Ideation Process

Innovation Situation Questionnaire

1. Brief description of the problem

Develop a low-cost, easy-to-use device intended to aid a minimally trained user in taking blood pressure measurements with a sphygmomanometer

2. Information about the system

2.1 System name

Non-Electronic Blood Pressure Assist Device

2.2 System structure

Typical sygmomanomters have built-in dampening of the oscillatory component of the pressure reading. To utilize the oscillatory signal in reading blood pressure, an adjuct device like a pressure can re-establish and amplify the oscillatory signal.

2.3 Functioning of the system

Adjunct devices like a pressure transducer can be attached to the tubing of the sphygmomanometer. Such a device is effective because it can amplify for the oscillatory signal for development of a simple blood pressure measurement technique.

2.4 System environment

The device is to be used in clinics located in developing countires; therefore, the environment will require durability and simplicity.

3. Information about the problem situation

3.1 Problem that should be resolved

While many philanthropic studies focus on “high-profile” killers such as HIV and malaria, the primary cause of death throughout the developing world still stems from issues related to the heart. The WHO has begun to seriously consider the growing number of hypertensive patients throughout the world, and as a result we are focusing specifically on improving the diagnosis of hypertension by designing an easy-to-use blood pressure measurement system.

3.2 Mechanism causing the problem

Current methods for blood pressure measurement require training to detect the Korotkoff sounds, which can lead to inaccurate measurements when training is absent or administered inproperly.

3.3 Undesired consequences of unresolved problem

If blood pressure is not accurately recorded, hypertensive patients have the potential to go unrecognized. This can lead to the progression of cardiovascular diseases, which could be treated if accurate blood pressure measurements were established for the patient before cardiovascular complications worsen.

3.4 History of the problem

According to the American Heart Association, the most common method is the auscultatory method, which uses Korotkoff sounds to identify systolic and diastolic blood pressure. The brachial artery is occluded by an inflatable blood pressure cuff, which is connected to a sphygmomanometer. A stethoscope is used to listen for the appearance and disappearance of sounds thought to be caused by the turbulent flow of blood underneath the cuff. The initiation of sounds signals systolic pressure and the termination of noise represents the diastolic pressure. This is inherently a difficult technique to master.

A second method for obtaining blood pressure without a stethoscope is the oscillatory method. This method measures the oscillations in pressure from a pressure above the systolic pressure to below the diastolic pressure. The maximum oscillation is called the mean arterial pressure, which can be used to calculate systolic and diastolic pressure. One issue with this technique is that the amplitudes can depend on other factors besides blood pressure. This method requires expensive electronic devices.

A third common method for measuring blood pressure is called tonometry. This involves measuring the pulsations of an artery as it is pressed up against bone. It is most commonly practiced at the wrist, where the radial artery lies over the radius bone. Other methods for measuring blood pressure include a finger monitor or ultrasound. These methods either require electronic systems or are inherently inaccurate.

All these methods either require substantial training or expensive equipment that is unobtainable by remote clinics.

3.5 Other systems in which a similar problem exists

Many other devices like EKGs also poses requirements of electricity, trained personnel, or expensive upkeep, which limits their implementation in remote clinics.

3.6 Other problems to be solved

It would be ideal to also determine the diastolic pressure with our adjuct device, but systolic is of upmost importance when diagnosising hypertension.

4. Ideal vision of solution

Our ideal device would accurately measure systolic and diastolic blood pressure. These measurements would be able to be acquired by users relying on a simple instruction manual pictorally describing the method in easly understandable terms. Also, the non-electronic device would be mass produced for $5 or less per unit.

5. Available resources

Professor Baudenbacher is our Vanderbilt Faculty advisor for the project. He had provided us with text resources for pressure transducers and blood pressure measurement systems. We also have patent search engins available for acquiring information of similar systems with somewhat aligning intentions.

6. Allowable changes to the system

We would allow the system to exceed the cost goal of $5 if meant producing a device that more easily achieved usability by the clinician. We would also allow detection of the oscillation signal by chaning the site of application from the sphygmomanometer tubing to other non-invasive locations.

7. Criteria for selecting solution concepts

Solutions must maintain a non-invasive application of the device. Also, the solution must maintain independence from energy sources.

8. Company business environment

The market for this device is diverse because remote clinics exist in developing countries all over the world. We are currently seeking financial resources for our design by submitting grant proposals.

9. Project data

  • Non-electronic Blood Pressure Assist Device
  • Goals
  • Decrease difficulty in obtaining blood pressure measurements for devloping countries
  • Meet affordability goal of $5 production cost
  • Design be easily mass produced
  • Reading from BP device be accurate enough for clinical diagnosis of hypertension
  • Ultimately, an easy method for identifying hypertension is the first steop in decreasing cardiovascular diseases related deaths in third-world settings
  • Timeline
  • Have design ready for submission to EWH Design Competition by April 30th
  • Project Team

Laura Allen

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James Berry

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Casey Duckwall

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David Harris

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Professor Franz Baudenbacher (Advisor)

<mailto:>

Mary Judd (Administrative Contact)

<mailto:>

Justin Cooper(EWH Contact)

Problem Formulation

1. Build the Diagram

2. Directions for Innovation

12/8/2009 11:02:36 PM Diagram1

1. Find a way to eliminate, reduce, or prevent [the] (Inaccurate Blood Pressure Measurements) in order to avoid [the] (Undiagnosed Hypertension), under the conditions of [the] (Complicated Training) and (No Resources for Advanced BP devices).

