BODY PULSATING APPARATUS AND METHOD

A device and method coupled to a therapy garment to apply pressure and repetitive compression forces to a body of a person has a positive air pulse generator and a user programmable time, frequency and pressure controller operable to regulate the duration of operation, frequency of the air pulses and a selected air pressure applied to the body of a person. The air pulse generator has rigid displacers that are angularly moved with crank power transmissions to draw air into the air pulse generator and discharge air pressure pulses to the therapy garment.

FIELD OF THE INVENTION

The invention relates to a medical device operable with a thoracic therapy garment and method to apply repetitive compression forces to the body of a person to aid blood circulation, loosen and eliminate mucus from the lungs and trachea and relieve muscular and nerve tensions.

BACKGROUND OF THE INVENTION

Clearance of mucus from the respiratory tract in healthy individuals is accomplished primarily by the body's normal mucociliary action and cough. Under normal conditions these mechanisms are very efficient. Impairment of the normal mucociliary transport system or hypersecretion of respiratory mucus results in an accumulation of mucus and debris in the lungs and can cause severe medical complications such as hypoxemia, hypercapnia, chronic bronchitis and pneumonia. These complications can result in a diminished quality of life or even become a cause of death. Abnormal respiratory mucus clearance is a manifestation of many medical conditions such as pertussis, cystic fibrosis, atelectasis, bronchiectasis, cavitating lung disease, vitamin A deficiency, chronic obstructive pulmonary disease, asthma, immotile cilia syndrome and neuromuscular conditions. Exposure to cigarette smoke, air pollutants and viral infections also adversely affect mucociliary function. Post surgical patients, paralyzed persons, and newborns with respiratory distress syndrome also exhibit reduced mucociliary transport.

Chest physiotherapy has had a long history of clinical efficacy and is typically a part of standard medical regimens to enhance respiratory mucus transport. Chest physiotherapy can include mechanical manipulation of the chest, postural drainage with vibration, directed cough, active cycle of breathing and autogenic drainage. External manipulation of the chest and respiratory behavioral training are accepted practices. The various methods of chest physiotherapy to enhance mucus clearance are frequently combined for optimal efficacy and are prescriptively individualized for each patient by the attending physician.

Cystic fibrosis (CF) is the most common inherited life-threatening genetic disease among Caucasians. The genetic defect disrupts chloride transfer in and out of cells, causing the normal mucus from the exocrine glands to become very thick and sticky, eventually blocking ducts of the glands in the pancreas, lungs and liver. Disruption of the pancreatic glands prevents secretion of important digestive enzymes and causes intestinal problems that can lead to malnutrition. In addition, the thick mucus accumulates in the lung's respiratory tracts, causing chronic infections, scarring, and decreased vital capacity. Normal coughing is not sufficient to dislodge these mucus deposits. CF usually appears during the first 10 years of life, often in infancy. Until recently, children with CF were not expected to live into their teens. However, with advances in digestive enzyme supplementation, anti-inflammatory therapy, chest physical therapy, and antibiotics, the median life expectancy has increased to 30 years with some patients living into their 50s and beyond. CF is inherited through a recessive gene, meaning that if both parents carry the gene, there is a 25 percent chance that an offspring will have the disease, a 50 percent chance they will be a carrier and a 25 percent chance they will be genetically unaffected. Some individuals who inherit mutated genes from both parents do not develop the disease. The normal progression of CF includes gastrointestinal problems, failure to thrive, repeated and multiple lung infections, and death due to respiratory insufficiency. While some persons experience grave gastrointestinal symptoms, the majority of CF persons (90 percent) ultimately succumb to respiratory problems.

Virtually all persons with cystic fibrosis (CF) require respiratory therapy as a daily part of their care regimen. The buildup of thick, sticky mucus in the lungs clogs airways and traps bacteria, providing an ideal environment for respiratory infections and chronic inflammation. This inflammation causes permanent scarring of the lung tissue, reducing the capacity of the lungs to absorb oxygen and, ultimately, sustain life. Respiratory therapy must be performed, even when the person is feeling well, to prevent infections and maintain vital capacity. Traditionally, care providers perform Chest Physical Therapy (CPT) one to four times per day. CPT consists of a person lying in one of twelve positions while a caregiver “claps” or pounds on the chest and back over each lobe of the lung. To treat all areas of the lung in all twelve positions requires pounding for half to three-quarters of an hour along with inhalation therapy. CPT clears the mucus by shaking loose airway secretions through chest percussions and draining the loosened mucus toward the mouth. Active coughing is required to ultimately remove the loosened mucus. CPT requires the assistance of a caregiver, often a family member but a nurse or respiratory therapist if one is not available. It is a physically exhausting process for both the CF person and the caregiver. Patient and caregiver non-compliance with prescribed protocols is a well-recognized problem that renders this method ineffective. CPT effectiveness is also highly technique sensitive and degrades as the giver becomes tired. The requirement that a second person be available to perform the therapy severely limits the independence of the CF person.

