Phoenix Ambulatory Blood Pressure Monitor Project
Patent References


The intent of the Phoenix Project is to create open hardware and software designs for an ambulatory blood pressure monitor (ABPM). That implies that all intellectual property located on this website is free from patent, copyright and trademark infringement. The patents listed below have been reviewed to determine if the technologies listed on this web site infringe on the patent rights of others. It is also used to determine if any newly issued patent attempts to protect technologies that have already been placed into the public domain by the volunteers of the Phoenix project. This is not a comprehensive list and should not be used as a substitute for legal counsel. The user assumes all responsibility for determining if their ambulatory blood pressure monitor design infringes on the intellectual property rights of others. Submissions to this list are encouraged, and should be sent to:

Patent documents and searchable databases are available on-line from:


Motivation(s) for the Patent Review

There are several reasons for reviewing these patents. The most important is to prevent patented technologies from entering the public Phoenix ABPM architecture. That's because the Phoenix ABPM is an enabling technology for an open marketplace. By definition, an open technology market can't be based around proprietary technologies. If it were, then the owner of the intellectual property could unfairly manipulate the market to their own advantage. Defending the public domain status of the Phoenix ABPM creates a technological safe harbors for those participating in the market.

In theory, it shouldn't even be necessary to review these patents. That's because most patent offices won't issue a patent unless it is for a novel invention, meaning that it hasn't been thought of before. However, inventors and patent examiners may not necessarily be aware of the Phoenix ABPM technology because it's been placed into the public domain by publishing it on the internet (i.e. it's a public works of invention). This means that it doesn't appear in the patent file system. It also means that the only way to defend the Phoenix ABPM commons area is by monitoring new patents.

The list of patent references also provides a good starting point for designers and other researchers who need to know if a specific blood pressure technology infringes on the rights of others. The patent documents are also a good place to learn how other people have solved similar problems. They are very good in this regard, as they must fully describe how to reproduce an invention.

An excellent tutorial on the subject of patents can be found in Patent It Yourself, by David Pressman (ISBN: 1-4133-0025-1). While intended for inventors, it's also an excellent guide for anybody attempting to negotiate the US patent system.


Public Use

The US Congress established several ways to place an invention into the public domain. Perhaps the easiest and least expensive way to do this is to destroy the novelty of the invention by publishing it for public use. Relevant regulations include 35 U.S.C. 102(b): Conditions for Patentability; Novelty and Loss of Right to Patent. In most cases this is sufficient to protect a patentable invention for public use.

US patent law allows inventors to publicly disclose an invention and then apply for a patent at later date (up to one year from the initial public disclosure). This can create problems if somebody else sees it and attempts to patent the invention themselves during the one year grace period. If an inventor intends to to make the invention available for public use then good record keeping should be maintained. At a minimum these should include a detailed description of the invention (with sample claims, if possible), date of conception and date of initial public disclosure. If possible, these should be witnessed by someone else with at least ordinary skill in the art of the invention. The US Patent and Trademark Office (PTO) also allows an invention to be deposited with them under terms of the Disclosure Document Program (DDP), using form PTO/SB/95.

The US Congress also provides for public inventions under 35 USC 157: Statutory Invention Registration and 37 CFR 1.293: Statutory Invention Registration. The invention registration is similar to a patent, except that it doesn't have its enforceable offensive attributes. It's generally used as a defensive measure to prevent others from protecting the same invention. On-line resources can be found in the Manual of Patent Examining Procedure (MPEP). That document contains the rules used by patent examiners at the US Patent Office. Relevant sections include: Section 1100 - Statutory Invention Registration and Pre-Grant Publications.

In some cases Statutory Invention Registration may not be practical because: (a) they are too expensive to obtain (the application procedures are the same as patents) and (b) technology innovations come from many users around the globe. Instead, it's probably best to publicly disclose the invention and then monitor published patent applications and newly issued patents. If trouble arises a posse of interested parties can be formed to defend it. This same approach has worked very well in the past on various standardization technologies, and there is good evidence that it's working in the GNU/Linux world as well.

The US Patent and Trademark Office (PTO) has a backlog delay due to the high volume of applications that it handles. The backlog delay is the time interval between a patent's application date and its issue date. The backlog delay is important for public domain engineering projects because it can take several years before a patented invention can be found. For example, if a new feature is added to the Phoenix ABPM technology, then it can take some time to figure out if somebody else had already invented it. In 2004 the typical backlog delays at the US PTO were about 29.5 months. A search of Published Patent Applications at is also possible.

