Operator s Manual. Team One

Transcription

1 The Assisted Leg Holding Device for Medical Procedures Operator s Manual Team One Jennifer Bruno Katherine Etter Gehendra Kunwar Client Contact Dr. John D. Enderle University of Connecticut: Biomedical Engineering Department Program Director & Professor for Biomedical Engineering Bronwell Building, Room 217C 260 Glenbrook Road Storrs, Connecticut Voice: (860) ; FAX: (860) jenderle@bme.uconn.edu

2 IMPORTANT SAFETY INSTRUCTIONS Be sure to keep all appendages away from moving parts of device To avoid injury, the device should always be covered with medical drapings when in use by a patient Always use Velcro straps to secure a patient s legs within the device supports Do not pull on wires attached to device NEVER touch exposed wire when the device is connected to a power supply ALWAYS disconnect power supply before adjusting the wiring of the device Check the device regularly to assure that all parts are properly connected and in working order Be sure that all appropriate parts are tightened into place before loading a patient into device ALWAYS support device while the motors are making adjustments Do not exceed device s weight limit 2

3 PARTS AND ACCESSORIES 1.5 x1.5 and 1 x1 Structural Aluminum Bars Bluetooth Equipped Scale 3

4 Braking System Drapings 4

5 Foot Support Linear Slide 5

6 Medical Table Motor with Motor Mount 6

7 PC with MPLAB Software 7

8 PIC Microprocessor and Motor Circuit Power Supply 8

9 Spring with Attachment Plate Tempered Steel Support Bars 9

10 Thigh Support 1/16 Uncoated Stainless Steel Cord 10

11 Welded I-Hook for Horizontal Adjustment 11

12 FEATURES Anti-gravity technology allows the practitioner to adjust the position of a patient s leg in a weightless environment Device is adjustable for patients weighing up to 300 pounds Device is adjustable for a patient leg range of 20 inches to 44 inches Device is adjustable for a variety of leg positions from fully bent to fully extended Device is adjustable for a variety of leg positions from close together to widely spread Device can be removed from table and stored when not in use Medical drapings allow the device to be sterilized easily between procedures Adjustable, Velcro-secured foot and knee supports allow for extra comfort and support during procedures and can accommodate amputees 12

13 TABLE OF CONTENTS I. Important Safety Instructions..1 II. Parts and Accessories.2-11 III. Features Introduction General Overview Operating Instructions Maintenance Between Procedures Electrical Mechanical Environmental Technical Description 3.1 Material Properties Device Dimensions and Mechanical Specifications Electrical Specifications Trouble Shooting

14 1. Introduction 1.1 General Overview The purpose of the assisted leg-holding device for medical procedures is to provide support for a patient s legs during any procedure that may require positioning a patient s legs in a specific way. Some of the procedures that have been considered while designing this device include gynecological and urological examinations, as well as surgeries of the legs or knees. In order to support a patient s legs, the assisted leg-holding device employs a gravity-balancing technique, using springs to counter-balance a patient s weight. In this way, the practitioner can adjust the device to any position while exerting minimal force. This feature is especially useful when considering disabled or overweight patients, as these patient populations often present additional difficulties for practitioners when attempting to adjust leg supports. The assisted leg-holding device consists of two multi-link leg supports attached to the end of a standard medical table. This set-up is shown in figure 1 below. Figure 1 The assisted leg-holding device for medical procedures As can be seen from the figure, this device is very complex and consists of many individual parts. This section will review the assembly instructions for the assisted leg-holding device. A large amount of weight is exerted on the table at the point of attachment of the device. Because the table was not designed specifically for this type of attachment procedure, it is 14

