Intelligent autoverification

Why use an expert system?

Valab® is an expert system used to assist the biological validation of medical test results. An expert system reproduces the reasoning of a human expert, reasoning which is based on choices taking into account the largest possible number of parameters.

When a decision is based on one or two criteria only, the reasoning is relatively easy to master. To evaluate the coherence and/or the acceptability of a medical test result however, multiple criteria come into play: the age and sex of the patient, his/her state of health, if he/she is treated in a hospital or at home, the previous results obtained for the same test, etc.

The reasoning rapidly becomes extremely complex. The assessment of the coherence / acceptability of the result must also take into account the results of all the other tests in the report. A classic algorithmic system used to assess the coherence / acceptability of a result will quickly be overwhelmed by so many combinatorial choices, only an expert system like Valab can handle such complexity.

Valab helps where and how?

In a typical laboratory process, the test results go through steps of technical validation and biological validation on the screen before they are released. Valab steps in after the technical validation step and before biological validation on the screen.

The LIS sends each report to Valab for biological verification just before the step of biological validation on the screen. Valab assesses the coherence and/or acceptability of each result of the report taking into account not only the demographic and contextual (medical and technical) parameters of the result itself, but also the influence of the other results in the report (inter-parametric verification) and their anteriority and kinetics if available.

In less than one second, Valab returns to the LIS the results of its verification and an indication on the validity of the report. The reports comprising a set of results considered to be coherent and/or acceptable by Valab can then be authorised for release. The reports containing results considered to be incoherent or inacceptable by Valab will be examined more closely on the validation screens of the laboratory to understand the origin of this incoherence / inacceptability.

The examination on the screen of the reports containing results judged to be incoherent or inacceptable by Valab is greatly facilitated as the results concerned are indicated by special indicators (or "flags"). In this way, Valab allows to perform an initial filtering of the reports considered a priori to be validatable and clearly shows up the incriminated results in the reports containing incoherent or inacceptable values.

The following schematic shows the implementation logic of Valab in the laboratory:

Specialities and tests

The standard version of Valab supports four specialities covering the basic tests of the laboratory:

  • biochemistry
  • hematology
  • coagulation
  • blood gases

Additional tests, fully modeled and ready to use, can be added to the basic tests. These additional tests complete the range of basic specialities or belong to other specialities: markers, hormones, serology, therapeutic drugs, toxicology, urinalysis . . .

If your need for specialities and tests is not covered by the basic or additional specialities and tests, you can create new ones yourself by using the Auto-Expert module provided with Valab.

Other types of tests cover specific needs. Duplicate tests allow to exploit the results of a test obtained under different technical conditions, linked tests inherit the verification result assigned to another test, blind tests allow the systematic validation of certain values (weight, temperature, …) if required, and redirected tests allow to redirect one or more test results or information items onto another test.

Operating modes and integrated tools

Autoverify mode is the main function of Valab. In this mode, Valab receives and automatically verifies the reports sent by the LIS. Through the Valab interface, the verification results can be displayed in real-time on the Valab workstation.

Simulation mode allows to analyse with total safety the verification results of the reports processed without compromising the real results sent to the LIS. It is possible in this way to study the influence of the verification rules applied by Valab (positive and negative influences). SImulation mode is also used during the development of new expertise models created with the Auto-Expert module.

The Auto-Expert module allows to create new specialities and expertise models for new tests. Many tests already created with Auto-Expert and ready to use are available for download on this site.

Consultative mode

In normal operation, Valab indicates by "blocking flags" only the non-validated results in the verified reports. However the laboratory may want to filter certain results "to be seen systematically" even if their inherent coherence would have allowed their validation.

Valab has a mechanism allowing to impose this "Valab-clinical scientist" double check, namely consultative mode. Consultative mode can be activated globally for all of the tests or individually at the level of each test.

In global consultative mode, all of the results otherwise judged to be validatable by Valab are marked with a special flag requiring them to be examined through manual validation. Operation in global consultative mode is recommended for example during the checking and optimisation phase following a first-time installation of Valab.

Consultative mode at the level of each test (activated thanks to a simple setup choice for the tests concerned) allows to check the behaviour of Valab for a given test. This mechanism is useful for example to test and validate new expertise models created or modified with the Auto-Expert module.

Mandatory validation

The "mandatory validation" mechanism allows to systematically block reports containing specific contextual items entered in the SIL-Valab correspondence tables. By activating mandatory validation for these items, each report which contains them will be systematically sent for manual validation.

The contextual items for which mandatory validation can be activated are:

  • the origin of the request (for example: to force the passage through manual validation of all the requests coming from the same prescriber or the same department)
  • therapeutic and clinical information (for example: to systematically see all of the reports concerning patients affected with diabetes)
  • complementary information (for example: to systematically see all of the results obtained in a context of "venous blood")
  • sex (for example: to systematically see all of the results obtained for patients with sex "other")
  • qualitative tests (for example: to systematically see all of the red cell morphology results at "other")
  • quantitative tests (for example: to systematically see all of the results out of range for an analyser "> 1000")

Safety and traceability

Safety and traceability are ensured by the creation of user accounts and the tracking of the modifications made to the Valab setup.

A user accounts administrator creates a secure account (login and password) for each Valab user and assigns specific consultation and/or modification rights for each user according to their role in the laboratory (user profiles).

As a complement to the traceability of the LIS, the communication history and verification results can be archived by Valab for a given period of time.

Communicating with the LIS through a serial link or network connection, any communication errors are analysed and categorised by severity level.

Activity statistics indicate the rejection and validation rates per test and allow to monitor the operation of Valab and make optimisation adjustments.

Ergonomics and functionality

Valab benefits from many setup options allowing to respond to the needs of the users. User-friendly and customisable, the Valab interface is currently available in French, English and German (modifiable by a simple menu option), other languages will be added later.

Valab handles the reception of complete and partial reports in cumulative / non-cumulative mode and many options complete its functionality (check on the calculations associated with differential requests and blood counts, ratio check for the results of duplicate tests, . . .).

A robust and flexible client-server architecture

Valab is based on a client-server architecture allowing operation that combines security, robustness and flexibility of use. Operating as a Windows® service, the Valab server can be installed on a classic workstation but also on a virtual machine or on a remote server thanks to the use of a software protection key.

User access is managed by a system of floating licences, a solution which makes the use of Valab more flexible according to the number of user accounts and the number of available floating licences. The Multilab option allows to connect more than one LIS or database to the Valab server with simultaneous access of a number of users thanks to the floating licences.

Setup and monitoring of the operation of Valab are peformed through the interface of one or more Valab clients, installed locally or remotely. The autoverification of patients' reports is carried out continuously by the Valab server independently of the operational status of the Valab client(s). Whether performed by a Valab client located directly on the Valab server installation workstation or from a remote workstation, setup is possible while the Valab server is working in production, the same is also true when using Simulation mode or the Auto-Expert module.