An excellent resource about intellectual property and the public domain can be found at the Duke University Law School - Center for the Study of the Public Domain (

The US code (USC) can be found on-line at:
The US Code of Federal Regulations (CFR) can be found on-line at:

Intellectual Property, Industry Standards and RAND Policies

One of the major goals of the Phoenix ABPM project is to create a set of royalty-free technologies. This is the same goal as many public standards organizations such as ANSI, IEEE, JEDEC and the OSI. All require that their standards be free of any overt intellectual property protection. This is accomplished by using RAND (Reasonable And Non Discriminatory) patent policies, which are summarized below.

Most standards organizations operate so that their RAND policies only apply to the inter operability of devices, and not to any related technologies. For example, the USB 2.0 Standard (used on your desktop computer) covers inter operability of USB devices, but does not attempt to control things that are connected to the USB port (e.g. mice or cameras).


ANSI (American National Standards Institute) Standards Patent Policy

The ANSI policy for intellectual property rights is presented in Guidelines for Implementation of the ANSI Patent Policy: An Aid to More Efficient and Effective Standards Development in Fields That May Involve Patented Technology (ANSI - March 2003). It is available on-line by searching the ANSI web site at ANSI and its approved standards development organizations have adopted a policy known as RAND, or Reasonable and Non Discriminatory terms and conditions. That document states that a party identified by a standards development group as a patent holder must supply ANSI with either:

"a general disclaimer to the effect that such party does not hold and does not anticipate holding any invention the use of which would be required for compliance with the proposed standard;

or a written assurance that either:

(1) a license will be made available without compensation to applicants desiring to utilize the license for the purpose of implementing the standard; or

(2) a license will be mode available to applicants under reasonable terms and conditions that are demonstrably free of any unfair discrimination."


IEEE (Institute of Electrical and Electronics Engineers) Standards Patent Policy

The IEEE Standards Association (IEEE-SA) in Section 6 of the IEEE-SA bylaws states that:

"IEEE standards may include the known use of essential patents and patent applications provided the IEEE receives assurance from the patent holder or applicant with respect to patents whose infringement is, or in the case of patent applications, potential future infringement the applicant asserts will be, unavoidable in a compliant implementation of either mandatory or optional portions of the standard [essential patents]. This assurance shall be provided without coercion and prior to approval of the standard (or reaffirmation when a patent or patent application becomes known after initial approval of the standard). This assurance shall be a letter that is in the form of either:

a) A general disclaimer to the effect that the patentee will not enforce any of its present or future patent(s) whose use would be required to implement either mandatory or optional portions of the proposed IEEE standard against any person or entity complying with the standard; or

b) A statement that a license for such implementation will be made available without compensation or under reasonable rates, with reasonable terms and conditions that are demonstrably free of any unfair discrimination. This assurance shall apply, at a minimum, from the date of the standard's approval to the date of the standard's withdrawal and is irrevocable during that period."


JEDEC Standards Patent Policy

The JEDEC Solid State Technology Association (Once known as the Joint Electron Device Engineering Council), is the semiconductor engineering standardization body of the Electronic Industries Alliance (EIA), a trade association that represents all areas of the electronics industry. The JEDEC patent and copyright policies are covered in Section 8 and Annexes A and B of the JEDEC Manual of Organization and Procedure (JM21-L July 2002). Their policy is summarized in Annex A.1:

"Standards that call for the use of a patented item or process may not be considered by a JEDEC committee unless all of the relevant technical information covered by the patent or pending patent is known. In addition, the chairperson must have received written notice from the patent holder or applicant that one of the following conditions prevails:


OSI (Open Source Initiative)

The patent and copyright clauses in the Open Source Definition [OSD] from the Open Software Initiative is relevant to open source software.

List of Reviewed Patents

All of these documents contain information relevant to ambulatory blood pressure monitors. Patents recently added to the list are marked '[*NEW*]', irrespective of the patent issue date. Currently the list only shows US patents. The following key words and phrases are helpful for patent searches: "blood pressure"; "non-invasive" and "ambulatory".


Non-invasive Blood Pressure Monitors Using Pulse Velocity Methods

Chen et. al. - US Patent No. 6,599,251 [Click Here]

Golub - US Patent No. 5,857,975

Hatschek - US Patent No. 5,309,916

Inukai et al. - US Patent No. 5,921,936

Inukai et al. - US Patent No. 6,645,155



About This Page

This page is maintained by Ellis S Nolley. It was last updated on 9 July 2006.

The author(s) provide this information as a public service, and agree to place any novel and useful inventions disclosed herein into the public domain. They are not aware that this material infringes on the patent, copyright, trademark or trade secret rights of others. However, there is a possibility that such infringement may exist without their knowledge. The user assumes all responsibility for determining if this information infringes on the intellectual property rights of others before applying it to products or services.

Copyright (C) 2006 Ellis S. Nolley. Copying and distribution of this page is permitted in any medium, provided this notice is preserved.

Back to the Phoenix Home Page