System and method for drum position detection

Abstract

A system (6000) and method (7000, 7050) for detecting the position of a rotating drum (6050) of a blood culture device relative to a stationary measurement plate (6060) disposed adjacent to the rotating drum (6050). The system (6000) and method (7000, 7050) may adjust at least one stored signal of a sensor (6062) of the measurement plate (6060) based on a detected position of the rotating drum (6050).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is related to PCT application number PCT / US2020 / 045065 filed on August 5, 2020, which is incorporated herein by reference. This application claims priority and the benefit of U.S. Provisional Patent Application No. 63 / 390,506 filed on July 19, 2022, which is incorporated herein by reference. Technical Field

[0003] The present technology relates to systems and methods for detecting the position (and changes thereto) of a rotating drum of a blood culture apparatus relative to a stationary measurement plate disposed adjacent to the rotating drum. The systems and methods of the present technology adjust at least one signal of a sensor of the measurement plate based on the detected position of the rotating drum. Background Art

[0004] Blood culture bottles are commonly used to determine whether biologically active substances, such as bacteria, are present in patient body fluids, especially blood. A small amount of blood is injected into a sterile bottle containing culture medium through a closed rubber septum, and the bottle is then incubated at about 35°C and monitored for growth of microorganisms.

[0005] Because it is so important to know if a patient has a bacterial infection, hospitals and laboratories have automated devices that can process multiple blood culture bottles simultaneously. An example of such a device is the BD BACTEC TM The invention relates to a blood culture apparatus for treating a patient's condition in a manner similar to that of a human. The invention relates to a blood culture apparatus for treating a patient's condition in a manner similar to that of a human. The invention relates to a blood culture apparatus for treating a patient's condition in a manner similar to that of a human. The invention relates to a blood culture apparatus for treating a patient's condition in a manner similar to that of a human. The invention relates to a blood culture apparatus for treating a patient's condition in a manner similar to that of a human. The invention relates to a blood culture apparatus for treating a patient's condition in a manner similar to that of a human.

[0006] 1, a culture medium and blood specimen mixture 22 is introduced into a sealable glass bottle 1, which includes an optical chemical sensing device 20 on its inner bottom surface 21. The optical chemical sensing device 20 emits different amounts of light depending on the amount of gas in the bottle 1. For example, the gas detected by the optical sensing device 20 may be carbon dioxide, oxygen, or any gas that increases or decreases depending on the presence or absence of microbial growth in the bottle 1.

[0007] As illustrated in Figures 1 and 2, a plurality of such bottles 1 are radially arranged on a rotating bell drum 2 in an incubator 5, with the bottom of the bottle 1 facing the drum axis 28. The bell drum 2 is hollow and supported by a shaft 24, one end of which is rotatably supported by two large ball bearings 3 and 4 mounted on a first side 51 of an instrument mainframe 50. In order to read the information from each optical chemical sensing device 20 in the bottle 1, a linear array 12 of sensor stages is mounted in the rotating bell drum 2 to a second side 52 of the instrument mainframe 50 at such a distance that during the rotation of the drum 2, each bottle 1 passes by a respective sensor stage 15 in the array 12. Each sensor stage 15 in the linear array 12 of sensor stages includes an excitation light source 11 and a collecting end of an optical fiber 14.

[0008] The axis 28 of the bell drum 2 is oriented horizontally and parallel to the door 13 located at the front of the incubator 5, as illustrated in FIG2 . The horizontal orientation of the axis 28 provides maximum agitation of the liquid culture medium and specimen mixture 22 and the gas within each bottle 1. During a loading or unloading operation, the door 13 is opened, which allows access to approximately one third of all bottles 1 simultaneously. The drum 2 then rotates until the next third of the bottles 1 are accessible. In three steps, all bottles 1 are accessible.

