Method and Apparatus for Locating the Surface of Solid Growth Culture Media in a Plate

Abstract

A method for locating the surface of a solid growth culture medium in a plate in a plate work position, the plate work position including a sensor and having a datum level fixed in one dimension (z), the method including: ˜placing the plate in the plate work position; ˜using the sensor to sense the medium surface for the positioned plate and measuring the distance to the medium surface; and ˜referencing the measured distance to the datum level to determine a surface positional reference, relative to the datum level, in one dimension (z) for the surface of the medium in the positioned plate.

1 . A method for locating the surface of a solid growth culture medium in a plate in a plate work position, the plate work position including a sensor and having a datum level fixed in one dimension (z), the method including:
 placing the plate in the plate work position;   using the sensor to sense the medium surface for the positioned plate and measuring the distance to the medium surface; and   referencing the measured distance to the datum level to determine a surface positional reference, relative to the datum level, in one dimension (z) for the surface of the medium in the positioned plate.   
   
   
       2 . A method according to  claim 1 , wherein the surface of a medium in a plate, which plate is in its normal, generally horizontal orientation, is located in at least the z dimension by virtue of the determination of the surface positional reference. 
   
   
       3 . A method according to  claim 1 , wherein the datum level is a surface that forms a part of a plate platform upon which the plate can be clamped and supported. 
   
   
       4 . A method according to  claim 1 , wherein the determination of the surface positional reference determines the height of the medium with reference to the plate platform upon which it rests. 
   
   
       5 . A method according to  claim 1 , wherein the medium is sensed in a sensing region, such that the measured distance is an average over the area of the sensing region. 
   
   
       6 . A method for locating the surface of a solid growth culture medium in a plate in a plate work position, the plate work position including a sensor and having a notional action line fixed in two dimensions (x,y) in a predetermined position and having a datum level fixed in one dimension (z), the method including:
 placing the plate in the plate work position;   using the sensor to sense the medium surface within a sensing region for the positioned plate and measuring an average distance to the medium surface within that sensing region;   referencing the measured distance to the datum level to determine a surface positional reference relative to the datum level in one dimension (z) for the surface of the medium in the positioned plate; and   using the surface positional reference and the notional action line to determine a line in three dimensions (x,y,z) that is representative of a line across the surface of the medium in the positioned plate.   
   
   
       7 . A method for locating the surface of a solid growth culture medium in a plate in a plate work position, the plate work position including a sensor and having a datum level fixed in one dimension (z), the method including:
 setting an upper limit and a lower limit to define a detection range between the upper and lower limits;   placing the plate in the plate work position;   using the sensor to sense, within the detection range, the medium surface for the positioned plate and measuring the distance to the medium surface; and   referencing the measured distance to the datum level to provide a surface positional reference relative to the datum level in one dimension (z) for the surface of the medium in the positioned plate.   
   
   
       8 . A method according to  claim 7 , wherein the upper detection limit is above the datum level and the lower detection limit is below the datum level. 
   
   
       9 . A method according to  claim 7 , wherein the detection range is provided with calibration sub-ranges. 
   
   
       10 . A method according to  claim 9 , wherein the calibration sub-ranges identify alarm conditions. 
   
   
       11 . A method according to  claim 10 , wherein the alarm conditions are where a plate positioned in the plate work position still includes its lid thereon or has been placed in the plate work position upside down. 
   
   
       12 . A method according to  claim 11 , wherein the detection range is set at about 30 mm, with the upper limit set 20 mm above the datum level and the lower limit set 10 mm below the datum level. 
   
   
       13 . A method for locating the surface of a solid growth culture medium in a plate in a plate work position, the plate work position including a sensor and having a notional action line fixed in two dimensions (x,y) in a predetermined position and having a datum level fixed in one dimension (z), the method including:
 setting an upper limit and a lower limit to define a detection range between the upper and lower limits;   placing the plate in the plate work position;   using the sensor to sense the medium surface, within the detection range, within a sensing region for the positioned plate and measuring an average distance to the medium surface within that sensing region;   referencing the measured distance to the datum level to determine a surface positional reference relative to the datum level in one dimension (z) for the surface of the medium in the positioned plate; and   using the surface positional reference and the notional action line to determine a line in three dimensions (x,y,z) that is representative of a line across the surface of the medium in the positioned plate.   
   