15 essential that the table be reinforced. Bent aluminum supports were used in order to carry out this reinforcement, as shown in figure 2 below. Aluminum Reinforcement Pivot Joint Figure 2 Bent aluminum supports for table reinforcement To allow abduction and adduction of the legs, pivot pieces were attached to these supports using 5/16 inch bolts inserted through the pivot pieces, the aluminum supports, and into the wooden table extension. The pivot pieces came equipped with extensions to attach to the device. Holes were drilled into these extensions large enough to accommodate 3/8 inch carriage bolts, which were also inserted through the framework of the device, as shown in figure 3 below. 15

16 Figure 3 Attachment of device to table As mentioned above, each leg support of the device consists of four links in order to optimize the device s range of motion and make it versatile for many procedures. All links are made of 10 or 12-inch extruded aluminum horizontal upper supports, 14 inch extruded aluminum vertical supports, and corresponding tempered steel horizontal lower supports. The profiles were organized so that all of the vertical supports are aligned, and so that the first and last links were closely aligned (to accommodate foot and thigh supports). All links were attached with ¼ inch carriage bolts secured with nuts. One of these attachments is shown in figure 4 below. 16

17 Figure 4 Attachment for links of assisted leg-holding device The anti-gravity portion of the device consists of motors coupled to threaded rods, linear slides that are designed to move up and down along the vertical supports, springs attached to the upper horizontal supports, and cords to attach the springs to the linear slides. The motors are attached to the device via custom machined motor mounts, as shown in figure 5 below. 17

18 Motor Screws Motor Mount Figure 5 Motor with motor mount As can be seen in figure 5, screws (10-24) were extended through the motor casing and into threaded holes within the motor mounts. Figure 5 also shows the two holes drilled into the bottom of the motor mounts. The bottom hole of each motor mount corresponds to the attachments for the lower horizontal supports, and the top hole of each motor mount is used to prevent rotation of the mount on the device. Figure 6 shows a motor mount attached to the legholding device. 18

19 Figure 6 Motor mount attached to device The motors are powered by electrical cords inserted into the back of each motor. These cords run to protoboards, and from there to a 12-volt power supply. The protoboards consist of PIC microcontrollers, wired to and controlled by the MPLAB program on a PC. Figure 7 shows a diagram of the entire wiring system, including the appropriate attachments based on wire color. The code used in the microcontrolled is explained in greater detail in the Technical section of this manual. 19

20 Figure 7 Wiring system controlling motors As mentioned above, the motors are coupled to linear slides used to control the vertical distance of the cord. The couplers used for this device were custom-made, round, hollow aluminum rods designed to fit the motors and threaded rods snugly, and are shown in figure 8 below. 20

21 Figure 8 Couplers from motors to threaded rods As can be seen in the figure, the couplers are fitted to the motors and rods using small Allenhead screws, which can be tightened using an Allen wrench. The threaded rods used for this application are ¼ inch, with 20 threads per inch. Corresponding 1/4x20 holes were drilled and tapped into the bases of the linear platforms, and the rods were threaded through so that when the motors rotate, the platforms are driven up and down. The platforms were also designed to fit along the vertical supports using adjustable bent-aluminum pieces that can be screwed into place. This set-up is shown in figure 9. 21

22 Linear Platform Threaded Rod Figure 9 Set-up for linear platforms As can be seen in figure 9, additional holes were drilled into the linear platforms. The purpose of these holes is to accommodate the cord attached to the springs. This cord is attached at both ends using cord locks, as shown in figure

23 Figure 10 Cord locks for cord attachment This figure also shows the proper cord manipulation to prevent the cord from slipping through the cord lock, a double-loop. The cord is inserted through the hole in each platform, so that the cord lock is underneath the platform. The cord then is inserted through the welded I-hook controlling horizontal adjustment, and is attached to the spring balancing each link via the double-loops of the cord locks. Finally, the springs are attached to the framework of the device using metal plates. These plates are attached to each upper horizontal support using 5/16 inch bolts that are inserted through clearance holes within the plates and into the tapped ends of the horizontal supports. This entire set-up is shown in figure