Persons confined to beds and chairs having adverse respiratory conditions, such as CF and airway clearance therapy, are treated with pressure pulsating devices that subject the person's thorax with high frequency pressure pulses to assist the lung breathing functions and blood circulation. The pressure pulsating devices are operatively coupled to thoracic therapy garments adapted to be worn around the person's upper body. In hospital, medical clinic, and home care applications, persons require easy application and low cost disposable thoracic garments connectable to portable air pressure pulsating devices that can be selectively located adjacent the left or right side of the persons.

Artificial pressure pulsating devices for applying and relieving pressure on the thorax of a person have been used to assist in lung breathing functions, and loosening and eliminating mucus from the lungs of CF persons. Subjecting the person's chest and lungs to pressure pulses or vibrations decreases the viscosity of lung and air passage mucus, thereby enhancing fluid mobility and removal from the lungs. An example of a body pulsating method and device disclosed by C. N. Hansen in U.S. Pat. No. 6,547,749, incorporated herein by reference, has a case accommodating an air pressure and pulse generator. A handle pivotally mounted on the case is used as a hand grip to facilitate transport of the generator. The case including the generator must be carried by a person to different locations to provide treatment to individuals in need of respiratory therapy. These devices use vests having air-accommodating bladders that surround the chests of persons. An example of a vest used with a body pulsating device is disclosed by C. N. Hansen and L. I. Helgeson in U.S. Pat. No. 6,676,614. The vest is used with an air pressure and pulse generator. Mechanical mechanisms, such as solenoid or motor-operated air valves, bellows and pistons are disclosed in the prior art to supply air under pressure to diaphragms and bladders in a regular pattern or pulses. Manually operated controls are used to adjust the pressure of the air and air pulse frequency for each person treatment and during the treatment. The bladder worn around the thorax of the CF person repeatedly compresses and releases the thorax at frequencies as high as 25 cycles per second. Each compression produces a rush of air through the lobes of the lungs that shears the secretions from the sides of the airways and propels them toward the mouth where they can be removed by normal coughing. Examples of chest compression medical devices are disclosed in the following U.S. patents.

W. J. Warwick and L. G. Hansen in U.S. Pat. Nos. 4,838,263 and 5,056,505 disclose a chest compression apparatus having a chest vest surrounding a person's chest. A motor-driven rotary valve located in a housing located on a table allows air to flow into the vest and vent air therefrom to apply pressurized pulses to the person's chest. An alternative pulse pumping system has a pair of bellows connected to a crankshaft with rods operated with a dc electric motor. The speed of the motor is regulated with a controller to control the frequency of the pressure pulses applied to the vest. The patient controls the pressure of the air in the vest by opening and closing the end of an air vent tube. The apparatus must be carried by a person to different locations to provide treatment to persons in need of respiratory therapy.

M. Gelfand in U.S. Pat. No. 5,769,800 discloses a vest design for a cardiopulmonary resuscitation system having a pneumatic control unit equipped with wheels to allow the control unit to be moved along a support surface.

N. P. Van Brunt and D. J. Gagne in U.S. Pat. Nos. 5,769,797 and 6,036,662 disclose an oscillatory chest compression device having an air pulse generator including a wall with an air chamber and a diaphragm mounted on the wall and exposed to the air chamber. A rod pivotally connected to the diaphragm and rotatably connected to a crankshaft transmits force to the diaphragm during rotation of the crankshaft. An electric motor drives the crankshaft at selected controlled speeds to regulate the frequency of the air pulses generated by the moving diaphragm. A blower delivers air to the air chamber to maintain a positive pressure above atmospheric pressure of the air in the chamber. Controls for the motors that move the diaphragm and rotate the blower are responsive to the air pressure pulses and pressure of the air in the air chamber. These controls have air pulse and air pressure responsive feedback systems that regulate the operating speeds of the motors to control the pulse frequency and air pressure in the vest. The air pulse generator is a mobile unit having a handle and a pair of wheels.

C. N. Hansen in U.S. Pat. No. 6,547,749 also discloses a body pulsating apparatus having diaphragms operatively connected to a dc motor to generate air pressure pulses directed to a vest that subjects a person's body to high frequency pressure forces. A first manual control operates to control the speed of the motor to regulate the frequency of the air pressure pulses. A second manual control operates an air flow control valve to adjust the pressure of the air directed to the vest thereby regulating the vest pressure on the person's body. An increase or decrease of the speed of the motor changes the frequency of the air pressure pulses and the vest pressure on the person's body. The second manual control must be used by the person or caregiver to adjust the vest pressure to maintain a selected vest pressure.

