Drug Delivery - Task 4

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This page provides a sample module for the Drug Delivery Challenge. Extensions, modifications, and other implementation options can be found at: Drug Delivery Extensions.


Contents

Magnetic sensors

The NXT Compass Sensor is a digital compass that measures the earth's magnetic field and outputs a value representing the current heading. The magnetic heading is calculated to the nearest 1° and returned as a number from 0 to 359. The NXT Magnetic Compass Sensor updates the heading 100 times per second. The Compass Sensor operates in two modes, Read mode and Calibrate mode. In Read mode, the current heading is calculated and returned each time to the NXT program executes a read command. In Calibrate mode the compass can be calibrated to compensate for externally generated magnetic field anomalies such as those that surround motors and batteries, thereby maintaining maximum accuracy.

Details on its usage and calibration procedure can be found here magnetic sensor

Develop a strategy that will allow you to use the magnetic sensor to detect a magnetic target.(HINT: Look for the disruption in the magnetic sensor readings close to a magnetic object)

Introduction to drug delivery

One of the major methods used by modern medicine to treat cancer is chemotherapy. Chemotherapy involves administering extremely potent drugs to the cancer cells of the patient. Unfortunately in order to be effective against cancer cells these medications must be delivered in such high concentrations that they are also dangerous to healthy tissue. This can cause many unwanted side effects such as fatigue, hair loss and nausea just to name a few. The side effects are a major part of what makes cancer treatment so difficult and there are constant efforts to reduce the side effects of cancer treatments. Generally, these strategies focus on decreasing the total amount of drug needed while increasing the ratio of drug delivered to cancerous cells rather than healthy cells.

A good example of this strategy can be seen in a dendrimer based molecule recently created and published by the University of Michigan. A dendrimer is a small (up to 10 nm diameter) molecule with a branching, tree-like structure. U-Michigan's research focused on functionalizing the dendrimer with both a cancer medication and the vitamin structures needed by the cancer cell for its growth process. The cancer attempts to absorb the vitamin molecule, but also pulls in the attached dendrimer and toxin. More detailed information on the research can be found in a press release from the University of Michigan.

An illustration of a dendrimer.
An illustration of a dendrimer.

This kind of approach, while effective, is extremely sensitive to the molecular geometry of both the cancer cell and the medications being used. In order for researchers to create effective medications, they must have a knowledge of these geometric and chemical structures. Understanding this information allows researchers to engineer ways around a cell's normal defense mechanisms and introduce medications as the University of Michigan team did by functionalizing the dendrimer with a vitamin. Successful research such as this allows drug developers to lower the overall concentration of drugs in a patient's system while ensuring that the drugs are as efficient as possible at killing the cancer cells.

The Challenge

In order to develop an appreciation for the concept and complexity of the geometric and chemical interactions we have scaled up the process of targeted drug delivery. You will be presented with a “stadium” that has representations of both healthy and cancerous cells. The challenge is to design andProxy-Connection: keep-alive Cache-Control: max-age=0

uild a drug delivery agent (e.g. your nanorobot) that can differentiate between the two types of cells based on nanoparticle marking of the cancerous cells. Based upon the marker effects, the agent can either attempt to kill the cell or leave it alone.

For the challenge, HEALTHY CELLS have the following parameters:

  • Their color is RED
  • They have 1 protein receptor open depending on the current state of the cell
  • They are NON-MAGNETIC

The simulated nanoparticle markers will infiltrate the CANCEROUS CELLS and alter them in the following way:

  • Their color will change to BLUE
  • An additional protein receptor will open, causing the cells to have 2 protein receptors open
  • The nanoparticles are MAGNETIC, so the cancerous cells will have a magnetic moment as well

Additional Issue: There is one important additional issue. When the nanoparticle markers are introduced into a system, they can undergo a process known as agglomeration. Agglomeration causes some nanoparticles to clump together and form a large mass. This has happened in our system, and there will be a free-floating non-cellular mass in the arena that has the properties of the nanoparticle markers: it is BLUE and MAGNETIC. You will need to address this issue as you design and code your nanobot.


Image:Arena.jpg


  • The stadium is square with "diseased cells" and "healthy cells." It is your task to "kill" as many of the diseased cells as possible while avoiding killing the healthy cells.
  • Once a cell has been killed it cannot be revived. I.e. after you have triggered a button sensor, its light indicator stays on and cannot be turned off.
  • Make your robot and its associated code as simple as possible, but also consider using a suite of sensors to accomplish your goal.
  • Your robot will have a total of ten minutes to complete the task. However, you may also terminate your turn by shouting "time" before ten minutes have elapsed. You will not be allowed to restart your turn.
  • At the beginning of your turn the Faculty Instructor or Teaching Fellow will place your robot at a random location within the stadium. After placement you may begin your turn by powering up the robot.
  • Your robot is to be autonomous. No remote control of any kind is permitted. This includes BlueTooth interactions or verbal commands.


Materials

  • LEGO Mindstorms NXT kit

For your robot you may use any and all parts found in the LEGO Mindstorms kit you are provided with, in addition to the extra sensors available in the Engineering Design Labs

Construction

As a base for your design, you will need to begin by building a chassis, configuring sensors, and writing a program to control the robot. When building your device you should consider different methods for wall following, as you will need a way to ensure you can inspect each and every 'cell'. The touch and distance sensors may be a good starting point for this. You will need a way of probing the 'cells' to determine their relative health. Consider how you can take advantage of the geometry and effects of the nanoparticle markers in order to make the determination.

Deliverables

  1. During class all students will be required to individually peform a simple programming task. Teams with members who cannot complete the task will not recieve full credit for the teamwork portion of the grade. It is the responsibility of all teams to allow all team members equal access to the design, building and programming tasks.
  2. Calibration curves for the magnetic sensor similar to those produced by the sensors characterized thus far.


Example

We created a simple device to test the idea for the challenge and the setup of the arena based on the Tribot chassis, which is detailed in the manual included with the NXT kit and on the LEGO web site. The balloon popper developed in a previous implementation of this module is based on the touch sensor assembly, which is again part of the kit instructions and on Lego's Site. We simply added a needle and a few bars to dictate appropriate entry into the 'cells'. The code which drives the unit is available and is relatively straightforward. The bot is driven forward until contact is made with the wall, it then backs up, rotates a few degrees, and continues onward. You can watch the unit in action in a video.


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