Disposable blood metering device

Abstract

A measurement system that can be used at the bedside of a patient to monitor the amount of blood drawn from the patient. The system uses a disposable sensor and electronics to accurately and in real-time measure the volume of blood drawn from the patient using a paddle wheel sensor, where the rotation of the paddle wheel is correlated to the volume of blood drawn and collected from the patient.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 62 / 883,294, filed on August 6, 2019, which is incorporated herein by reference. Technical Field

[0003] The device described in this article is a measurement system that can be used at the patient's bedside to monitor the amount of blood drawn from the patient. The system uses disposable actuation and sensor electronics to measure and control the amount of blood drawn from the patient for analysis. Background Technology

[0004] During blood collection from a patient for blood cultures in a hospital or other setting, it is important to provide the target blood volume to the blood culture bottle to ensure that the volume drawn is neither too much nor too little, as inoculating blood cultures with undersized or oversized samples can adversely affect the accuracy of blood culture analysis results. Currently, the only feedback to the medical staff drawing blood from the patient is (typically) visually monitoring the fluid level in the blood culture bottle during blood collection and interrupting collection when the filling volume is determined to have been reached.

[0005] Currently, healthcare professionals visually determine this volume. Blood culture bottles have volume measurement markings on the bottle or label. Typically, healthcare professionals need to mark the target filling volume of blood on the side of the bottle. However, this method is prone to error. While healthcare professionals are drawing blood into the blood culture bottle, they may not hold the bottle with a precise vertical orientation, making it difficult or even impossible to determine the actual volume of blood collected, and potentially resulting in the target blood volume not being obtained. Another problem affecting the accuracy of the drawn blood volume is the lack of standardized guidelines on how to properly inoculate blood culture bottles with the target blood volume. Furthermore, patient needs (patients may have difficulties during blood draws that distract healthcare professionals from accurately monitoring the blood draw) can adversely affect the accuracy of the blood volume drawn by healthcare professionals.

[0006] Successfully culturing and detecting bacteria in an infected patient largely depends on the bacteria present in the blood sample obtained from the patient. The probability of bacteria in a blood sample increases with the volume of blood collected. Therefore, accurately collecting the required target volume in the blood culture bottle is crucial; an example of a blood culture bottle is the BACTEC. TM Culture flask.

[0007] As mentioned above, currently, medical personnel collecting blood samples must visually determine when the correct volume of blood has been drawn and collected into the culture bottle, and stop collection at exactly this point to avoid overfilling the blood culture bottle. Therefore, there is a continued need to seek methods and devices for blood collection that can ensure the accurate collection of the target volume of blood. Summary of the Invention

[0008] The blood measurement device described herein measures the volume of blood passing through it and flowing into a blood collection vessel attached thereto. A blood collection vessel is any suitable container used to receive a blood sample. An example is a blood collection tube, such as a BD tube. Tube. BD Vacutainer is a registered trademark of Becton, Dickinson and Company. Another example is a blood culture bottle, such as the BACTEC bottle described above. The blood measurement device provides at least one of the following: 1) an indication when a target volume of blood has passed through the device and entered the blood culture bottle; or 2) automatic shut-off when a target volume of blood has passed through the device and entered the blood culture bottle.

[0009] A blood measurement device is a standard blood collection apparatus in fluid communication with a mechanically rotating paddle wheel that rotates in response to blood flow through a housing, wherein the paddle wheel is rotatably mounted within the housing. The paddle wheel is positioned within the housing to allow it to rotate freely. In one embodiment, the axis of rotation of the paddle wheel is a pin fixed within the housing and defining the axis of rotation of the paddle wheel. The paddle wheel communicates with a measuring sensor capable of tracking the rotation of the paddle wheel. An example of such a sensor is a Hall effect sensor actuated when the magnet passes the sensor, with the paddle wheel rotating. Each actuation is a rotation count. The sensor converts the number of rotations into blood volume. In some embodiments, the speed of rotation of the paddle wheel is also measured to calculate the volume of the sample passing through the blood measurement device. Another example of a sensor is an optical sensor (e.g., an LED) that cooperates with an optical reference disposed on the paddle wheel to count the number of rotations of the paddle wheel or the speed of rotation of the paddle wheel, or both.

[0010] The blood metering device has a controller capable of performing one or more of the following functions: i) correlating the number of rotations with the volume of blood flowing through the device; ii) correlating the speed of the impeller rotation with the volume of blood passing through the impeller; iii) shutting off blood flow in response to determination that a target blood volume has been reached; and iv) providing medical personnel with a signal regarding the volume of blood that has passed through the blood metering device. For example, the blood metering device may emit a green light when the blood volume is below a certain threshold. The green light may change to yellow as the blood volume that has passed through the device approaches the target volume. Once the target blood volume has passed through the blood metering device and entered the blood culture bottle, the sensor may change to another color (e.g., red) to indicate that the target volume has been received by the blood culture bottle. Blood does not flow through the sensor. In this respect, the blood metering device is a component consisting of a sensor unit and a metering / culture bottle adapter unit.

