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Proposal: Biomedical Engineering Design Project
This fictional unsolicited proposal is based on a real situation in Columbia, Maryland. It is
written by a Case Western Reserve University student, a senior majoring in biomedical
engineering, to the Department of Biomedical Engineering. The proposal asks for time and
money to extend a senior design project, even though the course is officially over.

                            To Rosemary Clooney, Chair
                               Department of Biomedical Engineering
                               Case Western Reserve University

                         From Erin Cardinal, Senior, Biomedical Engineering Major

                          Date December 12, 2000

                            Re Proposal to Continue Senior Design Project

         Overview     My consulting team, Rehabilitative Assistive Devices, Co. (RAD),
                      proposes to design a new nurse alarm for a quadriplegic patient in
                      Columbia, Maryland. The patient's current alarm is so sensitive that
                      the patient frequently activates it accidentally, which causes distress
                      both for the patient and for the nurses who care for him.

                      For our senior design project at Case Western Reserve University,
                      we have already designed and tested a prototype of a new alarm
                      (Super Switcher Prototype I). Testing revealed the need for further
                      design modifications, which we are proposing to complete over the
                      next 16 weeks. Our team is requesting $16,765 and an extension on
                      the project deadline to complete the project. This new device
                      (Prototype II) will be less placement-sensitive, reducing the number of
                      false alarms and need for adjustments.

                      This proposal provides details about the patient's condition and
                      needs, specifications about the alarm design, and a plan for
                      completing the project. Please let us know if you have any questions.

      Introduction    Problem
                      Mr. Willie Wong is a 45-year-old bed ridden quadriplegic resident of
                      Lorien Nursing and Convalescent Home in Columbia, MD. His
                      condition often requires him to call a nurse for assistance, but his
                      present mechanism is plagued with placement issues. Mr. Wong
                      frequently activates his alarm unintentionally because it is so
                      sensitive. However, if the sensitivity of the device is reduced, he is
                      unable to activate it when he desires.

                      Project goal
                      Rehabilitative Assistive Devices, Co. (RAD) would like to design a
                      new nurse alarm for Mr. Wong. This new device will be less
                      placement-sensitive, reducing the number of false alarms and need
                      for adjustments. Beginning in September 2000, RAD began designing
             this device, but was unable to produce an adequate replacement by
             December 2000 (although dramatic progress was made). With an
             extension on the project deadline, RAD feels that it can produce a
             quality product to assist Mr. Wong.

             Significance of the project
             A reliable nurse alarm would greatly benefit Mr. Wong. He suffers
             from weak breathing and a lack of a significant cough reflex, so a
             dependable mechanism could greatly increase his quality of life.
             Calling for assistance can be critical. By replacing the current
             signaling system, RAD can add more functionality and reliability.
             Additionally, the high number of false alarms and the constant
             readjustment of the current device distract the nurses from their other
             duties. By eliminating these issues with his switch, RAD can return
             these nurses to tasks that are more productive.

Background   The patient's condition (syringomyelia)
             Mr. Wong suffers from high-level quadriplegia due to syringomyelia.
             This chronic disorder is characterized by cerebrospinal fluid entering
             the spinal cord, forming a syrinx cavity. This syrinx expands gradually
             over time, successively destroying the spinal cord. As the nerve fibers
             inside the spinal cord are damaged, a wide variety of symptoms can
             occur. Mr. Wong's condition was diagnosed approximately twenty
             years ago, and his deterioration was rapid during the first few years.
             The condition eventually led to complete paralysis from the neck
             down. The condition also gradually limited his head movement.
             Currently, Mr. Wong has no movement below the neck, and can
             rotate his head approximately 30 degrees to the left. Other effects of
             his condition include weakened breathing and a lack of significant
             cough reflex. Mr. Wong has an open tracheotomy that has not been
             closed because of several life-threatening bouts of pneumonia. These
             periods of illness have compromised his cough reflex. Recently, low
             blood oxygen levels have required Mr. Wong to use a respirator from
             10:30 pm until noon.

