Exhibit 10.61

FOURTH AMENDMENT
TO
LOAN AND SECURITY AGREEMENT

This Fourth Amendment to Loan and Security Agreement (“Fourth Amendment to Loan
and Security Agreement”) is dated as of June 19, 2015 and is made by and among
UniBank for Savings (together with its successors and assigns, the “Bank” or
“Lender”), Arrhythmia Research Technology, Inc., a corporation duly organized
and validly existing under the laws of the State of Delaware (sometimes referred
to herein as “Arrhythmia”) and Micron Products Inc., a corporation duly
organized and validly existing under the laws of the Commonwealth of
Massachusetts (sometimes referred to herein as “Micron”).
 
RECITALS

A.    The Bank extended a line of credit dated March 29, 2013 to the Borrowers
as evidenced by the $4,000,000.00 Commercial Revolving Line of Credit Promissory
Note made by the Borrowers in favor of the Bank, as amended by First Amendment
to Commercial Revolving Line of Credit Promissory Note dated October 3, 2013 (as
amended to date and as may be further amended from time to time, the “Line
Note”).

B.    The Bank extended a term loan dated March 29, 2013 to the Borrowers as
evidenced by the $1,500,000.00 Commercial Term Promissory Note made by the
Borrowers in favor of the Bank (as amended to date and as may be further amended
from time to time, the “Term Note”).

C.    The Bank extended an equipment line of credit dated March 29, 2013 to the
Borrowers as evidenced by the $1,000,000.00 Commercial Equipment Line of Credit
Promissory Note made by the Borrowers in favor of the Bank, as amended by First
Amendment to Commercial Equipment Line of Credit Promissory Note dated April 10,
2014 (as amended to date and as may be further amended from time to time, the
“Equipment Note”).

D.    The Bank extended an equipment line of credit dated June 26, 2014 to the
Borrowers as evidenced by the $1,000,000.00 Commercial Equipment Line of Credit
Promissory Note made by the Borrowers in favor of the Bank (as amended to date
and as may be further amended from time to time, the “2014 Equipment Note”).

E.    Except where the context requires otherwise, all capitalized terms used
herein shall have the meanings set forth in the Loan and Security Agreement
between the Bank and the Borrowers dated as of March 29, 2013 (as amended to
date and as may be further amended from time to time, the “Loan Agreement”).

F.    The Borrowers have requested that the Bank:

(i)
Modify certain provisions in the Loan Agreement; and

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Exhibit 10.61

(ii)
Provide an extension to the Termination Date of the Line of Credit and Line Note
to June 30, 2017; and

(iii)
Provide additional financial accommodations to the Borrowers in the form of a
$1,000,000.00 Equipment Line of Credit Loan to the Borrowers.

Now therefore, in order to induce the Bank to enter into this Fourth Amendment
to Loan and Security Agreement, the Fourth Modification Documents (as hereafter
defined), to provide the additional financial accommodations to the Borrowers
and for other valuable consideration, the receipt and sufficiency of which is
acknowledged, the Borrowers jointly and severally make the following
representations, warranties, covenants and agreements effective as of the date
of this Fourth Amendment to Loan and Security Agreement:

1.Inducement Representations. The Borrowers hereby jointly and severally
represent, warrant and covenant to the Bank that: (a) no Event of Default has
occurred, and no event has occurred which with notice or lapse of time or both
would constitute an Event of Default under any of the Loan Documents; (b) the
Loan Documents, including this Fourth Amendment to Loan and Security Agreement
and the other Fourth Modification Documents are the valid, binding and
enforceable obligations of the Borrowers, as applicable; (c) the Borrowers have
no defenses, setoffs, claims or counterclaims against the Bank with respect to
any of the Loans and to the extent any such defenses, setoffs, claims or
counterclaims exist, the Borrowers hereby waive and release the same; (d) the
execution and delivery of this Fourth Amendment to Loan and Security Agreement
and each of the other Fourth Modification Documents have been duly authorized by
all necessary corporate action; (e) all of the representations and warranties of
the Borrowers set forth in the Loan Agreement and the other Loan Documents, as
amended hereby, are true, accurate and complete on and as of the date hereof;
(f) the payment and performance of all Obligations of the Borrowers to the Bank
(as defined in the Loan Agreement) are secured and shall continue to be secured
in accordance with the terms of the Loan Agreement and all other Loan Documents
which create or perfect security interests in favor of the Bank; and (g) all
facts set forth in the Recital Section of this Fourth Amendment to Loan and
Security Agreement are true, accurate, and complete.

2.Amendment to Definitions in Section 1 of the Loan Agreement.

(a)     Section 1 of the Loan Agreement is hereby amended by adding thereto the
following new definitions and, for terms already defined therein, amending and
restating such definitions as set forth below:

2015 Equipment Line of Credit means the Borrowers’ Equipment Line of Credit Loan
with the Bank referred to in Section 2 hereof, the indebtedness of which is
evidenced by the 2015 Equipment Note.

2015 Equipment Note means the Commercial Equipment Line of Credit Promissory
Note dated June 19, 2015 made by the Borrowers in favor of the Lender in the
original face amount of $1,000,000.00 evidencing indebtedness for the 2015

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Exhibit 10.61

Equipment Line of Credit, as the same may be amended, modified, restated or
replaced from time to time.

Agreement or Loan Agreement means the Loan and Security Agreement, as amended by
the First Amendment to Loan and Security Agreement dated October 3, 2013, as
further amended by the Second Amendment to Loan and Security Agreement dated
April 10, 2014, as further amended by Third Amendment to Loan and Security
Agreement dated June 26, 2014, as further amended by Fourth Amendment to Loan
and Security Agreement dated June 19, 2015, as the same may be further amended
from time to time. Any and all references to the Agreement or Loan Agreement
shall include the First Amendment to Loan and Security Agreement, the Second
Amendment to Loan and Security Agreement, the Third Amendment to Loan and
Security Agreement and the Fourth Amendment to Loan and Security Agreement.

Fourth Amendment to Loan and Security Agreement means this Fourth Amendment to
Loan and Security Agreement, which amends the Loan and Security Agreement
between the Bank and the Borrowers dated as of March 29, 2013.

Fourth Modification Documents mean the following:

(i)
the Fourth Amendment to the Loan and Security Agreement;

(ii)
the Second Amendment to Line Note;

(iii)
the 2015 Equipment Note; and

(iv)
all other documents executed by the Borrowers listed on the Closing Agenda
attached hereto as Schedule H.

Loan Documents - the definition thereof shall additionally include this Fourth
Amendment to Loan and Security Agreement and the Fourth Modification Documents.

Loans mean:

(i) the Line of Credit evidenced by the Line Note;

(ii) the Term Loan evidenced by the Term Note;

(iii) the Equipment Line of Credit evidenced by the Equipment Note;

(iv) the 2014 Equipment Line of Credit evidenced by the 2014 Equipment Note;

(v) the 2015 Equipment Line of Credit evidenced by the 2015 Equipment Note; and

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Exhibit 10.61

(vi) any other loans made by the Bank to Arrhythmia or Micron or both at any
time.

Second Amendment to Line Note means the Second Amendment to Commercial Revolving
Line of Credit Promissory Note dated June 19, 2015, which amends the Commercial
Revolving Line of Credit Promissory Note dated as of March 29, 2013. Any and all
references to the Line Note shall include the First Amendment to Line Note and
the Second Amendment to Line Note.

