US3913156A - Levitation beds - Google Patents

Levitation beds Download PDF

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Publication number
US3913156A
US3913156A US454286A US45428674A US3913156A US 3913156 A US3913156 A US 3913156A US 454286 A US454286 A US 454286A US 45428674 A US45428674 A US 45428674A US 3913156 A US3913156 A US 3913156A
Authority
US
United States
Prior art keywords
pressure
air
patient
pockets
supply
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US454286A
Other languages
English (en)
Inventor
Frederick Hugh Howorth
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Howorth Airtech Ltd
Original Assignee
Howorth Air Conditioning Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Howorth Air Conditioning Ltd filed Critical Howorth Air Conditioning Ltd
Application granted granted Critical
Publication of US3913156A publication Critical patent/US3913156A/en
Assigned to HOWORTH AIRTECH LIMITED reassignment HOWORTH AIRTECH LIMITED ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: HOWORTH AIR ENGINEERING LIMITED
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61G—TRANSPORT, PERSONAL CONVEYANCES, OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS; OPERATING TABLES OR CHAIRS; CHAIRS FOR DENTISTRY; FUNERAL DEVICES
    • A61G7/00—Beds specially adapted for nursing; Devices for lifting patients or disabled persons
    • A61G7/05—Parts, details or accessories of beds
    • A61G7/057—Arrangements for preventing bed-sores or for supporting patients with burns, e.g. mattresses specially adapted therefor
    • A61G7/05769—Arrangements for preventing bed-sores or for supporting patients with burns, e.g. mattresses specially adapted therefor with inflatable chambers
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61G—TRANSPORT, PERSONAL CONVEYANCES, OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS; OPERATING TABLES OR CHAIRS; CHAIRS FOR DENTISTRY; FUNERAL DEVICES
    • A61G7/00—Beds specially adapted for nursing; Devices for lifting patients or disabled persons
    • A61G7/05—Parts, details or accessories of beds
    • A61G7/057—Arrangements for preventing bed-sores or for supporting patients with burns, e.g. mattresses specially adapted therefor
    • A61G7/05761—Arrangements for preventing bed-sores or for supporting patients with burns, e.g. mattresses specially adapted therefor where patient is supported on a free, unbounded, film or cushion of air

