Uni-directional Devices
A unidirectional interfaced is for an analyzer which requires that the order be placed at the analyzer i.e. Clinitek Status. The interface allows a test result to be communicated from analyzer and to the LIS.
Uni-directional device interfaces normally allow the lab technician to enter patient identifying information (e.g. Medical Record Number (MRN, Name, Date of Birth and sex) using the device data entry function. The device will include this information when it transmits to the Apex LIS when the test is completed. When the LIS receives the patient identifying data it will the data to match the results against an existing order.
Bi-directional Devices
A bi-directional interface is used for analyzers which are capable of receiving an order from the LIS and then transmitting the result back to the LIS (i.e. ACE Alera, Olympus Architect). When the LIS receives an order from an EHR or a manual input, the LIS will print a specimen label for each test ordered and stage the test on the lab device. When the specimen's barcode is read by the analyzer, the unique ID from the specimen label is matched with the order previously downloaded to the instrument.
This system is also called "Batch Download". This type of lab device eliminates the need for the lab tech to enter patient information at the device and virtually eliminates exception processing.
Host Query Devices
A Host Query interface is similar to a bi-directional interface with the addition that with a Host Query interface the analyzer can request information from the LIS (i.e. AU480). This is a more efficient system because the instrument reads the barcode on the specimen and "queries" the LIS for the test orders. The LIS will be listening on a communication port for queries and will download the requests only when required. In cases where the LIS transmits data such as test orders or control messages to analyzers the communication is set up to be bi-directional.