Hospital bed control apparatus

1. A method of determining and setting pressures for a patient support including a head section and a seat section, the method comprising the steps of:

measuring force exerted upon the patient support,

measuring an angle that a head section of the patient support assumes relative to horizontal,

calculating patient weight from the force measurement and the head section angle measurement,

setting baseline pressures in the sections of the patient support in response to the calculated patient weight,

re-measuring the force exerted upon the patient support,

selectively adjusting the pressure in at least one of the sections of the patient support based upon the re-measured force,

determining if the re-measured force is outside a defined limit, and

if the re-measured force is outside the defined limit, re-setting the baseline pressures.

2. The method of claim 1 wherein the setting step comprises the step of:

providing a fluid supply and a plurality of valves fluidly coupled to the fluid supply; and

controlling the fluid supply and the plurality of valves.

3. The method of claim 1 further comprising the steps of:

recording the calculated patient weight.

4. The method of claim 1 wherein the calculating step comprises the steps of:

comparing the force measurement and the angle measurement comparison to a table including a plurality of associated force measurements and angle measurements, and

generating baseline pressure values from the comparison table.

5. The method of claim 1 wherein the calculating step comprises the steps of:

inputting the force measurement and the angle measurement to a predefined algorithm; and

generating baseline pressure values from the algorithm.

6. A method of determining and setting pressures for a patient support including a head section and a seat section, the method comprising the steps of:

measuring force exerted upon the patient support,

measuring an angle that a head section of the patient support assumes relative to horizontal,

calculating patient weight from the force measurement and the head section angle measurement,

setting baseline pressures in the sections of the patient support in response to the calculated patient weight,

recording the calculated patient weight,

re-measuring the force exerted upon the patient support,

selectively adjusting the pressure in at least one of the sections of the patient support based upon the re-measured force,

comparing the re-measured force exerted upon the patient support to defined limits,

determining if the re-measured force is outside the defined limits, and

if the re-measured force is outside the limits, recalculating the patient weight by re-measuring the force and the head section angle, and re-setting the baseline pressures for the sections.

7. A method of determining and setting pressures for a patient support including a head section and a seat section, the method comprising the steps of:

measuring force exerted upon the patient support,

measuring an angle that a head section of the patient support assumes relative to horizontal,

comparing the force measurement and the angle measurements to a set of predetermined values in a comparison table,

determining weight of a patient from the comparison table,

setting baseline pressures in the sections of the patient support based upon the determined weight of the patient,

adjusting the pressure in at least one section of the patient support based upon the measured force,

comparing the measured force to a defined limit, and

if the measured force is outside the defined limit, re-determining the patient weight and re-setting the baseline pressures.

8. The method of claim 7 further comprising the steps of:

recording the determined weight of the patient,

re-measuring the force exerted upon the patient support, and

selectively adjusting the pressures in the sections of the patient support based upon the re-measured force.

9. A method of determining and setting pressures for a patient support including a head section and a seat section, the method comprising the steps of:

measuring force exerted upon the patient support,

measuring an angle that a head section of the patient support assumes relative to horizontal,

comparing the force measurement and the angle measurements to a set of predetermined values in a comparison table,

determining weight of a patient from the comparison table,

determining baseline pressure values in the sections of the patient support based upon the determined weight of the patient,

setting baseline pressures in the sections of the patient support to the determined baseline pressure values,

recording the determined weight of the patient,

re-measuring the force exerted upon the patient support,

selectively adjusting the pressures in the sections of the patient support based upon the re-measured force,

comparing the re-measured force exerted upon the patient support to defined limits,

determining if the re-measured force is outside the defined limits, and

if the re-measured force is outside the limits, recalculating the patient weight by re-measuring the seat force and the head section angle, and resetting the baseline pressures for the sections.

10. A control apparatus for determining and setting pressures for a patient support including a head section and a seat section, the control apparatus being configured to:

measure force exerted upon the patient support,

measure an angle that a head section of the patient support assumes relative to horizontal,

calculate a patient weight from the force measurement and the head section angle measurement,

set baseline pressures in the sections of the patient support in response to the calculated patient weight,

measure a first force applied to the patient support at a first sensor,

determine a first measured weight of a patient supported on the patient support from the first force,

measure a second force applied to the patient support at a second sensor,

determine a second measured weight of the patient from the second force,

compare the first measured weight to the second measured weight, and

provide an output if a differential between the first measured weight and the second measured weight exceeds a predetermined value.

11. The control apparatus of claim 10 , further configured to:

determine a weight value of the patient detected by a weigh scale;

determine an angle of the patient support; and

adjust the weight value detected by the weigh scale based on the angle of the patient support.

12. The control apparatus of claim 11 , wherein the patient support is movable about an axis transverse to the patient support, and the control apparatus is configured to determine an angle of movement of the patient support about the transverse axis relative to a horizontal position.

13. The control apparatus of claim 11 , wherein the patient support is rotatable about a longitudinal axis of the patient support, and control apparatus is configured to determine an angle of rotation of the patient support about its longitudinal axis relative to a horizontal position.

14. The control apparatus of claim 11 , further configured to calculate a cosine of the angle of the patient support in at least one direction and divide the measured weight value by the cosine of the angle or angles.

15. A control apparatus for determining and setting pressures for a patient support including a head section and a seat section, the control apparatus being configured to:

measure force exerted upon the patient support,

measure an angle that a head section of the patient support assumes relative to horizontal,

calculate a patient weight from the force measurement and the head section angle measurement,

set baseline pressures in the sections of the patient support in response to the calculated patient weight,

detect an actual pressure within a fluid-filled zone of the patient support,

measure force applied to the patient support by a first force sensor,

determine a first measured weight of a patient supported on the patient support from the first force sensor,

set a baseline pressure within the fluid-filled zone based upon the first measured weight,

measure force applied to the patient support by a second force sensor,

determine a second measured weight of the patient from the second force sensor,

compare the first measured weight to the second measured weight, and

provide a diagnostic output if a differential between the first measured weight and the second measured weight exceeds a predetermined value.

16. The control apparatus of claim 15 , further configured to adjust the pressure within the fluid-filled zone in response to changes in output from the first force sensor.

17. The control apparatus of claim 15 , wherein the first force sensor comprises a bed scale.

18. The control apparatus of claim 17 , wherein the patient support comprises a mattress operably coupled to the bed scale and including a head section, a seat section, and a foot section, and the second force sensor is operably coupled to the seat section of the mattress.

19. The control apparatus of claim 15 , further configured to activate an alarm in response to the diagnostic output.

20. The control apparatus of claim 15 , further configured to establish a new baseline pressure within the fluid filled zone independent of the first measured weight in response to the diagnostic output.