Mixing device and measurement method of thickened fluids

Abstract

A mixing device for blending and measuring the thickness of fluids comprises a rotational motor with a motor shaft and a blade with a blade shaft. A torque sensor assembly connects the motor shaft to the blade shaft. The mixing motor operates in two modes. In mixing mode, the motor rotates in one direction at a high speed to mix and thicken fluids. In measuring mode, the motor rotates in the opposite direction at a low speed to assess the fluid's thickness. The rotation speed in this mode adapts to the thickness level of the fluid. A lift mechanism adjusts the height of a fluid container, allowing the blade to reach different depths for thorough mixing. Additionally, the device includes a powder container that dispenses a measured amount of thickening powder at the edge of the fluid container in a single release.

Description

[0001] MIXING DEVICE AND MEASUREMENT METHOD OF THICKENED FLUIDS

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a mixing device for the mixing and measurement of the thickness (viscosity) of thickened fluids based on an Internation Dysphagia Diet Standardisation Initiative (IDDSI) framework for viscosity measurement of thickened fluids for consumption by persons with swallowing impairment (Dysphagia). The mixing device with automatic powder dispensing and drink container lift mechanism for homogenize and clump free mixing.

[0004] BACKGROUND

[0005] Dysphagia is a medical condition that often arises as a symptom of many different medical conditions. It refers to swallowing difficulties often because of inappropriate timing, strength or coordination of muscle contraction leading to aspiration into the airway or the accumulation of post-swallow residue. Swallowing impairment (or dysphagia) can develop with age or major illnesses, such as deconditioning after surgery, dementia, stroke, Parkinson's disease, and head and neck cancer.

[0006] Dysphagia has negative effects on health, nutritional status, and quality of life. It also puts patients at risk of developing life-threatening aspiration pneumonia. To overcome the situation, thickened liquids are a widely used intervention, based on the idea that slower flow of these thicker liquids provides the person with ample time in which to achieve airway closure as well as enabling better control of liquid flow by the tongue and other swallowing muscles. Thickeners come in various forms such as powder or liquids and are all used to thicken foods and fluids to various consistencies. Thickeners can help slow the transit of foods and fluids to allow more time to coordinate the swallowing process safely. This prevents the foods and fluids from entering the lungs accidentally with serious consequences resulting in health complications such as chest infections and even resulting in death due to choking or aspiration pneumonia.

[0007] In healthcare institutions and home care for Dysphagia patients, nurses or caregivers thicken drinks manually by mixing in powdered thickener every time drinks or medications are served. This is a labour-intensive process require the manual hand stirring of the drink and thickener combination. Forsome types of beverages, forexample, thicker or milk-based drinks, a longertime is required from a combination of both longer times required to manually stir and remove clumps formed along with longer settling times for the drink to fully thicken.

[0008] DISCUSSION OF PRIOR ART

[0009] The IDDSI framework uses an objective and practical measurement for liquids which could be used in kitchens and bedside as well as laboratories. IDDSI has recommended an IDDSI Flow Test using a standard 10 mL BD syringe or 10mL IDDSI Funnel as the test syringe or funnel. The liquid food which is to be checked for the right consistency has to be loaded into the test syringe or funnel with another syringe. Instead of measuring the time required fora sample to flowthrough the syringe, the IDDSI flow test classifies liquid thickness based on the volume of the residual liquid in the test syringe after a period of 10s flow. These steps for measuring and classifying the thickness of fluids prepared using thickeners are carried out manually. Manual preparation of thickened fluids is therefore time consuming and variable in desired viscosity under IDDSI requirements due to manual measurement.

[0010] One solution is the Imperial Auto-Thick™ System as shown in the website

[0011]

[0012] This system has a dispensing system offering fixed thickened beverages (IDDSI Level 2 or Level 3) stored in a plurality of containers. This system automatically blends thickened water (IDDSI Level 2) and Honey- Thick Water (IDDSI Level 3) with beverage concentrates. As such, the user can only select thickened beverage of either IDDSI Level 2 or IDDSI Level 3. The dispensing system has to be replenished with the thickened beverages (with a number of standard flavours) once the beverages run out. This system uses pre-hydrated thickened bases. Another similar solution is the BigSCatering BevoSanoR&

[0013]

[0014] be vos a no /

[0015] Another approach is using Manual Mixers. Manual mixers, such as U.S. Pat. No. 8540415, normally consisting of a long, uneven sculptured handle attached to a shaft with a unique blade with multiple fins at the end of it. The blade is main component for mixing, with big and small holes punched out in the fins separated from each other at equal distance, allowing for a portion of food to be blended, mixed, stirred or mashed manually. Other types of manual mixers, such as US10368697, is specific for egg mixing and includes a container and a “blade” in the form of a ball using a spring wire. Any assessment of the viscosity of the mixture has to be carried out manually.

