Design and development of mechatronics weight loss pill
Chua, Xing Rong.
Date of Issue2013
School of Mechanical and Aerospace Engineering
Robotics Research Centre
This report aims to design a mechatronic weight loss pill that can make one fill satiety by occupying the space in the stomach cavity. It also aims to improve efficacy and reduce discomfort in patients. This will aid patient to reduce food intake and lose weight more effectively. In the report, various methods of weight loss methods have been discussed and compared. The proposed design of the pill is similar to Intragastric balloon(IGB) where uses the inflation of balloon either by gas or liquid . But current IGB has several major drawbacks. Firstly, patients feel discomfort while inserting and removal of balloon through endoscopic procedure. Secondly, the patient cannot remove pill immediately when they experience intolerance to the balloon volume but require a trip down to the hospital for removal of balloon through endoscopic procedure. The proposed design uses a stepper motor system which consists of : stepper motor, microcontroller, drivers and power supply. The micro-controller define the step and direction of the motor which is incorporated in the slitting mechanism. The slitting mechanism will consists of a coupling equipped with blades to allow slitting of thin plastic film and allow mixing of chemical to produce gas for inflation of balloon. The chemical chosen for inflating the balloon is Sodium Bicarbonate and Acetic Acid where by product of CO2 is produced. Both reactants used are safe for consumption and varying amount can produce optimal balloon volume. The optimal balloon size to be inflated in the stomach provided by studies of IGB is around 400-700ml. With 0.5g of Acetic Acid and 5g of Sodium Bicarbonate produced 170ml of balloon volume. The prototype of the proposed design is being tested and validated of its feasibility to inflate and deflate the balloon. However due to size of the microcontroller and driver that is connected externally of the pill, the size of the pill in prototyping is unsuitable for consumption. Further implementation on the electronic system has to be simplified and miniaturized with equipped remote control to activate the stepper motor. With a new electronic system incorporated, the electronic system can be placed within the capsule with insulation to prevent short circuit. The proposed design of the pill realization has also provided air tight and waterproof features like screwing mechanism and slotting mechanism. With the screwing mechanism, the capsule is able to tighten the front and end cap with the middle capsule to prevent leakages. Whereas the slotting mechanism allows simple assembly of the pill where alignment of the parts reduce stress while housing the motor and chemical solutions. The proposed design allows precise control of the inflating and deflating of the balloon freely. It also neglect the use of endoscopic procedure to insert and remove the balloon but rather just swallow the pill like any other medicine and deflate to pass out naturally.
Final Year Project (FYP)
Nanyang Technological University