             The problem with the current switch
             When Mr. Wong had more head control, he used a mouth stick to
             alert nurses and control his computer. However, as his condition
             deteriorated, his degree of head control decreased to the point where
             the stick was no longer a viable option. To call for assistance, Mr.
             Wong now uses a simple single pillow switch placed nearly beneath
             his head on the left side. This device is a low-voltage, momentary,
             single-pole single-throw (SPST) switch that plugs into a wall
             receptacle where it closes a latching relay to activate a light outside
             his room. When he moves his head slightly to the left, the wall call
             outlet is engaged to notify a nurse that he requires assistance.
             However, this system is plagued by many false alarms, since any
             slight head movement to the left, even unintentional movement,
             triggers the nurse alarm. Also, the current switch is extremely
             placement sensitive because its contact area is small. This requires
             specific placement beneath and to the left of Mr. Wong's head so
             contact is possible. These two factors have led to slight
             dissatisfaction by the nursing staff, and in general, take nurses away
             from other duties. The act of calling for assistance is critical, due to
           Mr. Wong's weak breathing and lack of a significant cough reflex.

           Project to date
           RAD began a project to replace the alert system of Mr. Wong in
           September 2000. After obtaining information and specifications from
           Lorien and Mr. Wong via Dr. Hambrecht, RAD designed and
           constructed Super Switcher Prototype I. This new device was tested
           on site on December 1, 2000. Although the switch correctly activated
           the wall outlet, Mr. Wong proved unable to activate the device
           himself. The test team from RAD then redesigned the casing of the
           switch and created Super Switcher Prototype II. This version allowed
           Mr. Wong to activate it and proved to be a better housing design.
           However, there are still problems with this second prototype.

Problem    The primary problem is that Mr. Wong cannot reliably request
Analysis   assistance. Due to his weakened breathing and lack of a cough
           reflex, the ability to call can be lifesaving.

           Mr. Wong and the Lorien facility have several switch constraints.
           These criteria limit the options available and dictate the types of
           designs that may be implemented. The switch must be clinically
           compatible. The output of the device must correctly interface with the
           existing call box via a "phono plug that is able to provide the
           momentary current to the internal SPST switch. The device must not
           produce sparks or a voltage because it will be close to Mr. Wong and
           the oxygen supplied to him. The casing must be waterproof,
           comfortable, and hypoallergenic. It must also not attach to Mr. Wong
           or be suspended above him as per the request of his caregivers.

           Mr. Wong has also expressed some preferences about a new device,
           and his condition dictates several other constraints. Since Mr. Wong
           has limited head control and weak neck strength, the mechanism
           must be able to be activated within 30 degrees from the vertical to the
           left and must not be greatly force or velocity dependent. The device
           must be usable during the time he is using a ventilator. Between
           10:30 pm and 12:00 pm, Mr. Wong's ventilator does not allow him to
           speak. Therefore, the device cannot be voice-activated. Also, the
           ventilator equipment placement cannot be compromised.

           The device must also have feedback to signify when it has been
           activated. Mr. Wong has specifically requested audible feedback for
           this task. The switch must also fit easily into the limited area available
           and be compatible with Mr. Wong's single bed position. He operates
           with his upper body slightly elevated to allow him to watch television.

           Additionally, RAD has provided device specifications, which must be
           met. The switch must reduce false alarms and be less placement-
           sensitive. Both of these improvements will increase the reliability of
           the signaling system. The device must be cost-effective in its design,
           construction, and maintenance. It must also be adaptable both to
           other patients and their needs, as well as to environmental control
               Although RAD has constructed a better device, improvements can
               still be made. The most current switch, Prototype II, implements a
               dual-phase switching mechanism with audible feedback for the initial
               contact. This single alarm notifies Mr. Wong when he has initiated the
               signaling process, but he still is unaware of when he actually
               activates the wall outlet. The device is also somewhat bulky in that it
               is 5 cm high. This dimension also makes it unstable and prone to
               tipping or sliding away when Mr. Wong attempts to activate it. This
               switch produced positive results, but still has much to be desired in
               order to fully meet the functional specifications of the device.

Statement of   Work to be accomplished
       work    RAD will further develop the Super Switcher Prototype II to suit the
               needs of Mr. Wong. The proposed modifications include:

                   1. Removal of one of the switches. This will further flatten the
                      device, making it more stable, easier to place, and less
                      motion-restrictive for Mr. Wong.

                   2. Addition of upper and lower plates. This will increase the
                      available contact area, which will reduce placement
                      restrictions. These rigid plates will better translate the applied
                      force into the center of the device where the internal switch

                   3. Addition of a second audible alarm. The first alarm will remain
                      activated at the beginning of the call process. It will serve to
                      notify Mr. Wong that he has activated the device and provide
                      him with an opportunity to cancel the action. The new second
                      alarm will be activated at the close of the call process, and
                      serve to notify Mr. Wong that he has successfully completed
                      the signaling process (i.e., when the wall outlet has been
                      activated). This second alarm will operate at 2,800 Hz (F) to
                      contrast the first alarm operating at 974 Hz (Bb).