[0016] Electrically powered mixers typically use an electric motor to rotate a blade for mixing. U.S. Pat. No. 20150069157A1 presents a mixer with a beverage container assembly on the topand a blade on the base. The container assembly is removably mountable on and off the base.

[0017] Most mixers have only one blade. However, there are designs using more blades, such as electrically powered mixers with two eggbeaters, or a dough hook.

[0018] Currently, however, there exists no manual or electrical mixers capable of preparing thickened fluids and capable of measuring viscosity as a feature, in order to serve a thickened fluid with a specified IDDSI level for dysphagia patients.

[0019] Viscosity can be measured using different ways. Gravimetric capillaries, flow cups, fallingball, rolling-ball are all different types of viscometers that are driven by gravity. Apart from viscometers driven by gravity, there are also pressurized devices using a weight, a motor, or gas pressure to apply a force. The IDDSI framework for drink thickness measurement is using the flow cups method. A benefit to these passive methods of measurement is the ability to measure without using electricity. However, the measuring process is time consuming, and the structure of some devices may be complicated.

[0020] VISCOCITY MEASUREMENT USING IDDSI

[0021] In healthcare institutions and home care for Dysphagia patients, nurses or caregivers thicken drinks manually by mixing in powdered thickener every time drinks or medications are served. The Table below shows a standard for the preparation of thickened fluids involving 4 levels of viscosity (Level 1 to 4) and the corresponding consistency described in words:

[0022]

[0023]

[0024] The amount of thickener required to thicken fluids to one of the desired stages will depend on the type of thickener used. The companies who are manufacturing these thickeners provide specific information to state how much thickener is needed for particular fluids. It is important to not confuse the types of thickeners as starch based and gum-based thickeners are two different products and are not interchangeable. The scoops provided by each manufacturer of these thickeners also vary in size.

[0025] The first type of thickeners is starch based and appropriate to use in catering / food production. In line with the development of standardisation for Dysphagia Diet through IDDSI, thickeners have also evolved over the years and factors such of appearance, ease of mixing, palatability and compliance have resulted in the development of new ranges of thickeners, which are not only safe but delicious. As more people suffer from Dysphagia, more healthcare providers are offering more choices for patients with dysphagia, turning away from traditional thickeners, to include high protein snacks, hydration jellies, puree dishes and other more palatable foods. As such, there is a great need fora mixer capable of preparing thickened fluids and soft foods with the function of accurate measurement of the viscosity of soft foods and drinks to align with the diet requirements of dysphagia patients.

[0026] The measurement of viscosity for the Dysphagia Diet discussed herein includes liquid food and thickened fluids used in Dysphagia Management as defined by the IDDSI framework. Viscosity of the thickened fluids is indicated by Levels, from Level 0 to Level 4.

[0027] PROBLEM TO BE SOLVED BY THE INVENTION

[0028] The Inventors observed that there are mixers for preparation of thickened fluids and liquid foods but healthcare workers would still use manual observation in measurement of viscosity in the preparation of thickeners and Liquid Foods (“thickened fluids”) for Dysphagia Diet.

[0029] In hospitals and hospices, a mechanical mixer with the function of viscosity measurement would expedite the preparation of thickened fluids for a large number of dysphagia patients, and do so accurately in accordance to their IDDSI level. This would lessen the manual work of preparing such fluids as well as take away the guesswork in measuring each batch based on experience and feel of the viscosity of the fluids.

[0030] What is desirable is a mixing and measurement device and a method using the device for preparing and measuring thickened fluids based on IDDSI levels for persons with swallowing impairments. The thickness level measurement is calibrated against the standard introducedby the International Dysphagia Diet Standardisation Initiative (IDDSI) framework, ranging from Level 0 to Level 4. This directly impacts the quality of care that healthcare workers can give to their patients by providing quicker preparation along with more accurate thicknesses for comfortable consumption of drinks. To more accurately measure the thickness of fluids across a range of thickness levels from level 0 (thin) to level 4 (extremely thick), an algorithm has been proposed to allow adapting the rotational speed of the blade according to the thickness of the drink with an inventive mixer.

[0031] SUMMARY OF THE INVENTION

[0032] A main object of the present invention is to provide a device fordrink preparation capable of mixing and measuring thickness of a drink, comprising:

[0033] a) a rotational motor having a motor shaft coupled to a blade shaft via a torque sensor assembly;

[0034] b) a lift mechanism comprising a lift motor attached to a lead screw; and

[0035] c) a lift carriage configured to hold a drink container, wherein:

[0036] the blade rotates bidirectionally to perform both mixing and thickness measurement of the drink,

[0037] the lead screw operates to vertically elevate the lift carriage, and

[0038] the clockwise and / or counterclockwise rotation of the blade provides thorough mixing of the drink while enabling measurement of the drink's thickness.