C. N. Hansen, P. C. Cross and L. H. Helgeson in U.S. Pat. No. 7,537,575 discloses a method and apparatus for applying pressure and high frequency pressure pulses to the upper body of a person. A first user programmable memory controls the time of operation of a motor that operates the apparatus to control the duration of the supply of air under pressure and air pressure pulses to a vest located around the upper body of the person. A second user programmable memory controls the speed of the motor to regulate the frequency of the air pressure pulses directed to the vest. A manual operated air flow control valve adjusts the pressure of air directed to the vest thereby regulating the vest pressure on the person's upper body. An increase or decrease of the speed of the motor changes the frequency of the air pressure pulses and changes the vest pressure on the person's upper body. The manually operated air flow control valve must be used by the person or caregiver to maintain a selected vest pressure. The vest pressure is not programmed to maintain a selected vest air pressure.

N. P. Van Brunt and M. A. Weber in U.S. Pat. No. 7,121,808 discloses a high frequency air pulse generator having an air pulse module with an electric motor. The module includes first and second diaphragm assemblies driven with a crankshaft operatively connected to the electric motor. The air pulse module oscillates the air in a sinusoidal waveform pattern within the air chamber assembly at a selected frequency. A steady state air pressure is established in the air chamber with a blower driven with a separate electric motor. A control board carries electronic circuitry for controlling the operation of the air pulse module. Heat dissipating structure is used to maximize the release of heat from the heat generated by the electronic circuitry and electric motors.

SUMMARY OF THE INVENTION

The invention is a medical device and method to deliver high-frequency thoracic wall oscillations to promote airway clearance and improve bronchial drainage in humans. The primary components of the device include an air pulse generator with user programmable time, frequency and pressure controls, an air inflatable thoracic garment, and a flexible hose coupling the air pulse generator to the thoracic garment for transmitting air pressure and pressure pulses from the air pulse generator to the thoracic garment. The air pulse generator has an air displacer assembly that provides consistent and positive air displacement, air pressure and air flow to the thoracic garment. The air displacer assembly has two rigid one-piece members or displacers that angularly move relative to each other to draw air from an air flow control valve and discharge air pressure pulses at selected frequencies to the thoracic garment. An alternative air displacer assembly has one rigid one-piece displacer that angularly moves to draw air from an air flow control valve and discharge air pressure pulses at selected frequencies to the thoracic garment to subject the thoracic wall of a person to high-frequency oscillations. Diaphragms and elastic members are not used in the air displacer assembly. A power drive system including separate eccentric crankshaft power transmissions angularly move the rigid displacers in opposite directions. These eccentric crankshafts power transmissions are driven by a variable speed electric motor regulated with a programmable controller. The air pulse generator is shown mounted on a portable pedestal having wheels that allow the generator to be moved to different locations to provide therapy treatments to a number of persons. The portable pedestal allows the air pulse generator to be located adjacent opposite sides of a person confined to a bed or chair. The pedestal includes a linear lift that allows the elevation or height of the air pulse generator to be adjusted to accommodate different locations and persons. The thoracic therapy garment has an elongated flexible bladder or air core having one or a plurality of elongated generally parallel chambers for accommodating air. An air inlet connector joined to a lower portion of the air core is releasably coupled to a flexible hose joined to the air pulse outlet of the air pulse generator. The thoracic therapy garment may be reversible with a single air inlet connector that can be accessed from either side of a person's bed or chair. The air pulse generator includes a housing supporting air pulse generator controls for convenient use. The air pulse generator controls include a control panel having user interactive controls for activating an electronic memory program to regulate the time or duration of operation of the air pulse generator, the frequency of the air pulses and the pressure of the air pulses directed to the therapy garment. The pressure of the air established by the air pulse-generator is coordinated with the frequency of the air pulses whereby the air pressure is substantially maintained at a selected pressure when the pulse frequency is changed.

DESCRIPTION OF INVENTION

A human body pulsing apparatus10for applying high frequency pressure pulses to the thoracic wall of a person, shown inFIG. 1, comprises an air pulse generator11having a housing12. A movable pedestal29supports generator11and housing12on a surface, such as a floor. Pedestal29allows respiratory therapists and patient care persons to transport the entire human body pulsating apparatus to different locations accommodating a number of persons in need of respiratory therapy and to storage locations. Air pulse generator11can be separated from pedestal29and used to provide respiratory therapy to portions of a person's body.