2. Find a way to eliminate, reduce, or prevent [the] (Complicated Training) in order to avoid [the] (Inaccurate Blood Pressure Measurements).

3. Find a way to eliminate, reduce, or prevent [the] (Undiagnosed Hypertension) under the conditions of [the] (Inaccurate Blood Pressure Measurements).

4. Find a way to eliminate, reduce, or prevent [the] (No Resources for Advanced BP devices) in order to avoid [the] (Inaccurate Blood Pressure Measurements).

5. Find an alternative way to obtain [the] (Easy Training) that offers the following: provides or enhances [the] (Successful Remote Clinic BP Device), eliminates, reduces, or prevents [the] (Inaccurate Blood Pressure Measurements).

6. Find an alternative way to obtain [the] (Sucessful BP Measurements) that offers the following: provides or enhances [the] (Diagnosis of Hypertensive Patients), does not require [the] (Successful Remote Clinic BP Device).

7. Find an alternative way to obtain [the] (Successful Remote Clinic BP Device) that offers the following: provides or enhances [the] (Sucessful BP Measurements), does not require [the] (Affordability), (Non-Electronic) and (Easy Training), is not influenced by [the] (Complicated Training).

8. Find an alternative way to obtain [the] (Affordability) that provides or enhances [the] (Successful Remote Clinic BP Device).

9. Find an alternative way to obtain [the] (Non-Electronic) that provides or enhances [the] (Successful Remote Clinic BP Device).

10. Find an alternative way to obtain [the] (Diagnosis of Hypertensive Patients) that offers the following: provides or enhances [the] (Reduction in Cardiovascular Disease), does not require [the] (Sucessful BP Measurements).

11. Find an alternative way to obtain [the] (Reduction in Cardiovascular Disease) that does not require [the] (Diagnosis of Hypertensive Patients).

12. Consider transitioning to the next generation of the system that will provide [the] (Reduction in Cardiovascular Disease) in a more effective way and/or will be free of existing problems.

Prioritize Directions

1. Directions selected for further consideration

First Priority:

Find a way to eliminate, reduce, or prevent [the] (No Resources for Advanced BP devices) in order to avoid [the] (Inaccurate Blood Pressure Measurements).

Second Priority:

Find an alternative way to obtain [the] (Easy Training) that offers the following: provides or enhances [the] (Successful Remote Clinic BP Device), eliminates, reduces, or prevents [the] (Inaccurate Blood Pressure Measurements).

Third Priority:

Find a way to eliminate, reduce, or prevent [the] (Complicated Training) in order to avoid [the] (Inaccurate Blood Pressure Measurements).

2. List and categorize all preliminary ideas

Systems that amplify the oscillatory signal:

  • Pressure Transducer

Systems that allow for detection of systolic reading:

  • Inherent oscillations in the sphygmomanometer
  • Existence of pulse in radial artery

Develop Concepts

1. Combine ideas into Concepts

Utilizing both the inherent oscillations in the sphygmomanometer and the existence of pulse in radial artery allows for redundancy in the detection of systolic because both methods are aimed at obtaining a simple, but possibly inaccurate, method for the systolic acquisition. By implementing both techniques, the accuracy of the methods may be improved.

2. Apply Lines of Evolution to further improve Concepts

We need to establish what accuracy in the systolic reading is necessary for diagnosis of hypertension. In particular, we need to determine what accuracy is acceptable for developing country clinics.

Evaluate Results

1. Meet criteria for evaluating Concepts

If the adjunct device does not meet the accuracy intended, other secondary methods such as controling the bleed rate of the pressure cuff may improve the accuracy but increase the cost of the system.

2. Reveal and prevent potential failures

The pictoral training manual will hopefully prevent any potential misuses of the device.

3. Plan the implementation

We are currently obtaining a baseline measurement system by using the sphygmomanometer by itself to detect systolic blood pressure. Once we have a prototype we will obtain more data to compare with the baseline data. This will hopefully validate the improvement in systolic acquisition that our device provides. By submitting the device to the EWH Design Competition, we hope to take the first step in implementation of the device into developing country clinics.

References

(1) WHO. “Fact Sheet: The Top Ten Causes of Death.” WHO. November 2008. Accessed October 28, 2009 < >.

(2) Pickering TG. , Hall JE, Appel LJ, Falkner BE, Graves J, Hill MN, Jones DW, Kurtz T, Sheps SG, Roccella EJ; Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research. Recommendations for blood pressure measurement in humans and experimental animals: Part 1: blood pressure measurement in humans: a statement for professionals from the Subcommittee of Professional and Public Education of the American Heart Association Council on High Blood Pressure Research. Hypertension. 2005 Jan;45(1):142-61.

(3) EWH. “Who We Are.” EWH. 2009. Accessed December 8, 2009 < >.

(4) Webster, John G. The Measurement, Instrumentation, and Sensors Handbook. CRC Press 1999.