Artificial smart valve for bag-free stoma

Project reference: SIE_24 This project has already been allocated and is no longer available for applications
First supervisor: Sebastien Ourselin 
Second supervisor: Carlo Seneci 

Start date: October 2020  

Project summary: Living with a stoma, a small opening on the abdomen where the remaining healthy portion of bowel is connected to release the stool, represents a great physical and mental challenge for the hundreds of thousands of patients living with one. On one hand, often, stoma forming surgery represents the only survival chance for patients. On the other hand, the everyday management of the stoma is usually characterised by a large number of inconveniences and problems, such as infections, skin blistering, stool leakage, bad odour, difficulty with sports and sexual life. The aim of this project is to deliver an implantable smart device, the first of its kind, that helps stoma patients tackle the challenges deriving from stoma management and allowing them to carry out the same activities and routines that they would be having prior to stoma surgery. The implant will feature a combination of flexible and hard materials, sensors and actuators to make stoma management easier and bag-free. This research work will be carried out with the input from patient groups and the support of surgical and nursing experts. To carry out the work, the PhD student will perform CAD design, biomechanical modelling, simulation, 3D printing, moulding and programming. 


Project description: Pathologies affecting the bowel are numerous and varying in nature, and often require surgical treatment. It is estimated that every year in the UK about 13,000 patients undergo surgeries that result in a stoma, such as colostomy and ileostomy surgery. These surgeries are performed when the patient loses temporarily or permanently the functionality of a portion of bowel, therefore requiring an alternative stool-excretion way. A stoma is a non-sealed opening created on the patient’s abdomen where the remaining healthy portion of the bowel or colon is attached to the abdominal wall to allow for the excretion of stool in a stoma bag that is taped to the patient’s abdomen. The prospect of such disruptive change in life for patients can be overwhelming; many patients prefer to avoid stoma forming surgery, even if that results in reduced lifespan. Patients that elect to undertake the surgery constantly deal with the psychological burden deriving from an external stoma bag, bad odours and frequent leakage. Sport and sexual life also can result hindered. Most importantly, the stoma bags are attached with tape that causes skin blistering and moreover, increases the risk of infection.  


Worldwide, industry and academia have invested substantial resources in the research of new technologies and solutions to provide prosthetics with additional functionalities, such as motion control and sensory feedback for prosthetic limbs. Unfortunately, not much effort has been devoted to assisting these sufferers, and virtually no progress has been made to improve their condition and their quality of life.  
The proposed project aims to develop an implantable device that enables creating a stoma that has a lower risk of infection as the bowel tissue is not exposed to the exterior of the body, while allowing for stool storage within the body (no need for stoma bags, nor tape) thanks to surgical techniques similar to already performed ones such as J-loop or S-loop ileostomy. Furthermore, a flexible controllable valve will be mounted within the implant to allow the patient to directly control the valve and allowing them to regain control of their bowel. The flexible portion of the valve will also carry a patch that will seamlessly cover the stoma valve, rendering this device also aesthetically appealing. Other limitations that we are able to address with our device are the possibility to willingly release gas when more appropriate and the valve will also feature easy cleaning to avoid odours. Furthermore, the use of smart sensing that will be embedded in the flexible valve will allow for direct data collection regarding the condition of the stoma to help managing it and predict possible issues that can be prevented, such as ph, temperature, pressure, etc. In a similar way, an embedded actuator will also be deployed to complete the device with all its functionalities and that will allow the patient to release the stool without even touching the valve itself.  
To reduce the risk in addressing all these challenges, a gradual approach will be followed: 


  • Year 1: Implant and valve design and construction, with consideration on the surgical technique and the science behind the materials used and biocompatibility. The valve will be directly actuated by the patient’s hand.

  • Year 2:  Design and construction of smart sensors array to measure: pressure, stool presence, ph and temperature.

  • Year 3: The final year will focus on the full system integration and on bench and ex-vivo testing of the device using phantoms and animal models. This will allow for reviewing and improving all the aspects of the device for the project completion.

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