That Takuma Sato was uninjured in his Austrian Grand Prix accident with Nick Heidfeld was something of a miracle; that he is able to continue his Formula One career in Monaco this weekend is testament to the advances in driver safety made by the FIA, the teams and medical experts.

Taku was apparently able to see the gravel trap in which he was left sitting at the A1-Ring through the bottom of his Jordan-Honda's cockpit but, despite necessary measures taken by Professor Sid Watkins and his crack medical team, was uninjured in the most vicious accident of the year so far.

Heidfeld lost control of his Sauber on the first lap after a lengthy safety car period and, caught out by cold brakes, spun backwards at speed directly into the side of Taku's EJ12. The velocity of the impact was frightening, but the Japanese rookie was saved by the survival cell mandatory in each and every grand prix car.

Ever since a series of accidents in the 1970s highlighted the vulnerability of the driver, particularly in the spaceframe chassis of the time, the Formula One rules have called for a 'safety cell' in which the pilot is to be cocooned. Previous protection amounted to reinforced bulkheads fore and aft of the drivers, with little in the way of lateral protection until the first defined 'cell' was mandated in 1981. Even this proved to be fallible, however, with Didier Pironi suffering appalling injuries in a crash at Hockenheim that ended his championship hopes in 1982, and further amendments continued to be introduced over the following years.

The strength of the cells remained largely unproven until frontal crash tests were introduced in 1985, and it was not until 1988 that the drivers' feet were required to fall behind the front axle line of their cars. At the same time, a static crash test of both the survival cell and the fuel tank, which lay directly behind it, was also introduced, but another three years passed before the regulations required a dynamic test of the same structures, which better mimicked 'real life' accidents.

To this point, however, no test had required the presence of a 'driver', thereby ignoring the possible effects that an impact could have on the most vulnerable part of the equation. In 1992, this was rectified, as the FIA insisted that a 75kg dummy be installed inside the cell to test the effects of deceleration on the torso, while also calling for a more realistic test of the effects of a full fuel tank being forced against the rear cockpit bulkhead.

Sadly, it took further fatalities and injuries before the requirements were next stepped up, with the Imola tragedy of 1994 prompting experts to take another look at cockpit safety. With both Ayrton Senna and Roland Ratzenberger killed on the same fateful weekend, the governing body increased the load under which the side area of the cockpit was to be tested from 2000daN to 3000daN, and introduced a minimum 75mm thickness to the mandatory headrest. It was not until the following year, however, that a full side impact test was brought in.

At the same time, the frontal impact test speed was increased from 11 to 12m/s, and rules introduced to ensure that all deformation after the test was confined to the nose box.

The following season, further advances were made, with the introduction of mandatory head protection extending along the sides of the cockpit. As with the more usual rear headrest, the new structure had to conform to a 75mm minimum thickness to prevent the driver's helmet making contact with the rigid cockpit sides in the event of a lateral accident.

The cockpit sides themselves were raised, and subjected to a static load test, provoking unwieldy designs in all but a few cars for the 1996 campaign, and data storage units were also to be kept within the survival cell to provide greater information about the impacts themselves and the forces they exerted on car and driver. By 1997, the FIA Accident Data Recorder [ADR] was obligatory on all cars.

Energy absorbing structures were then introduced on gearboxes, and tests were devised to determine the energy absorbing properties of steering wheels, columns and racks.

Twelve months later, cockpit dimensions increased to allow better driver ingress and egress - as well as improved access for rescue crews in the event of the driver being trapped, or rendered unconscious, by an accident. And, although the side headrests were also extended to reach steering wheel, these remained removable so as not to prove an unwelcome obstruction. A front roll hoop test was introduced and survival cell dimensions forward of dash increased.

More importantly, in the light of what would happen to Taku some years later, however, the side impact test speed was increased to cater for almost 100 per cent more energy, and the test site moved forward 200mm to provide a more applicable examination.

With the cars becoming ever faster, despite attempts to slow them via the introduction of grooved tyres in place of the more traditional slicks, impact testing took on greater significance and, in 1999, the frontal impact test had both its speed and maximum permitted average deceleration increased - from 12 to 13m/s and 25 to 40g respectively.

In addition, the distance a driver's helmet had to be below an imaginary line drawn between the front and rear roll hoops was increased from 50 to 70mm - which mitigated somewhat against the taller driver - while both rear and lateral headrests now had to be one-piece, with a standard quick-release method. The Lear seat was also introduced by Jackie Stewart, amongst others, allowing injured drivers to be extracted from their cars without undue disturbance, while cable tethers were made mandatory in an effort to prevent stray wheels entering the cockpit.

The removable seat became almost standard across the grid by 2000, and the governing body insisted on a common method of attachment to enable the rescue crews to extract injured drivers with the minimum of fuss. The top of the roll hoop was given a three centimetre maximum distance from the back of the cockpit, and the rear impact structure minimum cross section became regulated at the same time, but greater focus was already beginning to fall on the side of the cars

Survival cell side heights became regulated, and their side panel outer skins had to be made from laminates that met strict FIA specifications for increased penetration resistance. By 2001, these panels were subjected to a full penetration test as more and more designers opted for high-nose configurations on their cars. The static load side test in the driver's leg area was increased by 20 per cent, and the side impact test speed increased from 7m/s to 10 m/s. Obligatory Confor padding was also fitted beside and above the driver's legs, no less than 25mm thick over its entire area.

Such are the advances that have been made in recent years, Takuma's cell survived an impact with the heaviest item Heidfeld could probably have chosen to hit it with - the Sauber's gearbox. This and the entire rear safety structure on the Swiss car punched a hole through the side of the Jordan, despite hitting part of the sidepod, and only narrowly missed piercing the unlucky Sato's right thigh.

''I remember everything about the accident,'' he said, ''I was turning into the corner with [Juan Pablo] Montoya almost alongside me. I was just starting to get on the throttle when I had the big smash. I heard a big bang and shut my eyes for a split second. I had no idea what it was and didn't see [Nick] Heidfeld coming at all.''

The Japanese driver had to be helped from the wreckage of his car after his legs became trapped in the tangled chassis and his helmet sandwiched by the deformable head restraint, but emerged with just heavy bruising despite his knees having hit the steering column with enough force to break it in two.

''When I opened my eyes, I could see my legs were squashed by the damaged monocoque and I could also see the ground through the hole!'' he explained, ''It was obvious that I had had a big accident. I was conscious and could feel my arms and legs and, although there was some pain, I knew nothing was broken. The car did a great job of saving me, although I hear there is nothing left of it.''

Although he was later sent to Graz hospital for overnight observation, Taku was laughing and joking with doctors and already preparing for a comeback just six days later at Monaco.

''It's just a miracle I think,'' he smiled gratefully.