NeoCuff Kathm Alismail, Joseph McNeil, Hussain Altuwairit Changes to the Project Materials Selection: The initial proposed material selected was using neoprene material for the outer part of the band and 70D Nylon. We selected these materials based on the materials used for the blood pressure cuffs that meet the regulations and standards. These materials are being fabricated for medical use. However, we were not able to obtain these materials because they are being sold in a large quantity and longtime shipment time. Currently, we are using high gauge vinyl (12G) for our bladder. In addition, 100% Nylon materials for the outer materials that make up the heel cuff. In addition, there is a possibility of using Nylon based bladders retrieved from neonate blood pressure cuff or strong balloon for the bladders in the device. The initial idea is a band with two bladders with one lead and hooks medical velcro that circulate the heel. We are going to test this shape structure band; however, we are suspecting that as the bladders inflate the band at the edges would bend toward outside rather than applying pressure to the heel. We have proposed alternative shapes to the band. See figure 1. figure 1. Updated shape of the Neo cuff For the valve, we initially purchased pneumatic aluminum electric solenoid air valve 12V DC. Then, it turned out the size is larger than what we anticipated for a valve. From talking with John, we found there are mini valves that he used in his senior project. So, we decided to use his valve until we receive the new mini
valve (figure 2). Figure 2. X-valve a miniature pneumatic solenoid Tasks We currently have multiple tasks being planned for the upcoming weeks. In order to stay on schedule, each member has owned a particular task or set of tasks. This will allow us to work independently and maximize our efficacy. Right now, we have plans to have a working code in the, a prototype bladder finished, and the entire circuit completed in the next two weeks. First, we plan to have the code finished in the next two weeks. One group member has been working on learning the Arduino code that will be used eventually to code our device. He has started to work on the structure of the code, in order to make sure the logic is correct and the device will work as intended. Then, he will need to research different open source codes for some of the sensors we are using, in order to properly gain information from the sensors. Finally, he will need to use the data in order to turn the pump on and off, as well as open and close safety valves we have incorporated into the device. Next, we plan to have a prototype bladder in the next two weeks. We have currently been testing out different prototype fabrication, and have been having difficulties sealing the plastics we ordered. Also, it has been a struggle to seal a port in the handmade bladder. In our first prototype, we have decided to use balloons to utilize a built in port, as well as a shape of bladder we are looking for. We are also testing the use of premade bladders to use in the final prototype. These bladders will then be used in calibration testing and functional testing of the device. Finally, we plan to have the circuit completely built in the next two weeks. We have created the schematic for the motor controller as well as the valve controller and the sensor circuit. We are waiting on a couple components to be shipped in for us to complete the circuit. Once the circuit is complete, we will be able to write the code with proper pin numbers. Also, we will be able to test the full device with the bladder when the circuit is complete. We have planned out future tasks and tests that we need to complete by the end of the semester in order to complete the entire project. These tasks include measuring the hand force of different nurses, calibrating the device, and finishing our final report and presentation.
We will need to measure the hand force of different nurses that have experience with performing heel stick blood draw procedures. This will allow us to use a pressure sensor on the skin of a doll to calibrate the device. The chart for the test is below in Table 1. Will also need to calibrate the device using pressure sensors. These sensors will tell us the exact pressure that is being applied to the cuff. We will use the data from the nurse hand clench force test to calibrate the cuff to the same pressure. We will calibrate by decreasing or increasing the pressure threshold of the device before the valve switches to deflate. Accomplished Tasks Since last semester, we have accomplished several tasks to word completion and finishing our project. First We have submitted an IRB application and the application was approved by our university board. Second, we have ordered and received the materials we proposed to use in our project. In addition, we evaluated the materials we ordered and ordered other parts that can be used for our project. For example, we ordered two neonate blood pressure (BP) cuffs because there is a potential in using the bladders in the BP cuffs in our device. The size of the bladders in the neonate cuff BP is relatively the same size of the bladders we want or our design (12cm X 3cm).Third, we have tried different techniques in fabricating the bladders. We tested sealing the bladders using iron, soldering machine, and a heat sealer. The heat sealer the best choice for our purposes because the bladders are relatively small and good and localized seal is needed. We conducted pressure measurement using bulb pressure transducer connected to the biopac system. each of the group members applied pressure on the pressure sensor in an amount that felt to be closer to the amount of pressure needed in heel blood draw procedure. We averaged the pressure measurement and found 20.432 kpa is needed. We will take pressure measurement from the nurses also and incorporate the data into our device. We have talked with Dr. Marie Therese Jamison to contact us another nurse. She asked us to write a procedure about the measurement method. So we have prepared a procedure for the nurses to follow in taking a measurement using Clench Force Bulb connected to Biopack. We have prepared the code for the pressure sensor. The sensor came with calibrated, so there is no calibration required for the sensor We have created a schematic for the device. The schematics include all circuit components on the board (figure 3). We anticipate to use the same pins shown in the figure.
Figure 3. Schematics of the NeoCuff Results of Clench Force on Ourselves In order to initially calibrate our device before meeting with the nurses, we ran a clench force test on ourselves. We used the Biopac Clench Force Bulb Sensor and the BioPac system. We were able to gather pressure data for each of the three patterns mimicking a heel stick blood draw on an infant. The data can be seen in Table 2. The results of the test show that we had an average applied pressure of 20431.7 Pa. This number can be used to initially calibrate our device using pressure sensors, our device, and an infant doll. Expanded Task List The project tasks are divided among the team members as the following: Kathm is responsible for the making the bladders. This task gives Kathm full responsibility to create the bladders. In other words, he is allowed to make changes at any time in order to have functioning bladders. His decisions and changes include the material selection, sealing, and testing. Hussain is responsible for coding. He is responsible to collect feedback from kathm and joe in how the microcontroller should process. This task includes creating, testing and developing the code at any time to fit the design. High Performance and safety are the main requirements of the code. Joseph is responsible for creating, testing and connecting the circuit. This task includes finding the right circuit component to perform the job and approximating the lifetime of the device. Also, suggest the proper packaging technique for the electric circuit.