(b)     All other existing definitions in the Loan Agreement are hereby ratified
and confirmed as amended to date.

3.Amendment to Section 2.1 of the Loan Agreement. Existing Section 2.1 is hereby
deleted and the following is hereby inserted in its stead:

“2.1 Line of Credit.

(a) Pursuant to this Agreement and the terms and conditions of the Line Note and
upon satisfaction of the conditions precedent in Section 5 hereof, the Borrowers
may borrow, repay and reborrow under the Line of Credit; provided, however, that
(i) the aggregate amount of all advances and borrowings at any one time
outstanding thereunder shall not exceed the face amount of the Line Note minus
the amount of all Open Credits or such lesser amount provided for in the
Availability Letter (such maximum permitted amount being referred to as the
“Maximum Availability”); and (ii) any privilege of the Borrowers to request
advances or to borrow under the Line of Credit shall terminate on June 30, 2017
(as such date may be extended by the Bank in writing from time to time, in the
Bank’s sole and absolute discretion, the “Termination Date”) or at the Bank’s
option, on the earlier occurrence of a Default or an Event of Default;

(b) All advances under the Line of Credit shall be evidenced by the Line Note,
shall bear interest thereunder and all principal, interest and other amounts due
thereunder shall be due and payable in full on the Termination Date;

(c) Borrower shall not request advances under the Line of Credit which would
cause the Maximum Availability to be exceeded if the advance were made.

(d) The making of any advances by the Bank to the Borrowers under the Line of
Credit in excess of the Maximum Availability is for the Borrowers’ benefit and
does not in any way effect the unconditional obligation of the Borrowers to
repay such advances under the terms of the Line Note and the other applicable
Loan Documents. Without limiting any other rights available to the Bank under
the Loan Documents, the Borrowers agree to pay to the Bank upon DEMAND (whether
or not an Event of Default exists) the principal balance of the Line of

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Exhibit 10.61

Credit outstanding in excess of the Maximum Availability together with all
accrued and unpaid interest owing on said excess amounts.”

4.New Section 2.3B. The following new Section 2.3B is inserted immediately
following the end of Section 2.3A and immediately preceding Section 2.4:

“2.3B 2015 Equipment Line of Credit.

(a) Pursuant to this Agreement and the terms and conditions of the 2015
Equipment Note and upon satisfaction of the conditions precedent in Section 5
hereof, the Borrowers may borrow and repay (but not reborrow) under the 2015
Equipment Line of Credit; provided, however, that (i) the aggregate amount of
all advances and borrowings at any one time outstanding thereunder shall not
exceed the face amount of the 2015 Equipment Note minus the amount of all Open
Credits (such maximum permitted amount being referred to as the “2015 Equipment
Maximum Availability”); (ii) any privilege of the Borrowers to request advances
or to borrow under the 2015 Equipment Line of Credit shall terminate on the
earlier of: (A) June 19, 2016 or (B) the date upon which the amount of all
advances under the 2015 Equipment Line of Credit are equal to the face amount of
the 2015 Equipment Note (such date as it may be extended in writing from time to
time, in the Bank’s sole discretion, being referred to herein as the “2015
Equipment Conversion Date”) or, at the Bank’s option, on the earlier occurrence
of a Default or an Event of Default.

(b) All advances under the 2015 Equipment Line of Credit shall be evidenced by
the 2015 Equipment Line Note, shall bear interest thereunder and all principal,
interest and other amounts due thereunder shall be due and payable in full on
the Maturity Date (as defined in the 2015 Equipment Note).

(c) Any advance under the 2015 Equipment Line of Credit shall not exceed eighty
percent (80%) of the invoice amount of the equipment being purchased with the
proceeds of the 2015 Equipment Line of Credit.

(d) Borrowers shall not request advances under the 2015 Equipment Line of Credit
which would cause the 2015 Equipment Maximum Availability to be exceeded if the
advance were made.

(e) The making of any advances by the Bank to the Borrowers under the 2015
Equipment Line of Credit in excess of the 2015 Equipment Maximum Availability is
for the Borrowers’ benefit and does not in any way effect the unconditional
obligation of the Borrowers to repay such advances under the terms of the 2015
Equipment Line Note and the other applicable Loan Documents. Without limiting
any other rights available to the Bank under the Loan Documents, the Borrowers
agree to pay to the Bank upon DEMAND (whether or not an Event of Default exists)
the principal balance of the 2015 Equipment Line

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Exhibit 10.61

of Credit outstanding in excess of the 2015 Equipment Maximum Availability
together with all accrued and unpaid interest owing on said excess amounts.”

5.Amendment to Section 5.1 of the Loan Agreement. Existing Section 5.1 of the
Loan Agreement is hereby deleted and the following is inserted in its stead:

“5.1 Initial Advances. The initial advance under the Line of Credit, the single
advance under the Term Loan, the initial advance under the Equipment Line of
Credit, the initial advance under the 2014 Equipment Line of Credit and the
initial advance under the 2015 Equipment Line of Credit shall be subject to the
following conditions precedent (unless waived by the Bank in its sole
discretion):

(a) Approval of Bank Counsel. All legal matters incident to the transactions
hereby contemplated shall be satisfactory to counsel for the Bank.

(b) Proof of Action. The Bank shall have received such documents evidencing each
Borrower’s power to execute and deliver this Agreement and the other Loan
Documents and the Bank shall have received evidence of compliance with all
conditions set forth in the Bank’s Commitment Letter to the Borrowers dated
March 12, 2013 in a timely fashion, all satisfactory to the Bank and its
counsel.

(c) The Note and Loan Documents. The Borrowers shall have delivered to the Bank
the Notes, this Agreement, the other Loan Documents and such other documents as
the Bank may request including without limitation all documents necessary to
confirm, secure and perfect the Bank’s security interest in the Collateral in
form and substance satisfactory to the Bank (the “Security Documents”) including
without limitation the Landlord’s Consents and Waivers, the Financing Statements
of the Borrowers, the Patent Security Agreements and Trademark Security
Agreements.

(d) Opinion of Counsel. The Bank shall have received from counsel for the each
of the Borrowers a written opinion, satisfactory in form and substance to the
Bank and its counsel, including without limitation due authority and
enforceability opinions for each Borrower.

(e) No Event of Default. No Event of Default has occurred, and no Default shall
have occurred, the Maximum Availability under the Line of Credit and the
Equipment Maximum Availability under the Equipment Line of Credit, as
applicable, shall not be exceeded at the time of the advance request or the
making of the advance.

(f) No Material Adverse Change. There shall have been no material adverse change
in the assets, liabilities, financial condition or business of the

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Exhibit 10.61

Borrowers since the date of any financial statements delivered to the Bank
before or after the date of this Agreement.

(g) Collateral Priority. The Bank shall have received evidence satisfactory to
it that all Loan Documents perfecting the Bank’s security interest in Collateral
have been duly recorded and filed and all other action necessary to perfect the
Bank’s liens in the Collateral have been taken such that the Bank’s liens shall
constitute first priority perfected liens in all Collateral, subject to no other
liens or encumbrances unacceptable to the Bank, all to the Bank’s complete
satisfaction.

(h) Evidence of Insurance. At or prior to Closing, the Borrowers shall deliver
to the Bank an insurance binder or binders evidencing insurance coverage(s) as
required in Section 6.3 hereof.