Human body pulsing apparatus10is a device used with a thoracic therapy garment30to apply pressure and repetitive high frequencies pressure pulses to a person's thorax to provide secretion and mucus clearance therapy. Respiratory mucus clearance is applicable to many medical conditions, such as pertussis, cystic fibrosis, atelectasis, bronchiectasis, cavitating lung disease, vitamin A deficiency, chronic obstructive pulmonary disease, asthma, and immobile cilia syndrome. Post surgical patients, paralyzed persons, and newborns with respiratory distress syndrome have reduced mucociliary transport. Air pulse generator11through hose61provides high frequency chest wall oscillations or pulses to a person's thorax enhance mucus and airway clearance in a person with reduced mucociliary transport. High frequency pressure pulses subjected to the thorax in addition to providing respiratory therapy to a person's lungs and trachea.

As shown inFIGS. 1 and 4, housing12is a generally rectangular member having a front wall13and side walls26and27joined to a top wall16. An arched member17having a horizontal handle18extended over top wall16is joined to opposite portions of top wall16whereby handle18can be used to manually carry air pulse generator11and facilitate mounting air pulse generator11on pedestal29. A control panel23mounted on top wall16has interactive controls24to program time, frequency and pressure of air directed to the therapy garment30. Other control devices including switches and dials can be used to program time, frequency and pressure of air transmitted to therapy garment30. The controls24are readily accessible by the respiratory therapists and user of pulsing apparatus10.

Private care homes, assisted living facilities and clinics can accommodate a number of persons in different rooms or locations that require respiratory therapy or high frequency chest wall oscillations as medical treatments. Air pulse generator11can be manually moved to required locations and connected with a flexible hose61to a thoracic therapy garment30located around a person's thorax. Air pulse generator11can be selectively located adjacent the left or right side of a person60who may be confined to a bed or chair.

Pedestal29has an upright gas operated piston and cylinder assembly31mounted on a base32having outwardly extended legs33,34,35,36and37. Other types of linear expandable and contractible devices can be used to change the location of generator11. Caster wheels38are pivotally mounted on the outer ends of legs33-37to facilitate movement of body pulsating apparatus10along a support surface. One or more wheels38are provided with releasable brakes to hold apparatus10in a fixed location. An example of a pedestal is disclosed by L. J. Helgeson and Michael W. Larson in U.S. Pat. No. 7,713,219, incorporated herein by reference. Piston and cylinder assembly31is linearly extendable to elevate air pulsator10to a height convenient to the respiratory therapist or user. A gas control valve having a foot operated ring lever39is used to regulate the linear extension of piston and cylinder assembly31and resultant elevation of pulsator10. Air pulse generator11can be located in positions between its up and down positions. Lever39and gas control valve are operative associated with the lower end of piston and cylinder assembly31.

A frame assembly41having parallel horizontal members42and43and a platform44mounts housing12on top of upright piston and cylinder assembly31. The upper member of piston and cylinder assembly31is secured to the middle of platform44. The opposite ends46of platform44are turned down over horizontal members42and43and secured thereto with fasteners48. Upright inverted U-shaped arms51and52joined to opposite ends of horizontal members42and43are located adjacent opposite side walls26and27of housing12. U-shaped handles56and57are joined to and extend outwardly from arms51and52provide hand grips to facilitate manual movement of the air pulse generator11and pedestal29on a floor or carpet. An electrical female receptacle58mounted on side wall27faces the area surrounded by arm51so that arm51protects the male plug (not shown) that fits into receptacle58to provide electric power to air pulse generator11. A tubular air outlet sleeve is mounted on side wall26of housing12. Hose61leading to thoracic therapy garment30telescopes into the sleeve to allow air, air pressure and air pulses to travel through hose61to thoracic therapy garment30to apply pressure and pulses to a person's body.

Thoracic therapy garment30, shown inFIG. 3, is located around the person's thoracic wall69in substantial surface contact with the entire circumference of thoracic wall69. Garment30includes an air core35having one or more enclosed chambers40for accommodating air pulses and air under pressure. The pressure of the air in the chambers retains garment30in flim contact with thoracic wall69. Air core35has a plurality of holes that vent air from chambers40. Thoracic therapy garment30functions to apply repeated high frequency compression or pressure pulses, shown by arrows71and72, to the person's lungs66and67and trachea68. The reaction of lungs66and67and trachea68to the pressure pulses causes repetitive expansion and contraction of the lung tissue resulting in secretions and mucus clearance therapy. The thoracic cavity occupies only the upper part of the thoracic cage which contains lungs66and67, heart62, arteries63and64, and rib cage70. Rib cage70also aids in the distribution of the pressure pulses to lungs66and67and trachea68.

