1. Field of the Invention
The subject invention relates to devices used to analyze and/or monitor the characteristics of fluids, including fluid mixtures. More particularly, the present invention relates to analyzing and/or monitoring over an extended period of time the characteristics of fluids located in places that are difficult to access. The invention has wide applicability ranging from industrial processes to monitoring the health of animals including, for example, ruminating animals such as cows and buffaloes.
2. Description of the Prior Art
A health and productivity monitoring rumen bolus is an electronic device inserted into the rumen or reticulum of a ruminant animal to monitor one or more physiological or physical parameters to detect subclinical symptoms of disease, evaluate production efficiency and provide a unique means of identification. Herein, the term rumen shall include the reticulum even if not specifically noted. They are often called intra-rumen bolus sensors and there are several versions of these types of sensing devices in existence. Most of the existing devices incorporate multiple sensors while some only provide a means of animal serialization. Some devices utilize a single sensor to provide limited information on the animal's well-being. In some versions, the sensors are disposed outside the bolus.
The U.N. estimates that food production must double by 2050 to feed the world's increasing population. 70% of this new demand must be produced on the industry's current land footprint, meaning that technology is needed to improve production efficiencies on dairy and beef operations. According to industry and USDA data, 40% of dairy production cows get sick (morbidity) and 8% die (mortality) each year while 20% of feedlot cows get sick and 3% die. Last year four million animals died in the U.S., with many more getting sick. The economic impact from these production inefficiencies far exceeds $5 billion each year in the U.S. alone from lost revenue, unrewarded expenses, feed costs, treatment costs and rendering fees.
These high morbidity and mortality rates for both dairy and beef production have been consistent for over a decade and experts argue that these percentages are rising as genetics breed higher producing but more disease-prone animals. The cause for these production inefficiencies stems from how dairy and feedlot productivity and health is managed. Animals are observed a couple times each day for thirty minutes or so to isolate animals showing physical symptoms of depression. At this point in an illness's progression, an animal is ‘clinical’ and very difficult to treat to achieve full recovery. For infectious diseases like Bovine Respiratory Disease (BRD), which is the top cause of death on feedlots today, any clinical animal showing observable, physical symptoms has already infected up to 40 of its herd mates, which, in turn, continue to infect others. This human labor-dependent, infrequent observation approach fails to catch issues in the subclinical stage where they can be more effectively managed and treated. This industry-wide practice of subjective, infrequent herd observation to monitor health and productivity is the fundamental cause for the industry's consistently high mortality and morbidity rates.
Intra-rumen health monitoring devices capture and make usable an animal's sub-clinical physiological, health and metabolic information, offering dairy farmers and feedlot operators an earlier and more frequent means of collecting information that is beneficial in optimizing their operations and is also noninvasive to the animal. This information also enables regulatory agencies to make timely, quality decisions and take regulatory actions to ensure proper regulatory compliance, monitor changes in feed and feed additives, minimize the transmission of zoonotic diseases, and increase the efficiency of production of animal-derived food.
These devices provide information on various health and metabolic parameters and the influence of changes to feed and feed additives on these parameters. In addition, they facilitate the generation of unique animal identification, enhancing biosecurity by creating a tamper proof, unalterable serialization that facilitates tracking animals throughout the production process. This capability can significantly aid in early detection of zoonotic diseases, such as Listeriosis and Salmonellosis. Some of these existing devices also provide the tools for detecting food-borne pathogens such as Leptospirosis and Brucellosis, which show no clinical signs except late term abortion.
Current intra-rumen analysis/monitoring devices utilize an outer shell, which houses and seals in the discrete sensor or sensors and electronics. This device design results in a product that cannot be tested until after final assembly when significant value has been added to the unit. This approach also leads to higher in-field failures since the seal is not always perfect and a leak in the housing destroys the entire sensor/electronics assembly. It also limits recycling and refurbishment since the methods used to establish a liquid-tight seal complicate the disassembly of the device. The combination of these challenges in current devices results in a high cost product with limited capabilities and, often times, high in-field failure rates.