(i) Organizational Documents. The Bank shall have received from each Borrower
and satisfactorily reviewed and approved certified copies of the organizational
documents for each Borrower and all amendments thereto, together with the
resolutions of the appropriate parties authorizing the execution and delivery of
the Loan Documents, said organizational documents to be in form and substance
satisfactory to the Bank and its counsel.

(j) Operating Accounts. Prior to Closing, the Borrowers shall establish its
operating accounts with the Bank.

(k) Certificates. The Bank shall have received from the Borrowers and
satisfactorily reviewed and approved Certificates of Legal Existence and
Certificates of Good Standing issued by the Secretary of State for each
jurisdiction in which each Borrower is registered to conduct its business,
Certificates of Tax Good Standing issued by the Delaware Division of Revenue and
the Massachusetts Department of Revenue and an accountant’s letter of tax good
standing with respect to filing and payment of any and all taxes for the
Borrowers.

(l) 2012 Financial Statements. The Bank shall have received and satisfactorily
reviewed the 2012 financial statements of the Borrowers, said financial
statements to be in form, scope and substance satisfactory to the Bank in its
sole and absolute discretion.

(m) Other Conditions. There shall be compliance with all other conditions and
provisions contained in this Agreement and the other Loan Documents as
applicable pertaining to advances.”

6.Amendment to Section 5.2 of the Loan Agreement. Existing Section 5.2 of the
Loan Agreement is hereby deleted and the following is inserted in its stead:

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Exhibit 10.61

“5.2 Subsequent Advances. Every subsequent advance under the Line of Credit, the
Equipment Line of Credit, the 2014 Equipment Line of Credit and the 2015
Equipment Line of Credit will be made subject to the continued satisfaction of
the conditions set forth in Sections 5.1 (a) through (m) inclusive above through
the date of the applicable advance and to the following additional conditions
precedent that:

(a) Representations and Warranties. The representations and warranties contained
in Section 4 hereof and in each other Loan Document shall be true and correct.
Any request for a borrowing shall be deemed a certification by each Borrower as
to the truth and accuracy of the representations and warranties contained in
Section 4 hereof and in each other Loan Document as of the date of such request.

(b) Termination Date; Conversion Date. As applicable, the Termination Date (as
defined in the Line Note) of the Line of Credit has not been reached, the
Conversion Date (as defined in the Equipment Note) of the Equipment Line of
Credit has not been reached, the 2014 Equipment Conversion Date (as defined in
the 2014 Equipment Note) has not been reached and the 2015 Equipment Conversion
Date (as defined in the 2015 Equipment Note) has not been reached.”

7.Amendment to Section H of Schedule A to the Loan Agreement. Existing Section H
of Schedule A to the Loan Agreement is hereby deleted and the following is
inserted in its stead:

“H. Use of Loan Proceeds.

1.
Proceeds of the Line of Credit are to be used to payoff and terminate the
existing Line of Credit with Citizens Bank and other obligations to Citizens
Bank, including but not limited to the letter of credit issued for the benefit
of the Bank of Nova Scotia and to pay costs and expenses and costs associated
with the Line of Credit, Term Loan and Equipment Loan with UniBank for Savings
(including without limitation UniBank for Saving’s legal costs and expenses) and
for working capital including without limitation those purposes and payees set
forth in the Authorization to Disburse associated with the Line of Credit dated
March 29, 2013 this day.

2.
Proceeds of the Term Loan are to be used to pay off existing debt owing under
existing equipment leases, to finance accounts payable and costs associated with
the closure of the Borrower’s Wireless DX division, and to pay costs and
expenses and costs associated with the Line of Credit, Term Loan and Equipment
Loan with UniBank for Savings (including without limitation UniBank for Saving’s
legal costs and expenses) and for working capital including without limitation
those purposes and payees set forth in

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Exhibit 10.61

the Authorization to Disburse associated with the Term Loan dated March 29,
2013.

3.
Proceeds of the Equipment Loan are to be used to purchase equipment and to pay
costs and expenses and costs associated with the Line of Credit, Term Loan and
Equipment Loan with UniBank for Savings (including without limitation UniBank
for Saving’s legal costs and expenses) and for working capital including without
limitation those purposes and payees set forth in the Authorization to Disburse
associated with the Equipment Loan dated March 29, 2013.

4.
Proceeds of the 2014 Equipment Line of Credit are to be used to purchase new and
used equipment and to pay expenses and costs associated with the 2014 Equipment
Line of Credit with UniBank for Savings (including without limitation UniBank
for Savings’ legal costs and expenses) all as more particularly set forth in the
authorization to disburse dated June 26, 2014.”

5.
Proceeds of the 2015 Equipment Line of Credit are to be used to purchase new and
used equipment and to pay expenses and costs associated with the 2015 Equipment
Line of Credit with UniBank for Savings (including without limitation UniBank
for Savings’ legal costs and expenses) all as more particularly set forth in the
authorization to disburse dated June 19, 2015.”

8.New Schedule H. The following new Schedule H attached hereto is added to the
Loan Agreement following the end of Schedule G.

9. Other Loan Document Amendments and Reaffirmation. The Line Note is being
amended this date pursuant to the Second Amendment to Line Note dated of even
date herewith.

10.No Waiver. The Borrowers hereby acknowledge that the Bank has made no waiver
of any provision of the Loan Documents nor of any Default or Event of Default
which may exist and that no such waiver shall be implied by virtue of this
Fourth Amendment or otherwise.

11.Costs and Expenses. The Borrowers will pay to the Bank upon demand all costs
and expenses (including attorney’s fees) reasonably incurred by the Lender in
connection with the documentation and closing of the Fourth Modification
Documents.

12.Conditions. The effectiveness of the Fourth Modification Documents shall be
conditioned upon, at the Bank’s option: (a) the execution and delivery of this
Fourth Amendment to Loan and Security Agreement and the other Fourth
Modification Documents by all of the parties thereto; and (b) the receipt by
Bank of all other documents and certificates reasonably requested by Bank and
its counsel including without limitation, the Bring Down Certificate for each
Borrower.

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Exhibit 10.61

13.Reaffirmation of Loan Documents. Except as expressly modified herein all
other terms and conditions of the Loan Documents are hereby ratified and
confirmed and the Loan Documents, as modified hereby, are and continue to be in
full force and effect. All references in the Loan Documents to any Loan Document
shall mean that Loan Document, as amended to date and as further amended from
time to time.

14.Reaffirmation of Cross-Collateralization and Cross-Default. The Borrowers
hereby acknowledge that the obligations of the Borrowers set forth in the Loan
and Security Agreement and the other Loan Documents are intended to capture all
obligations and debts of the Borrowers owing to the Bank. This includes any
agreements, loan agreements, security agreements, mortgages, letters or credit,
and any other existing or future loans. The Borrowers acknowledge that all
obligations of the Borrowers owing to the Bank are cross-collateralized and
cross-defaulted with all obligations outstanding.

[This space intentionally left blank; signature page to follow.]

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Exhibit 10.61

IN WITNESS WHEREOF the parties have executed this instrument under seal as of
the 19th day of June, 2015.

Borrowers:

Arrhythmia Research Technology, Inc.

_____________________________            By: /s/ Salvatore Emma, Jr.
Witness
Salvatore Emma, Jr., President and

Chief Executive Officer
Duly Authorized

Micron Products Inc.