[0009] Optionally, the axis 28 of the bell drum 2 is oriented vertically, slightly inclined about 20 degrees from the door 13. By adjusting the angle of inclination, the degree of agitation can be varied as desired to maintain optimal growing conditions.

[0010] In operation, the bell drum 2 is rotated by means of a motor 6 and a belt 7. The circular member 8 and the sensor 9 form an angle encoder which provides information about which row of bottles 1 has passed the sensor stage array 12. Preferably, the motor 6 is a stepper motor, allowing the drum 2 to rotate in a continuous mode, or to stop the drum 2 at a suitable angle in order to read from the sensing devices 20 inside the bottles 1 in a steady-state mode. The entire system is controlled by a control system 10 located inside the rotating drum 2. The output ends of all optical fibers 14 of the linear array 12 of sensor stages are fed to a common light detector (not shown) in the control system 10, so that only one excitation light source 11 needs to be turned on at a time. Thus, the control system "knows" from which sensor stage 15 the sensing light is to be collected, and therefore from which bottle 1 the sensing light is to be collected.

[0011] The device illustrated in Figures 1 and 2 positions the bottle to be inspected by means of a sensor. However, a technical solution to any misalignment between the sensor and the bottle continues to be sought. Summary of the invention

[0012] Described herein are systems and methods for detecting the position (and changes thereto) of a sample container (e.g., a bottle) carried by a rotating drum in a blood culture processing device relative to a measurement plate disposed adjacent to the rotating drum. The systems and methods of the present technology have a measurement and alignment module that can adjust at least one signal provided from a sensor of the measurement plate based on the detected position of the rotating drum.

[0013] In one aspect, a system for detecting the position of a drum and bottles carried in the drum is described. The system includes a drum-shaped fixture, a measurement board, a plurality of timing targets, a target sensor, and a controller. The drum has an outer perimeter and a plurality of receptacles, each for receiving a blood culture bottle. The outer perimeter is arranged around the rotation axis of the drum. The plurality of receptacles are arranged in the drum as a receptacle array. The array has vertically and horizontally arranged receptacles, and the vertically arranged receptacles form columns, and the horizontally arranged receptacles form rows. The measurement board is arranged at a stationary position adjacent to the drum, and includes a sensor column configured to interrogate a column of bottles in the drum that moves past the measurement board as the drum rotates around the axis. A plurality of timing targets are arranged around the outer perimeter of the drum, which rotate with the drum. The target sensor is arranged at a stationary position adjacent to the drum, and the target sensor is configured to detect one or more features of the timing target when each timing target moves past the target sensor as the drum rotates around the axis. The controller is configured to determine the position of the drum based on data from the target sensor.

[0014] In one aspect of the system, the determined position of the roller includes a roller offset and a roller angle.

[0015] In one aspect of the system, the controller is configured to detect a position of the drum based on timing data associated with detected characteristics of a timing target moving past the target sensor as the drum rotates.

[0016] In one aspect of the system, the timing data includes timing ratios associated with a plurality of timing targets.

[0017] In one aspect of the system, the controller is configured to normalize the timing ratio.

[0018] In one aspect of the system, the controller is configured to fit the normalized timing ratio to a sinusoidal function.

[0019] In one aspect of the system, the controller is configured to calculate the roller offset from the amplitude of the sinusoidal fit of the normalized timing ratio.

[0020] In one aspect of the system, the controller is configured to calculate the drum angle from the phase of the sinusoidal fit of the normalized timing ratio.

[0021] In one aspect of the system, the target sensor is an optical sensor.

[0022] In one aspect of the system, the optical sensor is configured to change state when a feature of the timing target interrupts an optical path of the optical sensor.

[0023] In one aspect of the system, the controller is configured to detect the position of the drum based at least in part on a change in state of the optical sensor.

[0024] In one aspect of the system, the one or more characteristics of each timing target include a first edge and a second edge of the timing target.