24 Figure 11 Set up for attachment of cord and spring by way of I-hook and platform In this way, the assisted leg-holding device is put together. 1.2 Operating Instructions This section outlines step-by-step instructions for operating the assisted leg-holding device. STEP 1: Loosen the wing-nuts controlling the welded I-hooks and braking system of device. 24

25 Figure 11 Step One STEP 2: Ensure that all wiring is properly inserted and has not become loose or disconnected, and should turn on the power supply controlling the motors. 25

26 Figure 12 Step Two STEP 3: Turn on the PC that runs the computer program controlling the microprocessor. STEP 4: Double click on the MPLAB icon on the desktop Figure 14 Step Four 26

27 STEP 5: Click File Open DESING1_FIN Design1.mcw to load the proper program Figure 15 Step Five STEP 6: Take strain off of the leg-holding device by placing a support underneath of the device. This support should cause the device to make a 45 degree angle with the horizontal. 27

28 Figure 16 Step Six STEP 7: Weigh patient 28

29 Figure 17 Step 7 STEP 8: Enter patient s weight into proper place within MPLAB program Figure 18 Step 8 STEP 9: Build, Program Target Device, and Release the program, in this order, in order for the motors to move to their proper positions 29

30 Figure 19 Step 9 STEP 10: Move the welded I-hook to the appropriate position for each link on both supports so that cord is taut, and tighten wing-nuts at appropriate position. This should be done with links A and C at a 45 degree angle above the horizontal, and with links B and D parallel to the horizontal. 30

31 Figure 20 Step 10 STEP 11: Cover leg-holding device with medical drapings 31

32 Figure 21 Step 11 Steps 12-14, Patient Loading STEP 12: Slide patient onto the table so that she is sitting perpendicularly to the device and in the center of the table 32

33 Figure 22 Step 12 STEP 13: Assist the patient in swinging her legs over the proximal leg support, so that both of the patient s legs are hanging off of the table in between the leg supports 33

34 Figure 23 Step 13 STEP 14: Adjust the device so that the patient s knees and thighs are secured safely and comfortably within the knee and thigh supports, and Velcro them securely into place 34

35 Figure 24 Step 14 STEP 15: Adjust the device to any height depending on the type of procedure that is to be performed STEP 16: Lock each link of the leg-holding device into place by tightening wing-nuts 35

36 Figure 26 Step 16 STEP 17: Lock each pivot to keep device from adducting or abducting 36

37 Figure 27 Step 17 STEP 18: Perform medical procedure 2. Maintenance 2.1 Between Procedures The assisted leg-holding device is designed to be sustainable throughout many medical procedures and to be used by many patients. For these reasons it was essential to ensure that the device can be sterilized quickly and easily in between each procedure. Several features were incorporated specifically for this purpose. Figure 28 shows the device equipped with medical drapings. 37

38 Figure 28 Medical drapings covering assisted leg-holding device These drapings serve several functions, as was mentioned above, including preventing injury to patients or practitioners by blocking the moving parts of the device and keeping the device out of sight to make it appear less intimidating to patients. However, the main function of the medical drapings is to ensure that the device can be sterilized quickly and easily between each procedure. Due to the complicated nature of this device, it would be very difficult to spray and wipe each piece of framework, motor, spring, cord, etc. in between every procedure, and liquid sprays also have potential to damage the motors or wiring or to cause electric shock if they come in contact with these parts. Having the medical drapings in place ensures that the device stays sterile and prevents any body parts or body fluids from coming in contact with the device, and it also serves to protect the patient from anything unsanitary that may have come in contact with the device. After each procedure, therefore, the practitioner simply must remove the medical drapings from their positions surrounding the medical device, send them to be laundered, and install a fresh pair of medical drapings before the next procedure, as shown in figures 29 and