_____________________________            By: /s/ Salvatore Emma, Jr.
Witness
Salvatore Emma, Jr., President and

Chief Executive Officer
Duly Authorized            

Bank:

UniBank for Savings

_____________________________            By: /s/ John Decker
Witness
John Decker, Vice President

                        

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Exhibit 10.61

SCHEDULE H

FOURTH MODIFICATION TO FINANCING ARRANGEMENTS
TO
ARRHYTHMIA RESEARCH TECHNOLOGY, INC. AND
MICRON PRODUCTS INC.
MADE BY
UNIBANK FOR SAVINGS

CLOSING DATE: June 19, 2015

Lender:
John Decker, Vice President
UniBank for Savings
24 Gold Star Boulevard
Worcester, MA 01605
Phone: (508) 849-4253
Fax: (508) 234-7603
Email: John.Decker@unibank.com

Borrowers:
Arrhythmia Research Technology, Inc.
Micron Products Inc.

Guarantors:
None
Lender’s Counsel:
Anthony J. Salvidio, II, Esquire
Fletcher Tilton, PC (“FT”)
370 Main Street, 11th Floor
Worcester, MA 01608
Phone: (508) 459-8004
Fax: (508) 459-8304
Email: asalvidio@fletchertilton.com

Karen M. LaFond, Esquire
Phone: (508) 459-8015
Fax: (508) 459-8315
Email: klafond@fletchertilton.com

Borrowers’ Counsel:
Paul J. D’Onfro, Esquire
Mirick O’Connell DeMaille & Lougee LLP (“MODL”)
100 Front Street
Worcester, MA 01608
Phone: (508) 929-1624
Fax: (508) 983-6249
Email: pdonfro@mirickoconnell.com

DOCUMENTS
RESPONSIBLE PARTY
 
 
Fourth Modification to Financing Arrangements
 
 
 
1.        Fourth Amendment to Loan and Security Agreement
FT
2.    Second Amendment to Commercial Revolving Line of Credit Promissory
FT
3.    $1,000,000.00 Equipment Line of Credit Promissory Note
FT
4.    Disbursement Authorization - $1,000,000.00 Equipment Line of Credit
Promissory Note
FT

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Exhibit 10.61

Lender:
John Decker, Vice President
UniBank for Savings
24 Gold Star Boulevard
Worcester, MA 01605
Phone: (508) 849-4253
Fax: (508) 234-7603
Email: John.Decker@unibank.com

Borrowers:
Arrhythmia Research Technology, Inc.
Micron Products Inc.

Guarantors:
None
5.    Copy of existing and continuing UCC-1 Financing Statements
a)    Arrhythmia Research Technology, Inc. (Delaware) All Asset
b)    Arrhythmia Research Technology, Inc. (Delaware) Specific Equipment
c)    Micron Products Inc. (Massachusetts) All Asset
d)    Micron Products, Inc. (Massachusetts) Specific Equipment
FT
6.    UCC-1 Specific Equipment Financing Statements of Arrhythmia Research
Technology, Inc. filed with:
a)    Delaware Secretary of State
b)    Worcester North District Registry of Deeds
c)    Any and all other applicable filing/recording offices where specific
equipment is possessed
FT
(to come upon purchase of each unit of specific equipment)
7.    UCC-1 Specific Equipment Financing Statements of Micron Products Inc.
filed with:
a)    Massachusetts Secretary of the Commonwealth
b)    Worcester North District Registry of Deeds
c)    Any and all other applicable filing/recording offices where specific
equipment is possessed
FT
(to come upon purchase of each unit of specific equipment)
8.    Evidence of Hazard and Liability Insurance coverage listing Lender as Loss
Payee and Additional Insured as applicable
a)    Arrhythmia Research Technology, Inc.
b)    Micron Products Inc.
In Lender’s Files
9.    Certificates of Good Standing
a)    Arrhythmia Research Technology, Inc.
b)    Micron Products Inc.
MODL
10.    Bring Down Certificates
a)    Arrhythmia Research Technology, Inc.
b)    Micron Products Inc.
FT
11.    Opinion of Counsel to Borrowers re: Authorization, Due Authority,
Enforceability
MODL
12.    Identification
In Lender’s Files

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Exhibit 10.61

COMMERCIAL EQUIPMENT LINE OF CREDIT
PROMISSORY NOTE

$1,000,000.00                         Worcester, Massachusetts
June 19, 2015

FOR VALUE RECEIVED Arrhythmia Research Technology, Inc., a corporation duly
organized and validly existing under the laws of the State of Delaware having a
principal place of business at 25 Sawyer Passway, Fitchburg, Massachusetts 01420
and Micron Products Inc., a corporation duly organized and validly existing
under the laws of the Commonwealth of Massachusetts having a principal place of
business at 25 Sawyer Passway, Fitchburg, Massachusetts 01420 (each and
collectively, the “Borrower”) jointly and severally promise to pay to the order
of UniBank for Savings (with its successors, assigns and any future holder or
holders of this Note being the “Lender”) at its offices at 49 Church Street,
Whitinsville, Massachusetts 01588 or at such other place as the Lender may from
time to time designate in writing, the principal sum of One Million and 00/100
Dollars ($1,000,000.00), or the aggregate unpaid principal amount of all
advances made by the Lender to the Borrower under terms hereinafter set forth,
whichever is less, in lawful money of the United States, to pay interest on each
advance at a variable per annum rate equal to the Interest Rate (as hereafter
defined), unless the Default Rate is in effect in which event the Interest Rate
shall be the Default Rate. All advances shall be due and payable as set forth
herein, but if not sooner paid, this Note and all amounts due hereunder shall be
due and payable on June 19, 2021 (said date as the same may be extended from
time to time in the Lender’s discretion, being the “Maturity Date”), without
notice or demand.

This Note evidences the Borrower’s indebtedness under the $1,000,000 Equipment
Line of Credit made by the Bank to the Borrower of even date herewith as defined
in the Loan and Security Agreement among the Borrower and the Bank dated March
29, 2013 (as the same may be amended or modified from time to time, the “Loan
Agreement”), incorporated herein by reference (the “2015 Equipment Line of
Credit”).

Subject to the terms and conditions set forth herein and in the Loan Agreement,
the Borrower may request advances and borrow funds under the 2015 Equipment Line
of Credit during the period from the date hereof until the earlier of: (i) June
19, 2016 or (ii) the date upon which the amount of all advances under this Note
are equal to the face amount of this Note (such date as it may be extended in
writing from time to time, in the Bank’s sole discretion, being referred to
herein as the “2015 Equipment Conversion Date”). The Borrower’s privilege to

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Exhibit 10.61

request advances and borrow funds under the 2015 Equipment Line of Credit shall
terminate on the 2015 Equipment Conversion Date or, at the Bank’s option, an
earlier Default or Event of Default. The aggregate amount of all advances
advanced under the 2015 Equipment Line of Credit shall not exceed $1,000,000.00.
Advances which are repaid may not be reborrowed. Should the amount of said
advances at any time exceed the maximum amount permitted herein, the Borrower
shall be obligated to immediately pay to the Bank the amount of such excess
together with accrued and unpaid interest.