[0025] In one aspect of the system, the first edge extends radially from the outer periphery of the drum, and the second edge includes a first end and a second end, wherein a radial distance from the outer periphery of the drum to the second edge continuously decreases from the first end of the second edge to the second end of the second edge.

[0026] In one aspect of the system, the first end of the second edge is connected to the first edge.

[0027] In one aspect of the system, the second end of the second edge is connected to a first edge of an adjacent timing target of the plurality of timing targets.

[0028] In one aspect of the system, a plurality of timing targets are each vertically aligned with a carriage column of rollers.

[0029] In one aspect of the system, the controller is configured to adjust at least one signal of at least one sensor in the sensor column in the measurement board based on the determined position of the roller.

[0030] In one aspect of the system, the at least one signal is a signal stored in a memory of the system.

[0031] In one aspect of the system, the drum has an upper end and a lower end, and a plurality of timing targets are disposed proximate the lower end of the drum.

[0032] In one aspect of the system, a target sensor is mounted to a measurement board.

[0033] In one aspect, a method for detecting the position of a drum and bottles carried in the drum is described. The method includes rotating a drum-shaped fixture having an outer perimeter about a rotational axis of the drum, the drum having a plurality of brackets, each bracket configured to receive a blood culture bottle, wherein a plurality of timing targets are disposed about the outer perimeter of the drum and rotate with the drum; accumulating sensor signals from a sensor column of a measurement plate disposed at a fixed position adjacent to the drum, the sensor column configured to interrogate the column of bottles in the drum moving past the measurement plate as the drum rotates about the axis; accumulating data from a target sensor disposed at a stationary position adjacent to the drum, the target sensor configured to detect a feature of the timing target as each timing target moves past the target sensor as the drum rotates about the axis; storing the accumulated sensor signals and the accumulated target sensor data in a memory; calculating a position of the drum relative to the stationary measurement plate based on the stored target sensor data from the target sensor; and adjusting at least one of the stored sensor signals based on the calculated drum position.

[0034] In one aspect of the method, the calculated position of the roller includes a roller offset and a roller angle.

[0035] In one aspect of the method, the position of the drum is detected based on timing data associated with detected features of a timing target that moves past a target sensor as the drum rotates.

[0036] In one aspect of the method, the timing data includes timing ratios associated with a plurality of timing targets.

[0037] In one aspect of the method, the method further comprises normalizing the timing ratio.

[0038] In one aspect of the method, the method further comprises fitting the normalized timing ratio to a sinusoidal function.

[0039] In one aspect of the method, the method further comprises calculating the roller offset from the amplitude of the sinusoidal fit of the normalized timing ratio.

[0040] In one aspect of the method, the method further comprises calculating the drum angle from the phase of the sinusoidal fit of the normalized timing ratio.

[0041] In one aspect of the method, the target sensor is an optical sensor.

[0042] In one aspect of the method, the optical sensor is configured to change state when a feature of the timing target interrupts an optical path of the optical sensor.

[0043] In one aspect of the method, the position of the drum is calculated based at least in part on a change in state of the optical sensor.

[0044] In one aspect of the method, the one or more features of each timing target include a first edge and a second edge of the timing target.

[0045] In one aspect of the method, the first edge extends radially from the outer perimeter of the drum, and the second edge includes a first end and a second end, wherein a radial distance from the outer perimeter of the drum to the second edge continuously decreases from the first end of the second edge to the second end of the second edge.

[0046] In one aspect of the method, the second end of the second edge is connected to a first edge of an adjacent timing target of the plurality of timing targets.

[0047] In one aspect of the method, a plurality of timing targets are each vertically aligned with a carriage column of rollers.

[0048] In one aspect of the method, the drum has an upper end and a lower end, and a plurality of timing targets are disposed proximate the lower end of the drum.

