Portable Automatic Arm
Blood Pressure Machine
Calibration
Project Proposal
Ross Hamilton
Lei Qu
Hanniff Nor
David Lee
2010
Abstract
Hypertension is one of the most common diseases in US. Approximately 32% of adults
are suffering from hypertension yet are non-institutionalized (Health, United States, 2009). In
order to fight this epidemic, close monitoring and regulation on the patients is strongly
suggested. Today’s digital blood pressure monitor is not designed to be self-recalibrated, thus
resulting clinical calibration process after 6 months period of usage. In this project proposal, we
are trying to solve this unnecessary and inefficient problem by designing a method that can rezero the digital blood pressure monitor. Our top three objectives are:

Understand how digital blood pressure monitor works, not only specific to one
brand but a general schematic working process; both mechanically and
electronically.

Design a re-zero or calibration method that will give the same reading as
mercury sphygmomanometer.

The calibration device can be attached
or plugged into the digital blood
pressure monitor and compatible with
all digital blood pressure monitor.
This project has high market potential because of how
necessary a device a blood pressure monitor is in
general, but more importantly it will change the
Figure 1: A common Omron digital blood
pressure monitor
current situation on blood pressure checking. In the long run, we hope to increase efficiency
and aid in the current progress being made in finding a cure for hypertension.
Introduction
Hypertension is one of the most common diseases in USA. There are approximately 32%
of over ages of 20 that are diagnosed with hypertension yet non-institutionalized (Health,
United States, 2009). Hypertension is also a leading cause to many other fatal diseases such as
strokes and heart attack. Currently, according to the report by Joint National Commission, the
best treatment for blood pressure is through close regulation of blood pressure by checking it
periodically throughout the day. The traditional method to measure blood pressure is done
through a mercury sphygmomanometer. This device gives a very accurate reading of an
individual’s blood pressure but it requires training and certain skill set. It is also hard to
determine blood pressure since it is done through listening. Thus it is not very convenient for
the patient to do the blood pressure checking alone. Hospital settings will also create a “white
coat” psychological affect which directly affect blood pressure; the affect can raise blood
pressure and can cause masked hypertension in 15-30% of patients (Picker, et al, 1988).
Currently, device used out in the field (and not in a medical office) is a digital blood pressure
monitor, such as Omron. However, Omron doesn’t have a method to calibrate the device thus
the device is required to be replaced pretty regularly in order to get an accurate reading of
blood pressure for the hypertension patient. This is an obvious problem considering how it is
very inefficient and not very realistic for poorer countries who cannot afford this luxury. In this
project, we are aiming to devise a method to calibrate the digital blood pressure device which
could greatly help the industry financially as well as help the world on a more global scale by
being able to help more individuals.
History and Context
Dr.Churchwell is our mentor for this design project. During the meeting, he told our team his
education and work backgrounds which lead him to be the Associate Professor of Medicine in
Cardiology Department. He explained that the majority of death in America is due to hypertension.
Thus, this design team became responsible to calibrate and re-design the current blood pressure device.
In doing so, he provided our team with some funds to get the actual blood pressure device on the
market. We are going to disassemble and do some research about the main operations of this device
through reverse-engineering . We are aiming to understand the schematic of the most common
automatic arm blood monitor by searching patent through US Patent Office. Currently, Omron can be
considered one of the most popular blood pressure devices that are used by consumers, which is shown
in Figure 1, which is why we are going to analyze it to see its positive and negative characteristics. Also,
we have to do more research about any other digital blood pressure devices on the market through the
American Society of Mechanical Engineers because there could be ideas already in use which could be
beneficial to the success of our project. Our main customer is Dr. Churchwell, and this whole team,
however in the long run we would be looking for Biomedical Companies around the world to be
purchasing our new and improved product (or calibration method). Also, any other patients in hospitals
or clinics would be considered consumers of this product. According to Dr. Churchwell, we are going to
be the first group of people to be testing the accuracy of the calibration for the digital blood pressure
monitor.
Team Members
Haniff Mohd Nor: Haniff is a senior who is pursuing a mechanical engineering degree at
Vanderbilt University. He is on this design team because he has the expertise on mechanical engineering
and can give valuable information and insight on why certain materials should be used for calibrating
the blood pressure monitor. He can also understand the mechanical systems in digital and mercury
blood monitor thus helping us to understand on how the digital blood pressure behave mechanically
with patient arms when measuring blood pressure. He will be the “go to guy” on questions about
mechanical part of the digital blood pressure monitor.
Ross Hamilton: Ross is a senior who is pursuing a biomedical engineering degree at Vanderbilt
University. Ross has sufficient knowledge in human physiology which will be a good addition on the
knowledge about hypertension. In addition to the knowledge of the human body, Ross also is very
efficient and quick to learn about equipment used in an operating room or laboratory setting. Ross has
many shadowing experiences, thus he can give us valuable advice on whether our design on blood
monitor can be performed in a "field" or hospital setting, or whether our design would be clinically
approved. Ross also has very good presenting, communication, leadership, and writing skills which will
help the team to present their ideas to any committee clearly and get the proper feedback that will be