[0011] In one example, the sensor is disposable. In this embodiment, the sensor has disposable electronics that measure the amount of blood flowing through the blood metering device during blood draw from a patient. The disposable system notifies the user, by means of visual or acoustic signals, whether a predetermined desired volume of blood has passed through the sensor.

[0012] The disposable sensor device is equipped with a sensor capable of electronically measuring blood flow. The disposable sensor unit is integrated into a disposable housing as part of the overall blood collection device. The disposable sensor unit is removably attached to a culture flask adapter unit, which includes a paddle wheel disposed within the housing and is adapted to form a blood path from the blood collection system to the collection vessel (e.g., blood collection tube, blood culture flask, etc.).

[0013] In some embodiments, the sensor does not need to be disposable. In such embodiments, the sensor unit does not come into contact with blood, and therefore the sensor unit can be reused or recycled.

[0014] The blood filling volume is measured and monitored by a microprocessor using sensors that count the number of revolutions or rotational speed of the paddle wheel. The sensors are calibrated and accurate measurement systems. The system interacts with the user using optical and / or acoustic signals and / or other sensory signals (e.g., vibration) to indicate that a predetermined volume of blood has been delivered into the blood culture bottle or blood collection vessel.

[0015] Optionally, the blood measurement device has an adapter unit that forms a housing defining a blood flow path, and the adapter unit is adapted to be connected to a blood collection device. The adapter unit has a volume indicator disposed therein for measuring the volume of blood flowing through the blood flow path. Optionally, this volume indicator is a paddlewheel flow detector. The volume indicator can also be a filament sensor, an acoustic sensor, or an optical sensor. The sensor can also be one of an axial rotor sensor, a peristaltic pump sensor, a magnetic field sensor, or a rotation sensor.

[0016] In this detector, the volume of blood flowing through the sensor is calculated from the number of rotations of the paddle wheel. The blood metering device also has a sensor unit that engages with an adapter unit. The sensor unit has: i) a sensor configured to detect a signal in response to blood flow through the blood flow path in the adapter unit; and ii) a processor that associates the sensor signal with the blood volume and controls the response of the sensor unit in response to the sensor unit determining that a predetermined volume of blood has passed through the adapter unit. The sensor unit is one that is detachably engaged with or integrated integrally with the adapter unit.

[0017] The impeller is positioned within the blood flow path but is freely rotatable within the housing, for example, via a pin supported within the housing providing an axis of rotation. The impeller has an axis of rotation that is orthogonal to or coaxial with the direction of blood flow within the blood flow path. The impeller can carry a magnet, and the housing can have a Hall effect sensor disposed therein, which is actuated when the magnet passes by.

[0018] 12. The blood measuring device according to claim 1, wherein the paddle wheel rotates freely within the housing on an integral pin supported by the housing.

[0019] Optionally, the processor correlates the rotation of the paddle wheel with the blood volume to determine the measured blood volume that has flowed through the blood metering device, and controls the response of the sensor unit in response to the sensor unit determining that a predetermined volume of blood has passed through the paddle wheel set in the adapter unit.

[0020] The adapter unit can be attached to a collection vessel. The collection vessel can be a blood culture bottle or a sample collection tube.

[0021] Optionally, the processor compares the measured blood volume with a predetermined blood volume, and when the measured blood volume equals the predetermined volume, the processor is configured to send a signal to close the blood flow valve, which cuts off the blood flow to the blood metering device.

[0022] Optionally, the adapter unit has an activation lever that activates the processor when the adapter unit is attached to a blood culture bottle. Optionally, the sensor unit has a battery that can be turned on via the activation lever to provide power to the processor.

[0023] Optionally, the sensor unit has a valve actuator for controlling the valve in the adapter unit. The valve actuator is one of a moving magnet actuator, a micro-actuator, a solenoid, or a mating magnet actuator.

[0024] Optionally, the blood metering device has a flow meter that acts as a pump. One example of such a pump has a motor with a rotor. A housing forms the stator of the pump. The rotor can have one or more magnets. The motor can have a Hall effect sensor that measures the rotational speed of the rotor. A processor determines the volume of blood flowing through the pump based on the motor's rotational speed. In operation, when the motor's rotational speed drops below a predetermined speed, the processor indicates venous constriction. The sensor unit can have an indicator light indicating that a predetermined volume of blood has passed through the adapter unit or a light indicating venous constriction based on a signal from the processor.

[0025] The blood measurement device is used by connecting an adapter unit to a blood collection device with a needle and tube for venipuncture. During operation, when the motor's rotational speed drops below a predetermined speed, the processor instructs the vein to narrow.