[0039] A further object of the present invention is to provide a method for mixing and measuring viscosity of thickened fluids, the method comprises:

[0040] (i) attaching a blade to the mixing device and positioning a container containing a fluid; (ii) elevating the container and inserting the blade into the fluid within the container;

[0041] (iii) dispensing a thickening powder from a thickening powder container onto the fluid while rotating the blade at a predetermined speed to facilitate effective mixing;

[0042] (iv) rotating the blade in a clockwise direction to combine the fluid with the thickening powder; (v) vertically displacing the container in an upward and downward motion to ensure thorough mixing of the fluid and thickening powder;(vi) decreasing the rotational speed of the blade and changing the rotation direction from clockwise to counterclockwise;

[0043] (vii) determining the viscosity of the thickened fluid at a predetermined rotational speed; and (viii) dispensing the thickened fluid for consumption.

[0044] Yet still an object of the present invention is to provide a device fordrink preparation, wherein the rotational motor provides an adaptable rotational speed for mixing and measuring of thickness of the drink, and the rotational speed for mixing is in a range of 50 to 2000 rpm in one direction, and in a range of 1 to 200 rpm in another direction for thickness measurement. The rotational speed of the blade is consistent and is used for final measurement of thickness of the drink. The adaptive speed of the blade is used for final measurement of thickness of the drink.

[0045] Still yet another object of the present invention is to provide a device for drink preparation, further comprises a thickening powder dispenser, which is positioned closely to the blade, allowing direct release of thickening power fordrink thickening.

[0046] Still yet another object of the present invention is to provide a device for drink preparation, wherein the container is vertically displaced in an upward or downward direction to enable the blade to traverse the entire depth of the container containing the fluid, thereby ensuring formation of vortices within the fluid in the container.

[0047] This summary introduces, in a simplified form, concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, and is not intended to be used as an aid in determining the scope of the claims. There are 5 key features in this invention:

[0048] 1. Dual-Function Rotational Mechanism:

[0049] A shaft-mounted blade and a motor shaft are coupled via a torque sensor assembly. The mixing and measurement functions operate in opposite rotational directions (clockwise / anti-clockwise).

[0050] A device for drink preparation capable of the dual features of mixing and thickness measurement. The device uses whether different rotational speeds or adaptable rotational speeds for mixing and measuring of thickness of the thickened drink. The rotational speed for mixing would be a range of higher speeds from 50 to 2000 rpm in one direction, while rotational speed for thickness measurement is a range of lower speeds from 1 to 200 rpm in another direction.2. Torque Sensor Assembly for Viscosity Measurement:

[0051] The motor and blade shafts are aligned along the same vertical axis to ensure stable rotation. This torque sensor assembly comprises an upper coupling connected to the motor shaft, and a lower coupling connected to the blade shaft, and the lower coupling has a through hole which allows the blade shaft to attach to a bearing which is attached to the upper coupling. A torsion spring is placed between the upper coupling (connected to the motor shaft) and the lower coupling (connected to the blade shaft). When torque is applied at low speeds, the torsion spring undergoes compression, causing an angle of separation between the motor and blade shafts.

[0052] A reflective optical sensor detects the angle of separation between the upper and lower couplings. This separation angle, generated by the torque applied during in low-speed rotation, determines the thickness (viscosity) of the fluid.

[0053] 3. Adapting Blade Rotation Speed According to Thickness Level for Higher Thickness Measurement Accuracy:

[0054] For a constant blade rotation speed, there is an increasing in torque (or angle of separation between the reflective markers in our case) as the thickness of drink increases. On the contrary, this torque in the lower thickness levels, such as level 0 and level 1 , is much smaller than compare to the thicker drink. This will result in low measurement accuracy in low thickness levels. In this invention, we present an adapting blade rotation speed according to thickness level for higher thickness measurement accuracy.

[0055] 4. Integrated Powder Dispenser for Efficient Mixing:

[0056] The device includes a powder dispenser positioned near the inner surface of the container. During mixing process, blade is rotated in a designed speed first and flow velocity of the drink is rotation accordingly; following, powder dispenser is actuated and release powder. Hence powder is released directly into the high-flow velocity region of the fluid during mixing. In the other hand, the powder dispenser adds any amount ofthickener powder in one go. This reduces the chances for clump formation. As thickener powder is gradually added to the liquid, the viscosity increases and the solubility of the powder decreases. Hence, adding all required volume of powder in one go will allow for the thickener powder to quickly disperse throughout the liquid before the thickening occurs resulting in less clumping of the powder.

[0057] 5. Lift Mechanism for Improved Mixing:A lift motor, connected to a lead screw, adjusts the vertical position of a lift carriage holding the container. This allows for the blade to reach throughout the depth of the cup containing the liquid. High thickness liquids do not easily create vortices, resulting in clumping of the powder. Moving the blade throughout the liquid while mixing creates a three-dimensional mixing profile. This process reduces clumps forming.