As shown inFIG. 4, air pulse generator11has a case100located within housing12. An electric motor101mounted on case100operates to control the time duration and frequency of the air pulses produced by generator11and directed to garment30. A sensor102, such as a Hall effect sensor, is used to generate a signal representing the rotational speed of motor101. A motor speed control regulator103wired with an electric cable104to motor101controls the operating speed of motor101. An electric power source105wired to motor speed control regulator103supplies electric power to regulator30which controls the electric power to electric motor101. The electric power source can be conventional grid electric power and/or a battery. Other devices can be used to determine the speed of motor101and provide speed data to controller106. A sensor-less commutation control of a 3-phase dc motor can be used to control the rotational speed of motor101. A controller106having user programmable controls with memory components and a look-up data table wired with an electric cable107to motor speed control regulator103controls the time of operation of motor101, the speed of motor101and the pressure of air directed to garment30shown by arrow143. The signal generated by sensor102is transmitted by cable108to controller's look-up data table that coordinates the speed of motor101and resulting frequency of the air pulse with a selected air pressure to maintain a selected air pressure when the speed of motor101and frequency of the air pulses are changed. The look-up table is an array of digital data of the speed of motor101and air pressures created by the air pulse generator predetermined and stored in a static program storage which is initialized by changes in the speed of motor101to provide an output to stepper motor126to regulate air flow control member122to maintain a preset or selected air pressure created by air pulse generator11. The look up table may include identifying algorithms designed to take several data inputs and extrapolate a reasoned response.

Screen24of control panel23may have three user interactive controls109,110and111. Control109is a time or duration of operation of motor101. For example, the time can be selected from 0 to 30 minutes. Control110is a motor speed regulator to control the air pulse frequency for example between 5 and 20 cycles per second or Hz. A change of the air pulse frequency results in either an increase or decrease of the air pressure in garment30. The pressure of the air in garment30is selected with the use of average or bias air pressure control111. The changes of the time, frequency and pressure may be manually altered by applying finger pressure along the controls109,110and111. Control panel may include a start symbol112operable to connect air pulse generator11to an external electric power source. Set and home symbols113and114may be used to embed the selected time, frequency, and pressure in the memory data of controller106. A cable116wires controller106with control panel23. One or more cables117wire control panel23to controller106whereby the time, frequency and pressure signals generated by slider controls109,110and111are transmitted to controller106. Other types of panels and devices, including tactile switches in the form of resistive or capacitive technologies and dials can be used to provide user input to controller106.

The air pressure in garment30is regulated with a first member shown as a proportional air flow control valve118having a variable orifice operable to restrict or choke the flow of air into and out of air pulse generator11. Valve118has a body119having a first passage121to allow air to flow through body119. An air flow control member or restrictor122having an end extended into the first passage regulates the flow of air through passage121into tube131. Body119has a second air bypass passage123that allows a limited amount of air to flow into tube131. The air in passage123bypasses air flow restrictor122whereby a minimum amount of air flows into air pulse generator11so that the minimum therapy treatment will not go down to zero. A filter124connected to the air inlet end of body119filters and allows ambient air to flow into and out of valve118. Air flow restrictor122is regulated with a second member shown as a stepper motor126. Stepper motor126has natural set index points called steps that remain fixed when there is no electric power applied to motor126. Stepper motor126is wired with a cable127to controller106which controls the operation of motor126. An example of a stepper motor controlled metering valve is disclosed by G. Sing and A. J. Horne in U.S. Patent Application Publication No. US 2010/0288364. The stepper motor control is described by L. J. Helgeson and M. W. Larson in U.S. Provisional Patent Application Ser. No. 61/573,238, incorporated herein by reference. Other types of air flow meters having electronic controls, such as a solenoid control valve, a rotatable grooved ball valve or a movable disk valve, can be used to regulate the air flow to air pulse generator11. An orifice member128has a longitudinal passage129located in tube131. Orifice member128limits the maximum air flow into and out of air pulse generator11to prevent excessive air pressure in garment30.

As shown inFIGS. 5 to 9, 11 and 13, air pulse generator housing100has a front wall132and a rear wall133with first pumping chambers137and140between walls132and133. An interior wall134and end wall136attached to opposite ends of walls132and133enclose chambers137and140. As seen inFIG. 14, interior wall134has a plurality of passages138and139to allow air to flow from chamber148into chambers137and140. Wall134can have additional passages, openings or holes to allow air to flow from chamber148into chambers137and140. End wall136has an outwardly projected tubular boss141having a passage142to allow air, shown by arrow143, to flow out of air pulse generator11into hose61and to garment30. The frequency of the air flow pulses is regulated by varying the operating speed of motor101. Air flow control valve118largely regulates the pressure of the air discharged from the air pulse generator11to garment30.