[0026] This document also describes a method for determining the volume of blood flowing from a patient to a collection bottle. In this method, an assembly comprising an adapter unit and a sensor unit is provided. The adapter unit has a housing defining a blood flow path, the housing being adapted for connection to a blood collection device. Optionally, a paddle wheel is disposed within the adapter unit, positioned within the blood flow path but freely rotatable within the housing. The sensor unit is as described above and has a sensor configured to detect a signal in response to blood flowing through the blood flow path in the adapter unit. The sensor unit also has a processor that associates the sensor signal with the blood volume and controls the response of the sensor unit in response to determining that a predetermined volume of blood has passed through the adapter unit. The sensor unit also has a valve actuator that communicates with and is controlled by the processor. In this method, the assembly is connected to a blood collection device having a needle and tube suitable for venipuncture, such that the blood collection device is in fluid communication with the blood flow path. The adapter unit is connected to a blood collection vessel, such that the blood flow path in the adapter is in fluid communication with the blood collection vessel. The pressure in the blood collection vessel is typically lower than atmospheric pressure to draw a blood sample from the patient and allow it to enter the vessel. This causes blood to flow through a paddlewheel sensor, and the rotation of the sensor is measured to determine the volume of blood flowing into the collection vessel from the blood flow path. The determined blood volume is compared to a predetermined blood volume. When the measured blood volume equals the predetermined volume, the processor sends a signal to the valve actuator to stop the flow of blood into the collection vessel. Attached Figure Description

[0027] Figure 1 The diagram illustrates the components used for blood collection, in which a flow meter device is coupled to a blood culture bottle;

[0028] Figure 2A The diagram illustrates the flow meter electronics component of the flow meter assembly;

[0029] Figure 2B The diagram shows the flow meter adapter portion of the flow meter assembly attached to the blood collection bottle;

[0030] Figure 2C The diagram illustrates the process. Figure 2B The diagram shows the blood flow path in the flow meter adapter section.

[0031] Figure 3A The diagram illustrates the workflow of using the flow meter device described herein in conjunction with blood culture bottles;

[0032] Figure 3B The diagram illustrates the workflow of using the flow meter device described in this article in conjunction with a blood collection tube;

[0033] Figure 4 yes Figure 2B An exploded view of the flow meter adapter section shown in the diagram.

[0034] Figure 5 yes Figure 2A An exploded view of the electronic components of the flow meter shown in the figure.

[0035] Figure 6 This is a schematic diagram of a flow meter device illustrating its operating principle;

[0036] Figure 7 The diagram illustrates the impeller assembly of the flow meter adapter section;

[0037] Figure 8 The illustration shows a housing that receives a paddle wheel coupled to a motor, which drives the paddle wheel;

[0038] Figure 9 The illustration shows an embodiment of a motor used to drive a propeller wheel;

[0039] Figure 10 The illustration shows alternative components for blood measurement equipment and blood culture bottles;

[0040] Figure 11 yes Figure 10 A breakdown view of the components in the document;

[0041] Figure 12 It is integrated into the blood collection system Figure 10 Components;

[0042] Figure 13 This is a perspective view of the blood metering device viewed from the front of the sensor section integrated with the adapter section;

[0043] Figure 14 This is a perspective view of the blood metering device as seen from the rear of the sensor unit; and

[0044] Figure 15 The diagram illustrates the use of in Figure 1 An example of a pinch valve used in a blood metering assembly. Detailed Implementation

[0045] Figure 1 The illustration shows a blood collection system including a blood measuring device according to the present technology, as an example. Figure 1 As shown, the blood collection system includes a needle 110, a tube 120, a blood measuring device 130, a sensor unit 140, an adapter unit 150, and a collection bottle 160. The adapter unit 150 includes a needle 152 (…). Figure 2B Collection bottle 160 includes cap 163. Figure 3ANeedle 152 pierced through cover 163.

[0046] During the process of collecting a blood sample from a patient, needle 110 is used to puncture a vein or artery in the patient. Driven by the vacuum pressure generated by collection bottle 160, blood from the patient is guided through tube 120 toward collection bottle 160. The blood flow is collected in collection bottle 160. The blood travels along the path through adapter unit 150 and needle 152. The sensor unit is also referred to herein as the electronics section because the sensor unit contains device actuators and sensor electronics.

[0047] refer to Figure 2A The sensor unit 140 has a housing 180, within which a processor 182, an indicator 184, a battery 186, and a valve actuator 188 are disposed. The valve actuator 188 controls a valve 189 on the housing inlet 164. The sensor unit includes device actuators and sensor electronics. In response to blood volume sensed by the metering device, the printed circuit board 182 (which carries the processor and other electronics) can indicate, using an indicator (illustrated as a colored light), when a predetermined target volume has passed through the metering device; however, an audible signal or vibration indication is also conceivable. The sensor can also send signals to other indicators of system status, such as indications of other flow conditions (i.e., blood flow rates higher or lower than the system-specified flow rate).