Definitions

  • This earlier bed is an inflatable chambenwith-an outlet formed bya number of pockets which :is self-- adjusting .inithree plane'srAs eachzpocket inflates it is forcedagainstits neighbour and it alsomeetsthe oppo-. site pockets along: the mid-line of the bed and along-the mid-line of each leg.
  • the inr flated bedthepressure is adjusted so that-the pockets are sdepressed sufficiently by the downward thrust of the body to allow pressurised air toleak between the body and the toptsurface of the pockets, Those portions of the pockets beneath the body are subject tothe same pressures on their inner and'outer surfaces and thus fall.
  • a control system for an air support levitation bedto maintain a. substantially constant air pressure in the pockets thereof forming .a mattress-comprises anair duct for supplying air to the pockets a.damper ,or valve in. the duct to open and.reg-. ulate .the supplyof. air, so that the. air maybe regulated tooppose the weight; of various patientssuch as chil-,
  • ing and compensating system calibrated to the weights of patients, controlling the supply of compressed air to a pneumatic cylinder, the piston of which operates a linkage to hold the damper or valve in the required position to obtain the correct constant air pressure to sup port the weight of the patient, and to open the damper or valve when any drop in pressure occurs in the pockets of the bed due to the movement of the patient, and to return to the required holding pressure once movement of the patient has stopped.
  • FIG. 1 is an end elevation of a bed.
  • FlG. 2 is a part side elevation of same showing diagrammatically a control circuit therefor.
  • FIG. 3 is a similar view of a further circuit arrangement.
  • FIG. 4 is a similar view incorporating a safety circuit.
  • a levitation air bed A is formed with a plurality of open ended pockets a forming a mattress extending from both sides of the bed frame to meet on the longitudinal centre line of the bed.
  • Air is supplied from a duct A to an annular chamber formed as an envelope a surrounding the pockets a.
  • the air passes into the pockets a the outer ends of which are connected to the envelope.
  • the air inflates the pockets a on each side of the bed and as each pocket is inflated it is forced against its neighbour and also meets the opposite pocket along the central longitudinal axis of the bed.
  • a control of the air supply is provided to compensate for excessive escape of air from the pockets and the subsequent loss of levitation pressure when the movement of a patient on the bed upsets the equilibrium of airpressure in the pockets.
  • Compressedair at a reference pressure of 20 p.s.i. is fed direct to a receiver 4 and also indirectly to the receiver through a restrictor valve 6 and a gradual switch.
  • Compressed air from the restrictor valve 6 is connected to a differential static" pressure transmitter 5 which senses the change in air pressure in the duct througha small bo're 'pipeTconnectedto a static tapping 8.
  • the air support or levitation bed is supplied with sterile condi- "tioned air froma remote air feed system.
  • the air pressure at the 'bed is adjusted according to the "weight of v the patient.
  • the correct air pressure for the weight of the' patient is selected by a variable control valve 9 which; allows the transmitter 5 to leak-off compressed airlfromitherestrictor valve 6 which in turn, reduces the compressed air feedback to the receiver.
  • the receiver 4 automatically adjusts the correct compressed air pressure to feed the cylinder 2 andthis moves the damper 1 to the correct position to maintain a constant air' pressure at the bed. Any drop in air pressure at the bed, due to the movement of the patient, will immediately be sensed by the static air pressure tapping 7 and conveyed to the transmitter 5 which leaks off more compressed air from the restric tor valve 6 which then reduces the compressed air pressure feed back to the receiver 4.
  • the receiver 4 automatically reduces the compressed 'air feed to the cylinder 2 which in turn opensjtlie -damper 1 and allows more air tothe bed,
  • a variable control feeds compressed air at a :maximum pressure of 20 p.s.i. through s solenoid valve 10 to the cylinder 2.
  • a single phase electrical supply is connected to terminals which in turn feed the solenoid valve 10.
  • the neutral line is connected direct to the solenoid valve 10 and the line supply passes through a normally closed microswitch 11 inside an air pressure switch 12 before being connected to the normally closed solenoid valve.
  • the air pressure switch 12 is connected by a small bore pipe 13 to the static pressure tapping 8. A fall in pressure in the supply duct A is sensed. by the pressure switch through the tapping 8 which opens the micro-switch 11 to cut off the electrical supply to the solenoid valve 10 and opens the valve. This sequence allows compressed air to escape from the cylinder 2 which opens the damper 1 or valve.
  • the air support system of the bed is supplied with sterile conditioned air from a remote air plant.
  • the air pressure at the bed is adjusted according to the weight of the patient and may vary from 6 inches to 15 inches water gauge.
  • the correct air pressure for the patients weight is selected with the variable control which allows the correct pressure of compressed air to be fed to the cylinder 2 which in turn, adjusts the damper l to the correct levitating position.
  • the compensating air pressure switch 12 is pre-set to operate at an air pressure below the normal operating range required for levitating the patient. If the patient moves excessively, when in a state of levitation, then this allows more air to escape past the patient and hence the pressure in the bed is lowered and the patient begins to sink into the bed until the pressure in the bed reaches the fixed setting of the air pressure switch. This immediately breaks.
  • the micro-switch ll inside the pressure switch and opens the solenoid l releasing the compressed air in the cylinder 2 which in turn, opens the damper l to admit full air to the bed. This gives maximum pressure in the bed and automatically raises the patient to the original setting of the variable control.
  • the pressure switch 12 will close the micro-switch 11 as the pressure in the bed increases past the fixed setting thus reestablishing a state of equilibrium.
  • a safety feature is incorporated to prevent the patient from falling to the bottom of the bed if the pneumatic compensating mechanism acts too slowly to withstand a sudden violent movement.
  • An electric pressure switch 15 and a solenoid valve 16 are provided, the pressure switch having an adjustable range and is set at a pressure below that required to levitate the patient. If the patient reacts violently and the pneumatic system does not compensate in time, then the electric pressure switch 15 immediately detects the drop in pressure and immediately energises the solenoid valve 10, which in turn, evacuates the damper control cylinder 2 and allows full air volume onto the bed. This reaction lifts the patient to the top of the bed and allows the pneumatic system to take over the nonnal levitating pressure control function.
  • a levitation bed of the type having a pressurized chamber the outlet of which is formed by a plurality of inflatable pockets arranged as a mattress for underlying a patient, means for supplying air under pressure to said chamber and pockets whereby the weight of a patient on the bed may cause escape of pressurized air to establish and maintain in equilibrium a supporting air cushion between the upper surfaces of the pockets and the body of the patient, means including valve means for controlling said supply air pressure,
  • valve means comprises a valve element movablein a supply duct and connected to be operated by a fluid pressure motor, and means is provided for sensing the pressure in said supply duct downstream of said element, correlating it with a reference pressure and applying a resultant control pressure to said motor.