The configuration and technology that facilitates the use of intra-rumen devices lends itself to remote monitoring of any fluid in a confined space where the fluid is difficult to access. The design of such devices allows for the placement in various environments with minimal impact to the environment. The wireless transmission and long battery life make it ideal for monitoring changes in fluid properties for extended periods with minimal maintenance. Unfortunately, the existing devices available to analyze and/or monitor fluids under a range of difficult-to-access locations have limitations that make them unreliable enough and costly enough to restrict their widespread acceptance.
The present invention solves the problems associated with existing devices used to analyze and/or monitor the characteristics of fluids located in confined spaces. The invention has wide applicability ranging from industrial processes to monitoring the health of animals including, for example, ruminating animals such as cows and buffaloes. The invention is a device and related method for most any desired analysis of monitoring of the characteristics of a fluid using at least ultrasonic spectroscopy. The invention provides a cheaper, more practical way of monitoring the composition of fluids in a variety of industries including, but not limited to, production and other animal health, waste water treatment, industrial processes, enhanced oil recovery, hydraulic fracturing, also referred to as “fracking.” The device includes a sensor that can be positioned into a container of fluid. It facilitates a process for gathering information on the contents of the container. In one embodiment, the invention may be used for monitoring bodies of fluid remotely for salinity, CO2 content, acidity/alkalinity, and other characteristics that may be of interest. In the production animal industry, the device can be used to monitor the health and metabolism of ruminant animals such as cows and buffalos. While this disclosure describes that particular functionality, it is to be understood that it is not limited thereto.
The device of the present invention includes, in an embodiment suitable for monitoring the health of a ruminating animal, a bolus that utilizes a sensor, typically a piezoelectric material, to measure physiological parameters such as temperature, the pH of the rumen fluid, the concentration of constituents of the rumen fluid, heart rate, breathing rate, activity level, and the like. The bolus includes a sensor module, a fluid analysis module, a fluid pumping module and a control and data transmission module. Each module may be fabricated, sealed, and tested separately and then assembled into a final liquid-tight configuration. The modules and their components interact electrically with each other using an interconnect system that isolates the electrical signals from the fluid under analysis/monitoring. This bolus configuration allows for the recycling and refurbishment of the individual modules after use if that is of interest to a user.
A version of the sensor module includes a transducer formed of or including a piezoelectric material. The transducer may be used passively to convert acoustic information, including sounds within the animal, into an electrical signal. These signals are used to evaluate the general health and behavior of the animal. The transducer may also be used actively to generate an acoustic pulse, which may be used to measure rumen fluid pH, concentration of rumen fluid constituents, and rumen fluid temperature. The transducer may also include one or more layers of acoustic modification, which may be positioned near the piezoelectric material to reduce interface reflections at the piezoelectric material. One such layer may also or alternatively be shaped and used to act as a lens to shape the generated acoustic pulse and increase the sensitivity of the transducer. The piezoelectric material may also or alternatively be shaped and used to act as a lens to shape the generated acoustic pulse and increase the sensitivity of the transducer. The sensor module is liquid tight with two leads extending beyond the sealed module for connection with the fluid analysis module.
In one embodiment, the fluid analysis module admits fluid (a body fluid in the case of the device's use in monitoring animal health) into a chamber thereof in order to determine the temperature, pH level, concentration of fluid constituents, and other fluid properties. It is noted that in other embodiments, the fluid analysis module could admit water, wastewater, industrial fluids or any other fluid of interest that is difficult to access. The fluid analysis module may house a liquid-tight interconnect configuration that allows electrical communication between the sensor module and the control and data transmission module. The interconnect scheme facilitates high-volume, low-cost manufacturing methods. The chamber may also include a material with an acoustic impedance characteristic that is mismatched with respect to the acoustic impedance of the fluid under analysis, creating a reflective surface spaced from the transducer.
In one embodiment, the fluid pumping module may be configured to generate fluid flow into and out of the module and to remove any trapped gas that might negatively impact fluid analysis. It also may house a magnet that can be used to generate power and a spring or similar element to generate axial motion as a function of compression and extension of the spring.
The control and data transmission module, in one embodiment, includes three discrete sub modules: a power cell, a data processing and control sub-module, and a data transmission sub-module that, when assembled, establish a functional sub-element of the bolus. The sub modules of the control and data transmission module may be sealed to reduce fluid contact with its electrical components. The module has two electrical leads protruding from a liquid-tight assembly housing, which connects to an interconnector of the fluid analysis chamber, thereby enabling interaction with the sensor module without electronics degradation due to fluid exposure.
