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 re-zero 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 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 after . We are aiming to understand the schematic of the most common automatic arm blood monitor by searching patent through US Patent Office. checking with the US Patent Office to make sure we are staying within the boundaries of the law(LEI IS THIS CORRECT? I was not sure what you mean't with the 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 it's 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 doingtheir 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 / Task
Lead / Start / End / Desired Outcomes for each tasks by the end of the period
1 / Planning the design / Lei Qu / 10/30/10 / 11/14/10 / Have a well planned procedure for the project
1.1 / Understand Omron Digital Blood Pressure Monitor / 11/01/10 / 11/02/10 / Able to know in detail on how Omron Digital Blood Pressure Monitor convert pressure into digital signal
1.2 / Reverse Engineering Omron Digital Blood Pressure Monitor / 11/02/10 / 11/09/10 / Understand both electric and mechanical concept behind the digital blood monitor device
21.2.21.2.1 / Purchasing and ordering the resourcesDesign A re-zero device attached to Omron Digital Blood Pressure Monitor / Lei Qu/Dr.Churchwell / 10/29/1011/09/10 / 10/29/103/01/11 / Buy necessary things as needed. A re-zero device that can be attached to Omron Digital Blood Pressure Monitor and can be re-zero to actual zero
2.11.2.31.2.2 / Ordering 3 Omron Digital Blood Pressure MonitorTrial and errors and redesign / 10/29/103/01/11 / 10/30/104/01/11 / These are for reverse engineering and design processes Test out the design, perfect the design
1.2.3 / Modify the re-zero method to be done in "away office" fashion / 4/01/11 / 5/01/11 / The re-zero device can be done by patient
2 / Purchasing and ordering the resources / Lei Qu/Dr.Churchwell / 10/29/10 / TBD / Buy necessary things as needed
2.1 / Ordering 3 Omron Digital Blood Pressure Monitor / 10/29/10 / 10/30/10 / These are for reverse engineering and design processes
2.2 / ordering the conjunction tools / 10/29/10 / TBD / Any possible tools that are needed during the design process

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