Interest on the outstanding principal of all advances hereunder shall be due and
payable commencing one month from the date hereof and continuing monthly
thereafter on the same day or last day, whichever shall first occur, of each
succeeding month (each a “Payment Date”) until the 2015 Equipment Conversion
Date.
    
Commencing with the first Payment Date after the 2015 Equipment Conversion Date,
principal and interest shall be due and payable in consecutive monthly
installments the number of which shall be equal to the number of months
remaining between the 2015 Equipment Conversion Date and the Maturity Date and
of which all but the last (the “Final Payment”) shall be in such amount as is
necessary to amortize the outstanding principal balance of this Note with
interest thereon at the rate applicable from time to time hereunder based upon
an assumed direct reduction amortization schedule equal to six (6) years from
the date of this Note. Each such monthly installment of principal and interest
shall be subject to adjustment by the Lender from time to time in order to
insure that payments are sufficient to properly amortize the then outstanding
principal balance of this Note with interest thereon based upon the applicable
assumed amortization schedule and changes in the rate of interest applicable
from time to time to the principal balance of this Note. The Lender may adjust
any monthly installment upon written notice to the Borrower if a failure to so
adjust would result in less than the total amount of all accrued interest due
being paid on any Payment Date (as hereafter defined).

The first of said consecutive monthly payments of principal and interest shall
be due and payable on the first Payment Date after the 2015 Equipment Conversion
Date and the remainder of said monthly payments shall be due on the same day or
last day, whichever shall first occur, of each succeeding month thereafter (each
a “Payment Date”). The Final Payment shall be in an amount equal to the then
outstanding principal balance of this Note plus all accrued and unpaid interest
and all other amounts owing hereunder. The Final Payment, unless sooner paid,
shall be due and payable on the Maturity Date, without notice or demand.

This Note has been executed and delivered subject to the following additional
terms and conditions:

1. Definitions. For purposes of this Note, the following terms shall have the
following meanings:

1.1 “Banking Day” means any day other than a Saturday or Sunday, or other day on
which commercial banks in the Commonwealth of Massachusetts are authorized or
required to close under the laws of the Commonwealth of Massachusetts.

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Exhibit 10.61

1.2 “Base Rate” means the Federal Home Loan Bank of Boston Five Year Rate of
interest, as disclosed on the rate sheet provided to Lender. In the event that
such rate of interest currently referred to shall no longer exist or no longer
be referred to as the “Federal Home Loan Bank of Boston Five Year Rate” or
“Federal Home Loan Bank of Boston Rate”, or in the event the Lender or a future
holder of the Note shall no longer use the Federal Home Loan Bank of Boston Five
Year Rate as its reference rate of interest, then the term “Base Rate” shall be
deemed to refer to the comparable reference rate of interest adopted or used in
lieu thereof by the Lender or any such future holder, which represents a
reasonable substitute in the form of Standards Rates used in the market at that
time such as the Treasury Rates or other indexes, whether such rate be referred
as to the “Base Rate” or otherwise.

1.3 “Default” means the occurrence of an Event of Default or the occurrence of
any event, which with the giving of notice or the passage of time, or both would
constitute an Event of Default.

1.4 “Event of Default” has the meaning given to it in Section 11 hereof and the
Loan Agreement and includes but is not limited to a failure by the Borrower to
comply with any term or condition of this Note or any other Loan Document.

1.5 “Governing State” means the Commonwealth of Massachusetts.

1.6 “Interest Rate” shall have the meaning given to it in Section 2 hereof,
unless the Default Rate is in effect, in which event the Interest Rate shall be
the Default Rate.

1.7 “Loan Agreement” means the Loan and Security Agreement between the Lender
and the Borrower dated March 29, 2013, as the same may be amended from time to
time.

1.8 “Loan Documents” has the meaning given to it in the Loan Agreement and
includes without limitation this Note and any and all agreements, instruments,
documents, security agreements, mortgages, financing statements, and supplements
thereto and relating to the loan evidenced by this Note (the “Loan”), or entered
into between the Borrower or any one of them in favor of, or with, the Lender,
at any time, for any purpose, all as amended, renewed or extended from time to
time.

1.9 “Obligations” mean all liabilities, indebtedness, obligations, advances,
covenants and loans now or hereafter due or owing by or from any Borrower
(including without limitation any obligation as a guarantor) to the Lender of
whatever kind, description or nature, whether or not evidenced by any note or
other instrument, whether or not for the payment of money, whether or not
currently contemplated at the time of this Agreement, whether now existing, or
hereafter arising or created, whether such obligations be direct or indirect,
absolute or contingent, primary or secondary, secured or unsecured, or due or to
become due, including, without limitation, all liabilities and obligations under
the Notes and other Loan Documents, and all indemnity and

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Exhibit 10.61

reimbursement obligations of any Borrower, actual or contingent, in respect of
letters of credit or banker’s acceptances issued by the Lender for the account
of or guaranteed by any Borrower, all obligations of any partnership of joint
venture as to which any Borrower is or may become liable and any so called SWAP
contracts entered into by or given by any Borrower to the Lender, regardless of
how they arise or by what agreement or instrument they may be evidenced or
whether evidenced by any agreement or instrument, any and all obligations
arising under any foreign exchange contracts, interest rate cap, floor or
hedging agreements, or similar agreements, all obligations of any Borrower to
the Lender arising out of or in connection with any Automated Clearing House
(“ACH”) Agreements relating to the processing of ACH transactions, all
obligations of any Borrower to the Lender to repay overdrafts whether or not
such obligations are related to the transactions described in the Notes and
other Loan Documents, and includes obligations to perform acts and refrain from
taking action as well as obligations to pay money. The term “Obligations” shall
also include without limitation all accrued interest and all costs and expenses,
including attorney’s fees, costs and expenses relating to the appraisal and/or
valuation of assets and all costs and expenses incurred or paid by the Lender in
exercising, preserving, defending, collecting, administering, enforcing or
protecting any of its rights under the Obligations or hereunder or with respect
to the Collateral or in any litigation arising out of the transactions evidenced
by the Obligations. The term “Obligations” shall be construed in its broadest
and most comprehensive sense.

1.11 “Open Credits” mean the face amount of all letters of credit or bankers
acceptances issued by the Lender for the account of any Borrower or guaranteed
by any Borrower.

1.12 “Prime Rate” means the highest per annum rate of interest published by the
Wall Street Journal from time to time as the Prime Rate. In the event that the
reference rate of interest currently referred to in the Wall Street Journal as
the “Prime Rate” shall no longer exist or no longer referred to as the “Prime
Rate”, or in the event the Lender or a future holder of the Note shall no longer
use the Wall Street Journal published Prime Rate as its reference rate of
interest, then such term shall be deemed to refer to the comparable fluctuating
reference rate of interest adopted or used in lieu thereof by the Lender or any
such future holder, whether such rate be referred as to the “prime rate”, “base
rate” or otherwise.

2. Interest Rate. Except as hereinafter provided, the outstanding principal
balance of this Note shall bear interest at a fluctuating per annum rate of
interest equal to the Prime Rate plus one quarter of one percent (0.25%) until
the 2015 Equipment Conversion Date. On the 2015 Equipment Conversion Date, the
per annum rate of interest shall be automatically adjusted to a fixed per annum
rate equal to the greater of: (i) the Base Rate as at the 2015 Equipment
Conversion Date plus three percentage points (3.00) or (ii) four and one quarter
of one percent (4.25%), at which time the interest rate shall be fixed until the
Maturity Date. Changes in the rate of interest resulting from changes in the
Prime Rate shall take place immediately without notice or demand of any kind.
For all purposes of this Note, the Lender’s written notice or

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Exhibit 10.61

statement to the Borrower of the applicable rate of interest shall be conclusive
and binding absent manifest error.