[0058] BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The accompanying drawings illustrate one or more embodiments of the invention and together with the description herein, serve to explain the workings and principles of the invention. The diagrams by no means restrict the invention to only what is shown.

[0060] FIG 1(a) is a perspective view of a mixing device of the invention with mixing blade attached and cup loaded to the mixing device in accordance with the present invention.

[0061] FIG 1(b) shows the working principle of the mixing device of the present invention, the mixing device being capable of mixing and measuring a thickened drink or fluid.

[0062] FIG 2(a) depicts a cross-section view of a torque sensor for measuring liquid thickness level. It is constructed with an upper coupling connected to a motor shaft and a lower coupling connected to a blade shaft. A reflective marking on both the upper and lower coupling is used. A reflective optical sensor is used to detect light reflected.

[0063] FIG 2(b) depicts the top-down view of the sensor showing its compact structure and small profile.

[0064] FIG 3(a) is a cross-section view of the torque sensor upper and lower coupling in accordance with the present invention.

[0065] FIG 3(b) is a cross-section view of the torque sensor showing the protrusions that enable the bidirectional control of the sensor. A torsion spring links up the upper and lower coupling.

[0066] FIG 4 illustrates a system with essential components used in the torque detection sensor for drink thickness measurement.FIG 5(a) shows a front perspective view of an embodiment of the inventive mixer fully assembled with a built-in dispenser.

[0067] FIG 5(b) shows a drink container lift up during mixing stage.

[0068] FIG 5(c) depicts lift up / down mechanism for the drink container.

[0069] FIG 5(d) and FIG 5 (e) depicts the location of the thickener powder dispenser with in the mixing device and the dispenser mechanism in an opened and a closed position.

[0070] FIG 6 shows the signal read from the torque sensor for measuring thickness level in constant blade rotation speed. The signals are read from reflash marks of the torque sensor assembly.

[0071] FIG 7(a) and (b), shows the torque angle measurements and the angle different for IDDSI thickness level 0 to level 4. This set of data uses constant speed measurement method.

[0072] FIG 8 illustrates 2 measuring algorithms used forthe thickness measurement forthe thickened fluid after mixing.

[0073] FIG 9 illustrates the accuracy window of the torque sensor assembly and increase rotation speeds for achieving higher measurement accuracy in low thickness level (e g. level 0 to 2), while decrease rotation speed in high thickness level (e.g. level 3 to 4).

[0074] FIG 10 shows the signals read from the torque sensor for measuring thickness level using adaptive speed measuring.

[0075] FIG 11(a) is a graph showing the measured RPM level at thickness level 0 to level 4.

[0076] FIG 11 (b) is a table showing the measured difference in angular velocity between levels.

[0077] FIG 12 depicts the blade of the mixing device being detached for ease of cleaning.

[0078] FIG 13 shows an embodiment setup of a plurality of mixing devices for saving space occupied and reducing electrical connection point.

[0079] DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTIONFIG 1(a) is a perspective view of the mixing device of the present invention with mixing blade attached and a cup or a container loaded. Encased in the device includes mechanisms enabling the device to achieve the 5 key features of the invention.

[0080] FIG 1(b) shows the working principle of the mixing device capable of mixing and measuring a thickened drink or fluid. The system comprises a rotational motor 1 which has a motor shaft 2. The motor shaft 2 is coupled to a blade shaft 4 which has a blade 5 at the end thereof. The coupling is achieved through a torque sensor assembly 3 between the motor shaft 2 and the blade shaft 4. In order to create a thickened liquid or drink, a fluid 6 with a viscosity of q will be combined with a thickener 8 in the container 7 with a radius of r2 for mixing and measuring purposes. The type of drink is not limited to water but includes most drinks including milkbased drinks such as coffee and tea with milk or fresh milk itself. The blade 5 with a height dimension h and a radius of n is immersed into the drink 6 to be thickened.

[0081] Before measuring, the thickened drink has to be mixed using the system. During the mixing phase the motor 1 will generate a higher range of rotational speeds (50 to 1000 rpm) in one direction (such as clockwise) to create turbulence and allowing a thickener to dissolve in the drink. Rotating this direction the torque sensor assembly 3 is locked and is not activated. The blade shaft 4 will be rotating at the same rotational speed as the motor shaft 2. During the measuring phase, the motor 1 generates a lower range of rotational speeds (less than 50 rpm) in the opposite direction i.e., counter-clockwise. In this direction, the torque sensor assembly 3 is unlocked and is activated.

[0082] To measure viscosity, the blade 5 rotates at a constant angular velocity of co. This generates a torque through the blade onto blade shaft 4. This torque value, M, can be used to calculate viscosity using the following equation:

[0083] >

[0084]

[0085] M

[0086] T] = A —

[0087] O)Ksis the coefficient of the liquid-mechanical system and A is a simplified constant.

