Design of an intrauterine insemination device

Design of an intrauterine insemination device

Tran, V.K.L.

Spitas, C. (mentor)
Langeveld, L.H. (mentor)

Industrial Design Engineering

Design Engineering

Master specialisation Medisign

2010-08-31

This master thesis shows the development and design of an intrauterine insemination (IUI) device. The graduation project is done by order of the VU medical university in Amsterdam. IUI is a treatment for couples that have problems with their fertility and is conducted by IVF-doctors. Basically the procedure contains the following steps: • Drug treatment, when applicable • Semen collection and preparation • Insemination of the semen via a syringe-catheter combination • Pregnancy test The insemination itself is a non-automated process, with a human factor involved. It appears that every IVF-doctor has her/his own velocity of injection of the semen into the uterus. The injection is not the only step with a human factor, but does seem to be the most important one that can be improved. The main challenge is that a device needs to be developed that controls the step of injection, but with variable velocities and therefore variable flow rates. The device should make it possible to standardize and control the IUI-procedure. The control occurs in different levels. Control has to do with the ability of the user to stabilize the device during the injection. Also, it has to with the technique/driving mechanism used to create a constant force output and therefore a constant velocity output of the syringe. The three injection velocities are 1.5, 2.5 and 3.5 [mm/sec]. The forces that are needed to create these velocities are 0.5, 0.8 and 1.1 [N] respectively. These numbers are based on experimental data and calculations through Bernoulli’s equation. Each force output has a range of minus 0.15 and plus 0.15 [N]. The starting point for the design phases was the search for a driving mechanism that can create the different velocities as mentioned above. Different solutions have been taken into: • Air pressure • Magnetic repulsion • Spring • Constant force spring When looking at the force output, only the ‘constant force spring’ fits inside the range. So this mechanism seems to be the best solution for the IUI device. The force output of the constant force spring depends on the material, thickness and the width. Basically, the manufacturer determines the force output of these springs and it’s not possible to choose the force output that fits inside the required range. Instead, a higher force output is chosen. The idea is to put the constant force spring inside a piston. This piston comes with o-rings that glide inside a tube. By making use of the friction of the rubber inside the hole of the tube, the force output can be controlled. When the diameter of this hole is reduced, then a higher load is applied to the rubber, resulting in a higher friction. By changing the diameter, three force outputs can be created. The device has two major functions: • Locking and unlocking of the piston • Attaching of the syringe Based on these functions, several solutions are presented. One of the solutions are chosen, which is done by the use of the Harris profile.

IUI
design
device
standardization

http://resolver.tudelft.nl/uuid:c7ada959-57bb-4559-bc3f-593914d49743

Campus only

Student theses

master thesis

(c) 2010 Tran, V.K.L.