What went wrong with the Therac-25?

For six unfortunate patients in 1986 and 1987, the Therac-25 did the unthinkable: it exposed them to massive overdoses of radiation, killing four and leaving two others with lifelong injuries.

Who was at fault for the Therac-25 accidents?

As long as AECL was convinced that their machine could not cause a radiation overdose, they were not going to discover any machine deficiencies. However, AECL was not completely to blame for the Therac-25 accidents; machine operators and technicians also contributed their share of mistakes.

What caused Therac-25?

Two software faults were to blame. One, when the operator incorrectly selected X-ray mode before quickly changing to electron mode, which allowed the electron beam to be set for X-ray mode without the X-ray target being in place.

What is the Therac-25 machine?

The Therac-25 was a radiation therapy machine manufactured by AECL in the 80s, which offered a revolutionary dual treatment mode. It was also designed from the outset to use software based safety systems rather than hardware controls.

What was one government agency involved in handling the problems with the Therac-25?

In March 1983, AECL performed a safety analysis on the Therac-25.

What made the Therac-25 different from the previous models?

The Therac-25 was designed to be solely computer controlled. The previous versions were related to other machines. Another feature was that the software used had more responsibility in controlling safety. Again, the previous machines had separate pieces of machinery and hardware to monitor safety factors.

Did the FDA approve Therac-25?

Therac-25 is Shut Down After another 6 months of negotiation with the FDA, AECL received approval for its final corrective action plan. This plan included numerous software fixes, the installation of independent, mechanical safety interlocks, and a variety of other safety related changes.

Who conducted the investigation of the Therac-25 accidents for this report?

What new feature were added in Therac-25 compared to its previous version?

Which mistake was not made by AECL the manufacturer of the Therac-25?

Which mistake was not made by AECL, the manufacturer of the Therac-25? one of its employees mistyped a sell order, and a bug in the Tokyo Stock Exchange trading program made it impossible to cancel the order.

Who programmed Therac-25?

Atomic Energy Canada Limited
The Therac-25 machine was a state-of-the-art linear accelerator developed by the company Atomic Energy Canada Limited (AECL) and a French company CGR to provide radiation treatment to cancer patients.

What are the principal reason or reasons why these systems failed to operate Ariane 5 Therac-25?

The machine was recalled in 1987 for an extensive redesign of safety features, software, and mechanical interlocks. Reports to the manufacturer resulted in inadequate repairs to the system and assurances that the machines were safe.