[0088] The torque value is relative to shape, design and structure of the blade, the roughness of the surface of the container, any mechanical friction etc.

[0089] As shown in the above equation:

[0090] 1) The torque M acting on the blade shaft 4 is linear with the blade rotation speed w and drink viscosity q. Higherthe rotation speed w or higherthe drink viscosity q, the higher the torque M.

[0091] 2) If the rotation speed co of shaft 4 keeps constant, the viscosity of the drink is linear with the torque.

[0092] Hence, measurement of the viscosity is by measuring the torque of the rotating shaft 4. Torque sensor assembly 3 is capable of measuring torque through measuring the angle of separation generated by the torque.

[0093] The torque sensor is key device for measuring liquid thickness level. FIG 2(a) shows a crosssection view of the torque sensor assembly 3 for measuring liquid thickness level. The torque sensor is locked and in-active in the mixing direction (e.g. clockwise). It is unlocked and is in active in the measuring direction (e.g. anti-clockwise). FIG 2(b) shows a top view of the torque sensor assembly 3 showing compact structure and small profile of the assembly. The compact nature of the torque sensor assembly 3 allows for tabletop designs while the reduction in materials decreases the cost of production.

[0094] As shown in FIG 3(a) and FIG. 2(a), the torque sensor assembly 3 consists of an upper coupling 9 connected to the motor shaft 2 and a lower coupling 10 connected to the blade shaft 4. The lower coupling 10 features a through-hole, allowing the blade shaft 4 to be secured to a bearing 11 , shown in FIG 2(a), which is mounted to the upper coupling 9. This design ensures precise alignment of the motor shaft 2 and the blade shaft 4 along the same vertical axis, resulting in stable rotations. A torsion spring 15 is positioned between the upper coupling 9 and the lower coupling 10 to facilitate torque transmission.

[0095] When torque is applied, the torsion spring 15 is compressed, causing a slight angular displacement between the motor shaft 2 and the blade shaft 4. This angle change is measured using the reflective markings 12 and 13, which are attached to the lower coupling 10 and the upper coupling 9, respectively. As the torsion spring 15 is compressed, the reflective markings move apart proportionally to the angle of separation. A reflective optical sensor detects this angular displacement. Using the measured angle and the known spring constant of the torsionspring 15, the applied torque can be calculated, allowing for an estimation of the fluid’s viscosity.

[0096] FIG 3(a) and (b) show an embodiment of the torque sensor assembly with protrusions that enable the bidirectional control of the sensor assembly. The illustrated drawings are only meant to encapsulate functionality and do not represent exact structure of the final sensor.

[0097] The upper coupling 9 and the lower coupling 10 are respectively provided with extrusions 16 and 17. The upper extrusion 16 and the lower extrusion 17 allow for bi-directional control of the sensor. When rotated in one direction i.e., clockwise, the upper extrusion 16 will push against the lower extrusion 17. This is known as the non-activated state. When rotated in the opposite direction i.e., anti-clockwise, the upper extrusion 16 compresses the torsion spring 15 which will then elastically push against the lower extrusion 17. This is also known as the activated state.

[0098] The compression of the torsion spring 15 allows for a calculatable angle change to occur between the motor shaft 1 and the blade shaft 4. The torque sensor assembly 3 will allow for dual functionality in opposite rotating directions with the activated and non-activated states. When in the non-activated state, the upper extrusion 16 pushes directly on the lower extrusion 9. High rotational speeds can occur for mixing as there is a direct translation of torque into the motor shaft 4 from the motor shaft 2. This protects the torsion spring 15 as it is only compressed during measurement which uses a lower rotational speed.

[0099] FIG 4 illustrates a system with essential components of the system fused in the torque detection sensor for viscosity measurement of a fluid thickener using the inventive mixer. A system 100 which uses the torque detection sensor 103 for measurement of the viscosity of the fluid thickener. Motor 105 generates rotations at a known constant angular velocity. It is controlled by a micro-controller unit 108 (MCU) and a motor controller unit 106. The motor’s torque is transmitted through motor shaft 104. A detachable blade 101 is connected to a blade shaft 102. The shaft of the motor and the shaft of blade connected by a torque sensor 102. When the rotating blade 101 is inserted to container 109 containing a thickened fluid 110, torque will be applied to the sensor. The sensor will generate an index signal. Constant rotation speed of the blade is one of the key requirements for accurately measuring the viscosity level, or thickness level. The rotation motor used in this application is a digitally controlled stepper motor with micro-stepping. One revolution of the blade steps from 200 to 51200 micro-steps, but is not limited to this range. The rotation speed ranges from 1 to 500 rpm. Higher rotational speeds are used for mixing before a lower speed is used for themeasuring. The rotation motor can also be a servo motor with encoder for rotational speed feed-back. When commencing use of this mixing device, the user will input the viscosity of choice (IDDSI Level 1,23 or 4) in the touch screen panel 107.

