MAMMARY GLAND PUMP SYSTEM WITH NATURAL SUCKLING CYCLE
FIELD OF THE INVENTION
The invention relates generally to mammary gland pumps and more particularly, to an improved mammary gland pump system which provides a natural suckling cycle.
BACKGROUND OF THE INVENTION
Mammary gland pump equipment has long been used for removing milk from the mammary glands of mammals. Devices used for pumping breast milk have featured either an intermittent on/off cycling or a finger control apparatus by which the mother can regulate the suction intervals applied to the breast. In all known units having automated cycling, the units have featured timed on/off cycles by which suction is applied to and released from the breast in a fixed pattern.
The infant mammal suckles in a distinct pattern, consistent among its species. In normal infants, the suckling patterns have been well documented. These patterns have been identified as "non-nutritive" and "nutritive" sucking. In the non-nutritive phase, the baby exhibits fast sucking patterns with very little suction applied to the breast. This "flutter suckling" stimulates the mother's "let-down" reflex, whereby milk is delivered to the nipple area due to the contracting of the milk-making cells located deeper in the breast. As the milk begins to flow freely from the nipple, the baby's sucking patterns change, with stronger suction and compression applied to the breast and slower patterns of sucking which now include enough time to swallow the milk being produced. This "nutritive" suckling is a signal that the breast is producing milk and the baby is, indeed, receiving milk. Since the lactiferous sinuses are full, each suck results in a larger quantity of milk than in the "non-nutritive" sucking stage. The baby continues to suck in this way, slowing down even more when the flow of milk
increases until the nursing session is nearly finished. When the milk in the breast becomes depleted, the baby returns to a faster, non-nutritive suck purportedly to assure complete emptying of the gland and the resulting stimulation needed to produce more milk at the next feeding. The thorough emptying of the breast on a regular, frequent schedule provides the stimulation for the production of a generous supply of milk. Breast milk remaining in the breast after a feeding or pumping is thought to trigger a reduction in milk production and simulates nature during the weaning process when the infant is taking other foods and has a decreased need for breast milk.
SUMMARY OF THE INVENTION The present invention provides a method, apparatus and system for providing mothers with the benefits associated with using a mammary gland pump that has been programmed to produce changing sucking rhythms closely approximating a real baby's nursing patterns during a typical nursing session. These patterns can be preprogrammed or developed by a microprocessor in response to physiological responses to sucking cycles. These patterns, referred to herein as a "natural suckling cycle", are incorporated into a powered microprocessor-controlled mammary gland pump.
In one embodiment, the present invention provides a mammary gland pump having a mammary gland receiving unit with a receptacle end configured to receive a mammary gland of a subject and a coupling end. An electro-mechanical valve is coupled to the coupling end, and is in vacuum communication with a vacuum source. The vacuum source may be a committed wall suction system, an electrically powered suction pump, or a manually operated suction pump. A microprocessor unit is in electrical communication with the electro-mechanical valve or suction system for regulating vacuum pressure, and a receptacle unit is in liquid communication with the mammary gland receiving unit for receiving mammary fluid extracted by variable suction from the mammary gland. The mammary fluid can be milk, colostrum or any fluid which is expressed from the mammary gland. The mammary gland receptacle end can be
configured to fit a human breast, preferably having a funnel-like configuration.
In another embodiment, an optical sensor is present for detecting mammary fluid flow resulting from the suction on the mammary gland. The optical sensor can be used to signal the microprocessor.
An electrical power supply may be present for providing power to the mammary gland suction pump. Such power can be either a DC source or an AC source. In one embodiment the power source is a battery.