3. Advances, Notice Of Borrowing.

3.1 When the Borrower desires to borrow hereunder, it shall give the Lender
notice specifying the date of the proposed borrowing (which shall be a Banking
Day) and the amount to be borrowed. If any advance is made, the Lender shall
record on the books and records of the Lender an appropriate notation evidencing
such advance, each repayment on account of the principal thereof and the amount
of interest paid; and the Borrower authorizes the Lender to maintain such
records or make such notations and agrees that the amount shown on the books and
records as outstanding from time to time shall constitute the amount owing to
the Lender pursuant to this Note, absent manifest error. Amounts borrowed under
this Note may not be reborrowed. Unless a Default or an Event of Default occurs,
the Borrower may borrow and repay under this Note; provided, however, that: (i)
each request by the Borrower for an advance hereunder shall be accompanied by an
invoice evidencing the price and specifications of the equipment being
purchased; (ii) at no time shall the outstanding principal balance of this Note
exceed an amount equal to the face amount of this Note minus the aggregate
amount of all Open Credits (the “2015 Equipment Maximum Availability”); (iii) at
no time shall advances be requested which would cause the outstanding principal
balance of this Note to exceed the 2015 Equipment Maximum Availability; (iv) all
outstanding principal plus accrued and unpaid interest shall be paid in full on
the Maturity Date; and (v) any privilege to request advances hereunder shall
terminate on the 2015 Equipment Conversion Date.

3.2 [Intentionally omitted].

3.3 Any advance hereunder shall not exceed eighty percent (80%) of the invoice
amount of the equipment being purchased with the proceeds of the 2015 Equipment
Line of Credit.

3.4 The making of any advances by the Lender to the Borrower under the 2015
Equipment Line of Credit in excess of the 2015 Equipment Maximum Availability is
for the Borrower’s benefit and does not in any way effect the unconditional
obligation of the Borrower to repay such advances under the terms of this Note
and the other applicable Loan Documents. Without limiting any other rights
available to the Lender under the Loan Documents, the Borrower agrees to pay to
the Lender upon DEMAND (whether or not an Event of Default exists) the principal
balance of the 2015 Equipment Line of Credit outstanding in excess of the 2015
Equipment Maximum Availability together with all accrued and unpaid interest.

4. Interest Rate/Payments.

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Exhibit 10.61

4.1. Interest Rate, Payment of Interest. So long as no Event of Default has
occurred and subject to the terms hereof, each advance hereunder shall bear
interest at the interest rate called for and calculated pursuant to the terms of
this Note.

4.2. Accounts; Records. The Lender is authorized (but not required) to charge
principal and interest and all other amounts due under this Note to any account
of any Borrower with the Lender when and as it becomes due. All advances made by
the Lender to the Borrower shall be evidenced by an appropriate notation on the
books and records of the Lender, which records shall reflect each repayment on
account of the principal thereof, and the amount of interest paid; and the
Borrower authorizes the Lender to maintain such records or make such notations
and agrees that the amount shown on the books and records of the Lender, as
outstanding from time to time shall constitute the amount owing to the Lender
pursuant to this Note, absent manifest error; provided, however, that the
failure by the Lender to make any such notation with respect to any advance or
payment shall not limit or otherwise affect the obligations of the Borrower
hereunder.

4.3 Additional Payments. If the Lender in its reasonable judgment determines
that the effect of an applicable law or government regulation, guideline or
order or the interpretation thereof by any governmental authority charged with
the administration thereof (such as, for example, a change in official reserve
requirements which the Lender is required to maintain in respect of loans or
deposits or other funds procured for funding such loans) is to increase the cost
to the Lender of making or continuing a Loan hereunder or to reduce the amount
of any payment of principal or interest receivable by the Lender thereon, then
the Borrower shall pay to the Lender on demand such additional amounts as the
Lender may determine in its sole and absolute discretion, to be required to
compensate the Lender for such additional costs or reduction. Any additional
payment under this section will be computed from the effective date at which
such additional costs have to be borne by the Lender. A certificate as to any
additional amounts payable pursuant to this section setting forth the basis and
method of determining such amounts shall be conclusive, absent manifest error,
as to the determination by the Lender set forth therein if made reasonably and
in good faith. The Borrower shall pay any and all amounts so certified to it by
the Lender within ten (10) days of receipt of such certificate.

5. 360 Day Year / Default Rate. All computations of interest under this Note
shall be made on the basis of a three hundred sixty (360) day year and the
actual number of days elapsed. To the extent allowed by applicable law, after
the occurrence of any Event of Default, after the Maturity Date or after
judgment has been rendered on this Note, all outstanding principal and unpaid
interest shall bear, until paid, interest at a rate per annum equal to four
(4.000) percentage points greater than the Interest Rate called for and
calculated pursuant to the terms of this Note (the “Default Rate”).

6. Late Charge. If a regularly scheduled payment is fifteen (15) days or more
late, Borrower will be charged five percent (5.000%) of the unpaid portion of
the regularly scheduled payment or twenty five dollars ($25.00), whichever is
greater. If the Lender demands payment of

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Exhibit 10.61

the Loan and the Borrower does not pay the Loan within fifteen (15) days after
the Lender’s demand, the Borrower will be charged either five percent (5.000%)
of the unpaid principal plus accrued unpaid interest or twenty five dollars
($25.00), whichever is greater.

7. Expenses. The Borrower further promises to pay to the Lender, as incurred,
and as an additional part of the unpaid principal balance, all costs, expenses
and reasonable attorneys’ fees (which may include, without limitation, the
allocable cost of the Lender’s internal legal counsel) incurred: (a) in the
protection, modification, collection, defense or enforcement of all or part of
this Note or any guaranty hereof or any other Loan Document; (b) in the
foreclosure or enforcement of any mortgage or security interest which may now or
hereafter secure either the debt hereunder or any guaranty thereof; (c) with
respect to any action taken to protect, defend, modify or sustain the lien of
any such mortgage or security agreement; (d) with respect to any litigation or
controversy arising from or connected with this Note or any mortgage or security
agreement or collateral which may now or hereafter secure this Note; or (e) with
respect to any act to protect defend, modify, enforce or release any of its
rights or remedies with regard to, or otherwise effect collection of, any
collateral which may now or in the future secure this Note or with regard to or
against the Borrower or any endorser, guarantor or surety of this Note.

8. Prepayment. The Borrower may prepay this Note in whole or in part, at any
time, without penalty or premium.

9. Mandatory Prepayment / Application of Payments.

9.1. The Borrower shall be required to prepay ON DEMAND all advances made under
this Note to the extent the aggregate of all such advances exceeds the amounts
permitted hereunder. In addition the Borrower shall pay, if applicable, charges
incurred pursuant to the terms hereof.

9.2. All payments, including any prepayments shall, at the option of the Lender,
be applied first to interest on the unpaid principal of all advances due under
this Note, and then to the payment of all fees, costs, and expenses incurred by
the Lender or owing to the Lender by the Borrower arising out of the loan
transaction evidenced by this Note which have not been paid or reimbursed to the
Lender, and then to the balance on account of the principal due under this Note.

