Patent Application
20130129331
This document concerns an invention relating generally to portable thawing devices, and more specifically to a battery-operated device well suited for heating biochemical products, such as animal semen to be used for artificial insemination.
In farms and laboratories, animals (such as bovines) that have high genetic value (because, for example, they are relatively less prone to disease or have higher milk production) are multiplied through artificial insemination (AI). Semen of high-value male animals is mixed with an extender (such as glycerol) and frozen in semen straws until the semen is to be used to inseminate female animals. Before insemination can occur, the semen is thawed and brought to an appropriate temperature. For bovine insemination, for example, semen is often thawed using a water bath heated to a temperature range of 96 to 98.6 degrees Fahrenheit (35 to 37 degrees Celsius). Because extenders can be toxic to sperm, semen should be used (thus diluting the extender in the cow's uterine tract) within ten to fifteen minutes of being thawed.
Traditional heating devices used to thaw semen straws must be plugged into an external energy source at all times. As the animals to be inseminated are often not located near power outlets, the AI technician generally needs to return to an office with a power outlet to thaw the semen. The AI technician has about ten minutes to use a thawed semen straw, so he or she cannot thaw more than can be used in ten minutes (taking into account the time it takes to travel from the heating device to the animals being inseminated). If three semen straws can be used in 10 minutes, the technician must return to the heating device each time three animals are inseminated. It is common to breed over 100 cows or more each day in dairy herds of the United States. If 100 animals are to be bred in one day, the technician must return to the office over 30 times to thaw semen straws using the traditional heating device.
What is needed is a convenient and easy-to-use portable thawing unit for heating biological fluids and cells, such as semen to be used for artificial insemination of animals.
The invention, which is defined by the claims set forth at the end of this document, is directed to a portable thawing unit that at least partially alleviates the aforementioned problems. A basic understanding of some of the features of preferred versions of the invention can be attained from a review of the following brief summary of the invention, with more details being provided elsewhere in this document. To assist in the reader's understanding, the following review makes reference to the accompanying drawings (which are briefly reviewed in the “Brief Description of the Drawings” section following this Summary section of this document).
Referring initially to
To provide for more efficient heating of the water, a propeller 420 is preferably included to help mix the water and enhance temperature uniformity. A motor unit 410 powered by the battery pack 400 spins the propeller 420 via motor shaft 415. Because the straws 570 are heated when they contact the heated water, the heated water should preferably be able to access the straws 570 from all sides. Accordingly, the straw rack unit 500 prohibits fluid straws 570 inserted into the main casing interior 110 from touching each other, enhancing the efficiency of straw heating. One or more straw rack units 500 allow fluid straws 570 to be lowered into and raised from the main casing interior 110. The straw rack unit 500 allows the fluid straws 570 to be transposable between an upper position (see the rightmost two straws in
The portable thawing unit 10 provides a convenient means of heating biological fluids without being tethered to power outlets. The thawing unit 10 is easy to use, allowing multiple straws 570 to be handled and heated efficiently. Because thawed sperm removed from a hot water bath is prone to cold shock, the thawing unit 10 allows semen straws to be thawed near the animals to be inseminated, minimizing the time the straw spends between thawing and insemination. The propeller 420 keeps water in constant motion for better temperature exchange between the water and fluid straws 570, increasing the thaw rate and likely improving sperm membrane integrity. The thawing unit 10 is easy to clean because it can be readily disassembled from the upper and lower bodies 200, 300. As the viability of the sperm is enhanced at least from decreased cold shock and decreased time spent in undiluted extender, the success rate of the insemination process is enhanced, saving time and lowering costs. Additional advantages and features of the invention will be apparent from the remainder of this document in conjunction with the associated drawings.