[0048] In one embodiment, when blood is drawn from a patient, valve actuator 188 maintains valve 189 ( Figure 2B and Figure 4 The valve actuator 188 controls the flow of blood collected from the patient. After blood collection begins, the valve actuator 188 receives a signal indicating that blood flow has begun. In response to this signal, the valve actuator 188 gradually causes the valve 189 to open. The valve actuator 188 is programmed to reduce the flow through the adapter unit ( Figure 2B The valve 189 is opened by hemolysis of the blood. In the illustrated embodiment, valve 189 and Figure 2B The adapter unit 150 shown in the figure is integrated. However, the valve 189 can also be integrated with the valve actuator 188. In either embodiment, the valve 189 is positioned coaxially with the inlet 164 in the adapter unit described below.

[0049] In an alternative embodiment, the sensor unit can be coupled to a sensor 111 positioned near the needle 110 (via wired or wireless communication). When this sensor 111 detects a flow condition indicating venous constriction or impending venous constriction (i.e., a reduction in blood flow exceeding a predetermined threshold), the valve actuator 188 responds by closing the valve 189, followed by a gradual reopening of the valve 189.

[0050] Suitable valve actuators are well known to those skilled in the art and are not described in detail herein. Such actuators include moving magnet actuators, microactuators, solenoids, mating magnets, etc., that cause valve 189 to open or close in response to a signal.

[0051] Suitable valves used in the blood metering devices described herein are not described in detail herein and are well known to those skilled in the art. Examples of suitable valves include shut-off valves that advance a valve seat into a channel to close the valve and retract the valve seat from the channel to open the valve. Another suitable valve is a pinch valve 500. Figure 15 The diagram illustrates this type of valve. The pinch valve 500 is opened and closed via a helical tube 510, which drives the valve body 520 between the open and closed positions (and vice versa). Figure 15 As illustrated, tube 530 passes through valve body 520. When valve body 520 is open, blood flows through tube 530. In the open position, valve body 520 does not clamp tube 530. In the closed position, valve body 520 closes onto tube 530, thereby preventing blood flow through valve body 520. Solenoid 510 receives power via wire 540 positioned in solenoid cap 570. Pinch valve 500 also has a panel 550 and a seal 560 to prevent the solenoid from contacting blood. A manual release button 580 is provided for pinch valve 500 in case of valve body failure and improper release. Other suitable valves include ball valves, diaphragm valves, slide valves, check valves, relief valves, etc.

[0052] refer to Figure 2B The adapter unit 150 has a small propeller 154, which is capable of rotating freely within the housing 156 on an integral pin 158. Figure 2B and Figure 4 In the embodiment illustrated, the integral pin 158 is part of the flow path 162 through the housing 156. The flow path exits the adapter unit 150 through the outlet 166. Blood flow is tangentially guided along the impeller 154 through the inlet 164. The impeller has a gap with the wall of the housing 156, allowing the impeller to rotate freely; there is no need for a tight seal. The adapter unit has an activation lever 190, which is activated only when the adapter unit 150 is placed in the blood culture bottle 160. Figure 3A After the device is activated, lever 190 activates the electronics. This allows the device to be "off" when not in use, thus saving battery power. When the needle 152 of adapter unit 150 pierces the blood culture bottle, the reduced pressure inside the blood culture bottle draws the patient's blood through the device and into the blood culture bottle. Optionally, the metering device is configured such that blood flows axially through the metering device rather than tangentially.

[0053] exist Figure 2C The diagram illustrates the blood flow path 162 through the adapter unit 150. Blood enters the adapter unit 150 through inlet 164. The blood flow path proceeds through impeller 154 and then upward through channel 169, in which valve 189 is disposed. If valve 189 is open, blood is allowed to flow in and through the adapter unit outlet channel 166.

[0054] exist Figure 3A and Figure 3B The diagram illustrates the operation of the equipment. (Reference) Figure 3A The blood metering device 130 is attached to the culture flask 160 by placing the adapter unit 150 on the neck of the culture flask 160 so that the needle 152 pierces the cap 163. During blood aspiration, the indicator light 184 is one color (e.g., red). Optionally, the indicator light 184 will flash. Optionally, the flashing frequency will be correlated with blood flow. When a target aspiration volume is detected or a predetermined blood aspiration duration has been reached, the indicator light 184 changes to a second color (e.g., green). Optionally, the metering device sends a signal to the valve actuator 188 that will cause the valve actuator 188 to close the valve, which will cut off blood flow from the patient. The blood metering device 130 is then detached from the culture flask 160. In one embodiment, the adapter unit 150 is spring-loaded, wherein the spring is biased to force the adapter unit to disengage from the culture flask 160. During operation, the metering device is pushed by the operator or the collection device to engage with the culture flask or other collection vessel. Once the collection is complete, the force holding the adapter unit 150 in contact with the collection vessel is released, and the spring-loaded bias force 171 of the adapter unit forces the adapter unit 150 to separate from the culture flask 160.

[0055] Figure 3B The illustration shows an alternative workflow where the blood metering device 130 is used to collect blood 210 into the blood collection tube 200 instead of the culture flask 160. The operation is as described above. Figure 3A The diaphragm cap 173 on the blood collection tube 200 is slightly different from the cap 163 on the blood culture bottle, but during operation, the needle 152 still pierces the diaphragm of the diaphragm cap 173, just as it pierces the diaphragm of the cap 153.