   
       14 . A method according to  claim 1 , wherein the sensor is an ultrasonic sensing device that includes an ultrasonic beam focusing element that is capable of providing a focused beam on the medium surface. 
   
   
       15 . A method according to  claim 1 , wherein the sensor is rigidly mounted to a main frame, thereby defining the general location of the plate work position. 
   
   
       16 . A method according to  claim 1 , wherein the sensor is mounted to be above the plate work position and operatively adjacent a positioned plate held immediately therebelow in a plate platform, the positioned plate having its medium surface open upwardly. 
   
   
       17 . An apparatus for locating the surface of a solid growth culture medium in a plate in a plate work position, the plate work position including a sensor and also having a datum level fixed in one dimension (z), wherein the sensor is capable of sensing the medium surface for the positioned plate and measuring the distance to the medium surface, the apparatus also including means for referencing the measured distance to the datum level to determine a surface positional reference, relative to the datum level, in one dimension (z) for the surface of the medium in the positioned plate. 
   
   
       18 . An apparatus for locating the surface of a solid growth culture medium in a plate in a plate work position, the plate work position including a sensor and having a notional action line fixed in two dimensions (x,y) in a predetermined position and having a datum level fixed in one dimension (z), wherein the sensor is capable of sensing the medium surface within a sensing region for the positioned plate and measuring an average distance to the medium surface within that sensing region, the apparatus also including means for referencing the measured distance to the datum level to determine a surface positional reference relative to the datum level in one dimension (z) for the surface of the medium in the positioned plate and then using the surface positional reference and the notional action line to determine a line in three dimensions (x,y,z) that is representative of a line across the surface of the medium in the positioned plate. 
   
   
       19 . An apparatus for locating the surface of a solid growth culture medium in a plate in a plate work position, the plate work position including a sensor and having a datum level fixed in one dimension (z), wherein the sensor has an upper limit and a lower limit to define a detection range between the upper and lower limits, and is capable of sensing, within the detection range, the medium surface for the positioned plate and measuring the distance to the medium surface, the apparatus including means for referencing the measured distance to the datum level to provide a surface positional reference relative to the datum level in one dimension (z) for the surface of the medium in the positioned plate. 
   
   
       20 . An apparatus for locating the surface of a solid growth culture medium in a plate in a plate work position, the plate work position including a sensor and having a notional action line fixed in two dimensions (x,y) in a predetermined position and also having a datum level fixed in one dimension (z), wherein the sensor has an upper limit and a lower limit to define a detection range between the upper and lower limits, and is capable of sensing the medium surface, within the detection range, within a sensing region for the positioned plate and measuring an average distance to the medium surface within that sensing region, the apparatus including means for referencing the measured distance to the datum level to determine a surface positional reference relative to the datum level in one dimension (z) for the surface of the medium in the positioned plate, and then using the surface positional reference and the notional action line to determine a line in three dimensions (x,y,z) that is representative of a line across the surface of the medium in the positioned plate. 
   
   
       21 . An apparatus according to  claim 17 , wherein the sensor is an ultrasonic sensing device that includes an ultrasonic beam focusing element that is capable of providing a focused beam on the medium surface. 
   
   
       22 . An apparatus according to  claim 17 , wherein the sensor is rigidly mounted to a main frame, thereby defining the general location of the plate work position. 
   
   
       23 . An apparatus according to  claim 17 , wherein the sensor is mounted to be above the plate work position and operatively adjacent a positioned plate held immediately therebelow in a plate platform, the positioned plate having its medium surface open upwardly. 
   
   
       24 - 31 . (canceled)