39 Figure 29 Removal of medical drapings from device Figure 30 Laundering of dirty drapings 39

40 All medical drapings should be washed, regardless of whether they have become visibly dirty, after every procedure to prevent the spread of microbes or disease between patients. EPA guidelines for disinfecting should be followed, including washing all drapings with chlorine bleach solution in a concentration of 5000 parts per million. (1) If drapings should remain dirty after laundering, they should be disposed of. Having removed the medical drapings, the practitioner should then spray any uncovered surfaces, especially the foot and thigh supports, with chlorine bleach solution in a concentration of at least 200 parts per million (1). Figure 31 Procedure for disinfecting foot and thigh supports This procedure should be repeated to sterilize the medical table as well. 2.2 Electrical Maintenance As mentioned at the beginning of this manual, it is essential to ensure that all wiring remain plugged into place properly to avoid exposure of unprotected wires. If these wires are touched by the practitioner or patient, electrocution could occur. Also, if an unprotected wire were to touch a conductive surface such as another wire or the metal of the device, this could cause a short within the system that would prevent the motors from working and could cause permanent motor 40

41 damage. Therefore, it is essential that the wires remain isolated from the device and plugged into position properly. For the leg-holding device, the proper motor wiring is shown in figure 32. Figure 32 Proper motor wiring for device Wires from the gray bundle are inserted into each of five slots on the side of the motor. Wires from all motors, within their isolated bundles, run along the bottom of the device and to the microcontroller. Before each time that the device is turned on for use, the practitioner should ensure that all wires are attached properly to every motor and to the microcontroller, and should fix any bad connections before using the device. Below, figure 33 shows the protoboard with the microcontroller that is in charge of motor control. The protoboard is attached to the power supply via the black and red wires at the top of the figure. The practitioner should be sure that these connections are secure before turning on the device, as the motors cannot work with faulty connections. 41

42 2.3 Mechanical Maintenance Figure 33 Protoboard controlling motor movement Just as the device should be checked before every use to ensure that wires have stayed in place and are plugged in properly, the mechanical components should also be checked in order to make sure that nothing has become loose or has fallen off of the device during storage or during a previous procedure. Several components should be targeted with this routine check. First, if the device has been removed from the medical table for any reason, the practitioner should make sure that the device is firmly fastened to the pivot before it is used, and that the nut used to keep the device in place is tightened fully. The proper attachment is shown in figure

43 Figure 34 Attachment of device to table Next, the practitioner should ensure that the springs are all attached to the device using the spring plates. It should be noted here that the springs have been left loose within their attachments, so that they are free to move to ideal positions and can be changed easily if necessary, however, this leaves a chance that the springs may become loose from the device, especially if the device is lifted above its normal range. In this case, the practitioner should simply re-connect the loose spring by inserting its free end through the spring attachment plate. This being said, if a spring should become worn out, which could happen if the device is used many times for different procedures or if the springs are stretched excessively, the practitioner can simply remove the broken spring by slipping it out of the spring attachment and slipping the cord loop from the other end, and replace it with another spring. This should only be done if the user makes sure to replace the spring with another in compliance with the spring technical specifications, which can be found in the Technical section of this manual. The assisted leg-holding device is designed to be modular, so that it is simple to remove worn or broken parts from the device and replace these components without disassembling the entire device. However, as mentioned above for springs, this replacement should only be done if the technician is comfortable locating replacement parts that comply with the specifications listed in the Technical section of this manual. 43

44 Another part of the device that has the potential to become loose over time or after extended use is the cord lock used to attach the cord to the spring and sliding platform. If this cord should become loose, a trained technician must come to re-calibrate the device before continuation of use. In order to calibrate the device, the technician must know which link is being adjusted (A-D) and at what angle the adjustment should be made. From here, he should consult table 1 below to decide the appropriate dimensions a and b (shown in figure 35) to move the linear platform and welded I-hook. Angle of adjustment a dimension (in) b dimension (in) Link A 45 degrees above horizontal Link B Horizontal to ground Link C 45 degrees above horizontal Link D Horizontal to groud Table 1 Re-calibration dimensions for each link of the device Figure 35 Labeling of links of device A through D Once the dimensions have been adjusted, the cord must be stretched until it is tight, and then inserted into the cord lock using the double loop method to prevent slipping. Once the cord is tightly attached to both the linear platform and the spring in the proper position, the cord lock should be tightened using a ratcheting 9/32 inch wrench, as shown in figure

