxx, Xx. VP Mfg

Print Name and Title

9/17/09

Date

55 Jewelers Park Drive, P. X. Xxx 000, Xxxxxx, XX 00000-0000

(000) 000-0000