A brief history of medical robot

This report covers the method that is used to transport blood in the hospital and how this method can be greatly improved with the use of the robotic sorting system.. A brief history of

COVER PAGE

Under the supervision and guidance of Assoc Prof Phan Bui Khoi at Hanoi university of Science and Technology for 4 months We have leant about robotic arm in theory and applied to create the real product

Students: Le Xuan Tu and Pham Van Hai

Position: Student of Hanoi university of Science and Technology

Class: Mechatronics – Advanced program – K56

Tu’s phone number : +84985799987 – ID 20110735

Hai’s phone number: +841659015834 – ID 20110272

Dates: January 2016 – April 2016

We write this report when we are going to complete our final thesis After 4 months we had improved our skills as programming , drawing and simulating which are essential to

do our final thesis and useful for us to find a suitable after that.

This report covers the method that is used to transport blood in the hospital and how this method can be greatly improved with the use of the robotic sorting system The report details the entire method of how the robot was designed, assembled, programmed, and

interfaced with software and hardware Also how the infrared sensor was coded and how the motors were synchronized to go to the necessary position.

CHAPTER 1: OVERVIEW ON ROBOTIC ARM

1. A brief history of medical robot

In 1985 a robot, The PUMA 560, was used to place a needle for a brain biopsy using CTguidance Three years later the same machine was used to perform a transurethralresection

Figure 1: PUMA 560

In 1987 robotics was used in the first Laparoscopic surgercy, a cholescytecotomy

In 1988, The PROBOT, developed at Imperial College London, was used to performprostatic surgery

Figure 2: PROBOT

The ROBODOC from Integrated Surgical Systems was introduced in 1992 to mill out

precise fittings in the femur for hip replacement

Figure 3: ROBOTDOC

2. Research motivation

Because the advantage is that robot-assisted surgery gives the surgeon better controlover the instruments and a better view, surgeons don't have to stand all of the timeduring the surgery and do not get tired as quickly Also, robots do not make the samemistakes that humans can make Robots are extremely more exact, and they do notmove by accident during the surgery This could also make patients feel less worriedbefore surgery Finally, we want the life become better, especially for people health

3. Objectives

The purpose of the project is to design a robotic sorting system for use in the medicalindustry This robot will be programmed to go through a routine to locate bloodsamples, in test tubes, and transport them into their desired location The robot willconsist of a fixed base plate, a rotating joint at gripper, a link robot arm and rotatingbase Fixed on the end of the arm will be an infrared sensor and a gripper to pick upthe test samples

CHAPTER 2: DESIGNING, MACHINING AND PROGRAMMING

1. Designing

Figure 4: 3D model

Figure 5: Fixed base and rotating joint

Figure 6: The first link

Figure 7: Rotating joint and gripper

Figure 8: Servo motor –Mg995

2. Machining

The parts of product

3. Programming

3.1. PIC Microcontroller

With the aid of a microcontroller the robot is able to have intelligence to completeprogrammed tasks The microcontroller can reduce product sizes, easeimplications and allow the development of intelligent computer products This iswhy a printed circuit board is necessary to minimize the microcontroller since onlypart of its development board is used

The 40-pin PIC that is used in robot design is the 16F877 embedded chip Thischip has all necessary capabilities to provided analog to digital conversation, sothe sensors can send the precise pulse wave to reach of the motors to maneuver therobot arm The port A analog input and output pins RA0 are used for the sensor.This sensor is used to detect if there are any obstacles in front of it Once thesensor detects a test tube the gripper hand will grip both sides of the tube and bring

it back to the desired bin

Figure 9: PIC 16F886 pin out

3.2. BMAX232 Converter

In order to connect a microcontroller to a serial port on a PC computer (or, in thiscase, the robot arm through the SSC-32 controller) it is necessary to adjust thelevel of the signals so communication can take place The signal level on a PC is –

10 V for logic one, and +10 V for logic zero Since the signal level on themicrocontroller is +5 V for logic one, and 0 V for logic zero, we need anintermediary stage that will convert the levels One chip specially designed for thistask is MAX232 This chip receives signals from -10 to +10 V and converts theminto 0 and +5 V We installed this chip onto a board with a series of capacitors Seeappendices for circuit diagram

up to 180 degrees of rotation, which is considered to be about 90 degrees higherthan most RC-based applications The position of the servos is based in general onabsolute positions resulting from pulse widths A position value of 2500 is a 2.50millisecond pulse The ratio of positioning is 0.09 degrees per 1 unit, for a total of

180 degrees per 2000 units The terms pulse width and position can be usedinterchangeably The following figure illustrates the positioning of a servomotor:

Figure 11: Servomotor Pulse Diagram

3.4. PIC16 RC Servo controller – PSC16A

The PSC16A is an integrated circuit board that controls the servomotors on therobot arm It mounts on the project board directly behind the robot arm itself Eachservomotor is attached (first we ensured that the wires were long enough) to itsrespective set of pins (0 through 5 were used in this case)

Figure 12: PSC16A Board

Due to its level of complexity, the PSC16A is more appropriately viewed as a

“black box” unit that simply controls the servos A detailed circuit diagram isincluded in the appendices

3.5. IRPD Sensor

To allow the robot arm to detect the presence of an object at a specific location, weused an Infrared Proximity Detector (IRPD) with a suitable range The IRPDemploys a Panasonic PNA4602M IR sensor accompanied by two LEDs Themodule itself has several amplifiers and filters The detector itself has what isknown as a modulated carrier, which allows for the elimination of excess sight(such as responding to sunlight) The sensitivity of the LEDs is adjustable, and thesight of the sensor includes the detection of objects on the left, right andcompletely in the center The information is then digitally sent to a receivingmicrocontroller, which is coded to either ignore the location if a test tube is notpresent, or complete a subroutine, which removes the tube if present

Figure 13: IRPD Sensor

4. Software

4.1. TOROBOT RIOS

(TOROBOT Robotic Arm Interactive Operating System) software (for use withthe PIC16RC controller) is used to test inputs and outputs, and to generallyconfigure the robotic arm (in particular the labeling and motion of theservomotors) After each servomotor has been “plugged in” to a specific channel

on the PIC16RC board, the user is ready to begin the process An image of themain screen is displayed below:

Figure 14: TOROBOT RIOS interface

The functionality of the code (to be compiled in C) was tested using TTY, which isessentially a text-based programmer, used directly through the serial port on thePIC16RC board By typing lines of code in directly, the user can set the positions

on the arm This is a lot quicker than recoding and recompiling in C each andevery time you want to make an adjustment Also, commands are typed veryintuitively

5. CONCLUSION

The goal of this project was to construct a model robot that could detect andtransport blood samples in the medical industry After starting out with a vagueidea of how to program a microcontroller and formulating a plan to achieve thecreated goal of the project, the robot kit was received and shortly after the robotwas created The infrared sensor was attached to the gripper for the purpose oflocating if there is a sample ready for delivery or not The robots motors andsensors were then connected to the PIC microcontroller board so they could beprogrammed to do the task at hand The end result of the project was a smallprototype that was capable of sensing objects and transporting them to a desiredlocation This robotic sorting system provides a more efficient and effective means

of locating and transporting blood samples It will allow lab technicians to betrained into different areas and shorten wait times in hospitals.

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// Stage 1: Initial Position

sensor = input_a ( ) ; /* Input byte from PORTA */