45 Figure 36 Tightening of cord lock Finally, each time before the device is used with a patient, the coupling between each motor and threaded rod should be examined and tightened if necessary. Figure 37 shows the proper procedure for tightening this coupling. An Allen wrench is used to ensure that each Allen-head screw stays flush against the motor shaft as well as the threaded rod. 45

46 Figure 37 Tightening of connection between motor shaft and threaded rod 2.4 Environmental Maintenance The assisted leg-holding device is designed for use in the environment of a hospital operating room or physician s examination room. Therefore, the device should only be operated under dry conditions and at a reasonable room temperature (approximately 50 degrees F to 80 degrees F). 3. Technical Description 3.1 Material Properties Nearly the entire framework for the assisted leg-holding device, including the upper horizontal and vertical structural bars, the table reinforcements, the motor mounts, the spring attachment plates, and the linear slides, was built using aluminum. Aluminum was chosen for this application mainly because it has a high strength to weight ratio, which was necessary for this project because the device has to deal with large forces being exerted onto the metal, while at the same time has to be light in order to keep the device from being too cumbersome. Table 2 below shows a general overview of some of the material properties for aluminum. 46

47 Density 2.70 g/cm 3 Modulus of Elasticity 70 GPa or ksi Shear Modulus 26 GPa or 3771 ksi Table 2 Some material properties of Aluminum The information in table 2 is useful in helping to determine the behavior of our device when forces are exerted on it. Figure 38 shows a free body diagram of the entire device, for the purposes of determining the reactions that will take place at the device s attachment to the table. Because the device employs anti-gravity technology, each link will support itself through the spring/cord system, and therefore the individual links are not subjected to large forces even when a patient is loaded into the device. However, at the point of attachment between the device and the table, the force of the entire system is felt. Table Bent aluminum support Rtop Mtop Rbottom Ldevice/2 Mdevice*g Figure 38 Free body diagram of entire system By employing a static analysis of this system, it is possible to determine the forces and moments that are acting on the bent aluminum support at any time. Certain assumptions have been made to simplify the calculations, including assuming that the entire weight of the device is concentrated at the device s center, L device /2. Also, there is no reaction moment at the bottom support s attachment to the table, because this is a pivot joint and therefore it does not resist bending. Equations 1 and 2 calculate the forces and moments being applied to the bent aluminum support if we assume that the system is in static equilibrium. 47

48 F M = R top = M top + R M bottom device M device * g * ( L * g = 0 device / 2) = 0 (1) (2) From section 3.2, we know that the maximum weight that will ever be applied to the device is pounds, and the maximum length of the device is 44 inches, or 3.67 feet. Using this information, we can determine that R top is equal to a maximum of approximately 31 pounds, and M top is equal to a maximum of approximately 227 pounds*ft, or 2724 pounds*inch. The information for the forces and moments applied to the bent aluminum supports can be applied to determine the maximum deflection that will be caused in this support. This analysis will be done using singularity functions. The free body diagram for the support is shown as figure 39. Again, the dimensions were taken from section 3.2. Figure 39 Free body diagram for aluminum support The singularity function for deflection is shown in equation 3 below. 2 deflection = (1/ EI)[( M top *5) ( R top *5) 3 (3) Filling in the values determined above, the deflection of the bent aluminum support is found to be 18.6/I, the moment of inertia of the bent aluminum support. If we assume that this moment of inertia is sufficiently large, then we will have a small deflection, corresponding to a safe design. As mentioned above, this device is designed so that each link will have very little deflection, and therefore this report does not calculate these values, as they are of little concern. Therefore, this section has confirmed that the device is attached to the table safely and securely, and a user should not be concerned about the device coming loose or falling off of the table. 3.2 Device Dimensions and Mechanical Specifications Table 3 shows some dimensions and weight tolerances for the assisted leg-holding device. 48