Also provided is a computer program residing on the microprocessor to control the vacuum pressure and rate of vacuum at the receptacle end of the mammary gland receiving unit. The computer program causes the electro-mechanical valve or the vacuum pump to begin a first cycle of vacuum pressure comprising a non-nutritive suckling pattern wherein the first cycle is maintained for a period of time sufficient to provide let-down of milk in the mammary gland of the subject. The computer program then changes the pressure by causing the electro-mechanical valve or vacuum pump to change to a second cycle of vacuum pressure comprising a nutritive suckling pattern. This second pattern is maintained for a period of time sufficient to empty the mammary gland.
In another embodiment, the present invention provides a method for obtaining mammary fluid from a mammary gland, comprising, contacting a mammary gland with a suction device providing a first suckling pattern comprising a non-nutritive suckling pattern for a period of time sufficient to provide let-down of the milk in the mammary gland, followed by a second suckling pattern comprising a nutritive suckling pattern for a period of time sufficient to empty the mammary fluid of the mammary gland.
These and many other features and attendant advantages of the present invention will
become better understood by reference to the following detailed description of the invention when taken in conjunction with the Examples.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 shows a diagrammatic representation of one embodiment of the mammary gland pump.
Fig. 2a shows a side view of the mammary gland pump configured for application to a human breast.
Fig. 2b shows a mammary gland receiving unit, including a flange.
Fig. 3 shows a flow chart representing the typical operation of the mammary gland pump.
DETAILED DESCRIPTION OF THE INVENTION
The mammary gland pump system of the present invention facilitates emptying of the mammary gland of a subject utilizing a mammary gland pump which provides cycling rates of suction {i.e., vacuum pressure). The suction can be provided by any number of means for example, a central suction system, a battery-powered suction pump, an electrical-line powered suction pump, and a manually operated suction pump. The invention has applicability to a large number of mammals including humans.
Following parturition, milk is secreted continuously into the alveoli of the breast, but milk does not flow easily from the alveoli into the ductal system and therefore does not continually leak form the breast nipples. Instead, the milk must be ejected, or "let -down", from the alveoli to the ducts before the baby can obtain it. This process is caused by a combined neurogenic and hormonal reflex involving the posterior pituitary hormone oxytocin.
When a baby suckles the mammary gland, sensory impulses are transmitted through somatic nerves from the nipples to the spinal cord and then to the hypothalamus, there causing oxytocin secretion at the same time that they cause prolactin secretion. The
oxytocin is then carried in the blood to the breasts where it causes the myoepithelial cells that surround the outer walls of the alveoli to contract, thereby expressing the milk from the alveoli into the ducts. Thus, within 30 seconds to a minute after a baby begins to suckle the breast, milk begins to flow. This process is called milk ejection, or milk let-down.
Using a microprocessor controlled mammary gland pump of the invention allows a user to select a cycle featuring the necessary programming to cause the mammary gland pump to simulate infant nursing patterns. These nursing patterns include non- nutritive and nutritive cycles. One advantage of using the mammary gland pump of the current invention is the ability to achieve "let-down" in a more natural way. This is because the breast tissue is not being subjected to suction levels and timing that may prove uncomfortable and unnatural prior to achieving let-down as is the case with other mammary gland pumps. Extreme discomfort associated with other mammary gland pumps as a result of the high suction levels and long timing intervals at the start of pumping may be a factor in a mother's inability to "let-down". Another advantage of the invention is that the "let-down" reflex resulting from the natural suckling cycle may be greater. As mentioned above, the let-down reflex is the result of hormonal secretions (e.g., oxytocin) originating form the maternal pituitary gland. The result of pre-pumping (i.e., a non-nutritive cycle) may be an increased amount of hormone released into the mother's blood stream, resulting in a greater number of milk making cells being contracted and a greater amount of breast milk being sent forward to the delivery area of the breast.
The microprocessor can be preprogrammed with sucking cycles which include both an initial "non-nutritive" cycle (i.e., rapidly repeating low vacuum pressure cycles) programmed for a particular time period followed by a "nutritive" cycle {i.e., slowly repeating stronger vacuum pressure cycles) programmed for an additional period of time. Several phases are included in programming of the microprocessor controller, resulting in a variable period of time for the pumping session, preferably a 12-minute
pre-programmed pumping session. For example, the 12 minute session can include a 30 second non-nutritive cycle followed by a nutritive cycle.