[0049] In one aspect of the method, a target sensor is mounted to a measurement board. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] FIG1 shows a front view of the interior of a blood culture device for detecting microorganisms of the prior art;

[0051] FIG2 shows a side view of the interior of a prior art blood culture device;

[0052] Figure 3A and Figure 3B illustrates a perspective view of a blood culture device housing for use with the modules described herein;

[0053] Figure 4 is a top view of an incubation and measurement module according to one aspect of the present technology;

[0054] Figure 5A-5C A bottle holder drum is illustrated in side and partial top view, with and without a section removed to show a bottle detection status indication (BDSI) plate;

[0055] Figure 6A-6E Illustration of the lifting mechanism used to service the motor inside the drum;

[0056] Figure 7A-7D illustrates a BDSI board, a measurement board and a controller connection board forming part of the measurement board, and alignment marks and a segment identifier sensor mark working with the alignment sensor and segment identifier sensor on the controller board;

[0057] Figure 8 illustrates the configuration of the drum position sensor that indicates to the BDSI board which drum section is aligned with the door of the drum module;

[0058] Fig. 9 illustrates one example of the progression of the drum / bottle status panel line pattern used to guide the user in aligning the drum with the BDSI plate;

[0059] Figures 10A-10I illustrates aspects of light sources and detectors used for bottle interrogation;

[0060] Fig.11 is the drum illustrated in FIG. 5 having a transparent internal reflective light tube forming a cradle for receiving a blood culture bottle;

[0061] Figure 12A-12C Illustrated for Fig.11 The light tube of the drum;

[0062] Fig.13 illustrates a top view of a bottle drum as described herein;

[0063] Fig.14 Diagram of bottles in a holder with light tubes;

[0064] Figure 15A-15E Diagram showing bottles retained in holders with light tubes;

[0065] Fig.16 is a block diagram of a measurement system for detecting the position of a rotating bottle drum relative to a measurement plate in accordance with various aspects of the present technology;

[0066] Fig.17 is the rotating drum and measuring plate and Fig.16 A partial side cross-sectional view of an optical switch and multiple timing targets of a measurement system;

[0067] Fig.18 yes Fig.16 Bottom view of the optical switch and multiple timing targets of the measurement system;

[0068] Fig.19 yes Fig.16 A detailed view of a portion of the measurement system showing the optical switches and multiple timing targets;

[0069] Fig. 20 , Fig.21 and Fig. 22 yes Fig.17 A partial perspective view of the rotating drum, measuring plate, optical switch and timing target;

[0070] Fig.23 is a graph illustrating a sinusoidal fit of distance measurement data to normalized roller position, used to determine changes in roller position;

[0071] Fig.24illustrates a flow chart for detecting changes in the position of the roller and the measurement of the sample bottle, and conditioning the sensor signal obtained from the sample bottle by the measuring board;

[0072] Fig.25 , Fig.28 and Fig.31 The radial diagrams of the position of the rotating drum under various load conditions are illustrated respectively;

[0073] Fig.26 , Fig.29 and Fig.32 The relationship between the percentage change of the measurement signal of the measuring plate and the change of the distance between the bottle in the drum and the sensor on the measuring plate is respectively illustrated;

[0074] Fig. 27 , Fig.30 and Fig.33 respectively illustrate a comparison of an unadjusted sensor signal and a sensor signal adjusted based on a detected change in drum position;

[0075] Fig.34 A rotating drum and a measuring plate according to another aspect of the present technology, Fig.16 A partial side cross-sectional view of first and second optical switches and a plurality of timing targets of a measurement system;

[0076] Fig.35 Another aspect of the present technology is illustrated. Fig.16 timing targets for use with measurement systems; and

[0077] Fig.36 Illustrated is a flow chart for detecting changes in roller position and adjusting the sensor signal obtained from the sample bottle via the measurement board. DETAILED DESCRIPTION

[0078] A blood culture device is described herein that is configured as an incubation and measurement module that can optionally be integrated into a larger end-to-end solution for processing biological samples to determine whether such samples are contaminated or infected with microorganisms. The module described herein can be placed in Figure 3A and 3B The cabinet 200 can provide power to the modules, provide a controlled thermal environment for the modules, and provide communication channels for the modules. Figure 3A Illustrated is a cabinet 200 with two three-door panels 201 providing access to three bottle drums on each side of a center panel 202. The center panel 202 has a touch screen 203 for data entry and usage control. The center panel 202 also has a central work station 204 for culture bottle input / output. Figure 3B A cabinet having only one three-door panel 201 is illustrated.