A second housing144joined to adjacent interior wall134accommodates a cover146enclosing a manifold chamber148, shown inFIGS. 9 and 13. A plurality of fasteners147secure housing144and cover146to interior wall134. A tubular connector149mounted on cover146and connected to tube131allows air to flow from air flow restrictor valve118into manifold chamber148. Passages138and139are open to manifold chamber148and pumping chambers137and140to allow air to flow from manifold chamber148into pumping chambers137and140.

As shown inFIGS. 9 and 10, an air displacer assembly151operates to draw air into pumping chambers137and140. Air displacer assembly151has two rigid air displacers152and153operable to swing or pivot between first and second positions to pump and pulse air directed to garment30. The air displacer assembly may be a single displacer operable to pivot between first and second positions to provide air pressure pulses to garment30. The single displacer includes the structures and functions of displacer152angularly moved with power transmission179. The opposite sides of rear section159of displacer152have outwardly extended axles or pins154and156. Pin154is rotatably mounted with a bearing157on end wall136. Pin156is rotatably mounted on interior wall134with a bearing158. A single pivot member may be used to pivotally mount displacer152on housing100. Displacer152is a rigid member that does not change its geometric shape when pivoting about the fixed transverse axis between the open and closed positions, shown inFIGS. 15 and 16. Displacer152has a generally rectangular shape with a transverse rear ridge159and a semi-cylindrical front section161. A generally flat middle section162joins rear ridge159to front section161. The entire outer periphery has a recess or groove165accommodating a seal assembly163. As shown inFIG. 12, groove165has a rectangular shape open to the outer end of outer section161of displacer152. Rear ridge159and middle section162of displacer152each have a groove165for retaining seal assembly163. As shown inFIG. 12, seal assembly163has a rigid component rib164and low density elastic foam component169. Seal assembly163comprises a high density polymer rib164partly located in groove165. The outer surface of rib164is in sliding engagement with the inside surface166of wall134. There is also sliding engagement of rib164with the concave curved inside surfaces167and168of walls132and133, as shown inFIGS. 11 and 14. Returning toFIG. 9, seal assembly163is in sliding engagement with the inside surfaces of walls132,133,134and136. Returning toFIG. 12, the foam component of seal assembly163is a close cell elastomeric foam material spring169located in the base of groove165. The spring169forces rib164into sealing engagement with surface166of wall134. The biasing force of foam material spring169also compensates for structural tolerances and wear of rib164. Other types of seals and spring biasing forces can be used with displacer152to engage walls132,133,134and136.

As shown inFIG. 11, the middle section162of displacer152has a plurality of holes171providing openings that allow air to flow, shown by arrow176, from chamber137to pulsing chamber177located between displacers152and153. A check valve172mounted on middle section162allows air to flow from chamber137to chamber177and prevents the flow of air from chamber177back to chamber137. Check valve172is a one-piece flexible member having a stem173pressed into a hole in middle section162and an annular flexible flange174covering the bottoms of holes171to prevent the flow of air from chamber177back to chamber137when the pressure of the air in chamber177is higher than the air pressure in chambers137,140and148. Other types and locations of check valves can be used to control the flow of air from chambers137and140into chamber148.

As shown inFIGS. 9, 10 and 11, the power drive system includes an anti-backlash device operable without lost motion to angularly move the first and second displacers between first and second positions. The anti-backlash device comprises an arm178located above middle section162of displacer152. A first end of arm178is pivotally connected to a support179with a pivot pin181. Support179is fastened to the rear section159of displacer152. The pivot axis of pin181is parallel with the pivot axis of pins154and156. The second or front end182of arm178extends in a downward direction toward the top of middle section162adjacent the semi-cylindrical section161. Front end182has an upright recess183and a bottom wall184spaced above the top of middle section162of displacer152. An upright bolt186located within recess183and extended through bottom wall184is threaded into a hole188in middle section162of displacer152. A coil spring187located between the head of bolt186and bottom wall184of arm178biases and pivots arm178toward the top of displacer152. Arm178and coil spring187provide crankshaft189with anti-backlash functions and compensate for wear and thermal expansion. Arm178cooperates with a power transmission mechanism179to pivot air displacer152for angular movement between open and closed positions.

