Treating the body electric

New and existing electrotechnologies offer interesting prospects for medicine

By Morand Fachot

Awareness of the effects of electricity on the human body is not recent. Mentions of treatment using electricity were first recorded in ancient Greece and Rome. In more modern times, the introduction of X-ray equipment in the early 20th century, quickly followed by a myriad of other electric medical devices, paved the way to major advances in medicine. The rollout of entirely new electrotechnologies and fresh approaches in the medical environment are likely to have similar impacts.

Surgeons operating using a da Vinci Si Surgical System (Photo: ©2011 Intuitive Surgical, Inc.) Surgeons operating using a da Vinci Si Surgical System (Photo: ©2011 Intuitive Surgical, Inc.)

(F)eeling the pain

Electric eels were reportedly used in ancient Egypt, Greece and Rome to treat joint pain, migraines or epilepsy.

In his ‘Compositiones Medicamentorum’ (written around 45 AD), a detailed compilation of drug compounds and formulas in use at that time, Scribonious Largus, a court physician to the Roman emperor Claudius, mentioned the use of electrical currents to relieve headaches and gout. Placing painful extremities on an electric torpedo fish (also known as the electric ray) or dipping them into a pool of water containing torpedo fish would numb the pain.

In the late 18th century, Italian scientists Luigi Galvani and Alessandro Volta made further discoveries regarding animals and electricity.

Galvani, observing muscle contractions in a dead frog when touched by a metallic probe, without an external electrical source, concluded that they were due to the existence of an "animal electricity". Galvanism, as it was known, led some to believe that dead creatures, including humans, might be brought back to life using electrical shocks. The theory inspired Mary Shelley's novel Frankenstein.

Following in Galvani's footsteps and conducting more experiments, Volta came to a very different conclusion; namely, that electric action was generated by contact between two different metals joined by a moist medium, not by some kind of animal electricity.

Volta's invention of the electric battery, or voltaic pile, made up of stacks of copper and zinc plates separated by cloth soaked in a salty solution, is said to have been based on observations of the anatomy of torpedo fish, in particular of its two electric organs. Volta called his invention the "artificial electric organ".

From electric rays to X-rays and more

EMDs (electric medical devices) first entered the healthcare environment well over a century ago. The most notable breakthrough in this domain was the discovery of X-rays by German physicist Wilhelm Röntgen in 1895.

X-ray equipment is still widely used for diagnosis and imaging, in particular for X-ray CT (computed tomography), introduced in the 1970s, which provides images of internal organs by sections (‘slices’). X-rays are also used in radiation therapy.

Other EMDs, relying on different electrotechnologies such as MRI (magnetic resonance imaging), acoustics, laser or ultrasonics, have been introduced into the medical environment over the years for diagnostic or therapeutic use (see article on medical ultrasonic equipment in this e-tech).

In conjunction with other TCs (Technical Committees) that work on standardization for these technologies, the SCs (Subcommittees) and WGs (Working Groups) of IEC TC 62: Electrical equipment in medical practice, have carried out the bulk of the medical equipment standardization work required to produce the IEC 60601 family of Standards. These cover the general and basic safety and performance requirements for ME (medical electrical) equipment and MES (medical electrical systems) in current use.

Latest kid on the operating block

Medical robots are the latest addition to the EMD stable and they look set to revolutionize healthcare.

One of the most promising and impressive applications in which medical robotics is involved concerns surgery. The robots have made laparoscopic surgery, also known as MIS (minimally-invasive surgery), even less invasive as well as extending their use beyond the initial main applications of gall bladder and prostate removal, gastrointestinal and gynaecological surgery and urology.

Robots are now used for more complex operations in cardiothoracic, orthopaedic and general surgery, and for internal radiation therapy allowing, for instance, precise implantation of caesium-131 isotopes to treat cancers that cannot be surgically removed, thus avoiding lengthy radiation treatment.

As medical robotics is a relatively new domain, the preparation of International Standards for it is emerging as a priority.