49 Maximum weight Minimum weight Maximum leg length Minimum leg length Maximum leg adduction Maximum angle with horizontal Minimum angle with horizontal 300 pounds 75 pounds 44 inches 20 inches 90 degrees/leg 45 degrees 0 degrees (parallel) Table 3 Mechanical specifications for leg-holding device The following series of tables summarizes the parameters for mechanical components of the device, in case any components must be replaced. Purchased from Model Number Spring Constant Resting Length Maximum Length Change in Length Outside Diameter Wire Diameter Maximum Load Initial Tension Lee Spring Company LE177L02M 46.9 pounds/inch 5 inches inches inches 1.5 inches.177 inches pounds pounds Table 4 Spring specifications Attachment of pivot and support to table 5/16x24 (6) Attachment of device to table 3/8 carriage bolts (2) Attachment of upper and lower links 1/4x20 (16) Linear slide assembly 1/4x20 (48) Motor attachment (32) Motor mount attachment to device 1/4x20 (16) Spring platform attachment 5/16x20 (8) Table 5 Dimensions of bolts used for various parts of device Upper horizontal structural bars 1.5 x1.5 x12 (2), 1.5 x1.5 x10 (2) Vertical structural bars 1 x1 x14 (8) Lower horizontal structural bars.5 x.25 x12 (2),.5 x.25 x10 (2) Table 6 Dimensions of support bars of device The following series of tables summarizes the parameters for mechanical components of the device, in case any components must be replaced. 49

50 6 inches 2.5 inches 5 inches. 5 in 3 in 1.5 in 1.5 in 3 in Top View Side View Figure 40 Dimensions of bent aluminum table reinforcement support.75 in.75 in 3 in Figure 41 Dimensions of spring attachment plate Figure 42 Dimensions of motor mount 50

51 Top View Side View 3 inches 1.5 in.5.25 in 1 inch.25 in 3 inches Figure 43 Dimensions of linear slide 12.5 inches 3 inches.5 in.5 in 2.75 in Figure 44 Dimensions of foot support 51

52 11 inches 4 in 3 inches.5 in.5 in 3.3 Electrical Specifications Stepper Motor: 2.75 in Figure 45 Dimensions of thigh support The stepper motor (MDrive 23Plus Microstepping) was purchased through IMS as shown in Figure 46 below: 52

53 Figure 46 IMS home webpage to purchase MDrive 23plus Microstepping The motor accepts a broad input voltage range from +12VDC to +75 VDC. It uses NEMA 23 frame size high torque brushless motor, combined with a Microstepping driver, and accepts up to 20 resolution settings from full to 256 micro steps per full step, including the degrees, metric and arc minutes. Figure 47 Standard Specification of MDrive23 plus Microstepping motor Technically, the input voltage ranged from +12 to +75 VDC as previously stated. On the other hand, for the input such as step clock, direction and enable, the voltage ranged from +5 to +24 VDC sourcing or sinking. The step clock types were variables including step/direction, quadrature, and step up/step down. The default frequency is 2 MHz and the max frequency is 5 MHz. In addition, various steps per resolution were specified ranging from 200 to 51,200. For our particular setup, the input voltage was +12VDC for the stepper motor and voltage for input such as step clock and enable was +5VDC. 53

54 Figure 48 Minimum required connection for MDrive 23 plus Microstepping The other technical consideration before running the motor would be connection of 5 ports as shown above in Figure 3. Pin 6 and Pin 7 are connected to the ground and to the +12VDC respectively while pin 3, pin 4 and pin 5 are connected to step clock, direction and enable supply of +5 VDC respectively. PIC Microprocessor and Programming: For our specific design, PIC16F877 was chosen because of 33 I/O ports that were available to control eight motors with hardware pulse width modulation (PWM). In addition, most PICs only had maximum of two software PWM. Figure 49 below shows the pin diagram of PIC16F877 and was purchased from Digikey as shown in Figure 50 below. 54