In one embodiment, the power cell sub module powers components of the control and data transmission module as well as the sensor module. In one embodiment of the control and data transmission module, a charging circuit of the data processing and control sub module stores voltage generated by the transducer of the sensor module in response to vibrations received by the transducer or as a result of the electric fields induced by the motion of the magnets on the fluid pumping module. The charging circuit is configured to supply this transducer-generated voltage to the power source to extend the life of the power cell and reduce the size and cost of this component.
In an embodiment of the control and data transmission module, the data processing and control sub module is configured to conduct on-board diagnosis of the subject animal. In this embodiment, the control sub module is configured to activate the transducer to provide a signal through the body fluid and to receive a signal generated by the transducer in response to vibrations. A microprocessor of the control sub module can be configured to measure the temperature of the module and thus the temperature of the subject animal under evaluation. Alternatively, a discrete temperature sensor, such as a thermistor, may be used with associated signal conditioning electronics, or an integrated circuit configured to measure temperature directly may be used to transmit signals to the microprocessor indicative of temperature characteristics.
In an embodiment of the control and data transmission module, the data processing and control sub module is configured to utilize the received signal from the pulse generated by the transducer to determine the concentration of constituents in, and/or the density of, the rumen fluid. This information allows for the calculation of the pH of the rumen fluid as well as the detection of increases in concentration of the constituents. It is noted that in other embodiments, the data processing and control sub module is configured to utilize the received signal from the generated pulse to determine the concentration of the various constituents and the density of other types of fluids including, for example, water, wastewater, industrial fluids or any other fluid used in a variety of industries, e.g., waste water treatment, industrial processes, enhanced oil recovery and hydraulic fracturing, but not limited thereto. The device may rely on calibration curves or various analytical, numerical or statistical models for predicting pH for determining the various constituents. Such information may be stored on the bolus or accessed in a location remote from the bolus.
The data transmission sub module optionally includes a transceiver that transmits data and stores in memory data and/or commands received from an external source. The data transmission sub module accomplishes signal exchanges with external mechanisms with an antenna that may be internal or external to the bolus.
In an embodiment of the invention, the bolus, through the data transmission sub module, transmits data to a retransmitting module of the invention located external to the bolus, which, in turn, transmits the data to a base station for further analysis on-site or remotely. The retransmitting module may be stationary or traverse an area in which the animals are contained. In the embodiment where the retransmitting module traverses the containment area, this may be accomplished via a wheeled or tracked or otherwise mobile platform. In this embodiment, the retransmitting module may be configured to, or be located in a device, such as a robotic device, that is configured to travel along one or more fixed paths that may be established by wires or tracks according to preprogrammed algorithms for speed, coverage, obstacle avoidance, etc. In this way, the retransmitting module and base station system utilizes fewer modules or base stations because they are mobile, covering more area than if they were stationary. In one embodiment, the retransmitting module or the base station may be powered via solar panels, one or more wind turbines, or other means of renewable energy.
Aside from the preferred embodiment or embodiments disclosed below, this invention is capable of other embodiments and of being practiced or being carried out in various ways. Thus, it is to be understood that the invention is not limited in its application to the details of construction, the analysis methods, and the arrangements of components set forth in the following description or illustrated in the drawings. If only one embodiment is described herein, the claims hereof are not to be limited to that embodiment. Moreover, the claims hereof are not to be read restrictively unless there is clear and convincing evidence manifesting a certain exclusion, restriction, or disclaimer.
The bolus 10 in
The sensor module 11 and the control and data transmission module 18 are sealed to prevent entry of the rumen fluid therein and are fitted with mechanical interfaces (e.g., threads, snap fits, etc.) to facilitate assembly and integration with each other using high volume, low cost manufacturing methods. The sensor module 11 and the control and data transmission module 18 are connected electrically through an interconnect method contained in the fluid analysis module 15 discussed below.