[0100] FIG 5(a) and 5(b) illustrates a front perspective view of an embodiment of the mixing device 200 fully assembled with a built in dispenser in different steps of the mixing operations. The mixing device 200 features a vertical lift 201 and a powder dispenser 202. The position and shape of the powder dispenser is illustrative and could be placed in any position in the mixer. Similarly the shape of the mixing device is illustrative and could be of any shape.

[0101] The device in FIG 5(a) is in the cup loading position where it is ready to receive a container or cup and the blade is at a height that does not interfere with the movement of the container or cup.

[0102] The device in FIG 5(b) is in the mixing and measuring position where the blade is positioned in the thickened liquid near the bottom of the cup. The vertical lift 201 during the mixing step has the option to move the cup between heights. This allows for the blade to reach throughout the depth of the cup containing the liquid which is especially useful for high thickness liquids that do not easily create vortices, resulting in clumping of the powder. Moving the blade throughout the liquid while mixing creates a three-dimensional mixing profile which enhances the mixing results by reducing the number of clumps observed at the end of mixing. The powder dispenser 202 is used to add any amount of thickener powder in one go. This reduces the chances for clump formation as time between scoops of thickener powder being added is removed. As thickener powder is gradually added to the liquid, the viscosity increases and the solubility of the powder decreases. Hence, adding all required volume of powder in one go will allow for the thickener powder to quickly disperse throughout the liquid before the thickening occurs resulting in less clumping of the powder.

[0103] FIG 5(c) depicts lift motor 203 is attached to a lead screw which drives the lift carriage 204 for achieving a three-dimensional mixing profile. Other lifting mechanism such as timing belt, can be used. Stepper motor, any motors such as DC motor, stepper motor within the internal structure of the mixer are possible.

[0104] FIG 5(d) illustrates a better illustration of the positioning of the powder dispenser 202. The position allows for direct release of powder near the blade. The blade will be spinning before powder addition to create a vortex in the premixed liquid. Once thickener powder is released it will quickly be dispersed throughout the liquid.FIG 5(e) illustrates a cross section view as to a possible structure and design of a powder dispenser mechanism in an opened and a closed position. The funnel 205 has a gate 206 that is opened and closed quickly using a solenoid 207. This powder dispenser design is simple and easy to replace when washing or disposal is required. Other variations of the powder dispenser mechanism and variation in its position in the mixing device are possible.

[0105] FIG 6 shows the signal read from the torque sensor for measuring thickness level using constant speed measuring. In FIG 6, the levels 1-4 indicated by (a) to (d), show the signal generated for increasing thickness levels. As discussed in the application of the equation for calculating viscosity, the angular velocity of the motor shaft 2 and the blade shaft 4 is known and constant. When a higher torque is applied to the sensor, the angle of change between the reflection markings 17 and 18 will be larger. The optical sensor will detect the reflection marking in the form of a signal. The optical sensor detects and outputs two index signals for every rotation of the blade. The higher the viscosity of the drink, the longer the time between index signals and hence the bigger the angle of change .

[0106] FIG 7 (a) and FIG 7(b) show measurement results across IDDSI levels 0 to 4 using fixed rotation speed algorithm. It is observed in FIG 7(a) that there is an increasing angle of separation between the reflective markers as the thickness of fluid measured increases. FIG 7(b) illustrates the difference in angles between each level. The difference in angles between the lower thickness levels, such as 0 and 1 or 1 and 2, is much smaller than the angle difference between the higher levels. This will result in low measurement accuracy in low thickness levels.

[0107] FIG 8 is detail flowchart of the mixing and measurement process using the 2 algorithms. The workflow begins when the blade is inserted into the unmixed drink and thickener mixture at step denoted as 818. The step of mixing denoted as 819 is carried out at high rotational speeds in one direction i.e., clockwise to generate turbulence which decreases the time needed for the thickener to dissolve. Once ready for measuring, there will be at a step of change in direction of motor, denoted as 820 i.e., anti-clockwise rotation, followed by a reduction of speed. It is during the change of rotational speed at step denoted as 821 (in anticlockwise direction) that the measurement of thickener takes place. The algorithm then undergoes the step of Boundary Measurement Check denoted as 822:-

[0108] (a) If the thickener has high initial thickness denoted as 823 (above angular offset limit), the rotational speed at step denoted as 824 is decreased. This allows the accuracy window to shift to a region of higher thickness at step denoted as 825.(b) If the thickener has low initial thickness at step denoted as 826 (below angular offset limit), the rotational speed at step denoted as 827 is increased. This allows the accuracy window to shift to a region of lower thickness at step denoted as 828.

