Improving Global Quality of Life

the HRI report which accounted for 64% of global MD&D product sales in 2004; cardiovascular disease,
musculo-sketetal disease, cancer, dental care, urology and renal conditions, diabetes, respiratory/ pulmonary
conditions, gastrointestinal disease, ophthalmic conditions, and hearing impairment and diseases of the ear
(otology). Of these, cardiovascular disease related components accounted for over 19.2%. The Orthopaedic
sector had a $26 billion global marketplace in 2006. Both the spine and trauma sectors experienced the
significant growth in 2006.
The following are some of the trends that affect materials joining for the medical market.
9.16.1 Hot topics
Miniaturisation: One continuing trend in the medical device market is the expansion of Minimally
Invasive Surgery (MIS) procedures. Expansion of the MIS market is due in large part to replacement
procedures for conventional, open surgery, treatment methods. The percentage of MIS procedures
(as a percentage of all surgical interventions) is expected to increase from the current level of 15-
20% to about 70% by 2010. Increased use of MIS in emerging markets of the Pacific Rim and Latin
America are likely to contribute significantly to this growth. As more and more surgical procedures
migrate to less invasive approaches, the drive to minimise the size of the medical devices will
continue.
New materials: Another important trend in the medical devices market is the increasing use of
biocompatible metals for the design and fabrication of surgical and implantable devices. Because
there is a drive to minimise the size of the devices for MIS or interventional cardiology procedures
or for implantation, medical device designers frequently must develop methods to directly join
two dissimilar metal materials. Key considerations in this joining include the biocompatibility and
resistance to bio-corrosion not only for the base metals, but for also any intermetallics formed by
the joining process. The radiopacity of the metals and/or intermetallics is also a concern, as the
surgeon must be able to use radiography to monitor the position of the devices within the body
during the procedure.
Increasing performance requirements: For implantable devices, fatigue life of the joint is extremely
important, since the device is often left in the body and therefore must not fail for the remainder of
the patient’s life. Other key concerns are corrosion of the component, due to the environment and
the ability to use magnetic resonance imaging (MRI) after surgery; since metal and other materials
properties could interfere with the ability to use MRI as a medical diagnostic tool.
Cost control: Medical device manufacturers are increasingly outsourcing manufacturing and
assembly of their products to contract manufacturers. One reason behind this shift is cost pressure;
specialised labour can be expensive for the assembly of sophisticated medical devices.
Laser welded
blood bag
Medical devices cover a very broad range of products from very simple sealed bags
to very complex ‘active’ implants. In general, medical devices, whether temporary
or permanent, used externally or inside the body, are becoming more complex
and sophisticated both in terms of their performance specification and structural
complexity. As a consequence, many devices in current use are multi-component and
require assembly in production. Joining is one of the key issues. Medical devices,
whether used outside the body (e.g. instrumentation, control systems or surgical
tools) or inside the body for diagnostic monitoring or therapeutic purposes (e.g.
sensors, catheters, pacemakers or prostheses) usually consist of many materials
which may need to be joined.
144 Improving Global Quality of Life Through Optimum Use and Innovation of Welding and Joining Technologies