Power transmission mechanism189is operatively associated with displacer152and arm178to angularly move displacer152toward and away from displacer153to draw air into chamber137and compress and pulse air in chamber177. Power transmission mechanism is a crankshaft having a shaft191with one end rotatably mounted on end plate136with a bearing192. The opposite end of shaft191is rotatably mounted on interior plate134with a bearing193. Other structures can be used to rotatably mount shaft191on housing walls134and136. Crankshaft includes a crank pin194offset from the axis of rotation of shaft191. A first pair of cylindrical roller members196rotatable mounted on crank pin194engage a first pad197retained in a recess in middle section162of displacer152. A second pair of cylindrical roller members198rotatably mounted on crank pin194engage a second pad199retained in a recess in middle section162of displacer152. Roller members196and198are axially spaced on opposite sides of arm178. As seen inFIG. 10, a roller member201rotatably mounted on the middle of crank pin194engages the bottom surface202of arm178. Roller member201is spaced above the top of displacer152. Rotation of shaft191moves crank pin194in a circular path whereby rollers members196and198angularly moves displacer152downwardly to the closed position and roller member201angularly moves displacer152upwardly to the open position. Spring187maintains arm178in continuous engagement with roller member201and creates reaction forces on pads197and199through roller members196and198thereby eliminating clearance, backlash or lost motion between arm178and roller member201.

Displacer153has the same structure as displacer152. Axles or pins203pivotally mount the rear section of displacer153. The axial axis of pins203is parallel to the axial axis of pins154and156. The entire outer peripheral edges of displacer153has a seal204located in engagement with curved surfaces206and207of housing101as shown inFIGS. 15 and 16and the inside surfaces of plates134and136. Seal204has the same rib and spring as seal163shown inFIG. 12. The middle section of displacer153has holes associated with a check valve208to allow air to flow from chamber140into air pulse chamber177and prevent the air in chamber177from flowing back to chamber140. Check valve208has the same stem and annular flexible flange as check valve172shown inFIG. 11. An arm209pivotally connected to a support211secured to the rear section of displacer153is operatively associated with a power transmission assembly212. Power transmission assembly212operates to angularly move displacer153between closed and open positions as shown inFIGS. 15 and 16. Power transmission assembly212is a crankshaft having a shaft213and roller members214engaging pads216mounted on displacer153. Power transmission assembly212has the same structure as power transmission assembly189. A check valve208mounted on displacer153controls the flow of air form chamber140to chamber142and prevents the flow of air from chamber142back to chamber140. Check valve208has the same structure as check valve172shown inFIG. 11.

As shown inFIGS. 15 and 16, power transmission assemblies189and212are driven in opposite rotational directions with a power train assembly217. Power train assembly217, driven by electric motor101, has a first belt drive comprising a timing pulley218drivably connected to motor101. Timing pulley218accommodates an endless tooth belt219trained around a driven tooth timing pulley221. A second belt drive powered by pulley221rotates a first pulley222connected to shaft191and a second pulley223connected to shaft213in opposite directions as shown by arrows224and226. The second belt drive operates power transmission assemblies189and212to turn their respective crankshafts in opposite rotational directions to concurrently angularly move displacers152and153to open and closed positions shown inFIGS. 15 and 16thereby pulsing air in chamber177. Pulley227driven by pulley221accommodates an endless serpentine double-sided tooth belt228that rides on idler pulleys229and231and trains about opposite arcuate segments of pulleys222and223. The entire power train assembly217is located within chamber148of second housing144. The power train assembly217and power transmission assemblies comprise a power drive system operable to angularly move the air displacers152and153to open and closed positions to cause air to flow from pumping chambers137and140into pulsing chamber177and direct air pressure pulses out of pulsing chamber177into hose61and garment30.

In use, as shown inFIGS. 1 to 3, garment30is placed about the person's upper body or thoracic wall69. The circumferential portion of garment30includes an air core35having one or more internal chambers40that is maintained in a comfortable snug fit on thoracic wall69. The elongated flexible hose61is connected to air core35and air pulse generator11. Operation of air pulse generator11discharges air under pressure and high frequency air pressure pulses into hose61which are transferred to the internal chamber40of air core35. As shown in FIGS.2and3, high frequency pressure pulses72are transmitted from air core35to the person's thoracic wall69thereby subjecting the person's thoracic wall69to respiratory therapy. The person60or a care person sets the time, frequency and pressure controls109,110,111associated with control panel23to program the duration of operation of air pulse generator11, the frequency of the air pressure pulses and the pressure of the air created by air pulse generator11. The time program controls the operation of motor101that operates air displacers152and153. As shown inFIGS. 15 and 16, air displacers152and153angularly pivot relative to each other between open first positions to closed second positions. Air displacers152and153draw air into pumping chambers137and140. The flow of air into pumping chambers137and140is regulated with air flow control valve118. Adjustment of air flow control valve118with stepper motor126controls the pressure of the air discharged by generator11to air core35of garment30. The flow of air into chamber148is limited by air flow orifice member128to control maximum air flow into chamber148and prevents excessive air pressure in garment30. The air in pumping chambers137and140is forced through check valves172and208into pulsing chamber177located between air displacers152and153. Angular movements of air displacers152and153toward each other pulses the air in pulsing chamber177and discharges air and air pulses through air outlet passage142into hose61. Hose61transports air and air pulses to air core35of garment30thereby subjecting the person's thorax to pressure and high frequency pressure pulses.