The fluid analysis module 15 and the fluid pumping module 19 work in concert to prevent entry of particulate matter via mesh screens (not shown) located at a plurality of fluid entry ports 12a and 12b in to the module 15, transport fluid in and out of the module 15, and provide a substrate for magnets shown in
As shown in
The spring 23 of the pumping module 19 rests against a mechanical stop 28 located on the base of the fluid analysis module 15. The mechanical stop 28 also prevents the fluid analysis module 15 from sliding past the fluid pumping module 19 by impacting 24 located at the top of 19. The spring 23 functions to extend the fluid analysis module 15 when it is compressed due to naturally occurring rumen contractions and motion. The magnets 22a-22d function to: a) capture stray metal ingested by the animal; b) act as a counter weight to facilitate motion of the pumping module 19; and c) generate additional power by interacting with components in the control and data transmission module 18 to harvest the current induced by the axial motion of the magnets 22a-22d.
The fluid analysis module 15 can be made of plastic or other suitable material. The fluid analysis module 15 has mechanical features that allow for the location and attachment of 25a, 25b 25c, and 25d of the sensor module 11 and the control and data transmission module 18 as well as a mechanical feature 28 that acts as a stop for the spring 23 located in the pumping module 19. The fluid analysis module 15 also contains the electrical interconnects that electrically connect the sensor module 11 and the control and data transmission module 18 to each other, while providing a liquid tight seal around the electrical conductors. That interconnection arrangement is described more fully with respect to
The sensor module housing 32 has features 39a and 39b to facilitate the alignment and positioning of the piezoelectric element 31 allowing for consistent placement of the piezoelectric element 31 radially and axially in the bolus 10. This enables automated electrical attachment (e.g. soldering, conductive adhesive, thin non-conductive bonding, etc.) to the piezoelectric element 31 and high volume, low cost manufacturing (e.g. pick and place, etc.). Passing through the length of the housing 32 are two electrical conductors 35a and 35b, which may be molded in place or inserted after fabrication of the housing 32. These conductors 35a and 35b protrude out of a base 39a and a top 39b of the housing 32. The conductor 35a/35b that protrudes through the top 39a can be attached as previously described to the piezoelectric element 31. The connections can be made on the same face of the piezoelectric element 31 when the conductors 35a/35b are positioned to allow for same side attachment (i.e., the conductors 35a/35b are isolated). In instances where the conductors 35a/35b are configured for opposite side attachment, an additional feature such as a through hole is added to allow addressing of the interior one of the two conductors 35a/35b when soldering is used. This feature may be back filled to ensure a liquid tight seal. In instances where conductive adhesives are utilized, no such sealing feature may be required.
The sensor module housing 32 also includes assembly features 37a and 37b (e.g., threads, snap fits, etc.) which mate with the fluid analysis module 15 to create a liquid tight seal. These features also provide alignment between matting interconnect elements in the sensor module 11 and the fluid analysis chamber 18. These features allow for automated assembly and electrical attachment processes.
Once the fluid analysis module 15 is sealed, the sensor module 11 and the control and data transmission module 18 can be integrated and joined together using automated manufacturing processes. In the instances when the mechanical alignment elements are threaded elements, the sensor module 11 and control and data transmission module 18 may have a male threading 38-1 with a male snap fit feature 38-2 that allows for locking the modules in place to prevent unthreading. A representation of that is shown in
The piezoelectric element 31 of the sensor module 11 can be used to generate an acoustic pulse, an example form of which is shown in
The fluid analysis module 15 can be produced in two sections and joined in a variety of means or as a single unit. The two sections can be connected in a clam shell configuration that folds together or exist as two discrete sections. The fluid analysis module 15 may have interlocking mechanical features (not shown) that facilitate the alignment and sealing of the housing 71 and may include a secondary sealant to provide a liquid tight seal.
The fluid analysis module 15 may be cast, molded, machined or fabricated in a manner suitable for high volume, low cost manufacturing. The electrical conductors 73a and 73b may be inserted into the housing 71 after fabrication or molded in place by suitable means and then the assembled and sealed to create a liquid tight unit.
