Interface unit and a measurement system

Abstract

The present invention relates to an extracorporeale interface unit ( 8 ), for an intravascular measurement system for measuring at least one physiological, or other, variable in a living body, adapted to generate a sensor signal in response of the variable. The interface unit ( 8 ) comprises a sensor interface circuitry ( 6 ) adapted to interface a sensor wire configured to be inserted into the living body and provided with one or many sensor element(s) at its distal region. The sensor interface circuitry ( 6 ) comprises a measurement unit ( 9 ) adapted to generate the measured data of the variable as a sensor signal. The interface unit ( 8 ) further comprises a control unit ( 1 ) adapted to control and supervise the different functions of the interface unit ( 8 ), wherein the different functions are performed by predefined tasks (T 1 , T 2 , . . ., T n ) during consecutive control periods CP having the same time duration. During each task (T 1 , T 2 , . . . T n ) a predefined function of the interface unit ( 8 ) is performed. Each predefined task (T 1 , T 2 , . . . T n .) has a designated task time period length (t 1 , t 2 , t 3 , . . . , t n ), and only one task (T 1 , T 2 , . . . T n ) is adapted to be executed at the same time, and each task (T 1 , T 2 , . . . T n ) in a control period CP has a designated task time slot within the control period CP, wherein the tasks (T 1 , T 2 , . . . T n ) within a control period CP are separated by a specified task separation time period t s . The present invention further relates to a measurement system ( 12 ) comprising the extracorporeale interface unit ( 8 ).

1 . An extracorporeale interface unit, for an intravascular measurement system for measuring at least one physiological, or other, variable in a living body, adapted to generate a sensor signal in response to said variable, which interface unit comprises:
 a sensor interface circuitry adapted to interface a sensor wire configured to be inserted into the living body and provided with one or more sensor element(s) at its distal region, the sensor interface circuitry comprises a measurement unit adapted to generate a sensor signal based on a sensor variable value related to said variable;   a control unit adapted to control and supervise a plurality of functions of the interface unit, wherein the functions are performed by predefined tasks during consecutive control periods having the same time duration, and during each task, a predefined function of the interface unit is performed, wherein the functions include measuring said at least one variable and one or more other functions selected from: processing measured data, performing radio communication with an external device, performing electrical stimulation of tissue, and/or performing ablation of tissue; and   
       an energy source configured to energize the sensor interface circuitry during said function of measuring said at least one variable, and to additionally energize the one or more other functions,
 wherein the control unit is configured such that each predefined task has a designated task time period length, only one task is executed at the same time, and each task in a control period is designated for a task time slot of said control period, wherein the tasks within a control period are separated by a specified task separation time period, and 
 wherein the energy source does not energize the sensor interface circuitry or any of the one or more other functions during the task separation time period. 
 
     
     
         2 . The interface unit according to  claim 1 , wherein each predefined task has a designated execution frequency rate of 50-500 Hz. 
     
     
         3 . The interface unit according to  claim 1 , wherein each predefined task has a designated execution frequency rate, the designated execution frequency rate determining in which control periods the predefined task is executed. 
     
     
         4 . The interface unit according to  claim 1 , wherein said task separation time period is between 10-1000 μs. 
     
     
         5 . The interface unit according to  claim 1 , wherein said sensor interface circuitry comprises two current source units adapted to energize said sensor element(s) via at least two connection points, and a switching unit, wherein said switching unit is adapted to alternately switch connection between said current source units and at least two of said connection points, said switching occurring at a time between a start of a first control period and a start of a second, subsequent control period. 
     
     
         6 . The interface unit according to  claim 5 , wherein said task time period length is essentially the same for each connection between said current source units and said at least two of said connection points, and said sensor variable value is measured at said at least two of said connection points. 
     
     
         7 . The interface unit according to  claim 5 , wherein said sensor signal is based on the average value of sensor variable values from at least one task time period at a time of a first connection state between said current source units and said at least two of said connection points, and at least one task time period at a time of a second, different connection state between said current source units and said at least two of said connection points. 
     
     
         8 . The interface unit according to  claim 1 , wherein said time duration of said control periods is between 0.5-20 ms. 
     
     
         9 . The interface unit according to  claim 1 , wherein said time duration of said control periods is 2.5 ms. 
     
     
         10 . The interface unit according to  claim 1 , wherein said interface unit is arranged in a transceiver unit adapted to transfer said sensor signal via a wireless connection to an external device. 
     
     
         11 . The interface unit according to  claim 1 , wherein said interface unit is arranged in a connector unit adapted to transfer said sensor signal via a cable connection to an external device. 
     
     
         12 . A measurement system for intravascular measurements of at least one physiological, or other, variable in a living body, comprising:
 a sensor wire, adapted to be inserted into the body, comprising a sensor element arranged in a distal region of said sensor wire; and   an external device, adapted to receive measured data,   wherein the measurement system comprises an extracorporeale interface unit according to  claim 1  adapted to be connected to a proximal end of said sensor wire.