Connectors in medical robotics

Traditionally employed in heavy industrial applications, robots are moving into other industries. In the medical field, they are used for surgery, therapy, diagnostics and much more.

Robots for specialised medical applications such as surgery bring together robotics and biology, and we’re seeing an increase in the number of robots specifically designed and developed for this market sector. These robots are clearly different from the traditional industrial robot, and spin-offs from research done in this domain may lead to new consumer medical devices.

Additionally, cross-fertilisation with other high-tech markets such as space, military and aerospace markets is likely to push the technological boundaries. Hospitals have already employed robots to deliver medications, monitor patient conditions, interact with patients and much more.

According to the International Federation of Robotics (IFR), 21,000 professional service robots were sold in 2013, a modest growth in units of 4% versus 2012. The sales value decreased by 1.9% to $3.57 billion. This means the average unit value for professional service robots was about $170K.

The IFR stated that sales of medical robots decreased by 2% in 2013 to roughly 1300 units. This represents 6.2% of the total unit sales of professional service robots. The most important applications are robot-assisted surgery and therapy. In 2013, more than 1000 of these types of medical robot systems were sold, 2% less (in units) than in 2012. The sales volume of medical robots, however, increased in 2013 to $1.45 billion. This represents 40.6% of the total sales value of all professional service robots and means an average unit cost of $1.12 million.

Medical robots are clearly the most valuable professional service robots. In 2013, North America had the largest share of the global medical robotics market, followed by Europe, then Asia. Asia is expected to outgrow the other regions, however, as healthcare spending in the region increases, healthcare markets are reformed and patients become more aware of the possibilities. The ROW (rest of the world) region will also show steady growth over the coming years.

The IFR expects that in the period from 2014 to 2017, about 7130 medical robots will be sold. This would represent a total market value of almost $8 billion if the average unit cost remains the same. It also means a compound average growth rate (CAGR) of about 12.4% in units. The increasing demand in the medical sector can be explained by the emphasis in the healthcare market on minimally invasive surgeries through the use of robots. In addition, surgical robots often improve the accuracy of surgeries and thus reduce the complication rates. Apart from accuracy, robotic procedures also offer significant savings to hospitals and patients in terms of pre- and post-operative care costs and lengths of stay at hospitals. Other market drivers include the ageing population, rise in the incidences of neurological and orthopedic disorders, and growth in the demand for telemedicine. Technological advances also help to drive this market as new opportunities open up and new applications are made possible.

OEMs and equipment makers in the medical robot market include, among others: Accuray Inc. (US); Aeon Scientific (Switzerland); Hansen Medical Inc. (US); Health Robotics S.R.L. (Italy); Intuitive Surgical Inc. (US); Mazor Robotics Ltd. (Israel); Stryker Inc. (US) — acquired MAKO Surgical Corp. in 2013; Titan Medical Inc. (Canada).

With Google signing an agreement for strategic collaboration with Ethicon, a division of Johnson & Johnson, to develop surgical robots that use artificial intelligence, it is clear that other market players are jumping on the bandwagon.

Types of robots

There are many types of medical robots, and the lack of clear (market) definitions makes it difficult to pinpoint exact volumes and market values. The following overview provides some guidelines to the various categories of medical robots we can distinguish:

Surgical robots

• Orthopedic surgical robots — such as the da Vinci surgical robot, the market leader with an installed base of more than 3300 units.
• Neurological surgical systems — includes the SYMBIS surgical system.
• Laparoscopic robotic systems — such as SPRINT (single-port laparoscopy bi-manual robot).
• Steerable robotic catheters — such as the Magellan Robotic System.

Furthermore, robotic systems in orthopedic surgery can be divided in the following three categories:

• Active systems, such as the ROBODOC (Curexo Technology Corp.) and CASPAR (computer-assisted surgical planning and robotics) technologies, can perform individual tasks autonomously, without control by the surgeon during the procedure.
• Semi-active systems are robot/computer-aided surgical actions, but final control is in the hands of the surgeon.
• Passive systems provide information during a surgical procedure; they do not perform an action and are controlled by a surgeon.

