Hospital bed with patient weight and displacement sensors

#The present invention relates to patient support apparatuses such as hospital beds. In particular, the invention relates to patient support apparatuses with improved weight and displacement sensors.

#For various reasons, it may be desirable to determine the weight of the patient lying on a hospital bed. Hospital beds typically comprise a plurality of load cells which are distributed across the area under a sleep surface and are secured to a patient support frame which is provided under the sleep surface.

#Some beds comprise three or four load cells which are located generally at the corners or near the perimeter of a sleep surface of the bed. The load cells are generally provided on a patient support frame which is located directly under the sleep surface. The load cells serve two purposes: determining the weight of the patient by calculating a sum of the weight measured by each load cell, and monitoring patient position on the bed by calculating which proportion of the total weight of the patient is measured by each load cell. Examples of this type of bed are shown in U.S. Pat. Nos. 5,276,432 and 5,802,640.

#Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration example embodiments thereof and in which:

#FIG. 1 is a top perspective view of a hospital bed, in accordance with one embodiment, with the elevation system in the lowered position;

#FIG. 2 is a top perspective view of the bed illustrated in FIG. 1, with the siderails removed and with the elevation system in the raised position;

#Referring first to FIGS. 1 and 2, there is shown a hospital bed 100, in accordance with one embodiment. The bed 100 comprises a head end 102, an opposite foot end 104 and spaced-apart left 105 and right 107 sides extending between the head end 102 and the foot end 104.

#Some of the structural components of the bed 100 will be designated hereinafter as “right”, “left”, “head” and “foot” from the reference point of an individual lying on his/her back on the support surface of the mattress provided on the bed 100 with his/her head oriented toward the head end 102 of the bed 100 and the his/her feet oriented toward the foot end 104 of the bed 100.

#The bed 100 includes a base 106, a patient support assembly 108 and an elevation system 110 operatively coupling the patient support assembly 108 to the base 106. In the illustrated embodiment, the patient support assembly 108 includes a frame 200 (best shown in FIG. 3) and a patient support surface 250 supported by the frame 200. In the illustrated embodiment, the patient support surface 250 includes an upper body surface or backrest 252, a lower body surface or lower body support panel 254 and one or more core body surfaces or core support panels 256, 258 located between the backrest 252 and the lower body support panel 254 for supporting the seat and/or thighs of the patient. In the illustrated embodiment, each one of the backrest 252, the lower body support panel 254 and the core support panels 256, 258 can be angled relative to the other panels. Alternatively, the patient support surface 250 could comprise a single rigid panel extending between the head end 102 and the foot end 104 of the bed 100 instead of multiple pivotable panels.