[0079] The number of doors will then depend on the number of rollers. The number of roller mounts in a module is primarily a matter of design choice, with single, double and triple roller configurations considered herein. The apparatus described herein is not limited to any particular number of rollers.

[0080] The module has a high-density bottle drum. High density as used herein is a description of a drum configuration that allows culture bottles to be placed closer to each other than in the prior art, thereby allowing a greater number of culture bottles to be loaded into the drum. The module is configured to align the bottle with a limited number of reading stations. That is, the number of reading stations is less than the number of bottle holders in the drum. Optionally, the drum is operated by a direct drive motor that can cause acceleration and deceleration motion of the drum (i.e., rocking motion, intermittent rotation, etc.). The heater and blower are provided in the drum housing, or in the space above or below the portion of the housing that receives the drum. The heater and blower circulate warm air around the drum. Optionally, the heater and blower will be configured to keep the temperature of all the contents of the culture bottles in the drum within a predetermined narrow range of a specific target temperature. The predetermined narrow range is ±0.5°C of the target temperature. The specific target temperature range is 30°C to 40°C. Optionally, the target temperature is 36.55°C. Higher temperature uniformity will allow the set point to be increased because the risk of "overheating" of the sample is less. Therefore, higher temperature uniformity at higher temperatures will allow faster detection times. The motor will allow the drum to be positioned so that the user or an automatic device can access any bottle carried by the drum. When the sample in the bottle is determined to be positive for microbial growth, the workflow is activated to retrieve the culture bottle from the module. The module is configured to assist in this workflow. The location of module components such as a blower in the module is primarily a matter of design choice and is not described in detail herein. The module may include other features such as vents, baffles, dampers, etc. to further regulate and control the temperature and temperature profile within the module.

[0081] The module is equipped with LEDs and light pipes to indicate positive culture bottles to the user. Figure 4, illustrates a top view of an optional configuration of the module described herein. The module 210 has a housing 224, a blower and heater 225 for maintaining the temperature of the bottles 230, and a drum 240 with a rack for accommodating culture bottles. In the illustrated aspect, located inside the drum are bottle presence sensor electronics 250 and culture bottle presence / status indicator electronics 260 (the BDSI board includes these electronic components in common). A drive motor 270 is provided to rotate the drum 240. In other aspects described herein, the electronics are located near the drum exterior. The housing 224 of the drum 240 has six panels 221 defining six drum sectors (222A-222F). As illustrated, approximately one-sixth of the contents of the drum (assuming the drum is full) can be accessed at any given time because the span of a sector is approximately the same as the span of the opening in the housing through which bottles are added to or removed from the drum 240. Figure 5A yes Figure 4 The culture bottles (not shown) are positioned neck-inwardly in the cradle 220 of the drum 240 and received by a cradle configured as a light pipe 515. The motor 270 is a direct drive motor that provides high torque, virtually no hysteresis, low noise, reliability, and simplicity.