Turning initially to the exemplary thawing unit 10 of
Returning to
As show in
The upper body 200 includes three pairs of straw openings 210A (I and II), 210B (III and IV), 210C (V and VI), and three corresponding lever openings 220A, 220B, 220C. Referring also to
A lever 530 having a lever flange 536 is used to transpose the position of the shafts 600, 610 by raising and lowering fluid straws 570 using a “rack-and-pinion” configuration. A gear axle 550 (see
Because the fluid is sealed in the straw 570, the tips of the straws 570 are cut off to access the fluid therein. Referring to
To use the thawing unit 10, the user may begin by securing the lower body 300 to a clean main casing 100 from below. Water is added to the main casing interior 110, and the upper body 200 is secured to the main casing 100 from above. The thawing unit 10 is preferably secured to the user's utility belt 30 (see
A portable cool chest or nitrogen tank (not pictured) is preferably also carried by the user (by, for example, also being secured to the utility belt 30). The cool chest might contain up to 50 straws 570 with frozen bovine semen therein, and allows the user to save trips otherwise required to retrieve frozen straws. When ready to inseminate a female cow, the user removes one of the frozen straws 570 from the cool chest and inserts the straw 570 into one of the unoccupied shafts 600, 610 by inserting one end through one of the straw openings (at one of the straw openings 210A, 210B, 210C) in the upper body 200. Once the inserted straw's bottom end abuts the shaft stop 640, the lever flange 536 can be turned to lower the straw 570 farther into the main casing interior 110. Convection in the heated water acts to thaw the frozen straw 570, with the propeller 420 helping replace colder water adjacent to the straws 570 with hotter water closer to the heating element 440. If several frozen straws 570 are inserted into the thawing unit 10 at once, the temperature of the water might initially drop substantially but rise again as the heating unit 430 reheats the water. The user can monitor the thermometer readout 480 as a guide to gauge the status of the frozen straws 570 being heated. Once a straw 570 has been in the hot water for 30 to 60 seconds, it is placed at the end of an AI gun for inseminating the cow. The cutter unit 700 is used to cut the tip of the straw 570 off so the semen therein can be accessed. If more than one straw 570 is being thawed at the same time, the straws can be removed from thawing unit 10 in turn. A towel dispenser 40 (see
The thawing unit 10 can be made using any suitable materials, such as, for example, neoprene or plastics. The thawing unit 10 preferably insulates heat therein, but is not too hot to the touch on its exterior. The towel dispenser 40 can be made from, for example, canvas or other materials.
It should also be understood that various terms referring to orientation and position are used throughout this document—for example, “above” (as in “secured to the main casing 100 from above”) and “bottom” (as in “the bottom of the main casing 100”)—are relative terms rather than absolute ones. In other words, it should be understood (for example) that the upper body 200 would be brought together with the main casing 100 from below if the main casing 100 is upside-down. Thus, such terms should be regarded as words of convenience, rather than limiting terms.
Also in the following description, it is to be understood that such terms as “forward,” “rearward,” “left,” “right,” “upwardly,” “downwardly,” and the like are words of convenience and are not to be construed as limiting terms.
Various preferred versions of the invention are shown and described above to illustrate different possible features of the invention and the varying ways in which these features may be combined. Apart from combining the different features of the foregoing versions in varying ways, other modifications are also considered to be within the scope of the invention. Following is an exemplary list of such modifications.
First, although the thawing unit is discussed with respect to straws containing semen, the thawing unit can be used to transfer heat to any biological/chemical (for example, embryos) and/or non-biological/chemical (for example, electrical or mechanical components and devices) solids and non-solids. The items to receive heat can be immersed directly into a hot water bath, or housed in one or more enclosures (such as the straws discussed above or other shell-like structures) so as to limit exposure to water and/or exert control over heat transfer dynamics. For example, a double-enclosure structure can be used (with, for example, an air gap between inner and outer enclosures) to not only keep dry the items being heated, but to limit heat shock from more direct contact with hot water.
Second, the various components of the thawing unit 10 can be rearranged as desired. For example, the lower body enclosure 310 might include only the battery pack 400 and recharge plug 490, with the motor and propeller 420 provided within the main casing interior 110. Alternatively, the motor unit 410 and propeller 420 might remain with the main casing 100 (by, for example, extending down from the floor 120), with the motor unit 410 and propeller 420 situated within the lower body enclosure 310 only when the lower body 300 is secured to the main casing 100.
Third, the main casing 100 need not have a floor 120. When the main casing 100 is secured to the lower body 300, the main casing interior 110 could be contiguous with the lower body enclosure 310. The battery pack 400 would preferably be configured to withstand being immersed in heated water for extended periods of time if this configuration is utilized.
Fourth, the number of straw shafts 600, 610 can be adjusted to be higher or lower than the six shown in the figures. Also, rather than two shafts 600, 610, each straw rack unit 500 can be provided with only one shaft, allowing shafts to be individually raised and lowered, or more than two shafts, allowing several shafts to be raised and lowered together. Moreover, the distance between the shafts 600, 610 can be adjusted so that, for example, all the six shafts in the thawing unit 10 are equidistant from each other and/or from the sidewall of the main casing 100.
Fifth, the heating unit 430 need not have a heating regulator 450, such that the heating unit 430 continues to heat the water in the main casing 100 as long as the thawing unit 10 is switched on. With such a thawing unit 10, the user can monitor the temperature of the water using the thermometer readout 480, and turn the thawing unit 10 on or off as needed to maintain the temperature within a desired temperature range. The heating regulator 450 is preferable if no thermometer is provided with the thawing unit 10, as overheating the liquid could damage biological fluids and cells being heated, and would tend to waste battery charge.
The invention is not intended to be limited to the preferred versions of the invention described above, but rather is intended to be limited only by the claims set out below. Thus, the invention encompasses all different versions that fall literally or equivalently within the scope of these claims.