Prepayments of principal (whether voluntary or involuntary) shall be applied to
unpaid principal installments under this Note in inverse order of their maturity
and shall not affect the obligation to pay regular installments due hereunder
until the entire indebtedness is paid in full.

10. Loan Agreement. This Note has been executed and delivered in accordance with
the Loan Agreement which sets forth further terms and conditions upon which the
entire unpaid principal hereof and all interest hereon may become due and
payable prior to the Maturity Date, and generally as to further rights of the
Lender and duties of the Borrower with respect hereto. Capitalized terms not
defined herein which are defined terms in the Loan Agreement shall have

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Exhibit 10.61

the meanings set forth therein. No reference to the Loan Agreement or other Loan
Documents or to any provision thereof shall affect or impair the absolute and
unconditional obligation of the Borrower to pay principal or interest or other
amounts owing under this Note.

11. Default.

11.1.    The happening of any of the following events or conditions shall
constitute an “Event of Default” under this Note:

11.1.1. Failure to make any payment of principal or interest or any sum due
under this Note or any other promissory note or instrument made by the Borrower
or any one or more of them in favor of the Lender; or

11.1.2. Failure by any Borrower to observe or perform any covenant contained
herein; or

11.1.3 A default or the occurrence of an event of default in any other Loan
Document including, without limitation, an Event of Default as defined in the
Loan Agreement.

11.2. Upon and after the occurrence of a Default or an Event of Default, the
availability of advances hereunder shall, at the option of the Lender, be deemed
to be automatically terminated. Upon and after an Event of Default, at the
option of the Lender, the whole of the indebtedness evidenced by this Note,
including principal and interest, and all other amounts which may be or become
due or owing by the Borrower to the Lender shall, at the option of the Lender,
immediately become due and payable without presentment, demand, protest, notice
of protest, or other notice of dishonor of any kind, all of which are hereby
expressly waived by the Borrower.

12. Waivers, Consent to Jurisdiction. Each Borrower agrees that no delay or
failure on the part of the Lender in exercising any power, privilege, remedy,
option or right hereunder shall operate as a waiver thereof or of any other
power, privilege, remedy or right; nor shall any single or partial exercise of
any power, privilege, remedy, option or right hereunder preclude any other or
future exercise thereof or the exercise of any other power, privilege, remedy,
option or right. The rights and remedies expressed herein are cumulative, and
may be enforced successively, alternately, or concurrently and are not exclusive
of any rights or remedies which holder may or would otherwise have under the
provisions of all applicable laws, and under the provisions of all agreements
between the Borrower and the Lender.

Each Borrower hereby waives presentment, demand, notice, protest and all other
demands and notices in connection with the delivery, acceptance, performance,
default or enforcement of this Note. Each Borrower hereby assents to any
extension or postponement of the time of payment or any other indulgence, to the
addition or release of any party or person

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Exhibit 10.61

primarily or secondarily liable, and to the addition, release and/or
substitution of all or any portion of any collateral now or hereafter securing
this Note.

Each Borrower hereby waives such rights as it may have to notice and/or hearing
under any applicable federal or state laws pertaining to the exercise by Lender
of such rights as the Lender may have regarding the right to seek prejudgment
remedies and/or deprive Borrower of or affect the use of or possession or
enjoyment of Borrower’s property prior to the rendition of a final judgment
against the Borrower. Each Borrower further waives any right it may have to
require Lender to provide a bond or other security as a precondition to or in
connection with any prejudgment remedy sought by Lender, and waives any
objection to the issuance of such prejudgment remedy based on any offsets,
claims, defenses or counterclaims to any action brought by the Lender.

EACH BORROWER AND LENDER MUTUALLY HEREBY KNOWINGLY, VOLUNTARILY AND
INTENTIONALLY WAIVE THE RIGHT TO A TRIAL BY JURY IN RESPECT OF ANY CLAIM BASED
HEREON, ARISING OUT OF, UNDER OR IN CONNECTION WITH THIS NOTE OR ANY OTHER
DOCUMENTS CONTEMPLATED TO BE EXECUTED IN CONNECTION HEREWITH OR ANY COURSE OF
CONDUCT, COURSE OF DEALING, STATEMENTS (WHETHER VERBAL OR WRITTEN) OR ACTIONS OF
ANY PARTY. THIS WAIVER CONSTITUTES A MATERIAL INDUCEMENT FOR LENDER TO MAKE THE
LOAN AND ACCEPT THIS NOTE.

Each Borrower hereby agrees that the following courts: State Court - Any state
or local court of the Governing State; Federal Court - United States District
Court for the District of the Governing State; or at the option of Lender, any
court in which Lender shall initiate legal or equitable proceedings and which
has subject matter jurisdiction over the matter in controversy, shall have
exclusive jurisdiction to hear and determine any claims or disputes between
Borrower and Lender pertaining directly or indirectly to this Note or to any
matter arising in connection with this Note. Each Borrower expressly submits and
consents in advance to such jurisdiction in any action or proceeding commenced
in such courts, hereby waiving personal service of the summons and complaint, or
other process or papers issued therein, and agreeing that service of such
summons and complaint, or other process or papers, may be made by registered or
certified mail addressed to Borrower at the address set forth herein. Should
Borrower fail to appear or answer any summons, complaint, process or papers so
served within thirty (30) days after the mailing thereof, it shall be deemed in
default and an order and/or judgment may be entered against it as demanded or
prayed for in such summons, complaint, process or papers. The exclusive choice
of forum set forth herein shall not be deemed to preclude the enforcement of any
judgment obtained in such forum or the taking of any action under this Note to
enforce the same in any appropriate jurisdiction.

This Note shall be governed by and construed in accordance with the laws of the
Governing State.

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Exhibit 10.61

13. Maximum Permissible Interest Rate. The Borrower shall not be obligated to
pay and the Lender shall not collect interest at a rate higher than the maximum
permitted by law or the maximum that will not subject the Lender to any civil or
criminal penalties. If, because of the acceleration of maturity the payment of
interest in advance or any other reason, the Borrower is required, under the
provisions of any Loan Document or otherwise, to pay interest at a rate in
excess of such maximum rate, the rate of interest under such provisions shall
immediately and automatically be reduced to such maximum rate and any payment
made in excess of such maximum rate, together with interest thereon at the rate
provided herein from the date of such payment, shall be immediately and
automatically applied to the reduction of the unpaid principal balance of this
Note as of the date on which such excess payment was made. If the amount to be
so applied to reduction of the unpaid principal balance exceeds the unpaid
principal balance, the amount of such excess shall be refunded by the Lender to
the Borrower.

14. Replacement Documents. Upon receipt of an affidavit of an officer of Lender
as to the loss, theft, destruction or mutilation of the Note or any other
security document(s) which is not of public record and, in the case of any such
loss, theft, destruction or mutilation, upon surrender and cancellation of such
Note or other document(s), the Borrower will issue, in lieu thereof, a
replacement Note or other document(s) in the same principal amount thereof and
otherwise of like tenor.

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Exhibit 10.61

15. Transfer and Assignment.

15.1.    The Lender may at any time pledge, endorse, assign, or transfer all or
any portion of its rights under the Loan Documents including any portion of this
Note to any of the twelve (12) Federal Reserve Banks organized under Section 4
of the Federal Reserve Act. 12 U.S.C. Section 341. No such pledge or enforcement
thereof shall release the Lender from its obligations under any of the Loan
Documents.