[0082] In one aspect, the drum 240 is configured such that the motor assembly 270 and the gearbox 271 are located inside the drum 240 . Figure 5A 2 illustrates a drum 240 with a rack 220 for receiving a culture bottle (the culture bottle is not shown). As described above, the drum 240 is assembled in sections of the rack 220, and Figure 5B The roller 240 is illustrated with a section of the carriage 220 removed. A status indicator panel 273, which is more visible when the panel is removed, is used to illuminate the light pipe 515 to indicate the status of the bottle held in the light pipe 515. The status indicator (BDSI panel) panel 273 can also be disassembled and removed from the frame 274 of the roller 240. As used herein, "status" is the status of the blood culture bottle determined by the module 210. The status of the blood culture bottle can be microbial growth positive or microbial growth negative. In one aspect, the status of the blood culture bottle is conveyed by colored lighting of the bottle carriage in the roller, in one aspect, green light indicates a bottle with microbial growth negative, and red light indicates a bottle with microbial growth positive. The BDSI panel 273 is also configured to indicate whether a bottle is present in the roller workbench or whether no bottle is present. The BDSI panel 273 is also configured to indicate an error of the workbench.

[0083] Reference Figure 5C, provides a top view of the frame 274 with the status indicator plate section removed therefrom. Cables 275 provide power to the motor assembly 270. The bottom 276 of the frame 274 is also illustrated. The drive motor assembly 270 drives the drum 240 in axial rotation. The bearings within the gearbox of the drive motor assembly 270 provide both axial alignment of the drum 240 and the necessary thrust load support required to propel the drum carrying a large number of bottles 230. Fig. 6A , the axis AA of the drive motor assembly 270 is aligned with the axis AA of the drum 240. Therefore, the center of gravity of the drum 240 / drive motor assembly 270 is located on the central axis. The drum 240 / drive motor assembly 270 is equipped with a lifting mechanism 272 to expose the motor assembly 270 for maintenance by lifting the drum 240. In one aspect, as Fig. 6E As illustrated in FIG, the lifting mechanism is a screw 2720 that travels through a motor assembly support plate 2721 and a guide nut 2722. When pushed upward, the screw 2720 forces a plate 2723 upward. The plate 2723 travels upward along the guide pin 2726. This causes the drum 240 to be lifted from the drum support 2400 and forms a lifting space 2401 between the drum frame 274 and the rotor 2724 of the motor assembly 270. Referring to FIG. Figure 6C A locking tool 2402 is provided and insertable into the lifting space 2401 to lock the drum in place relative to the motor assembly 270 so that the motor can be serviced without bearing the weight of the drum 240. Fig.6D An example of a suitable locking tool 2402 is illustrated in FIG. As illustrated, the locking tool 2402 has a handle 2403 secured to a support frame 2404. The locking tool 2402 is inserted between the rotor 2724 and the drum frame 274 (illustrated in phantom). The weight of the rotor 2724 and the drum frame 274, which is secured to the rotor via hexagonal bolts 2725, is supported by the maintenance frame 2405 when the motor assembly 270 is serviced. Fig. 6E A detailed view of the lifting assembly 272 is provided in FIG. Cable 275 provides power to the motor assembly 270. As previously explained, the screw 2720 advances upward through the plate 2721 and the guide nut 2722 to raise the support frame 2723 (traveling along the guide pins 2726), thereby lifting the weight of the drum 240 from the motor assembly 270 for servicing.

[0084] As previously mentioned, the device is provided with a status indicator panel 273. Figure 5A and Figure 5BAs explained, the drum 240 is arranged in rows of racks 220, divided into sections, each section having multiple rows (e.g., four rows). In one aspect, one row in a section is reserved for reference bottles. Users can enter and exit the various sections in the drum via a door that provides access to a single section (one of 222A-222F in the rack 220). Figure 4 A drum divided into sections is illustrated in FIG.

[0085] To sense bottle entry and removal and provide feedback to the user during entry and exit of sections 222A-222F in drum 240, there are bottle presence sensors 250 (bottle sensors) and culture bottle / status indication electronics 260 (e.g., lights) on status indicator plate 273. Fig. 7A The bottle sensors 250 each sense when a bottle is inserted into or removed from a rack 220 in a section 222A-222F accessible through a door of the drum 240. The indicator lights illuminate a light pipe 515 in the drum-shaped rack 220, which transmits light so that it is visible to a user viewing the rack through the open door. This requires that the light pipe 515 of the rack 220 is aligned with the culture bottle / status indication electronics 260 in the status indication plate 273. When properly aligned, the module 210 can positively indicate the status of the bottle (e.g., positive for microbial growth or negative for no microbial growth) and detect when a bottle is inserted or removed.