extremely helpful for the progress of this project.
David Lee: David is a senior at Vanderbilt University pursuing a biomedical engineering degree.
David has gained many engineering experiences through volunteering and conducting research in
various labs. He also brings another unique creative aspect which can be beneficial toward the design of
the project.
Lei Qu: Lei is a senior at Vanderbilt University and pursuing a biomedical engineering degree. Lei
is the team communicator for this whole design group. He will manage the communication between the
supervisor, the other project teams and other responsibilities that are related to communication. He will
be responsible to post updated report and update the webpage for the group. He also has many
research experiences which will be valuable hand on process during the design process. He will
coordinate the meetings and work load for each group member to make sure each team member is
doing their job to the best of their abilities and to have a good level of understanding and
communication with each other.
Dr.Churchwell: Dr.Churchwell is the supervisor of this design project. He has a BME
undergraduate degree and a MD degree also. Dr.Churchwell can give us valuable information on
physiology and engineering aspects of our design.
Work Plans and Outcomes
WBS
Tasks
1
Planning the design
1.1
Task
Lead
Lei Qu
Start
End
10/30/10
11/1/10
Understand Omron Digital Blood
Pressure Monitor
11/01/10
11/02/10
1.2
Reverse Engineering Omron Digital
Blood Pressure Monitor
11/02/10
11/09/10
21.2.2
Purchasing and ordering the
resources
10/29/10
10/29/10
2.11.2.3
Ordering 3 Omron Digital Blood
Pressure Monitor
10/29/10
10/30/10
Lei
Qu/Dr.Churchwell
Desired
Outcomes
for each
tasks by
the end of
the period
Have a well
planned
procedure for
the project
Able to know in
detail on how
Omron Digital
Blood Pressure
Monitor convert
pressure into
digital signal
Understand
both electric
and
mechanical
concept behind
the digital
blood monitor
device
Buy necessary
things as
needed.
These are for
reverse
engineering
and design
processes
The table above shows the tentative outline of the tasks for the design project and also the tentative
schedule for each task. We will first follow a reverse engineering process on figuring out how Omron
digital blood pressure monitor works. From there we will then design a re-zero or calibrate processes
that can be tested to see if the device is actually at the true zero. The project has a high possible chance
of success because currently many Omron digital blood pressure monitor must be using some standard
as a zero standard. Thus if we can set the standard to the true zero standard, the design will be success.
The final design can be patented thus it can be mass produced into many digital blood pressure
monitors. This can be beneficial to millions of patients who are suffering from hypertension. This design
project can be very educational to the whole design team. In the end of this project, we hope to be able
to gain sufficient knowledge on blood pressure monitors in general, both electronical and mechanical
concepts. We also hope to gain enough physiological understanding on hypertension.
The design process followed will be the devised protocol written through repetitive
experimentation; the blueprint will be a step by step elaboration of the backbone guideline suggested
below:
1. the purchased Omron digital blood pressure monitors
2. Reverse engineering on Omron digital blood pressure monitors, understand both mechanical
and electronical aspects of them.
3. Study calibration/re-zero method in the digital blood pressure monitors and other devices
4. Design re-zero device for the Omron digital blood pressure monitors
5. Check to see the method is can be done when a physician or technician is in the field
All of the process for the step-by-step procedure will be fully supervised under the discretion of the
engineering team and their collaboration; the engineers will conduct the experimentation under the full
oath toward the Engineering Code of Ethics.
Once the project is actualized and reaches the original goals, the administrative teams will manage
the enterprise through instillation of official website and alongside launch advertisement strategies for
marketing purposes.
The main milestone to achieve is to design a re-zero device that can be attached or be plugged into
the current Omron digital blood pressure monitor. The next one can be have the process to be available
for any in the "field" methods.
The suggested overall budget: 500 dollars
Allocation
1. Omron digital blood pressure monitors: 200 dollars, 5 total, 60 to 40 dollars each
2. Miscellaneous tools/parts: 300 dollars. This section will be allocated to the tools or parts such as
resistors, digital convertors or any other parts that we may need during the design process
Evaluation and sustainability
Currently, digital blood pressure devices are being sold on the market at a reasonable price but
there are flaws in this device. Because the machines cannot be calibrated once they become inaccurate,
the consumers need to buy a new device after only a short period of usage (REFERENCE THIS LEI). Thus,
one measurement of the success of this project would be if this device can be used for a long period of
time without any defects or inaccuracies. In general, for a device to be patented, it has to be useful
which is what would be accomplished in this project. However, before it can be used in most of the
hospitals or clinics, it would probably be best to monitor its performance within a cardiovascular lab
first. The most important indicator as a measure of success would be to actually ‘zero’ this device for
better accuracy in measuring blood pressure. Finally, this project can be developed into a new
generation of blood pressure monitors which would result in huge market potential. Future
engineering team can work on how to make the device even better to give higher levels of accuracy or
maybe not even need to be calibrated.
References
Chobanian, Aram, et al, “The Seventh Report of the Joint National Committee on Prevention, Detection,
Evaluation, and Treatment of High Blood Pressure”, JAMA. 2003;289:(doi:10.1001/jama.289.19.2560).
National Center for Health Statistics, “Health, United States, 2009 With Special Feature on Medical
Techonolgoy”, Hyattsville, MD, 2010.
Pickering T, James G, Boddie C, Harshfield G, Blank S, Laragh J (1988). "How common is white coat
hypertension?". JAMA 259 (2): 225–8. doi:10.1001/jama.259.2.225