Determining couch frame shift

1 . A computer-implemented method, comprising:

receiving an indication of a weight on a moveable support of a couch assembly, wherein the moveable support is moveable relative to a couch frame of the couch assembly;

receiving an indication of an expected position for the moveable support to move to a modified position relative to the couch frame to provide the moveable support at a specified position relative to the imaging apparatus; and

determining, for the expected position, a horizontal shift of the couch frame relative to an imaging apparatus associated with the couch assembly based on a shift model indicative of the horizontal shift as a function of:

the weight on the moveable support; and

a horizontal position of the moveable support relative to the couch frame.

2 . The method of claim 1 , comprising:

causing the moveable support to move to the modified position based on a difference between the expected position and the horizontal shift, such that the moveable support is provided at the modified position.

3 . The method of claim 1 , wherein the indication of the weight comprises an indication of electrical current supplied to a couch frame actuator of the couch assembly, wherein the couch frame actuator is configured to control a height of the moveable support relative to a surface supporting the couch assembly.

4 . The method of claim 1 , further comprising determining the shift model from a set of measured values for the horizontal shift and a corresponding set of indicated values for the horizontal position of the moveable support where the horizontal shift is measured.

5 . A non-transitory machine-readable medium comprising instructions which, when executed by at least one processor, cause the at least one processor to perform the method of claim 1 .

6 . The method of claim 2 , wherein causing the moveable support to move to the modified position comprises causing a moveable support actuator of the couch assembly to move the moveable support to the modified position.

7 . The method of claim 6 , wherein causing the moveable support to move to the modified position comprises:

generating a command configured to cause the moveable support actuator to move the moveable support to the modified position; and

sending the command to the moveable support actuator to cause actuation of the moveable support actuator according to the command.

8 . The method of claim 6 , further comprising using the moveable support actuator to move the moveable support in a horizontal direction relative to a surface supporting the couch assembly, such that the moveable support is provided at the modified position.

9 . The method of claim 3 , further comprising using the couch frame actuator to maintain the moveable support at a specified height during the horizontal shift of the moveable support relative to the couch frame.

10 . The method of claim 3 , comprising:

receiving the indication of the weight by receiving the indication of the electrical current;

estimating the weight by using a vertical force balancing model of the electrical current needed to provide the moveable support at a specified height;

receiving a command specifying an expected position to which the moveable support is to move to relative to the couch frame;

determining an expected shift of the couch frame according to the shift model based on the estimated weight and the expected position; and

generating a revised command specifying a modified position to which the moveable support is to move to relative to the couch frame based on a difference between the expected position and the expected shift for the expected position.

11 . The method of claim 4 , wherein the shift model is based on a linear function fitted to the set of measured values for the horizontal shift and the corresponding set of indicated values for the horizontal position of the moveable support.

12 . The method of claim 4 , wherein the shift model is determined from the set of indicated values for the horizontal position of the moveable support at each of a set of indicated values for the weight on the moveable support.

13 . An apparatus, comprising:

an interface configured to receive an indication of a weight on a moveable support of a couch assembly, wherein the moveable support is moveable relative to a couch frame of the couch assembly; and

at least one processor communicatively coupled to the interface and configured to execute a plurality of instructions to:

receive the indication of the weight;

receive an indication of an expected position for the moveable support to move to a modified position relative to the couch frame to provide the moveable support at a specified position relative to the imaging apparatus; and

determine, for the expected position, a horizontal shift of the couch frame relative to an imaging apparatus associated with the couch assembly based on a shift model indicative of the horizontal shift as a function of:

the weight on the moveable support; and

a horizontal position of the moveable support relative to the couch frame.

14 . The apparatus of claim 13 , wherein:

the interface is further configured to:

send a command to a moveable support actuator of the couch assembly, wherein the command is configured to actuate the moveable support actuator; and

wherein the at least one processor is further configured to:

receive the indication of the expected position;

determine the horizontal shift for the expected position; and

cause the moveable support to move to a modified position determined based on a difference between the expected position and the horizontal shift, such that the moveable support is provided at the specified position by:

generating the command configured to cause the moveable support actuator to move the moveable support to the modified position; and

sending the command, via the interface, to the moveable support actuator to cause actuation of the moveable support actuator according to the command.