Vibrating patient support apparatus with a resonant referencing percussion device

Abstract

A vibrating patient support apparatus has a resonant referencing percussion device preferably located internally to a cover of a mattress of the apparatus. The percussion device delivers a percussion or vibration at a controlled operating frequency that is preferably slightly less than a resonant frequency located internal to the mattress of the apparatus. With the various weight distributions of a patient, the device is capable of determining the ever shifting resonant frequency via control signals received by a controller from a pressure sensor or accelerometer of the device. Because the operating frequency is slightly less than the natural resonating frequency, energy of the system is conserved. Because the operating frequency is not the controller calculated resonant frequency, wear on the device and potential damage is minimized.

Description

CROSS REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of U.S. provisional patent application Ser. No. 60 / 677,728, filed May 4, 2005, the advantages and disclosure of this application is hereby incorporated by reference.FIELD OF THE INVENTION [0002] The present invention relates generally to a patient support apparatus and more particularly to a resonant frequency referencing percussion device of a vibrating patient support apparatus. BACKGROUND OF THE INVENTION [0003] Patient support systems are well known in the art for providing therapy to a patient. A typical patient support apparatus comprises a mattress having a plurality of air bladders for supporting the patient against the bias of gravitational forces, a percussion device that alternates inflation and deflation of air bladders to provide percussion and vibration therapy to the patient, and a rotation device, usually positioned beneath the mattress, to rotate the patient from side to side. Percussi...

AI Technical Summary

Benefits of technology

[0007] A vibrating patient support apparatus has a resonant referencing percussion device preferably located internally to a cover of a mattress of the apparatus. The percussion device delivers a percussion or vibration at a controlled operating frequency that is preferably slightly less than a resonant frequency located internal to the mattress of the apparatus. With the various weight distributions of a patient, the device is capable of determining the ever shifting resonant frequency via signals received by the controller from a pressure sensor or accelerometer of the device. Because the operating frequency is slightly less than the natural resonating frequency, energy of the system is conserved. Because the operating frequency is not the controller calculated resonant frequency, wear on the device and potential damage is minimized.

[0008] Preferably, the patient support apparatus includes a number of other devices for patient comfort and therapeutic treatment substantially located in a manageable and light weight mattress. All the devices are generally light weight with moving parts generally being bladders, thus relatively quiet when operating. For ease of manufacturing and cost, a substantial portion or all of the devices operate off of a common pump for preferably flowing pressurized air to an assortment of bladders. For instance, the percussion device preferably has bladders. Moreover, the apparatus preferably has a bladder operated rotation device for rotating a patient to minimize bed sores, a bladder operated firmness setting device for providing patient comfort, and an air loss control system for flowing air through the mattress to control temperature.

[0009] Objects, features and advantages of the present invention include a patient support apparatus that has a relatively lightweight and manageable mattress having numerous devices for therapeutic treatment. Other advantages of the apparatus include a relatively simple and robust design that is inexpensive to manufacture, reduces wear and warranty costs and reduces energy consumption.

Problems solved by technology

Unfortunately, controllers of known percussion devices do not sense or process displacement amplitude with displacement frequency of the vibrating media of the bladders.

Hence, known percussion devices are not capable of detecting and / or utilizing natural resonant frequencies of the vibrating media.

If the operating vibration frequency of known percussion devices is too distant from the natural resonant frequency, energy is wasted.

If the operating vibration frequency is unintentionally at the natural resonant frequency, then damage or accelerated wear of the patient support apparatus may occur.

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