                   4. Implementation of a time-delay mechanism. The circuitry will
                      be redesigned to utilize digital logic. When the switch is
                      initially closed, the first alarm will sound and a 555 timer will
                      be activated. The clock will cycle once for a period of 5
                      seconds. A second closure of the switch will be required
                      during the active portion of the clock to activate the call outlet.
                      This will be accomplished with a standard AND gate to
                      compare the clock signal and the second signal from Mr.
                      Wong. If the second signal is detected within the 5s clock, the
                      AND gate sends a positive signal out. This signal in turn
                      activates the second audible alarm and the wall call outlet.
                      This system is expandable into environmental control by
                      requiring multiple signals within the clock to perform different
                      functions, such as turning on the light and television. It is also
                      adaptable to other potential clients by changing these
                      functions and altering the duration of the clock signal.

               Evaluation techniques
               After the completion of the modifications to Prototype II, RAD will
            conduct testing to increase reliability in the clinical setting. The switch
            will be evaluated for comfort, audible feedback level, degree of
            visibility, placement sensitivity, and stability. These tests will be
            performed both directly after construction within RAD, and in the
            clinical setting with Mr. Wong. According to RAD specifications,
            comfort and stability should be high, degree of visibility and
            placement sensitivity should be low, and audible feedback level
            should be "okay." The number of false alarms will also be recorded,
            and the caregivers will be asked to evaluate the device as well.

            A verbal survey will be used to evaluate the different aspects of the
            device. Each question will be given a scale of responses, and the
            tester will be instructed to use this scale to provide feedback about
            the switch. Both audible feedback mechanisms will be evaluated for
            presence, tone, and volume. The presence factor indicates if the
            feedback exists and is consistently activated as planned. The tone of
            each alarm is rated on a scale of "too high," "too low," or "okay." The
            volume of the sound is similarly rated on a scale of "too loud," "too
            quiet," and "okay." The other questions all make use of a scale of 1 to
            10 with 10 being the high end corresponding to "completely agree."
            The tester will be asked to rate the comfort on this scale. He will also
            be asked about the degree of visibility of the device. This question
            measures how much the switch restricts the vision of the tester. If the
            device is highly visible, the tester gives it a high score, which is
            interpreted as undesirable. The stability of the device is evaluated on
            the scale with 10 being highly stable and not prone to tipping or
            sliding. Finally, the individual placing the device (a caregiver) will be
            asked to rate the placement sensitivity on the scale. A high placement
            sensitivity score indicates that if the device moves, it can no longer be
            activated. Therefore, high scores are undesirable. If Mr. Wong feels
            comfortable with the switch, it will be left with him for his continued
            evaluation. The number of false alarms and required placement
            adjustments will be recorded for a 48-hour period. Finally, Mr. Wong
            and the Lorien employees will be given an opportunity to make
            suggestions to improve the device.

Personnel   All personnel working on this project are senior biomedical
            engineering students at Case Western Reserve University. The team
            consists of four members: Erin Cardinal, Darshan Gad, Vanessa
            Hassibi, and Kristen Roenigk. These students operate under the
            direction of Dr. P. Hunter Peckham and Dr. J. Lawrence Katz of the
            Biomedical Engineering Department of Case Western Reserve
            University. Dr. F. Terry Hambrecht M.D., who is based in Columbia,
            Maryland with Mr. Willie Wong, will also remotely direct the group.

            Ms. Cardinal, Ms. Hassibi, and Ms. Roenigk are all biomechanicians.
            Mr. Gad's specialty is in bioinstrumentation. He focuses on the
            internal circuitry construction while the other three design the casing
            and conduct the testing. The physicians serve to guide the group
            through the design process and provide support as needed. This
            team is the same group who designed Super Switcher Prototype I
            and Prototype II, so they are all familiar with the project.
Budget   Category    Item                            Cost Subtotal
         Personnel   10 hr/wk x 16 wks x 4 workers   25/hr   16,000
         Equipment   3-amp regulated DC power          40       91
                     supply                             3
                     555 timer chips                    5
                     digital logic gates                6
                     piezo buzzers                      3
                     1/8" panel-mount phono jack        4
                     1/4" phono plug                    5
                     "Y" splitter cable                 3
                     SPST interface relay contacts     10
                     rigid plates                       2
                     heat-shrink tubing                10
                     basic soldering kit
         Travel      tolls                             17      674
                     hotel (2 nights)                 160
                     car rental                       110
                     gas                                5
                     (x 2 trips)
                                                Total Cost   16,765

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