Once the fluid analysis module 15 is sealed, the sensor module 11 and the control and data transmission module 18 can be integrated and joined together using automated manufacturing processes. One or more of the joining and/or alignment features, previously described, may be present on each of the modules. This joining of two or more of the modules of the bolus 10 may also be accomplished via the use of a sealing compound. For the mechanical joining configuration, the housing 71 of the fluid analysis module 15 includes a female threading with a female snap feature 72-2 and a recess to accept the male snap fit feature 724 as shown in
The data processing and control sub modules 172 and 173 also include a data analysis sub module 175 responsive to the control circuitry 173 for processing data such as comparing measured responses to a stored template derived from the various signals and/or conditioning the data via filtering, smoothing, compressing, and the like to facilitate transmission and reduce upstream processing. Memory 176 may also be provided to store these data, and condition and disease templates or analysis programs as well as a unique identifier (e.g. serial number). Antenna 180 and receiver/transmitter (transceiver) section 181 are used to transmit these data and/or some analysis of it, such as the partial or fully diagnosed condition or disease, as well as, optionally, a unique identifier, to outside of the bolus 10. Transmission will typically use RF frequencies and can also function to receive commands and data to modify the operation of the bolus 10.
The control and data transmission control module 18 further includes charging circuitry 174 that includes a power source 177, such as a battery, a capacitor or a hybrid system, to provide power to a transceiver 181 of the control and data transmission module 18 and the control circuitry 173. In one embodiment of the invention, the charging circuitry 174 is responsive to voltages generated by the transducer element 311 and these voltages are used to charge the power source 177. Voltages are generated by the transducer element 311, for example, in the passive mode, in response to vibrations. The result is that the bolus 10 has an energy harvesting subsystem. The charging circuitry 174 may also contain a coil conductor (not shown) such as copper wire that facilitates the generation of electricity as a result of current generated by linear induction resulting from the motion of the magnets 22a-22d located on the exterior of the pump housing 21.
The control circuitry 173 provides a charge signal, a pulse signal, or it receives a signal from the transducer element 311 when the transducer element 311 is in a passive mode. A pulse signal activates a transmit/receive switch 179, which may be amplified by an amplifier 171 as required, and then activates the transducer element 311 in the active mode to emit an acoustic signal.
Signals detected by the transducer element 311 in the passive mode pass through the transmit/receive switch 179, which determines if the charging circuit 174 is sending an electrical signal to the transducer element 311 or receiving an electrical signal from the transducer element 311. The received signal may be amplified by the amplifier 171 before or after the switch 179. The control circuitry 173 determines, for example, the time it takes for a signal to traverse the fluid in the fluid analysis module 15, reflect off the wall and traverse the fluid in the fluid analysis module 15 again before activating the transducer element 311. The control circuitry 173 may also determine, for example, the signal characteristics after reflection off body tissue or the signal characteristics after received by the transducer element 311 in the passive mode.
The data processing sub module 172 determines the type of data characterized by the signals received from the transducer element 311. The data processing, data analysis and control sub modules 172 and 175, and control circuitry 173, then process the signals to determine temperature, pH level, heart rate, respiration rate, motion, vocalizations, body fat content, digestive activity and the like. Typically, a microprocessor, application specific integrated circuit, controller, or the like is used to implement this functionality, wherein such a processing device implements instructions embodied in computer-executable software or firmware. Data analysis sub module 175 also preferably determines, based on these physiological parameters, one or more possible conditions of the subject and stores data indicating the same in the memory 176. This partially or fully diagnosed data is then transmitted. The data analysis sub module 175 may also send the raw data for independent analysis.
The data analysis sub module 175 then signals the transceiver sub module 181 of the control and data transmission module 18 to transmit this diagnosis via an antenna 180. The antenna 180 may be a separate discrete element or included as part of a signal transmission circuit 181. The data analysis sub module 175 may be configured (e.g. programmed) to activate transceiver 181 to send transmissions only if certain selectable conditions are characterized and then the transmission may occur on a selectable time basis, including ad hoc, sporadically or periodically. A signal receiver spaced away from the bolus 10, such as a base station 186 and/or a retransmitter 185 (discussed below with respect to
The control circuitry 173 is configured to, at predetermined or selectable intervals, or at the direction of the base station 186, pulse the transducer element 311 to generate an acoustic signal for analysis. These intervals, or duty cycles, are based on optimizing the balance between power management and generating enough readings to provide sufficient fidelity to accurately characterize the health of the animal. Adjusting the duty cycle, using either on-board algorithms or by direction from the base station, extends the life of the power cell and allows for more intensive investigation of a particular animal or environment, as required. The received acoustic signal, when converted to an electrical signal by the sensor module 11, may be processed by the bolus 10 or sent to the base station for processing.