[0086] To make all bottles in drum 240 accessible, the user must rotate the drum by causing module 210. As each section of drum 240 is rotated to be visible through the open door, the user can then ensure that the exposed section of drum 240 (one of 222A-222F) is aligned with bottle presence sensor 250 and status indicator light 260 of status indicator plate 273. Fig. 7A In one aspect, the module 210 may have an alignment mechanism (located on the measurement plate 545 or BDSI 273) for aligning the carriers 220 in the drum 240 with the bottle presence sensors 250 and status indicator lights 260 provided on the status indicator plate 273. Those skilled in the art will appreciate that alignment may be accomplished in many different ways, and that the alignment mechanism is just one example of a sensor that may be used to align the drum 240 with the module door, and thus achieve alignment of the bottle carriers with the bottle presence sensors 250 and status indicator lights 260. Such alignment may be manual (e.g., an operator aligns the drum faceplate with the door opening); semi-automatic (an operator may control a mechanism that advances the drum in increments until alignment is achieved) or automatic (a fiducial (e.g., an alignment mark) is detected, and based on its detected position, the drum is aligned with the fiducial(s).

[0087] In one aspect, the alignment mechanism also includes alignment marks and segment identifier marks attached to the drum panel that separates the drum segments. The measurement board or BDSI may include an alignment section with an optical sensor disposed on the measurement board 545 that detects the marks on the drum panel as they pass the optical sensor as the drum rotates. See Figure 5B The BDSI 273 is located near the interior of the drum so that it can detect the markings on the drum panel 221. The optical sensor communicates with the main controller which, in one aspect of the module described herein, notifies the user / operator that entry and exit to the drum section is possible through the open door.

[0088] The status indicator board 273 is also referred to as a bottle detection and status indicator (BDSI) board 273. Fig. 7A As illustrated in FIG, the status indicator plate 273 may be located behind the drum and aligned with the door opening. As described above, the module may also have a measurement plate 545. In one aspect, the measurement plate 545 is Figure 7B The controller board is shown in the figure. Fig.13 In one aspect, the measurement plate 545 is fixed near the exterior of the drum 240 .

[0089] In one aspect, each column of status indicator boards 273 can be a single board or multiple interconnected boards. In the illustrated aspect, the four columns of status indicator boards are interconnected by, for example, a flexible ribbon cable (not shown). The measurement board 545 is connected to the main controller board (not shown) for system communication. Fig. 7A As illustrated in , the status indicator plate 273 is mounted inside the drum frame. In contrast, the measurement plate 545 (which may include an alignment section) is located outside the drum so that the markings 2734, 2735 can be detected by the sensor 2739 on the measurement plate 545.

[0090] Reference Figure 7C , the optional alignment section 2731 can have an array of alignment sensors 2732 and an array of segment identifier sensors 2733. In one aspect, the alignment sensors and segment identifier sensors can all be simple optical switches on the measurement board 545. Figure 7C As illustrated in FIG. 1 , the top row may include four alignment sensors 2732, and the bottom row may include segment identifier sensors 2733. The alignment sensors 2732 and segment identifier sensors 2733 may each have a recess 2738 in which a sensor 2739 (e.g., an optical switch) is disposed. Adjacent segments of the drum 240 may be separated by vertical panels 221 (also referred to as drum ribs or walls) extending from the outer surface of the drum. This Figure 4 and Figure 6C This is illustrated in Figure 2. Figure 4As illustrated in FIG, the drum panels or ribs 221 on either side of the sections (222A-222F) are aligned with the fascia 2240 of the housing 224 for full viewing when the user opens the door. The drum ribs 221 also extend to the inner surface of the drum, as shown in FIG. Figure 5C As illustrated in .

