RESEARCH

Weaving in the Human Body

An interview with Todd Blair at Confluent Medical

In an ingenious blend of art and science, American company Confluent Medical uses pattern in the design, development, and manufacturing of biomedical textiles. In other words, Confluent applies the technology of spinning and weaving to applications for use in the human body.
The company has expertise in medical manufacturing techniques using permanent and absorbable fibres with technologies including weaving, braiding, knitting and non-woven processing. We were able to interview Director of Sales and Marketing Todd Blair to find out more about the company, and in particular how pattern – specifically weaving – is so important to what they do.

How does Pattern shape your practice, research or design process?
The pattern of the textile creates the functionality and functionality is the primary end-point in creating something that will be used for repair, replacement or regeneration in the body.

A textile structure can vary the application of a fabric a great deal. How do the different structures and patterns affect purpose in biomedical use and how have you tried and tested these?
The pattern of the fabric absolutely affects the purpose. At Confluent we have the manufacturing expertise, engineering, technical, and artistic depth to help shape the medical device specification and build to meet the anatomical and structural requirements.

For our purposes, the pattern is not the primary end point but the pattern helps guide the functional outcome of the textile being designed.  The pattern may aid in tissue in growth for example, or the pattern may directly alter the inherent stretch or drape of the material.  The materials are often tested mechanically through ASTM test methods for break, elongation, burst and thickness.

Photo: specialist looms are used at BMS to fabricate the exacting woven textiles

How does the pattern of the weave affect the application of the fabric; what does a more complex weave add to the textile and how does a woven fabric differ from another structure?
A woven fabric has the greatest structural integrity within the textile space. When designing a structure that has a requirement of either high density or stability, a woven material is particularly suitable. The parallel fibres that make up the body of the weave will have high linear integrity and when designing a fabric for low elongation and creep, a woven material will outperform other textile such as a knit or a braid.  A more complex weave (3D weaving) can have higher fibre density and will change the water permeability which can be critical to certain vascular applications. Other low elongation, high strength woven fabrics are being used in orthopaedic applications.

"Pattern helps guide the functional outcome of the textile being designed"
Todd Blair, Confluent Medical
How do you manufacture the textiles?
“There are unique pieces of manufacturing equipment that we have sourced as well as custom engineered equipment. We have the ability to braid, knit, weave and produce non-woven structures using these specialist machines. Looms are used to create simple weaves or more complex 3D structures, depending on the textile’s purpose.
Looms are used to create simple weaves or more complex 3D structures, depending on the textile’s purpose.

Where do you research information and inspiration for the fabric? Do you look to other technologies, patterns or existing structures in nature or do you have to develop the technology from scratch each time?
We utilise both monofilament (made from just one strand) and multifilament (made from many strands) fibres in our materials and patterns are often brought about by the choice of fibre style and type. The inspiration comes from the anatomical applications that we are being asked to help design solutions toward; soft tissue support requires an open structure, commonly a knit, whereas tissue engineering solutions tend to need extreme surface area such as a non-woven. We take these empirical inputs found through research and try to match them to a design or pattern that can be created on an existing piece of equipment, or look to customise the equipment to manufacture the fabric.

What are the main uses of the woven textiles that you produce?
The primary uses are for cardiovascular applications, such as in Aortic Abdominal Aneurysm graft, or a heart valve skirt. Other applications are for fixation devices for orthopaedic injuries. Some of the manufacturing equipment has to be specially engineered in order to create the fabrics to exact specification.

Where do you research information and inspiration for the fabric? Do you look to other technologies, patterns or existing structures in nature or do you have to develop the technology from scratch each time?
We utilise both monofilament (made from just one strand) and multifilament (made from many strands) fibres in our materials and patterns are often brought about by the choice of fibre style and type. The inspiration comes from the anatomical applications that we are being asked to help design solutions toward; soft tissue support requires an open structure, commonly a knit, whereas tissue engineering solutions tend to need extreme surface area such as a non-woven. We take these empirical inputs found through research and try to match them to a design or pattern that can be created on an existing piece of equipment, or look to customise the equipment to manufacture the fabric.

What are the main uses of the woven textiles that you produce?
The primary uses are for cardiovascular applications, such as in Aortic Abdominal Aneurysm graft, or a heart valve skirt. Other applications are for fixation devices for orthopaedic injuries. Some of the manufacturing equipment has to be specially engineered in order to create the fabrics to exact specification.
Some of the manufacturing equipment has to be specially engineered in order to create the fabrics to exact specification.