To carry out this work IEC SC 62A: Common aspects of electrical equipment used in medical practice, formed JWG (Joint Working Group) 9 with ISO (International Organization for Standardization) TC 184/SC 2 in June 2011. Nearly 70 experts are currently active in SC 62A/JWG 9, reflecting the importance of standardization for the sector.

Known unknowns

Some new technologies have now advanced from an experimental stage to limited deployment in the medical environment, but their full potential is not yet known. This is particularly the case for 3D printing and printed electronics, with nanotechology also seen as holding out interesting prospects.

Of these technologies, 3D printing (often merged with printed electronics) has so far seen the widest range of actual applications in the medical field.

It has been used to help surgeons prepare for difficult operations, such as the separation of twin sisters born joined at the head, carried out in London in September 2011. In this case, surgeons first used X-rays, MRI and CT scans to see how the skulls were fused, whether the twins’ brains were joined and to have a clear picture of the network of arteries and veins shared by the sisters. Based on the information gathered they asked Cavendish Imaging, a company specializing in providing medical anatomical models, to prepare models to plan and rehearse the operation. The models were produced using 3D printing and the operation was successful.

Reconstructive surgery has recently emerged as a promising application of 3D printing after a man's face was reconstructed using 3D-printed parts in what he described as a "life-changing" operation following a serious motorbike accident.

In late March 2014 University Medical Center Utrecht, Netherlands, announced that its surgeons had carried out a life-saving operation on a Dutch woman. The 22-year-old was suffering from a rare disorder, which saw the bone in her skull thicken abnormally to 5 cm, leading to vision loss and motor coordination impairment. Surgeons replaced the top part of her skull with a 3D-printed plastic version, three months after her operation the patient was reported to be doing fine.

3D printing is also being used to design and make customized dental implants, joint replacements and medical devices, such as hearing aids. These result in faster recovery times, better functionality and, in the case of hearing aids, smaller, custom-made devices.

A prototype of a lightweight, washable and thin 3D-printed cast for fractures, which could replace the traditional plaster or fibreglass cast has been produced, showing another potential 3D printing application.

Printed electronics also offer many possibilities, often in combination with 3D printing. A customized implantable glove-like cardiac monitoring device was developed recently using a 3D printer and was fitted with tiny printed sensors. This type of device is seen as potentially providing a path to the introduction of a new type of pacemaker .

Small is beautiful

Nanotechnology, the manipulation of matter on atomic and molecular scales, is a rapidly growing technology, but one that is still, to a great extent, in a developmental phase. However, it is seen as having great potential in medical applications. IEC TC 119 and TC 113 prepare International Standards for printed electronics and nanotechnology, respectively. 3D printing applications in medicine rely partly on standardization work from TC 119 but a number of other IEC TCs will also help to develop their full potential.

When the future meets the past

In an interesting twist of history, bioelectronics or “electroceuticals”, the treatment of certain conditions and illnesses using electrical signals, evoking the use of electricity by ancient Greeks and Romans to alleviate pain, is seen as offering potentially interesting prospects.

The decision of a global drug company to launch a USD 50 million strategic capital venture fund to help develop electroceuticals to modulate neural impulses shows that the industry is confident that fresh paths for the use of electricity in medicine are still to be discovered. Electroceuticals will rely to a great extent on nanotechnology.

All existing ME equipment and systems depend on IEC International Standards for their safe operation and for the wellbeing of the patients and staff that use them.

Surgeons operating using a da Vinci Si Surgical System (Photo: ©2011 Intuitive Surgical, Inc.) Surgeons operating using a da Vinci Si Surgical System (Photo: ©2011 Intuitive Surgical, Inc.)
This 3D-printed skull was implanted on a 22-year old woman in a life-saving operation in the Netherlands (Photo: University Medical Center Utrecht) This 3D-printed skull was implanted on a 22-year old woman in a life-saving operation in the Netherlands (Photo: University Medical Center Utrecht)
Engineers have developed a custom-fitted, implantable device with printed embedded sensors to replace pacemakers Engineers have developed a custom-fitted, implantable device with printed embedded sensors to replace pacemakers