[0056] Figure 4 yes Figure 2BAn exploded view of the adapter unit 150. The adapter unit itself is an assembly containing a paddle wheel housing 156 with an inlet 164 and the adapter 150. A valve 189 and a paddle wheel 154 are disposed between the paddle wheel housing 156 and the adapter 150. The paddle wheel is rotatably mounted on a pin 158. Blood flows through a flow path 162 of the adapter 164 through the paddle wheel housing and exits from the needle 152. An activation lever 190 is disposed on the housing and fitted through a cutout 187 in the paddle wheel housing 156. This allows the activation lever 190 to be activated by placing a sensor unit housing 180 on the paddle wheel housing 156.

[0057] Figure 5 yes Figure 2A The figure shows an exploded view of the sensor unit 140. A processor 182, an indicator 184, a battery 186, and a valve actuator 188 are housed within the housing 180. The valve actuator 188 controls a valve 189 located near the paddle wheel housing 156 of the adapter unit 150. The sensor unit 140 includes device actuators and sensor electronics. In response to the blood volume sensed by the metering device, the printed circuit board 182 (which carries the processor and other electronics) can indicate when a predetermined target volume has passed through the metering device using the indicator 184 (illustrated as a colored light), but indication via audible signals or vibration is also possible.

[0058] refer to Figure 6 The inlet 164 to the housing 156 may optionally have a small nozzle 167 that aims a concentrated jet of blood onto the impeller 154A. Figure 8 In the embodiment illustrated, a small magnet 168 is integrated into a propeller 154. A non-contact Hall effect sensor (not shown, but disposed in sensor unit 140) is capable of measuring the rotation of the magnet 168 through a housing 156A (in which the flow path 164 through the housing 156A is linear), in which the propeller 154 is disposed. Other examples of sensors include axial rotor sensors, where the turbine is orthogonal to the direction of blood flow. In response to blood flowing through the turbine, the turbine causes the rotor to rotate, and the rotation of the rotor is used to determine the blood flow through the sensor. Other suitable sensors include peristaltic pump sensors, magnetic field sensors, and rotation sensors.

[0059] In one embodiment, the blood metering device 130 is programmed to provide several different selectable blood volume presets for the blood volume passing through the impeller 154. The presets are common blood volumes drawn from patients (e.g., 10 mL).

[0060] Zhen, W. et al.'s "Computational study of the tangential type turbine flowmeter" (Flow Measurement and Instrumentation, Vol. 19, pp. 233-239 (2008), which is incorporated herein by reference) describes the calibration of tangential turbine flowmeters. Figure 6 In the equation, W1 is the import speed, and r o This is the axis between the shaft and the axis of the injection outlet. As described in Zhen et al., the rotor drive torque (T) is calculated using the following formula. r ):

[0061] Tr=ρQ(V1rcosα1-V2rcosα2) (1)

[0062] Where ρ is the fluid density, Q is the volumetric flow rate, r is the rotor radius, α1 is the angle between V1 and U1, and α2 is the angle between V2 and U2. The absolute velocity V1 is determined by the following formula:

[0063] V1=Q / A (2)

[0064] Where A is the injection orifice diameter. The rotational speed (n) is calculated as follows:

[0065] V²cosα²=u=2πr o n (3)

[0066] Calculate the rotor drive torque from the above. Then calculate the metering performance using the following formula:

[0067] T r -T rm -T rf -T re =0 (4)

[0068] Where T r It is the rotor drive torque, T rm It is the journal bearing's resisting torque, T rf This is due to the rotor blade stall torque caused by hydrodynamic resistance, and T re This is due to the resistive torque caused by the attractive force of magnetic pickup. As further described by Zhen et al., these values ​​are used to calculate values ​​for turbine metering performance. This allows the volumetric flow rate to be determined from rotor speed, impeller flow meter size, etc.

[0069] The dimensions of the impeller 154 and housing 156 are primarily a matter of design choice. A smaller impeller 154 will achieve a greater blood flow rate per milliliter through the impeller than a larger impeller. The individual impeller blade 154A within the impeller 156 ( Figure 6 The width of the nozzle should be slightly larger than the width of the blood jet (this width will be comparable to the opening in the nozzle portion 167 of the housing inlet 164). Other non-contact means of detecting the movement of the propeller, such as LEDs and photosensitive receivers, can be used. This is in Figure 6 The middle part is shown as 170.

[0070] exist Figure 7-8 The diagram illustrates an alternative coaxial housing configuration 156A. In this configuration, the housing inlet 264 and outlet 266 are coaxial, and the blood flow path is linear. Figure 2B The diagram shows a housing 156 with housing inlet 164 orthogonal to housing outlet 166.