55 Figure 49 Pin Diagram of PIC16F877 Figure 50 Digikey webpage to purchase PIC16F877 55

56 3 2 1 Figure 51 Image of protoboard to control 8 stepper motors Figure 6 above shows the circuit design to control the stepper motors. As seen above (1) is PIC16F877 with 6 MHz oscillator on pins 12 through pin 14 and 1k ohm resistor in pin 1 while grounding pin 12 and 31. In addition, pin 11 and pin 32 were connected to +5V. Also, seen above (2) is a voltage regulator (7805) that regulates +12V as input while outputting +5V for the PIC16F877. In addition, the voltage regulator shown above (2) is a 7805 which has the following setup shown as Figure 7 where 1uF and 10uF capacitors were needed to regulate +12VDC input to +5DVD output. More importantly, MPLAB ICD 2 In-Circuit Debugger as shown above (3) was used to program the PIC. The programming was done in C code using MPLAB software version Detailed technical steps to program the PIC are shown below in various Steps. 56

57 Figure 52 Schematic image of Voltage regulator 7805 In addition, the Microchip MPLAB ICD2 debugger shown above should be connected properly in order to program the PIC. The debugger circuit consists of two ports where one port gets connected to the computer and the other gets connected to the PIC16F877. As seen above in Figure 6, various wires are connected from the ICD cable to the PIC. Five out of the six wires should be connected to the PIC. The blue wire should be connected to pin 1 of PIC16F877; the black and red wires should be connected to pin 39 and pin 40 respectively while the yellow wire and red wire should be connected to +5DVC and ground respectively. In addition, make sure +12VDC is supplied through DC power supply as shown below in Figure 8 while programming. Figure 53 DC Power Supply of +12VDC 57

58 (Step 1 - Step 17 below shows detailed technical steps to start programming PIC16F877) Step 1: Click on MPLAB IDE 8.00 Figure 54 Step One Step 2: Click on Project Wizard to start a new project 58

59 Figure 55 Step Two Step 3: Click Next to create the new project Figure 56 Step Three 59

60 Step4: Choose the PIC device that you will be programming Figure 57 Step Four Step 5: Click on HI-Tech compiler for Active Toolsuite Figure 58 Step Five 60

61 Step 6: Create a folder to save your project file Figure 59 Step Six Step 7: Add any files if needed, if not, click NEXT 61

62 Figure 60 Step Seven Step 8: Click File >> New to start new file ( C language) Figure 61 Step Eight 62

63 Step 9: Click on Configure >> MPLAB ICD2 to set ICD2 to debug the program to the PIC Figure 62 Step Nine Step 10: The output toolbox verifies the connection of the ICD cable to the circuit Figure 63 Step Ten 63

64 Step 11: Click on FILE>> SAVE AS to save your new project file Figure 64 Step Eleven Step 12: Start writing the program in C language Figure 65 Step Twelve 64

65 Step 13: Right click on source file or header file to add your new saved file Figure 66 Step Thirteen Step 14: In order to program the PIC, click on Build project as shown below Figure 67 Step Fourteen 65

66 Step 15: Upon completion of building, verification will be shown as shown below Figure 68 Step Fifteen Step 16: Now, click on program target device to target the PIC Figure 69 Step Sixteen 66

67 Step 17: Click on Release from reset to make sure the program is running Figure 70 Step Seventeen The attached program below shows the main program used to rotate the motors at specific rotation. As seen below, #include command was used to include the header files that were used while programming the PIC. Next, all the pins were defined and the direction were defined using #define command as shown below. Following the definition of various terms, integers (i) were set to be long integers. Various (i, j, k and l) alphabets were defined as long integers to control four different motors. Following that, ports were set as output. Following the port setup, forwhile loop was created in order to rotate the motor for desired rotation. The for loop basically provides the pulses required to make each rotation and the while loop basically stops the program after completing the for loop. // Program to rotate the motor #include <pic.h> #include <math.h> #include <delay.h> CONFIG(HS & WDTDIS); // Define Terms #define PWM_output1 #define PWM_output2 RD7 RD6 67