15.2.    The Lender shall have the unrestricted right at any time or from time
to time, and without any Borrower’s consent, to sell, assign, endorse, or
transfer all or any portion of its rights and obligations hereunder to one or
more lenders or other entities (each an “Assignee”), and each Borrower agrees
that it shall execute, or cause to be executed such documents including without
limitation, amendments to this Note and to any other documents, instruments, and
agreements executed in connection herewith as the Lender shall deem necessary to
effect the foregoing. In addition, at the request of the Lender or any such
Assignee, the Borrower shall issue one or more new promissory notes, as
applicable, to any such Assignee and, if the Lender has retained any of its
rights and obligations hereunder following such assignment, to the Lender, which
new promissory notes shall be issued in replacement of, but not in discharge of,
the liability evidenced by the note held by the Lender prior to such assignment
and shall reflect the amount of the respective commitments and loans held by
such Assignee and the Lender after giving effect to such assignment. Upon the
execution and delivery of appropriate assignment documentation, amendments, and
any other documentation required by the Lender in connection with such
assignment, and the payment by such Assignee of the purchase price agreed to by
Lender and such Assignee, such Assignee shall be a party to this Note and shall
have all of the rights and obligations of the Lender hereunder (and under any
and all other guaranties, documents, instruments and agreements executed in
connection herewith) to the extent that such rights and obligations have been
assigned by the Lender pursuant to the assignment documentation between the
Lender and such Assignee, and the Lender shall be released from its obligation
hereunder and thereunder to a corresponding extent.

15.3.    The Lender shall have the unrestricted right at any time and from time
to time, and without the consent of or notice to the Borrower to grant to one or
more institutions or other persons (each a “Participant”) participating
interests in the Lender’s obligations to lend hereunder and/or any or all of the
loans held by the Lender hereunder. In the event of any such grant by the Lender
of a participating interest to a Participant, whether or not upon notice to the
Borrower, the Lender shall remain responsible for the performance of its
obligations hereunder and the Borrower shall continue to deal solely and
directly with the Lender in connection with Lender’s rights and obligations
hereunder. The Lender shall furnish any information concerning the Borrower in
its possession from time to time to any prospective assignees and Participants,
provided that the Lender shall require any such prospective assignee or
Participant to maintain the confidentiality of such information.

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Exhibit 10.61

16. Setoff. Each Borrower hereby grants to the Lender a lien, security interest,
and a right of setoff as security for all of the Obligations, upon and against
all deposits, credits, collateral, and property of any Borrower, now or
hereafter in the possession, custody, safekeeping, or control of the Lender or
any entity under the control of the Lender, or in transit to any of them. At any
time, without demand or notice, the Lender may set off the same or any part
thereof and apply the same to any liability or obligation of the Borrower even
though unmatured and regardless of the adequacy of any other collateral securing
the Obligations. ANY AND ALL RIGHTS TO REQUIRE THE LENDER TO EXERCISE ITS RIGHTS
OR REMEDIES WITH RESPECT TO ANY OTHER COLLATERAL WHICH SECURES THE OBLIGATIONS,
PRIOR TO EXERCISING ITS RIGHT OF SETOFF WITH RESPECT TO SUCH DEPOSITS, CREDITS,
OR OTHER PROPERTY OF EACH BORROWER ARE HEREBY KNOWINGLY, VOLUNTARILY, AND
IRREVOCABLY WAIVED. The Lender shall not be required to marshal any present or
future security for, or guarantees of, the Obligations or to resort to any such
security or guarantee in any particular order and each Borrower waives, to the
fullest extent that it lawfully can: (a) any right it might have to require the
Lender to pursue any particular remedy before proceeding against them; and (b)
any right to the benefit of, or to direct the application of the proceeds of any
collateral until the Obligations are paid in full.

17. Security. This Note and all other Obligations are secured by all assets of
each Borrower whenever arising or created in accordance with the terms of the
Loan Agreement and all other documents which create or perfect security
interests in assets or properties of any Borrower. This Note and all other
Obligations are further secured by that certain specific equipment of the
Borrower to be purchased with the proceeds of the Loan.

18. Extension of Relevant Dates. In the event that any relevant date upon which
a payment is due and payable under this Note or which affects any interest rate
option of the Borrower shall fall on a date which is not a Banking Day, then any
such relevant date may be extended by the Lender in accordance with the Modified
Following Banking Day Convention and interest shall continue to accrue, and the
relevant due dates shall also be extended, for the period of that extension at
the interest rate or rates then in effect. For purposes hereof, the “Modified
Following Banking Day Convention” shall mean the convention for adjusting any
relevant date if it would otherwise fall on a day that is not a Banking Day.
When used in conjunction with the term, “Modified Following Banking Day
Convention”, and a date, such term shall mean that an adjustment will be made if
that date would otherwise fall on a day that is not a Banking Day so that the
date will be the first following day that is a Banking Day.

Notwithstanding anything to the contrary hereinabove contained, if application
of the Modified Following Banking Day Convention would cause any payment due
under the terms of this Note to be due and payable in a calendar month which
differs from the month in which the payment would otherwise have been due, then,
at the Lender’s option, the Modified Following Banking Day Convention shall not
apply and such payment shall be due and payable on the immediately preceding
Banking Day.

19. Joint and Several Obligations; Miscellaneous. This Note and all
representations and covenants of the Borrower herein shall be the joint and
several obligation of the Borrower

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Exhibit 10.61

and each provision of this Note shall apply to each and all jointly and
severally and to the property and liabilities of each and all. This Note is the
final, complete and exclusive statement of the terms governing this Note. No
modification or amendment hereof shall be effective unless the same shall be in
writing and signed by the Lender and the Borrower. If any provision of this Note
shall to any extent by held invalid or unenforceable, then only such provision
shall be deemed ineffective and the remainder of this Note shall not be
affected. The provisions of this Note shall bind the heirs, executors,
administrators, assigns and successors of each and every Borrower and shall
inure to the benefit of Lender, its successors and assigns. This Note shall be
governed by and construed in accordance with the laws of the Commonwealth of
Massachusetts.
    
20. Acknowledgment of Borrower. The Borrower acknowledges receipt of a copy of
this Note, and attests that each advance is to be used for general commercial
purposes and that no part of such proceeds will be used, in whole or in part,
for the purpose of purchasing or carrying any “margin stock” as such term is
defined in Regulations U and X of the Board of Governors of the Federal Reserve
System, 12 C.F.R. Parts 221 and 224.

21. COMMERCIAL TRANSACTION. EACH BORROWER ACKNOWLEDGES THAT THE ADVANCES
EVIDENCED BY THIS NOTE ARE PART OF A COMMERCIAL TRANSACTION.

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Exhibit 10.61

This Note has been executed as a sealed instrument on the date first above
written.
                            
Arrhythmia Research Technology, Inc.

_____________________________        By: /s/ Salvatore Emma, Jr.
Witness
Salvatore Emma, Jr., President and Chief Executive Officer

Duly Authorized

Micron Products Inc.

_____________________________        By: /s/ Salvatore Emma, Jr.
Witness
Salvatore Emma, Jr., President and

Chief Executive Officer
Duly Authorized

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