Alternatively, the mammary gland pump may have an automated learning processor in which a subject applies the mammary gland pump of the invention and the mammary gland pump cycles both the non-nutritive and nutritive cycles for periods of time to find the optimal period for milk let-down. This heuristically determined period for let-down will be retained by the processor as a "non-nutritive" cycle time, followed by an additional period of time defined as the "nutritive" cycle time.
The let-down period can be detected by an optical sensor in the mammary gland pump which detects increased milk flow from the breast. Upon sensing the increased milk flow, the mammary gland suction pump changes to a nutritive cycle session. The sensor can detect a decrease in milk flow indicating that the mammary gland is empty, at which point the mammary gland suction pump is turned off either manually or automatically. Alternatively, upon detecting decreased milk flow the pump and electro-mechanical valve may revert back to a non-nutritive cycle simulating natural suckling of an infant upon emptying of the mammary gland.
The advantages of a simulated nursing session replicated by a mammary gland pump may include a faster, more comfortable pumping session that results in a greater amount of milk pumped at each session. By closely simulating baby's nursing patterns, the breast is approached and emptied in a more natural response, minimizing trauma to the breast and triggering the secretion of maternal lactation hormones in a manner and at similar levels as are triggered by a nursing baby. This bio-mimicry ensures that mothers who must pump a large percentage of their breast milk (e.g., due to prematurity of their baby or other separation) will produce an ample amount of breast milk to satisfy the needs of the infant. Maternal compliance with pumping schedules may improve with this technology due to the increased comfort, shorter pumping times and greater milk production associated with this natural suckling cycle.
As shown in Fig. 1 and Fig. 2, a mammary gland pump 5 embodied in the present invention includes a vacuum source 20, an electro-mechanical valve 30 in vacuum communication with the vacuum source 20, a mammary gland receiving unit 40 having a first mammary gland receiving end 41, and a coupling end 42 in vacuum communication with the electro-mechanical valve 30, a power supply 45 in electrical communication with the electro-mechanical valve 30 and a microprocessor 50 is in electrical communication with electro-mechanical valve 30. A mammary fluid receptacle 60 is disposed intermediate the electro-mechanical valve 30 and the mammary gland receiving unit 40 for collecting mammary fluid.
The mammary gland receiving end 41 preferably includes a soft mammary gland flange 41a comprising an easily sterilizable, pliable material such as a polyurethane, polypropylene, or other polymer material. The flange 41a reduces pain and provides effective generation of milk and production of prolactin.
The electro-mechanical valve 30 of the present invention is adapted to automatically modulate the application of suction to the mammary gland pump flange, to thereby mimic the suckling intervals of a nursing baby. Milk production is increased or maximized compared to previous systems using vacuum sources as a result of mimicking the natural sucking patterns of an infant. The electro-mechanical valve 30 may be of an analog, rotary, and/or digital-type. Additionally, a tubular protrusion may extend from the electro-mechanical valve 30 to the coupling end 42 of the mammary gland receiving unit 42.
The vacuum source 20 may be a wall vacuum, such as those found in hospitals, diaphragms that can be manually operated or automated, or a vacuum pump, ranging from a small hand size pump to a larger more industrial size vacuum pump. The vacuum source 20 provides a suitable pressure below ambient pressure (e.g., a suction), wherein the pressure is sufficient to cause mammary fluid to be expressed yet not so low as to cause physiological damage to the mammary gland. The suction
is provided at the first mammary gland receiving end 41, the mammary gland receiving unit 40 being in vacuum communication with the vacuum source 20. In one embodiment a vacuum system may be present in a hospital. The electro-mechanical valve 30 can be connected to the central vacuum system, and can remain in place for the duration of the subject or the mother's stay.