[0071] The blood jet is tangentially ejected onto the impeller 154, resulting in a torque (or moment) on the impeller 154, which in turn causes the impeller 154 to rotate. This is caused by the kinetic energy of the blood jet. After the impeller housing 156 is initially filled with blood, air bubbles form and impede the movement of the impeller 154.

[0072] As mentioned above, the relationship between the impeller rotation speed and the actual blood volume passing through is not linear. In addition to the driving jet of fluid on the impeller, there is also a damping effect from the impeller rotation within the fluid. This causes "slippage," which will vary due to differences in pressure and viscosity. Optionally, the impeller behavior can be monitored and modeled to predict slippage based on flow conditions. Once slippage is determined, the flow conditions can be provided to a processor, which can then account for slippage to correct the volume calculated based on the impeller rotation speed. This can lead to large fluctuations in the volume measured using actual measurements.

[0073] Optionally, the device will be calibrated to correlate the measured volumetric volume with the actual volumetric volume. This will ensure that the blood metering device described herein accurately draws the target volume of blood (typically 8 mL to 10 mL) at all times. The rate at which blood is drawn also affects the accuracy of the measured volume. It is conceivable that the metering device described herein will be calibrated such that the effect of flow rate on the measured volume is known. In one embodiment, the number of revolutions of the impeller is correlated with the volume of blood flowing through the impeller. In an alternative embodiment, the rotational speed (i.e., the impeller's RPM) is used to determine the flow rate, which is then used to calculate the volume of blood passing through the impeller. Once calibrated, the metering device measures the rate of blood flow and adjusts the measured volume to compensate for known inaccuracies in volume measurement at a given blood flow rate. Optionally, the blood metering device has a switch to power on and reset the system whenever a new blood culture bottle is presented for filling.

[0074] Although the embodiments described herein depict paddlewheel flow meters, other metering devices, such as filament sensors, acoustic sensors, optical sensors, etc., are also conceivable. Such sensors are well known to those skilled in the art and are not described in detail herein. In some embodiments where the sensor unit does not come into contact with blood, the sensor unit can be reused.

[0075] As previously described, the combined flow meter / pump (the blood metering device described herein) can be configured to detect venous constriction (by detecting reduced or insufficient blood flow) and venous re-expansion (by stopping blood flow through the metering device without removing the needle used for blood extraction from the patient). As mentioned above, the blood metering device described herein can be actuated once the device has determined that a target volume of blood has been extracted, thereby stopping blood flow through the metering device.

[0076] To actively measure blood flow, a low-density commutated magnetic field can be induced by the controller to assist rotor rotation at low flow rates. Figure 9 The diagram illustrates a disposable flow meter / pump 300. As shown, the stator 310 (i.e., housing) and rotor 320 are completely separate and can be easily disassembled. The rotor 320 can be a single-piece sintered and magnetized part. A magnet 330 is placed on the rotor 320. A Hall effect sensor 340 detects the passing magnet and determines the rotor RPM. The volume of blood flowing into the culture bottle is determined from the obtained RPM. In pump function, the rotor is driven by coils A and B 350. Figure 9 The device shown in the diagram should be noted that the flow meter and pump functions cannot be performed simultaneously. The Hall sensor can be omitted by measuring the back EMF from coil 350.

[0077] The magnet 330 on the rotor 320 also acts as a blade (such as...) Figure 6 (The impeller 154A). Therefore, the motor 300 can act as a paddlewheel flow sensor, or as a centrifugal pump when driven by the coil 350. The housing 310 surrounding the rotor 320 is airtight / waterproof and made of a non-conductive material, so it does not interfere with the magnetic field required to drive the rotor. There are tangential inlets / outlets 360 entering the housing and axial inlets / outlets (not shown in the image). Figure 9 (See diagram). Optionally, the two coils are positioned such that the coils and Hall sensor cover less than 180 degrees of the rotor's circumference. This makes disassembly much easier compared to current stator designs that cover the entire 360 ​​degrees.

[0078] A low-power rotating magnetic field is provided for commutation of motor 300 to facilitate driving the impeller in the device even at low flow rates. Optionally, rotor 320 is made of a single piece of magnetizable material. Optionally, rotor 320 is annular with protrusions 330 on its outer circumference that act as magnetic poles and impeller blades. Stator 310 has at least two poles, which is why two coils 350 are illustrated. Coils 350 are positioned no more than 180 degrees apart on the stator. This ensures easy assembly / disassembly of rotor / housing 320 and stator 310. The illustrated device 300 can be incorporated into devices for measuring blood flow and / or pumping blood, drugs, samples, reagents, etc., into a patient or into a vessel (such as a collection tube). In this example, the poles / magnets are radially oriented; they can also be axially oriented. The motor is preferably synchronous, but asynchronous commutation is also possible.

[0079] Figure 10 The illustration shows an alternative configuration of the blood metering device and the blood culture bottle. The blood metering device 430 is attached to the blood culture bottle 460. In this embodiment, the sensor portion 440 and the adapter portion 450 are integrated to form the blood metering device 430.