As shown inFIG. 13, motor101drives power transmission assembly217to rotate crankshafts189and212to concurrently angularly pivot air displacers152and153between open and closed positions. Arms178and208pivotally mounted air displacers152and153cooperate with crankshafts189and212to limit the angular movement of air displacers152and153. The outer ends of arms178and208support coil springs187that provide crankshafts189and212with anti-lash functions and compensate for wear and thermal expansion.

A modification of the air pulse generator300, shown inFIGS. 17 and 18, is operable to establish air pressure and air pulses which are directed by hose61to garment30to apply repetitive forces to the thoracic wall of a person. Air pulse generator300has a housing including end walls301and302. A displacer assembly303located between end walls301and302has a pair of displacers304and306pivotally mounted on end walls301and302for angular movements relative to each other to draw air from a manifold chamber308into air pumping chambers312and313. The air in pumping chambers312and313flows through check valves mounted on displacers304and306into a pulsing chamber315located between displacers304and306. Displacers304and305have the same structure and functions as displacers152and153shown inFIGS. 9, 15 and 16which are incorporated herein by reference. As shown inFIG. 18, displacer304has an axle or pin316retained in a bearing317mounted in a cylindrical boss318joined to end wall302. The opposite side of displacer304has an axle or pin rotatable mounted on end wall301. Displacer316located below displacer304has an axle or pin319retained in a bearing321mounted in a cylindrical boss322joined to end wall302. Displacers304and306angularly move relative to each other about laterally spaced parallel horizontal axes of pins316and319. A housing or casing302joined to end wall307surrounds manifold chamber308. A cover with an air inlet tubular member (not shown) attached to housing307encloses manifold chamber308. End wall302, shown inFIG. 18, has passages or openings309,310and311to air to flow from manifold chamber308into pumping chambers312and313. Crankshafts314and320are power transmission mechanisms that operate to angularly move displacers304and305in opposite arcuate directions to draw air from chamber308through openings309,310and311and into pumping chambers312and313and pulse air in pulsing chamber315whereby air pressure and air pulses are directed by hose61to garment30.

A power transmission assembly323driven with an electric motor324rotates crankshafts314and320whereby the crankshafts concurrently angularly move displacers304and306. Power transmission assembly323has a first power train326driving a second power train327that rotates crankshafts314and320. First power train326has a drive timing pulley328mounted on motor drive shaft329engageable with an endless tooth belt331located around a driven timing pulley332. Pulley332is secured to a shaft333retained in a bearing334mounted on a fixed support336. Support336is attached to housing307with fasteners337and338. Second power train329has a drive timing pulley339mounted on shaft333. A bearing334holds shaft333on support336. Belt341extended around timing pulleys339,342and343rotates pulleys342and343mounted on crankshafts314and320thereby rotating crankshafts314and320and angularly moving displacers304and306relative to each other. The movement of displacers304and306draws air into manifold chamber308and through openings309and311into pumping chambers312and313. When the air pressure in pumping chambers312and313is greater than the air pressure in pulsing chamber315, the air flows through the check valves from pumping chambers312and313into pulsing chamber315. When the displacers304and306move toward each other, air pressure and air pulses are forced into hose61and carried by hose61to the air core35of garment30. The air pressure and air pulses in air core35of garment30subjects the thoracic wall of the person with repetitive forces.

The body pulsing apparatus and method has been described as applicable to persons having cystic fibrosis. The body pulsing apparatus and method is applicable to bronchiectasis persons, post-surgical atelectasis, and stage neuromuscular disease, ventilator dependent patients experiencing frequent pneumonias, and persons with reduced mobility or poor tolerance of Trendelenburg position. Person with secretion clearance problems arising from a broad range of diseases and conditions are candidates for therapy using the body pulsating apparatus and method of the invention.

The body pulsating apparatus and method disclosed herein has one or more angularly movable air displacers and programmed controls for the time, frequency and pressure operation of the air pulse generator and method. It is understood that the body pulsating apparatus and method is not limited to specific materials, construction, arrangements and method of operation as shown and described. Changes in parts, size of parts, materials, arrangement and locations of structures may be made by persons skilled in the art without departing from the invention.