The electro-mechanical valve 30 is controlled by a microprocessor 50 which has been programed to modulates the fixed-suction from the central vacuum system to mimic the suckling of a baby. Preferably the electro-mechanical valve 30 modulates the cycle beginning first with a rapidly cycling low vacuum-release cycle (i.e., non- nutritive cycle), and then a longer stronger vacuum period-release cycle (i.e, nutritive cycle).
The electro-mechanical valve 30 can be any regulator or valve capable of automated control by a microprocessor 50. Examples of valves useful in the invention include those disclosed in U.S. Patent Nos. 5,139,226 and 4548,089.
The microprocessor 50 can be any microprocessor capable of controlling an electromechanical valve 30 with respect to pressure and temporal changes in the valve's operation. Such a microprocessor is envisioned to include programmable microprocessors designed to be pre-programmed with instructions for controlling the electro-mechanical valve 30 in a specific manner. For example, such a preprogrammed microprocessor would include instructions for causing the valve to provide a first pressure for a specific period of time followed by a second pressure for a specific period of time. Alternatively, the microprocessor 50 may be a programmable microprocessor with instruction to detect changes in the pressure or flow of air or fluids in response to additional input and to respond accordingly. For example, optical sensors maybe included in an embodiment of the invention to detect changes in mammary fluid flow from the mammary gland. Such sensors would provide signals to the microprocessor 50 to change the vacuum pressure according to
the fluid flow. In another embodiment, user can select the pressure and timing of the valve's operation at the time of use by entering the information on a control panel associated with the mammary gland pump 5 and in operable communication with the microprocessor 50. In another embodiment, the microprocessor 50 may be an application specific integrated circuit (ASIC).
The receptacle unit 60 is in liquid communication with the mammary gland receiving unit 40. During operation the mammary gland pump 5 suctions the mammary gland to elicit mammary fluid. The mammary fluid is then collected into the receptacle unit. The receptacle unit may be proximal and/or fixable associated with the mammary gland receiving unit 40 or may be distal to the mammary gland receiving unit 40. The receptacle may be made out of any material which is capable of holding a fluid (for example, glass and plastic), and should be easily sterilizable.
A power source may be used with the mammary gland pump 5. Such a power source may be either a DC source, AC source, or a modulating source ( . e. , a source which cycles between DC and AC). The power source can be used to power a vacuum pump which in turn provides the vacuum pressure for the mammary gland pump 5. Where the DC source is present the power can be provided by a plurality of batteries, or by an power adapter which plugs into an automobile outlet. Alternatively, it is envisioned the where a wall vacuum is used, the wall vacuum can provide enough energy to power the microprocessor 50 and the electro-mechanical valve 30.
In another embodiment, an optical sensor is used to detect the fluid flow from the mammary gland. The optical sensor may be any type of sensor which detects a change in light transmission. Such sensors are easily identifiable in the art, for example, infrared sensors having long wavelength lights which is detectable at a detector.
With reference to Fig. 3, during operation, the operator begins by applying the
mammary gland receiving end to the mammary gland of the subject. Upon application, the operator may than turn the mammary gland suction pump "on", or alternatively, the pump may be automatically turned on. Once on, the pump will begin by applying a non-nutritive suction cycle to the mammary gland. This non- nutritive cycle may continue for a pre-programmed period of time {e.g., about 15-30 seconds), be manually changed to a different cycle, or be heuristically determined by an optical sensor which can sense milk let down. When any of the foregoing occurs, the pump will change from a non-nutritive cycle to that of a nutritive suction cycle. Similar to the previous cycle the nutritive cycle may continue for a pre-programmed period of time (e.g., about 5-20 minutes), be manually changed to a different cycle, or be heuristically determined by an optical sensor which can sense flow of mammary fluid (i.e., reduce flow). After a preprogrammed time or heuristically detected change in fluid flow, the nutritive cycle of the pump may be manually turned off, automatically turned off, and/or cycled back to the non-nutritive cycle.