[0109] The measurement of viscosity (thickness) is then carried out at step denoted at 829. If the thickener is found to possess initial thickness (above angular offset limit) or is found to possess low initial thickness, the rotational speed would increase or decrease accordingly at step denoted as 830. The measurement of viscosity (thickness) continues in accordance to the algorithm until finally the thickness is measured to be at the correct IDDSI level as set by the user forthat specific level of IDDSI for the thickened fluid. Once the final measurement of thickness at step denoted as 831 is found to be as set, the mixing is stopped.

[0110] Two Methods proposed for measuring thickness level

[0111] In this invention, we propose two methods for measuring the thickness level of a mixed thickened fluid.

[0112] Method 1 : Maintain a single rotational speed of the blade during measurement, and Method 2: Adapting the rotational speed of the blade according to thickness of the drink Method 1 : Maintain a single rotational speed of the blade during measurement

[0113] In the first method, the mixing goes through four steps:- Step 1 - Blade is inserted into container with drink and thickener

[0114] Step 2 - Mixing is started in one direction (clockwise)

[0115] Step 3 - Direction of blade is changed to opposite direction (anti-clockwise)

[0116] Step 4 - Rotation speed is changed to slower speed.

[0117] Step 5 - Final measurement of thickness is conducted before immediately outputting the final measurement of thickness at step 831.

[0118] In this method, the spring must have very wide range of rotation angle (e.g. up to 180 degree).

[0119] Method 2 - Adapt rotational speed of the blade according to thickness of the thickened fluidDuring measurement process, the rotational speed of the blade will be adapted according to viscosity (thickness) of the thickened fluid.

[0120] In Method 2, the first four steps of Method 1 is followed:- Step 1 - Blade is inserted into container with drink and thickener

[0121] Step 2 - Mixing is started in one direction (clockwise)

[0122] Step 3 - Direction of blade is changed to opposite direction (anti-clockwise)

[0123] Step 4 - Rotation speed is changed to slower speed.

[0124] If Boundary Measurement Check (measurement of thickness) shows High initial thickness. Step 5A- Boundary check shows High Initial thickness (above angular offset limit) - decrease rotational speed of motor.

[0125] Step 6 A - Accuracy window shifts to region of higher thickness.

[0126] Step 7A Measure thickness. If angular offset within limits, output final measurement of thickness.

[0127] If Boundary Measurement Check (measurement of thickness) shows Low initial thickness. Step 5B - Boundary check shows Low Initial thickness (below angular offset limit) - increase rotational speed of motor.

[0128] Step 6B - Accuracy window shifts to region of lower thickness.

[0129] Step 7B Measure thickness. If angular offset within limits, output final measurement of thickness.

[0130] FIG 9 illustrates the accuracy window of the torque sensor assembly and how to increase or decrease the rotational speed for better thickness measurement accuracy. This algorithm is to vary the rotation speed to achieve a constant separation angle. Base on the initial thickness measurement, if the results are smaller than the limits of the angular offsets, the device will be directed into a low thickness adaptive routine. The rotational speed of the motor will then be increased. This will shift the window of accuracy of the torque sensor towards the lower levels of thickness. Following the shifting of accuracy window, a final measurement is conducted.Similar measuring routines are processed for high thickness level drink measurement as shown in FIG 9 for thickness level 3 and 4, where the rotation speed is decreasing.

[0131] Using this algorithm has allowed for accurate, reliable and fast preparation of thickened drinks by introducing a “zoom” feature to better relocate the range of accuracy of the sensor towards the thickness region of interest.

[0132] FIG 10 indicates relationship of rotation speed and measuring angle. Higher thickness level means the liquid is more viscous, requiring a lower rotation speed to maintain the set angle. Conversely, for lower thickness level drink, a less viscous liquid, a higher rotation speed is needed. This adaptive speed control ensures that the system compensates for different fluid properties, maintaining the desired angle throughout the process.

[0133] FIG 11 (a) gives the measured RPM level at each thickness level with a given separation angle of 85 degree using adaptive angular velocity method. The possible target angle set for measurement in this situation is 85 degrees. FIG 11 (b) provides the angle difference from thickness level 0 to level 4. The angle difference between low thickness levels and the high thickness levels are high.

[0134] FIG 12 depicts a mixing device with a detachable blade for ease of cleaning. This enables disposal or washing of the blade for hygiene purposes while still retaining ease of use for users. A possible method to achieve this feature is using magnetic coupling.

[0135] When plurality of mixing devices are used, FIG 13 (a) (b) provide an example arrangement for saving space used and reduce the number of power supply inlet needed. This arrangement allow healthcare providers in hospitals / nursing home to prepare more drinks in short time, compare to a stand-alone standard mixing device.