[0080] Figure 11 yes Figure 10 An exploded view of the components. In this illustration, the integrated blood metering device 430 is removed from the blood culture bottle 460.

[0081] Figure 12 The diagram illustrates a blood collection system comprising a needle 410, a tube 420, a blood metering device 430, a sensor section 440, an adapter section 450, and a collection bottle 460. During the process of collecting a blood sample from a patient, the needle 410 is used to puncture a vein or artery in the patient. Driven by the vacuum pressure generated by the collection bottle 460, blood from the patient is guided through the tube 420 toward the collection bottle 460. The blood is collected in the collection bottle 460.

[0082] Figure 13This is a perspective view of a disposable blood measuring device 430, viewed from the front of the sensor section 440 integrated with the adapter section 450. The blood measuring device 430 has a processor 482 with a small embedded memory and a disposable printed circuit board (PCB). Information controlling the operation of the blood measuring device is stored in the processor's embedded memory. Non-limiting examples of this information include the total blood volume passing through the device (i.e., the predetermined fill volume); the maximum duration of blood extraction (after which the device terminates further blood collection from the patient); and changes in the blood flow rate from the patient indicating venous constriction. An LED indicator 484 provides an indication of the volume of fluid (e.g., blood) that has passed through the blood measuring device 430. Other indications (for both the user and the actuator) that the predetermined fill volume has been received by the container include sensory warnings, such as vibration warnings.

[0083] Figure 14 This is a perspective view of the blood metering device 430 as seen from the rear of the sensor section 440 integrated with the adapter section 450. The blood metering device 430 has a paddle wheel 454 placed in a blood flow path 462, which enters through the top 431 of the blood metering device 430. A Hall sensor 469 senses a magnet 468 in the paddle wheel, and the number of rotations sensed by the Hall sensor 468 is converted into volume by a processor 482. A mechanical contact 490 senses contact between the blood metering device 430 and the collection bottle 460 and initiates / initiates blood extraction from the patient into the collection bottle 460.

[0084] In this specification, the word "comprise" should be understood in its "open" sense, that is, in the sense of "including," and therefore not limited to its "closed" sense, that is, in the sense of "consisting of only...". The corresponding meanings belong to the corresponding words "comprise," "comprised," and "comprise (include)" in the places where they appear.

[0085] While specific embodiments of this technology have been described, it will be apparent to those skilled in the art that the technology can be implemented in other specific forms without departing from its essential characteristics. Therefore, these embodiments and examples are to be considered illustrative rather than limiting in all respects. For example, while this disclosure has described the collection of blood from blood culture bottles, the same principles are applicable to the collection of other fluids from other containers.

[0086] It should be further understood that, unless otherwise indicated, any reference in this document to subjects known in the art does not constitute an endorsement of such subjects as commonly known to those skilled in the art.

Claims

1. A blood measuring device, characterized in that it comprises: An adapter unit includes a housing defining a blood flow path, the adapter unit being adapted to be connected to a blood collection device, wherein the adapter unit is provided with a paddle wheel for measuring the volume of blood flowing through the blood flow path, wherein the paddle wheel rotates freely within the housing on an integral pin supported by the housing, the integral pin being part of the blood flow path; and A sensor unit, which is coupled to the adapter unit; The sensor unit includes: i) a sensor configured to detect rotation of the paddle wheel in response to blood flow through the blood flow path in the adapter unit; And ii) a processor, which associates the rotation of the paddle wheel detected by the sensor with the blood volume, and controls the response of the sensor unit in response to determining by the processor that a predetermined volume of blood has passed through the adapter unit.

2. The blood measuring device according to claim 1, characterized in that the sensor unit is either detachably coupled to the adapter unit or integrally integrated with the adapter unit.

3. The blood measuring device according to claim 1, characterized in that the paddle wheel is disposed in the blood flow path.

4. The blood measuring device according to claim 1, characterized in that the paddle wheel has a rotation axis orthogonal to the blood flow direction in the blood flow path.

5. The blood measuring device according to claim 1, characterized in that the paddle wheel has a rotation axis coaxial with the blood flow direction in the blood flow path.

6. The blood measuring device according to any one of claims 3-5, characterized in that the processor controls the response of the sensor unit in response to determining by the sensor unit that the predetermined volume of blood has passed through the paddle wheel disposed in the adapter unit.

7. The blood measurement device according to claim 1, characterized in that the adapter unit can be attached to a collection vessel, wherein the collection vessel is selected from the group consisting of a blood culture bottle and a sample collection tube.

8. The blood measuring device according to claim 6, characterized in that the processor compares the measured blood volume with the predetermined blood volume, and when the measured blood volume is equal to the predetermined volume, the processor is configured to send a signal to close the blood flow valve, thereby cutting off the blood flow to the blood measuring device.

9. The blood measuring device according to claim 1, characterized in that the sensor is one of a filament sensor, an acoustic sensor, and an optical sensor.

10. The blood measuring device according to any one of claims 1-5, characterized in that the sensor is one of an axial rotor sensor, a peristaltic pump sensor, a magnetic field sensor, and a rotation sensor.