68 #define PWM_output3 RD5 #define PWM_output4 RD4 #define CW 1 #define CCW 0 // Routine to obtain PWM for Port D's int main (void) { long i; long j; long k; long l; // Setting the ports TRISD = 0x00; //sets PORTD for output PORTD = 0x00; //clear PORTD for(i=0;i<=80000;i++) { PWM_output1=1; DelayUs(1); PWM_output1=0; DelayUs(1); } for(j=0;j<=80000*2;j++) { PWM_output2=1; DelayUs(1); PWM_output2=0; DelayUs(1); } for(k=0;k<=80000*3;k++) { PWM_output3=1; DelayUs(1); PWM_output3=0; DelayUs(1); } for(l=0;l<=80000*4;l++) { PWM_output4=1; 68

69 DelayUs(1); PWM_output4=0; DelayUs(1); } while(1); } //wait forever // END OF PROGRAM Figure 71 Program to control motors of assisted leg-holding device 4.0 Trouble Shooting Motors Problem: Motors are not running Are the motors connected to a power supply? Is the power supply on? Make sure the power supply is turned on Make sure the wires are connected to the motors in the following fashion: Leaving the first two holes empty, the wires enter the holes in the following order: Blue Green White Black Red 69

70 Figure 72 Attachment of wires to motor Problem: Motors are powered but do not turn Are the motors connected to the microprocessor? Check the PCB board and make sure the wires from the motor are connected to the microprocessor as shown in table 7. Blue Pin 30 on microprocessor Green N/A White +5 on protoboard Black V- Red V+ Table 7 Wire connections Also, again check the wire connects to the motors themselves as stated above. If a wire has been found to be disconnected, simply push the wire back in. Even if the wire looked pushed into the motor, there may not be enough exposed bare wire to complete the circuit. To remove the wires, press on the orange button to release the wire 70

71 Figure 73 Release button for wire Obtain wire strippers, cut and remove additional plastic coating to expose more bare wire so that about ¼ inch is exposed. 71

72 Figure 74 Procedure for wire stripping Locate a soldering iron and solder, heat the wire and melt the solder to the exposed wire thus tinning the wire. 72

73 Figure 75 Procedure for soldering Check that the wires are not being cramped or crimped in any of the links or joints which may have caused a break in the wire. If this occurs, the entire bundle of wires will have to be replaced. Again, strip both ends as noted above and complete the circuit as instructed above. Problem: Motors need to be reset Reset the motors by turning off the power supply and then turning back on. This should reset all the motors to zero and allow the program to start fresh Links Problem: Links will not move Check and make sure nothing is in way of the links. Note that some links have a limited range do to their relationship to other links. Remember that the both the lengths of a and b have to change to move the links. Make sure the motors have turned and that the eyehook was unlocked during the process to allow for movement Support Devices Problem: Patient support devices will not move There are several reasons why the patient support devices will not move 73

74 1. The device is locked, check to see if the locking mechanism, shown below, is locked, if so unscrew to loosen Figure 76 Twist handle to release foot support 2. The polyethelene pieces that fit into the grooves may have worn down and need to be replaced. Replacement pieces are available from the 80/20 website. 3. The linear actuator maybe caught on another piece of the device, make sure the entire length of travel is clear 4. The linear actuator maybe off track, the device will have to be reloaded into the bar matching up the grooves. Please note: Should there be any problems with the software, please contact a licensed software technician, as the practitioner should never attempt to correct software issues. 74

75 References 1) Guidelines For Environmental Cleaning And Disinfection of Norovirus Michigan Department of Community Health,