The signal including information of interest or to be processed to be transmitted by the bolus 10 may be transmitted by the transceiver 181 either to the retransmitter module 185 or the base station 186 described herein. The transceiver 181 is configured to broadcast a signal to the retransmitter module 185 to determine the readiness of such retransmitter module 185 to accept a subsequent transmission of information including data acquired in the course of processing the fluid. When the retransmitter module 185 is ready, i.e., not communicating with a bolus of a different location and is in range of the bolus 10, it will begin transmission of its data. The bolus 10 is configured to store transmittable data until such time as the transmission is possible; that is, that there exists a suitable recipient of such data including, for example, base station 186 or retransmitter module 185 ready and capable of receiving the transmission.
The interaction between the bolus 10 and the retransmitter module 185 can be used to locate the animal associated with that particular bolus 10 as required. Multiple retransmitters can be used to triangulate the bolus 10. When a disease condition is identified, or when the animal needs to be located or data from it simply gathered, a signal is sent to the bolus 10 to begin transmission of a location signal. This signal may be activated at the base station or locally by an operator communicating with the base station to start transmission. The position of the animal can be determined by measuring either the radial distance, or the direction, of the received signal from the bolus and two or more different retransmitters.
The bolus 10 may also interact with adjacent devices to create an ad hoc network. This network may be used to retransmit data when a particular device is not in range of the retransmitter module 185. The bolus 10 may also interact with other devices to perform analysis such as using the temperature output or other health information from adjacent devices to generate a profile of the herd temperature at a particular location or other health conditions.
The retransmitter module 185 shown in
The retransmitter module 185 will receive the bolus data at a particular frequency, perform preprocessing as required, and transmit the data to the base station 186 at a higher frequency. The bolus 10 may contain memory to store data until such time as it is ready for transmission to the base station 186. Control circuitry and software to perform required data processing and manage transmission of data to the base station, as the base station is available to receive the data.
The retransmitter module 185 may draw power directly from an existing power source such as existing 120V/240V circuits, may utilize a photovoltaic array or wind turbines to charge a battery, or some combination of both. It may also have a backup battery or other uninterruptable power source to continuously supply power to the unit, in the event of a temporary loss of power.
The retransmitter module 185 may be located at a fixed point such as a feed bunk or watering trough or may move in a random or predetermined path. If the device is not at a fixed location, it may continuously charge its power cell, as previously described, or return to a predetermined location to recharge the power cell. A non-stationary device may traverse the area of interest above ground using wires or some other means and may draw power from this means or a wire above, for example. Alternately, it may traverse the area of interest utilizing a mobile platform that has wheels, tracks, or other suitable means of locomotion.
The base station 186 shown in
The health monitoring bolus 10, when installed in the animal, will transmit data to a recipient such as the retransmitter module 185 described herein that may, in turn, transmit the data to a base station such as the base station 186 as described herein. The bolus 10 may process the data and send the final results to the base station 186 via the retransmitter module 185. Alternately, the bolus 10 may send raw signal data for analysis to be performed at the retransmitter module 185 or the base station 186. In this instance the bolus 10 may perform minor preprocessing to prepare the data for transmission to the retransmitter 185 or base station 186.
Also, when the transducer element 311 generates voltages because of the subject's motion, for example, the control circuitry 173 periodically routes this charge signal for charging the power cell 177, which provides power for the various components of the bolus 10.
As part of completing the fabrication of the bolus 10, the sensor module 11 and the control and data transmission module 19 are sealed and tested for mechanical and electrical performance. Units that perform adequately are integrated with the fluid analysis module 15 using high volume, low cost assembly techniques. Upon completion of service, the units can be disassembled, tested, refurbished, sterilized and reintroduced into the manufacturing process.
The proposed assembly methods are facilitated by the use of mechanical features such as the threads, snap fits, mechanical stops, etc., previously described.