11. The blood measuring device according to any one of claims 1-5, characterized in that the paddle wheel carries a magnet, and the housing has a Hall effect sensor disposed thereon, wherein the Hall effect sensor is actuated when the magnet passes by the Hall effect sensor.

12. The blood measuring device according to claim 1, characterized in that the housing defines a blood flow path, wherein the flow path exits the adapter unit through an outlet.

13. The blood measuring device according to claim 1, characterized in that the adapter unit includes an activation lever that activates the processor when the adapter unit is attached to a blood culture bottle.

14. The blood measuring device according to claim 1, characterized in that the sensor unit includes a battery.

15. The blood measuring device according to claim 1, characterized in that the sensor unit includes a valve actuator.

16. The blood metering device according to claim 15, characterized in that the valve actuator is one of a movable magnet actuator, a micro-actuator, a solenoid, or a paired magnet actuator.

17. The blood measuring device according to claim 1, characterized in that the impeller is a combination of a flow meter and a pump.

18. The blood measuring device of claim 17, characterized in that the pump includes a motor, the motor includes a rotor, and wherein the housing forms a stator for the pump.

19. The blood measuring device according to claim 18, characterized in that the rotor comprises one or more magnets.

20. The blood measuring device according to claim 19, characterized in that it further comprises a Hall effect sensor for measuring the rotational speed of the rotor.

21. The blood measuring device according to claim 20, characterized in that the processor determines the volume of blood flowing through the pump based on the rotational speed of the motor.

22. The blood measuring device according to claim 21, characterized in that the blood collection device comprises a needle and tube suitable for venipuncture.

23. The blood measuring device according to claim 22, characterized in that, during operation, when the rotational speed of the motor drops below a predetermined rotational speed, the processor instructs venous constriction.

24. The blood measuring device according to claim 1, characterized in that the sensor unit has an indicator light that indicates, based on a signal from the processor, that a predetermined volume of blood has passed through the adapter unit.

25. The blood measuring device according to claim 23, characterized in that the sensor unit has an indicator light that indicates, based on a signal from the processor, that venous constriction has occurred.

26. A blood measuring device, characterized in that it comprises: An adapter unit includes a housing that defines a blood flow path, the adapter unit being adapted to be connected to a blood collection device, wherein a paddle wheel is provided in the adapter unit, the paddle wheel being disposed in the blood flow path but being freely rotatable within the housing on an integral pin supported by the housing, the integral pin being part of the blood flow path; A sensor unit, which is coupled to the adapter unit; The sensor unit includes: i) A sensor configured to detect a signal from the sensor in response to blood flow through the blood flow path in the adapter unit; ii) A processor that associates the sensor signal with blood volume and controls the response of the sensor unit in response to a determination by the sensor unit that a predetermined volume of blood has passed through the adapter unit; and iii) A valve actuator that communicates with and is controlled by the processor.

27. The blood measuring device of claim 26, characterized in that the adapter unit includes an activation lever that activates the processor when the adapter unit is attached to a blood culture bottle.

28. The blood measuring device according to any one of claims 26 and 27, characterized in that the processor associates the rotation of the paddle wheel with the blood volume to determine the measured blood volume that has flowed through the blood measuring device, and controls the response of the sensor unit in response to determining by the sensor unit that a predetermined volume of blood has passed through the paddle wheel disposed in the adapter unit.

29. A method for determining the volume of blood flowing from a patient to a collection bottle, the method comprising: An assembly comprising an adapter unit and a sensor unit is provided, the adapter unit including a housing defining a blood flow path, the adapter unit being adapted to be connected to a blood collection device, wherein a paddle wheel is disposed within the adapter unit, the paddle wheel being disposed in the blood flow path but being freely rotatable within the housing on an integral pin supported by the housing, the integral pin being part of the blood flow path; The sensor unit includes: i) A sensor configured to detect a signal from the sensor in response to blood flowing through the blood flow path in the adapter unit; ii) A processor that associates the sensor signal with blood volume and controls the response of the sensor unit in response to a determination by the sensor unit that a predetermined volume of blood has passed through the adapter unit; and iii) A valve actuator that communicates with and is controlled by the processor; The component is connected to the blood collection device, which includes a needle and a tube, such that the blood collection device is in fluid communication with the blood flow path; The adapter unit is connected to the blood collection vessel such that the blood flow path in the adapter is in fluid communication with the blood collection vessel, wherein the pressure in the blood collection vessel is less than atmospheric pressure. The needle is used to draw a blood sample, thereby causing blood to flow through the blood flow path to the blood collection dish; This allows the blood to flow through the paddle wheel sensor; Measure the rotation of the propeller sensor; Measure the volume of blood flowing into the blood collection dish from the blood flow path; and Compare the measured blood volume with the predetermined blood volume; When the measured blood volume equals a predetermined blood volume, the processor sends a signal to the valve actuator to stop the blood from flowing into the blood collection vessel.

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