Table 1: Future Tests to be Completed Name of Experiment Nurse Hand Force Measurement Pump Functional Test Bladder Sealing Bladder Failure test Cuff Pressure Test/ Calibration Purpose of Experiment To determine average force applied to infants foot during heel stick blood draw procedure To ensure the pump does not leak during the deflation cycle To ensure the bladder do not leak any air Determine the amount of force that fails the bladders To calibrate the pressure applied by the cuff Equipment to be used Biopac Computer Clench Force Bulb Sensor Our Device Pressure Dial Gauge, Pump Mechanical Testing Machine Our Device Infant Model Equipment Location Bioinstrumentation Lab Bioinstrumentation Lab Bioinstrumentation Lab Engineering Building Bioinstrumentation Lab Responsible Team Member Hussain Altuwait Projected Date of Completion 3/25/2018 Joey McNeil 3/15/2018 Kathm Alismail Kathm Alismail Kathm Alismail 3/12/2018 3/31/2018 3/28/2018 Table 2: Biopac Data from the Clench Force Measurements on Team Members Joseph Kathm Hussain 1622 3845 1094 2000 3846 888 1814 3021 1312 1964 3123 1053 2027 2952 1066 2537 2582 869 2617 2477 1042 average 2083 3120.857143 1046.285714 * all values
in kgf/m3 total average 2083.380952 kgf/m3 20431.717 Pa Items Purchased We have purchased many different materials and devices to help in the construction of our device. Each item, as well as the application of the item, is located in table 3. Table 3: Items Purchased for Project Item Neoprene Nylon DC Pump Micro Solenoid Medical Grade Cuff (Neonate) Power Source Heat Sealer Transistor Pressure Sensor X Valve Balloons Vinyl (Gauge 8 & 12) Description To be used as a protective layer around the bladder Possible material for sealed bladder and outer layer To use as an air pump to inflate bladder Used to direct air into and out of bladder (replaced by Xvalve) To harvest the hose, port, and bladder from. Also used as a prototype. To run the pump at 12 Volts. Device that is used to seal plastic. Used to make bladders. Item needed for our circuit. Item needed for our circuit. Item used to direct air into and out of bladder Used as a prototype bladder. Used as bladder Meeting Minutes We have been meeting as a group at least once a week every Monday at 1:30. In addition, we have assigned biweekly meetings with our advisor every Wednesday 12:30. For recording minutes and tasks, every time one of the members record the minutes and upload the document to our shared google drive. (see
Appendix). Meetings with group members and advisor are been very beneficial. each member talks about the progress of his assigned part and receives advice. Updated Timeline Figure 4. Updated timeline Appendix Materials and Procedure for the Pressure measurement Materials: System: Biopack BSL 35 MP Sensor: Bulb pressure Sensor (figure 2) Procedure: Procedure Before Recording 1. Connect the Clench Force Pump Bulb to CH2 in Biopac 2. Turn on the Biopac software (lesson two) 3. Change sensor preferences to Clench Force Pump Bulb before starting Procedure for Recording the Data (Nurse) 1. Grasp the pump bulb with your dominant hand
2. Apply pressure for 2 seconds and release (Calibration) 3. Recording data, apply pressure on the bulb similar to what you apply on the heel while performing heel blood draw. (maximum)
Team Meeting Minutes Design Organization:Senior Project Date: 1/25/2018 Agenda: Measurement Setup Calibration Schedule Materials Discussion: Prepare an experiment setup to be used in the hospital Send the material list to dr. Lancina Divide the tasks for the coming two weeks Decisions Made: Send the material list to dr. Lancina Meet tomorrow to continue Action Items Person Responsible Deadline Ordering materials Joe Preparing setup Hussain Calibration Time line Kathm Team member: Date for next meeting: 1/25/2018 at 12 The Mechanical Design Process Designed by Professor David G. Ullman Copyright 2008, McGraw Hill Form # 3.0
Team Meeting Minutes Design Organization: Senior Project Date: 10/26/2017 Agenda: Distribute the works Test the new force transducer (bulb) Discuss the type of the valves Order pressure sensor Discuss the bladder fabrication methods Decisions Made: Work Distribution: 1) Bladder research and fabrication (Kathm) 2) Pump and pump setup (Joseph) 3) Coding of the overall system (Hussain) For the Force transducer, we used lesson 2 (student lesson) biopac system to get the measurement. Initially we had difficulties swithching the units and the readings seems off. Them, we figured that we needed to change the system preferences to bulb pressure sensor. The units are kgf/m^2. Valve received is very large for our system. After discussing this with John, we agreed to purchase a small valve (X-Valve) We found a pressure sensor that sense from 0 to 500KPA. For bladder fabrication, Iron soldering are not possible because the low mechanical properiy yielded and sealing problems. We decided to use heat sealer that is used for food sealing and other materials Action Items Person Responsible Deadline Purchase heat sealer K 2/17/18 Purchase pressure sensor K,H 2/17/18 Work on the pump setup J 2/24/18 Code of the pressure sensor H 2/24/18 Team member: Team member: Team member: Team member: The Mechanical Design Process Designed by Professor David G. Ullman Copyright 2008, McGraw Hill Form # 3.0
Figure 5. 8 Gauge vinyl sealed using Soldering machine Figure6. 12 gauge sealed vinyl shows higher sealed are with better seal
Figure 7. Failed sealing using heat sealer on neonate blood pressure cuff size 3
Figure 8. Pump circuit on the board