Who are Moredun? Pentlands Science Park near Edinburgh is home to the Moredun Research Institute independently ranked as one of the top ten animal health research institutes worldwide.
Moredun Research Institute has established a global reputation for the quality of its scientific research to improve animal health and welfare, through the prevention and control of infectious diseases of livestock. Their research spans all levels of animal disease, from basic molecular work through cellular, tissue, organ, whole animal and population studies.
4c have been working with Moredun’s scientists since 2004, designing and building bespoke equipment to enable them to stay at the forefront of their field. The most significant of these has been three labour saving machines which allow a novel vaccine for an important roundworm parasite to be produced more cost effectively.-
This machine opens the contents of the abomasum to allow the nematode worm to be extracted by NemEsys.
Once the abomasum’s are opened, this machine extracts and filters the worms from the waste material
Once the vaccine has been produced, this machine bottles it under sterile conditions.
Currently there are no commercial vaccines for any roundworm parasites which infect the gut of any host. However, pioneering trials at Moredun have shown that it is possible to successfully immunise sheep against Barbers Pole worm, which is the most important species to infest sheep and goats in the world.
This parasite prefers warm, damp climates and so is particularly prevalent in the tropics and sub-tropics. It is normally controlled by drugs which have to be repeatedly administered to the sheep, but strains resistant to such chemicals have evolved and are now commonplace. Large numbers of parasites are required to make the millions of doses of vaccine needed for the Australian market alone, but these can be obtained by deliberately infecting donor sheep which are subsequently processed through an abattoir in the usual way. The infected stomachs are collected and then processed by two machines developed by 4c design so that large numbers of clean worms are harvested rapidly. The parasites are then frozen until enough have accumulated to make a large batch of vaccine which is then dispensed into 250ml packs by a third machine developed at 4c.
The first machine in the system was developed to open sheep abomasums. Sheep have four stomachs, the fourth, known as the abomasum, is where Barbers Pole Worm lives inside. In order to harvest these worms, the abomasum must be opened. Doing this manually with a knife is time consuming especially when hundreds need to be opened rapidly.
4c were tasked with designing a machine capable of slicing open in excess of 400 abomasums per hour. The slipperiness and resilience of what we were trying to cut proved to be a particularly challenging element. However, 4c’s in house prototyping workshop proved invaluable when developing the solution. We iterated our way through numerous ‘quick and simple’ mock-ups and quickly focussed on a workable concept. Confident that we had a functional solution, our computer aided modelling (CAD) engineers, refined the design to include the essential safety features that would be required for this machine to operate in a production environment.
After extensive testing at Moredun, 4c design engineers commissioned the final machine in Albany, Western Australia in Nov 2013, where it has proven to be extremely fast and effective. The need for sharp, rotating cutting blades resulted in operator safety being no.1 in our design criteria and we thought carefully about the geometry to ensure the operator’s hands could not get caught in the rotating parts. Electrical cut-outs, emergency stops and extensive guarding were further safety features. The machine has been designed to work in harsh conditions. IP65 was a requirement as it will be continuously doused in water during operation and for cleaning. Simplicity and robustness of design for servicing was paramount as these machines will be used mainly in the southern hemisphere, a long journey for a 4c engineer breakdown visit!
NemESys is short for Nematode Extraction System. As its name suggests the purpose of this machine was to rapidly extract and purify large numbers of clean, living Barbers Pole Worms from abomasums. This was quite a challenging remit because the worms are only about 1.5 cm long and not much thicker than a hair. About half of them are mixed with the partially digested grass in the stomach contents but the rest are attached to the stomach wall. Several opened stomachs and their contents in 10L warm water were poured into the yellow cement mixer illustrated above which gently dislodged the attached parasites. The semi-fluid mixture was then passed over a sieve conveyor which retained the worms but got rid of most of the digesta. Further back washing and mechanical decanting resulted in a preparation highly enriched for living worms, suitable for vaccine production
After a rigorous product testing and refinement, three of these machines have been built and are deployed in Australia and the UK. NemESys is a vital element in enabling efficient cost effective vaccine production.
Barbers Pole Worm vaccine will be produced in 1000L batches. Under sterile conditions the vaccine must be dispensed into 250ml vaccine packs and returned to the chiller as soon as possible. Doing this manually, would be a time consuming, tedious and expensive process. Off the shelf equipment was not an option due to the unique shape of the vaccine packs and the fill characteristics of the vaccine. A bespoke solution was required.
While the scale of the final machine is relatively small (1.4m x 5.7m), the task presented technical challenges similar to those need for a large scale bottling plant. Much of the same methods of sorting, transporting and controlling can be seen echoed in both scenarios. We broke down the machine into small and simple tasks; for instance orientating the bottle or crimping a cap onto the bottle. We then proceeded to design and fabricate a range of prototypes to confirm the viability of concepts, each working within the tight constraints of the brief. These varied from rough cardboard cut outs to precisely machined alloy components. Our objective was to make each mechanism as simple and hence cheap and reliable as possible. As the concepts became more refined we had to consider material selection, given the requirement of complete sterility within the machine we had to choose our materials carefully. We knew that ultimately the machine would be placed inside an isolation chamber (sealed plastic tent) and the interior sterilized using a gas, so we had to use materials that would not corrode, absorb liquids or germs and would be easy to machine and work with. As the sub-assemblies were developed it became important to concurrently consider the layout of the machine. Each assembly needed to fit with each other, but also needed space for maintenance and assembly. Also the machine needed to be shipped to Australia and then transported through narrow corridors before reaching its final destination. With all the mechanical design worked out, an electrical system had to be developed to monitor and control the machine. This was a complex task involving multiple sensors and inputs to control a multitude of motors, pumps and movements. The result being a smart machine that requires very little input from its operators and would sense any potential errors before they became a problem.
The completed machine was shipped off to Albany, Western Australia where the 4c team commissioned it. The machine is capable of processing 1,000,000 doses of vaccine in about a day ; should the need arise the machine will operate 24hrs a day. That’s a lot of happy sheep and even happier farmers!