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LABORATORY HEWLET PACKARD (HP) CAREVUE INTERFACE Patch LR*5.2*254 and Patch LA*5.2*53











LABORATORY HEWLET PACKARD (HP)
CAREVUE INTERFACE
Patch LR*5.2*254 and Patch LA*5.2*53

INTERFACE SPECIFICATIONS





Version 5.2

May 2000








Department of Veteran Affairs
V
IST
A Software Service
Clinical Specialties Product Line





May 2000
V
IST
A Laboratory HP CareVue Interface
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Interface Specifications
Introduction

The purpose of this document is to describe the Veterans Health Information Systems and
Technology Architecture (V
IST
A) Laboratory Test result systems use of the HL7 Interface
Standard (Version 2.3) and to provide a reference guide for implementing this interface with the
CareVue system.

The focus of this document is to describe the HL7 Observation Request Unsolicited (ORU)
control message used for sending V
IST
A lab test results to the CareVue system. The interface is
designed to generate an ORU message upon verification of lab results for any patient whose
reporting location is identified as either a CareVue location.


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IST
A Laboratory HP CareVue Interface
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Interface Specifications
Overview - VISTA Laboratory Interface

The V
IST
A Laboratory interface provides the capability for V
IST
A to broadcast laboratory results
that are entered into V
IST
A. Each time laboratory results are verified in V
IST
A, the laboratory
interface determines if those results should be sent to the Interface Engine (see paragraph below).
Figure 1: V</b><i>IST</i><b>A Laboratory Interface














VISTA Filtering of Results

Not all laboratory results are sent to the Interface Engine. Each time laboratory results are
verified in V
IST
A, the location designated as the report routing location (this defaults to the
ordering location entered at the time of ordering the laboratory tests in V
IST
A) is checked to see if
the results should be sent to the CareVue. V
IST
A uses the FOREIGN INTERFACE file
(#62.487) for this purpose.
If there is an entry in this file for the specified location, an HL7 message is generated and sent to
the Interface Engine. The location must match exactly an entry in the FOREIGN INTERFACE
and must be a valid location in the Hospital Location file (#44).


V<i>IST</i>A

Laboratory

HP
CareVue
Laboratory

Interface
Engine

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IST
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Interface Specifications
VISTA System Environment

V
IST
A uses standardized HL7 messaging software, HLLP, for communicating with external
systems. Within V
IST
A, different instances of the HLLP software (VMS processes) are
associated with different applications. Each instance of the HLLP software is assigned a unique
name in the V
IST
A device file.
Table 1 identifies the HLLP process names associated with the HOST integration.

HLLP Operation - VISTA Results Interface

V
IST
A provides the optional capability to automatically restart HLLPs each time the running
process is terminated (because of an interruption on the communications connection with the
Interface Engine or other system interruption). This option should be selected for each HLLP
communicating with the Interface Engine.
Table 1: VISTA HLLP Processes - HOST Integration Example
VISTA Interface
VISTA HLLP
Process
VISTA Virtual
Device
V
IST
A Outgoing Interfaces (V
IST
A to Interface Engine)
ADT - Test
OG_TEST
LTA_9297
ADT - Production
OG_PROD
LTA_9299
Laboratory Results - Test
OG_LAB_TEST
LTA_9333
Laboratory Results -
Production
OG_LAB_PROD
LTA_9334
V
IST
A Incoming Interfaces (Interface Engine to V
IST
A)
Results - Test
IC_TEST
LTA_9161
Results - Production
IC_PROD
LTA_9296



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IST
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Interface Specifications
VISTA Network Connectivity to Interface Engine

The V
IST
A HL7 software uses asynchronous type communications. Separate communications
lines have been dedicated for each of the V
IST
A interfaces that have been implemented with the
Interface Engine. Configuring the system to support both a test interface and a production
interface requires an additional set of dedicated lines.
The communication lines between V
IST
A and the Interface Engine are implemented by dedicating
ports on a Digital terminal server. Each of the lines requires two terminal server ports, one for the
V
IST
A end of the communication and one for the Interface Engine end of the communication. The
two terminal server ports are physically connected using a null modem cable.
Both V
IST
A and the Interface Engine communicate with the terminal server(s) using the Local
Area Transport (LAT) protocol over the Ethernet backbone.
Figure 2
illustrates how the connections between V
IST
A and the Interface Engine are
implemented.

Figure 2: VISTA to Interface Engine Network Connections

These ports can be provided by any terminal server(s) connected to the network with the only
requirement being that each pair (V
IST
A end and Interface Engine end) be physically connected
using a null modem cable.

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IST
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Interface Specifications
Table 2
identifies the terminal server ports, which are being used to communicate between V
IST
A
and the Interface Engine.

Table 2: Terminal Server Ports - VISTA to Interface Engine Communications
Example
VISTA Interface
HL7 LLP
Terminal Server Port
(VISTA Connection)
VISTA Virtual Device
Terminal Server Port
(Interface Engine
Connection)
Interface Engine
Virtual Device
Laboratory Results I/F -
Production
INTERFACE
ENGINELABRESULTS
LLP
DSV 104 Port 2
LTA_9334
OG_LAB_PROD
DSV 104 Port 1
LAT device 649
vista_ic_lab

Laboratory Results Interface (vista_ic_lab)

The laboratory interface is an outgoing interface from V
IST
A to the Interface Engine which
transmits HL7 ORU messages to communicate laboratory results that have been verified in
V
IST
A. The Interface Engine translates these incoming messages for communication to HP
CareVue.

Communications lines and terminal server port designations are assigned in V
IST
A by the IRM
operations staff and are defined as follows:

Outgoing

NAME: OG_LAB_PROD $I: _LTA9334:
LOCATION OF TERMINAL: COMPUTER ROOM ASK HOST FILE: YES
SUBTYPE: C-OTHER TYPE: TERMINAL
LAT SERVER NODE: DSV104 LAT SERVER PORT: PORT_6

Incoming

NAME: IC_LAB_PROD $I: _LTA9296:
LOCATION OF TERMINAL: IRM COMPUTER ROOM
SUBTYPE: P-OTHER TYPE: TERMINAL
LAT SERVER NODE: DSV104 LAT SERVER PORT: PORT_8

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IST
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Interface Specifications

Communication between V
IST
A and the Interface Engine is accomplished using an asynchronous
serial communications protocol as if the systems were connected using a standard RS232
asynchronous serial communications line.

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IST
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Interface Specifications
Table
3 and Table 4 identify the terminal server port settings for the V
IST
A interface with the
Interface Engine. These settings are used for terminal server ports, one for the V
IST
A end, and
the other for the Interface Engine end. IRM operations staff can modify terminal server port
settings.

Table 3: Terminal Server Port Settings - VISTA to Interface Engine ADT Interface
Port n

Server: DSV<i>nnn

Character Size:
8
Input Speed:
9600
Flow Control:
XON
Output Speed:
9600
Parity:
None
Signal Control
Enabled
Stop Bits:
Dynamic
Signal Select:
CTS-DSR-RTS-DTR




Access:
Remote
Local Switch:
None
Backwards Switch:
None
Name:
PORT_<i>n
Break:
Remote
Session Limit
1
Forwards Switch:
None
Type:
Soft
Default Protocol:
LAT




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