Control systems for air pads or mattresses

Claim 3

A method according to Claim 1, characterised in that the air pad or mattress has a plurality of sets of air cells -(A,B) and wherein the sets of cells are inflated alternately.

Claim 4

. A method according to Claim 1, characterised in that the air pad or mattress has one set of cells (A) and wherein the cells of said set are inflated sequentially.

Claim 5

A method according to Claim 3, characterised in that the cells of said set (A) are individually inflated sequentially.

Claim 6

0168213 5. A method according to Claim 3, characterised in that the cells of said set (A) are inflated sequentially in groups.

Claim 7

A method according to Claim 1 or Claim 2, and wherein the air pad or mattress has two sets of cells (A,B), each selectively inflatable and deflatable, characterised in that the selected air pressure value is selected by the control means (10) by inflating the sets of cells (A,B) to a predetermined pressure value, venting one set of cells (A) until a preselected sensing pressure value is reached, venting the other set of cells (B) until the air pressure in the one set of cells (A) begins to rise as a result of body weight acting thereon, measuring the air pressure in the other set of cells (B) at this point, performing a first calculation within the control means using this measurement to derive a first pressure value, inflating the one set of cells (A) and deflating the other (B) until they reach said first pressure value and said sensing pressure value respectively, inflating the one set of cells (A) until the pressure in the other set of cells (B) begins to decrease, measuring the pressure in the one set of cells (A) at this point, performing a second calculation using this second, measured pressure value within the one set of cells (A) and the said first pressure value to derive the selected operating air pressure value.

Claim 8

A method according to Claim 6, characterised in that, following derivation of the selected operating air pressure value, the control means (10) operates the valve means (18-21) so as to inflate and deflate alternately the sets of cells (A,B) to around the respectively selected operating air pressure value and a lower air pressure value.

Claim 9

A method according to Claim 7, characterised in that the lower air pressure value comprises the preselected sensing pressure value.

Claim 11

A method according to Claim 9 together with Claim 7, characterised in that the steps of deriving a selected operating air pressure value is repeated after a predetermined number of inflation/deflation cycles of the sets of cells (A,B).

Claim 12

A control system for an air pad of mattress of the kind having at least one set of air cells (A,B) which in use are selectively inflatable and deflatable so as to change from time to time the portions of the pad or mattress supporting a body thereon, comprising a pump (14) for delivering pressurised air, valve means (18-21), operable through control means (10) to control selectively the feeding of pressurised air from the pump to the cells and the exhausting of air therefrom in order to inflate and deflate respectively the cells, characterised in that the system includes pressure sensing means (25) connected with the control means (10) for sensing air pressures within the cells (A,B), and in that the control means (10) is arranged to sense operational air pressure characteristics of the cells (A,B) and derive information dependent upon a body's weight and disposition acting on the cells, and to select an operating air pressure value in accordance therewith, and thereafter to control the valve (18-21) means in order to inflate selected ones of the cells or sets of cells (A,B) to around the selected air pressure value.

Claim 13

A control system for an air pad of mattress of the kind having at least one set of air cells (A,B) which in use are selectively inflatable and deflatable so as to change from time to time the portions of the pad or mattress supporting a body thereon, comprising a pump (14) for delivering pressurised air, valve means (18-21), operable through control means (10) to control selectively the feeding of pressurised air from the pump to the cells and the exhausting of air therefrom in order to inflate and deflate respectively the cells, characterised in that the system includes pressure sensing means (25) connected with the control means (10) for sensing air pressures within the cells (A,B), and in that the control means (10) is arranged to sense operational air pressure characteristics of the cells (A,B) and derive information dependent upon a body's weight and disposition acting on the cells, and to select an operating air pressure value in accordance therewith, and thereafter to control the valve (18-21) means in order to inflate selected ones of the cells or sets of cells (A,B) to around the selected air pressure value.

Claim 14

A control system according to Claim 12 and for use with an air pad or mattress having two 'sets of cells, characterised in that the pressure sensing means (25) is connected pneumatically to each of the sets of cells (A,B) to sense air pressure therein via a change over valve (24) operable by the control means (10).

Claim 15

A control system according to Claim 12, characterised in that the control means (10) comprises a microprocessor (30) operable under the control of a stored program (31).