Rehabilitation robots

Rehabilitation robots aid in therapy for patients recovering from injuries and include:

• Assistive robots: These robots help patients, such as those that assist the elderly with basic household tasks.
• Prosthetics
• Orthotics
• Therapeutic robots: These robots help reduce stress and agitation, minimise feelings of isolation, and give people something to touch and be touched by.
• Exoskeleton robotic systems: These are robots that are worn on the body, much like in the movie Iron Man, to improve mobility and/or strength.

Non-invasive radio surgery robots

An example is the CyberKnife, which is dedicated to Linac (linear particle accelerator) radiosurgery, in which a compact Linac is mounted onto a robotic arm that moves around the patient and irradiates the tumour from a large set of fixed positions.

Hospital and pharmacy robots

• Telemedicine robots: These types of robots allow physicians to monitor patients remotely, such as after surgery.
• IV robots: This automated robotic system is designed for the preparation of injectable drugs.
• Pharmacy robots: These robot systems can be used for automatic suspension of medication or even a post-order-type service for medication.

Other robots

Examples of other robots not mentioned above include those used to assist with laboratory analysis, medication testing or cosmetic surgery.

Connector designs

Connectors used in medical applications create a unique combination of challenges for connector manufacturers. Medical equipment often must survive multiple sterilisations that employ heat, steam or radiation and be fabricated from corrosion-resistant materials. Safety for the patient and staff is a key consideration, making reliability and ergonomic finger-proof designs essential. Historically, connectors designed for use in medical equipment applications tended to be high-reliability/high-cost interfaces with relatively low volume.

The market for home-based medical monitoring and diagnostic devices is beginning to take off in Western economies and Asia/Japan. These devices are also a perfect fit for inclusion in the emerging Internet of Things (IoT). This market is in the early developmental stage and high-volume standard interfaces are yet to be defined, but once the market really takes off, the excellent growth potential for specific interconnects used in these applications will become clear. We also anticipate growing use of fibre-optic connectors in medical applications, not only for their signal integrity and lighter weights but also for their performance capabilities in video streaming (bandwidth requirements).

Wearable electronics and sensors are also trending in the medical world. Smartwatches and fitness bands are only the first wave of medical monitoring devices and will probably be followed by even more sophisticated devices.

For medical robots, connector designs must fulfil all these criteria, too. They need to be high-reliability interconnects that can withstand harsh conditions (cleaning, sterilising, radiation) and are properly sealed (often IP68). Other critical performance attributes may include: quick mate/un-mate features, often push-pull; corrosion-resistant materials; impact-resistant shells; hybrid variations of signal, power, coaxial and fibre-optic contacts; colour coding; mechanical keys to ensure proper mating; designs to ensure user safety (finger-proof); lightweight, ergonomic; use of ‘soak cap’ to protect the interface during cleaning; custom over-moulded assembly; fabricated from non-magnetic materials in MRI equipment; often shielded; can be handled by gloved hands.

Connector types frequently used in medical robot applications include: plastic circular pin-and-socket connectors; spring-loaded Pogo-type contacts; hybrid connectors that integrate power, signal, coax and fibre-optic contacts; micro and nano connectors.

To ensure the best connectors are used in the medical devices market, connector designs must comply with a range of standards and obtain the necessary approvals. Some of the applicable industry standards/approval agencies include: UL/CSA; CE; FDA; ISO 13485; ISO 80369-1; DIN 42802-1 and DIN 42802-2; IEC 60601-1; ANSI/AAMI EC53-1995.

With current market trends in technology and demand clearly in favour of the medical robotics market, we expect this market to outpace the general connector market in the coming years. The expectations of the IFR are in line with this expectation and various industry analysts expect even higher growth rates. This bodes well for the connector makers that are well established in this market.

For more information, contact Robin S Pearce, Bishop and Assoc – ANZ, apearce4@bigpond.net.au.

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