During operation, a partial vacuum or suction is provided by the vacuum source 20 through the electro-mechanical valve 30 to the mammary gland receiving unit 40. The mammary gland receiving unit 40 is fit to the mammary gland of the subject using the receptacle end of the mammary gland receiving unit 40 which is configured to the mammary gland of the subject. For example, the receptacle end of the mammary gland receiving unit 40 can be configured for application to any number of mammals, including bovines, primates, and humans. During human use, the receptacle end of the mammary gland receiving unit 40 may be configured in a funnel shape as depicted in Fig. 2. However, additional configurations or additions to the funnel shape are also encompassed by the present invention. For example, the funnel portion or mammary shield may further include a nipple receiving unit centered radially in the shield for receiving the nipple of the mammary gland. In such instances, the vacuum source 20 would preferably be in vacuum communication with the nipple unit.
During operation the microprocessor 50 controls the rate and suction pressure, for
example, by controlling the rate of opening and closing as well as the degree of opening and closing of a valve aperture within the electro-mechanical valve 30. Such control may be elicited by direct analog signaling between the microprocessor unit 50 and the electro-mechanical valve unit 30. The suction is thereby provided through the 5 electro-mechanical valve 30 to the mammary gland receiving unit 40 and provides a suction force upon the mammary gland. The suction force elicits biological responses in the subject causing milk let-down and expression. The expressed milk is then collected into the mammary fluid receptacle 60.
The suction, vacuum or negative pressure can be modulated by a valve to change both
10 the degree and/or force of suction as well as allow for intermittent cycling of the suction between an on-off state. For example, a steady vacuum or suction provided by a vacuum pump to the mammary gland receiving unit 40 may be cycled between an on-off position using an electro-mechanical valve 30, such as electro-mechanical valve 30. The rate at which the valve is cycled between on-off can be any range of
15 speeds from rapid {e.g., 100 cycles/second) to slowly {e.g., 1 cycle/day) and any range therebetween. Furthermore, the degree of suction or vacuum may be altered by a valve, such as electro-mechanical valve 30. The pressure may be negative pressure or positive pressure. The amount of force can be regulated by controlling the degree and period of a valve's occlusion of a port. In this way, an electro-mechanical valve
20 30 in communication with a vacuum source 20 can regulate the rate (i.e., the "on-off period of vacuum or "open-closed" period of vacuum) as well as the amount of vacuum pressure created at the mammary gland receiving end of the mammary gland receiving unit 40. For example, a non-nutritive suckling cycle may be created by a mammary gland pump 5 by effecting the rate of cycling between an on-off
25 configuration in the valve while at the same time limiting the degree of opening of the valve during the on cycle thereby limiting the amount of pressure. Similarly, a nutritive suckling cycle can be created by lengthening the "on" period of the on-off cycle while simultaneously increasing the degree of opening of the valve thereby lengthening the suction cycle and suction force.
In another embodiment, the invention provides a program which is capable of controlling the vacuum pressure of a mammary gland pump 5. Each such program may be implemented in any desired computer language (including machine, assembly, high level procedural, or object oriented programming languages) to communicate with a computer system. In any case, the language may be a compiled or interpreted language.
Each such computer program is preferably stored on a storage media or device {e.g., ROM, CD- ROM, silicon chip, or magnetic or optical media) readable by a general or special purpose programmable computer, for configuring and operating the computer when the storage media or device is read by the computer to perform the procedures described herein. The system may also be considered to be implemented as a computer-readable storage medium, configured with a computer program, where the storage medium so configured causes a computer to operate in a specific and predefined manner to perform the functions described herein.
In the foregoing description, it will be readily appreciated by those skilled in the art that modifications may be made to the invention without departing from the concepts disclosed herein, such modification are to be considered as included in the following claims, unless these claims expressly state otherwise.