Landscapes

  • Health & Medical Sciences (AREA)
  • Nursing (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Invalid Beds And Related Equipment (AREA)
  • Nozzles (AREA)
  • Mattresses And Other Support Structures For Chairs And Beds (AREA)
  • Dry Formation Of Fiberboard And The Like (AREA)
  • Laminated Bodies (AREA)
US454286A 1973-04-19 1974-03-25 Levitation beds Expired - Lifetime US3913156A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1913173 1973-04-19

Publications (1)

Publication Number Publication Date
US3913156A true US3913156A (en) 1975-10-21

Family

ID=10124275

Family Applications (1)

Application Number Title Priority Date Filing Date
US454286A Expired - Lifetime US3913156A (en) 1973-04-19 1974-03-25 Levitation beds

Country Status (8)

Country Link
US (1) US3913156A (enrdf_load_stackoverflow)
JP (2) JPS50129672U (enrdf_load_stackoverflow)
AU (1) AU6761274A (enrdf_load_stackoverflow)
BR (1) BR7403034D0 (enrdf_load_stackoverflow)
DE (1) DE2416479A1 (enrdf_load_stackoverflow)
FR (1) FR2226152B1 (enrdf_load_stackoverflow)
IT (1) IT1004469B (enrdf_load_stackoverflow)
SE (1) SE387238B (enrdf_load_stackoverflow)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0168213A3 (en) * 1984-07-10 1987-07-15 Talley Medical Equipment Ltd. Control systems for air pads or mattresses
US5235713A (en) * 1990-11-06 1993-08-17 Bio Clinic Corporation Fluid filled flotation mattress
US9267102B2 (en) * 2013-03-15 2016-02-23 James D. Osterloh Algae pond circulation

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57142656A (en) * 1981-02-27 1982-09-03 Minolta Camera Co Ltd Paper feed controller of apparatus provided with manual insertion paper feed mechanism
JPS5725812A (en) * 1980-07-25 1982-02-10 Aisin Seiki Air lamber support
JPS61146256A (ja) * 1984-12-19 1986-07-03 富士電機株式会社 流動ベツドシステム

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3340551A (en) * 1965-04-27 1967-09-12 Nat Res Dev Apparatus for supporting a body on a gaseous cushion
US3822425A (en) * 1971-07-09 1974-07-09 J Scales Inflatable support appliance

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4830587A (enrdf_load_stackoverflow) * 1971-08-20 1973-04-21

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3340551A (en) * 1965-04-27 1967-09-12 Nat Res Dev Apparatus for supporting a body on a gaseous cushion
US3822425A (en) * 1971-07-09 1974-07-09 J Scales Inflatable support appliance

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0168213A3 (en) * 1984-07-10 1987-07-15 Talley Medical Equipment Ltd. Control systems for air pads or mattresses
US5235713A (en) * 1990-11-06 1993-08-17 Bio Clinic Corporation Fluid filled flotation mattress
US9267102B2 (en) * 2013-03-15 2016-02-23 James D. Osterloh Algae pond circulation

Also Published As

Publication number Publication date
IT1004469B (it) 1976-07-10
AU6761274A (en) 1975-10-09
BR7403034D0 (pt) 1974-11-19
JPS5434726Y2 (enrdf_load_stackoverflow) 1979-10-23
JPS50129672U (enrdf_load_stackoverflow) 1975-10-24
SE387238B (sv) 1976-09-06
DE2416479A1 (de) 1974-11-14
FR2226152B1 (enrdf_load_stackoverflow) 1977-03-04
JPS501209U (enrdf_load_stackoverflow) 1975-01-08
FR2226152A1 (enrdf_load_stackoverflow) 1974-11-15

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Legal Events

Date Code Title Description
AS Assignment

Owner name: HOWORTH AIRTECH LIMITED, ENGLAND

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:HOWORTH AIR ENGINEERING LIMITED;REEL/FRAME:005302/0512

Effective date: 19890925