[0136] The fully automatic mixing system would raise the cup in each holder to allow each blade to reach throughout the depth of the cup containing the liquid. Thorough mixing is especially useful for mixing large numbers of cups of varying thickened fluids to ensure mixing easily create vortices. Moving the blade throughout the liquid while mixing would also creates a three-dimensional mixing profile to enhance the mixing results by reducing the number of clumps observed at the end of mixing. This reduces the chances for clump formation during making of a large number of cups. Such fully automatic mixing systems would commence by adding thickener powder from the dispenser at the start of making each cup. Therefore,thorough mixing of the thickener with the fluid is important to ensure the thickened powder is dissolved completely.

[0137] The fully automatic mixing system would also use any one of the two methods for measuring the thickness level of a mixed thickened fluid. For such a high volume fully automatic mixing system, use of detachable blades would be advantageous for hygiene reasons.

[0138] It should be noted that the above descriptions are merely preferred embodiments of this invention and are not intended to limit the invention. Although this invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still make modifications to the technical solutions described in the embodiments, or make equivalent replacements of some technical features. Any modifications, equivalent replacements, improvements, etc., made within the spirit and principle of this invention should be included within the protection scope of this invention.

Claims

The invention claimed is:

1. A device for drink preparation capable of mixing and measuring thickness of a drink, comprising:a) a rotational motor having a motor shaft coupled to a blade shaft via a torque sensor assembly;b) a lift mechanism comprising a lift motor attached to a lead screw; andc) a lift carriage configured to hold a drink container, wherein:the blade rotates bidirectionally to perform both mixing and thickness measurement of the drink,the lead screw operates to vertically elevate the lift carriage, andthe clockwise and / or counterclockwise rotation of the blade provides thorough mixing of the drink while enabling measurement of the drink's thickness.

2. The device of claim 1 , wherein the rotational motor provides an adaptable rotational speed for mixing and measuring of thickness of the drink, and the rotational speed for mixing is in a range of 50 to 2000 rpm in one direction, and in a range of 1 to 200 rpm in another direction for thickness measurement.

3. The device of claim 1, wherein a consistent rotational speed of blade is used for final measurement of thickness of the drink.

4. The device of claim 1 , wherein an adaptive speed of the blade is used for final measurement of thickness of the drink.

5. The device of claim 1 , further comprising a thickening powder dispenser, which is positioned closely to the blade, allowing direct release ofthickening powerfordrinkthickening.

6. The device of claim 1 , wherein the torque sensor assembly is adapted to measuring torque of the blade in rotating via measuring an angle of separation generated by the torque.

7. The device of claim 1 , wherein the torque sensor assembly comprises an upper coupling connected to the motor shaft, and a lower coupling connected to the blade shaft, and the lower coupling has a through hole which allows the blade shaft to attach to a bearing which is attached to the upper coupling, and a torsion spring is positioned between the upper coupling and the lower coupling.

8. The device of claim 1 , wherein the motor shaft and the blade shaft are aligned along a vertical axis which generates a stable rotation.

9. The device of claim 7, wherein the torsion spring being compressed provides a calculable angle change to occur between the motor shaft and the blade shaft.

10. The device of claim 7, wherein if a torque is applied to the torsion spring, the torsion spring is activated due to compression, resulting in an angle of separation between the motor shaft and the blade shaft.

11. The device of claim 7, further comprising: (I) an upper extrusion connected to the upper coupling; and (ii) a lower extrusion connected to the lower coupling;wherein the upper and lower extrusions provide bi-directional torque control of the sensor assembly such that: when the blade rotates in a first direction, the upper extrusion directly contacts and applies force against the lower extrusion; and when the blade rotates in the opposite direction, the upper extrusion compresses the torsion spring, causing the upper extrusion to apply pressure against the lower extrusion.

12. A method for mixing and measuring viscosity of thickened fluids using a mixing device of claim 1 , the method comprising:(i) attaching a blade to the mixing device and positioning a container containing a fluid; (ii) elevating the container and inserting the blade into the fluid within the container;(iii) dispensing a thickening powder from a thickening powder container onto the fluid while rotating the blade at a predetermined speed to facilitate effective mixing;(iv) rotating the blade in a clockwise direction to combine the fluid with the thickening powder; (v) vertically displacing the container in an upward and downward motion to ensure thorough mixing of the fluid and thickening powder;(vi) decreasing the rotational speed of the blade and changing the rotation direction from clockwise to counterclockwise;(vii) determining the viscosity of the thickened fluid at a predetermined rotational speed; and (viii) dispensing the thickened fluid for consumption.

13. The method as set forth in claim 12, wherein the container is vertically displaced in an upward ordownward direction to enable the blade to traverse the entire depth of the container containing the fluid, thereby ensuring formation of vortices within the fluid in the container.

14. The method as set forth in claim 12, wherein the mixing of the thickening powder with the fluid facilitates thorough incorporation of the components such that the thickening powder is completely dissolved in the fluid.

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