Table 1 provides data on the typical concentration of volatile fatty acids in rumen fluid and associated physical properties. These acids are considered weak acids since they partially disassociate in water (eq. 1).
HA+H2OH3O+A− (1)
Several analytical, numerical and statistical methods exist to calculate the pH of mixtures of weak acids and bases. One such equation for calculating the pH of weak acids under specific conditions is shown in equation 2 where pH is the value of the Hydrogen ion concentration and in a mixture of acids the summation of the concentration of the contribution of the individual Hydrogen ion concentrations (equation 3).
Equation 4 represents the generalized solution of equation 2 where F is the concentration and x is the Hydrogen ion concentration. This equation can be rearranged into a second order polynomial and solved using the quadratic equation.
If the concentrations of the individual acids are known, then using tabulated values for acid dissociation constant, Ka (pKa=−log(Ka), the concentration of Hydrogen ions can be determined (equation 5 under specific conditions and in a more general form using equation 4) and used to calculate pH (equation 3).
[H3O+]=√{square root over (Kaca)} (5)
In addition to weak acids, bases in the rumen fluid (e.g., ammonia, bicarbonate bases compounds from saliva, etc.) also contribute to the pH. To calculate the impact on pH of the rumen fluid, a similar method to the above for weak bases can be used. Equation 6 is typically used in the calculation of the pH. In this instance pH=14−pOH.
pOH=−Log10[OH−] (6)
To determine pOH, equation 7 can be used to find the concentration (x) of OH− by rearranging the equation into a second order polynomial and solving the equation using quadratic formula and tabulated values of Kb.
Using the above equations, solving for Hydrogen ions of various constituents the pH can be determined by a variety of analytical, statistical, and numerical models.
The bolus 10 in active mode sends a pulse of a form similar to that shown in
The fluid acts on the pulse to reduce its amplitude and modify its frequency content. Analysis of the spectral content of the frequency both at the principle and higher harmonics of the received signal can be used to determine the concentration of various components of the rumen fluid including VFA content, dissolved gas, proteins, and other relevant constituents.
This process can be repeated for the various constituents of rumen fluid at various temperatures to determine their concentrations. These values can be used directly or in conjunction with various analytical (such as those described above), statistical, and numerical methods to make predictions about the nature of the rumen fluid and ultimately the health and metabolic (production) efficiency of a particular animal or the herd in general.
The speed of sound of most fluids, including rumen fluid, is determined by the temperature, density, and bulk modulus of the fluid. The composite speed of sound is a function of the constituents of the fluids and their relevant physical properties. The relationship between speed (c), density (ρ) and bulk modulus (K) of either a composite fluid or its constituent fluids is represented in equation 8. Density is a function of temperature and impacts the speed of sound accordingly, i.e., increasing temperature equals a decrease in density resulting in a larger speed of sound.
Based on reported values of bulk modulus for water, the primary constituent of rumen fluid, the change in bulk modulus over the expected temperature range of a cow is less than 0.5%. In practice this means that the speed of sound is primarily a function of the change in density of the liquid. This allows one to make predictions on the density of the rumen fluid using a secondary temperature sensor or prediction on the fluid's temperature using the speed of sound. Calibrations curves, similar to the ones described for the spectral method, can be created to characterize the various relationships between speed of sound and the properties of the rumen fluid. This information, when combined with the spectral data, allows a complete in-vivo characterization of the rumen fluid.
The fully analyzed data from a specific individual bolus of an animal under observation as well as from other devices in the herd can be used to diagnose the physiological and metabolic state of the particular animal and of the herd. This can be done via the base station 186 or remotely by a veterinary professional, nutritionist or other qualified party. This form of telemedicine allows analysis of animals and herds in various locations and the compilation of a profile of the health of animals in a multi-feedlot operation or at the national or international level. This information can be used by multiple parties both involved in the care and feeding of animals as well as agencies involved in the regulation of animal welfare and export.
The previously described analysis can be performed at the base station 186 or at a remote location. The data can be stored in physical storage devices or in a cloud based system. Storage on a cloud based system allows for the combination of data from various sets for a comprehensive analysis program as previously described.
The present invention has been described with respect to specific examples and particular usages. It is to be understood that various modifications may be made to the devices and methods described herein without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the claims appended hereto.