[0091] Each drum rib 221 within the drum will have multiple marks (2734, 2735), one mark 2734 for drum alignment and another set of one or more marks 2735 for segment identifiers below the drum alignment mark 2734. Marks 2734 and 2735 are detected when they pass through the groove 2738 and in the respective alignment sensors 2732 and segment identifier sensors 2733.

[0092] As mentioned above, each panel or rib 221 carries two markings, an alignment mark and a sector identifier mark. Fig.7D As can be seen in , the alignment mark can be a continuous mark that spans all four alignment sensors 2732. When the drum is rotated so that all four optical switches in the alignment sensors 2732 register the presence of the mark, this indicates that the drum is in an aligned state. In one aspect, the sensor has a light beam that passes through the sensor gap. When the mark enters the gap, the light beam is interrupted, and this interruption is recorded as an indication that the mark is present. Although the mark interrupts the signal, this is referred to as the "on" state of the sensor because in this state, the sensor detects the presence of the mark. The segment mark 2735 is configured as a unique identifier for a specific segment of the drum. Therefore, the size and number of segment marks for each segment are different, so that each segment produces a unique signal for its specific segment. As illustrated, the sensors 2739 are located in respective grooves 2738, through which the alignment mark / segment identifier mark passes. The sensors are configured as a transmitter / receiver pair, Figure 7C Only one of these is illustrated in Figure 1. In normal operation, the signal from the transmitter to the receiver is uninterrupted. As the marks pass through the sensor, they "break" the light beam and this provides an indication that the mark is present in the sensor. To get a positive indication of alignment, the alignment mark must break the light path of all alignment sensors. The amount of signal "broken" by the segment sensor at that precise point will indicate which segment is about to be rotated into position. Figure 8, the number of sensors that have the segment mark "fired" across the identifier sensor tells the control software which segment is present at the sensor location. At the point when the alignment mark 2734 fully activates all alignment sensors 2732, the segment identifier mark 2735 activates the segment identifier mark sensor 2733 by a wide margin. This will ensure that the correct segment of the drum 240 is identified when the alignment is correct. As previously described, the size and configuration of the alignment mark are the same for each segment, while the segment marks each have a unique configuration so that the signal generated by the segment mark indicates a specific segment of the drum. As described above, the above-mentioned alignment mechanism is an example of a mechanism that can be used to align the drum. Those skilled in the art are aware of other suitable mechanisms for achieving alignment of the drum with the door and other module electronic devices (e.g., the status indicator plate 273).

[0093] The above arrangement allows the module controller (e.g., measurement board 545 or BDSI 273) to manage roller alignment without the need to communicate with the main controller. Once the module door is opened, the measurement board 545 can handle the process of helping the user align the rollers with the bottle detection and status indicator board (BDSI). Whenever proper alignment is determined / indicated as described above, the module will display the status of the workstation.

[0094] The master controller can also handle the alignment of the drum before the door is opened, so that the bottle status of the drum section visible when the user opens the door can be already lit when the user opens the door. In one aspect, the master controller determines when the local controller (i.e., the controller opposite the master controller in the module) activates the status indicator light on the status indicator board 273. For example, to start a manual workflow, the master controller can send a start alignment instruction to the module controller. Thus, the master controller or the module controller can manage the drum movement and status display. The local controller can be located anywhere in the module. In one aspect, the local controller is located on the measurement board 545. In another aspect, the local controller can be located on the status indicator board 273. Due to various reasons described herein, the door of the module can be opened. When the module door is closed, the status indicator light goes out. Instructions from the master controller can start alignment. When the door is opened, the alignment process begins, and the drum advances until the alignment mark activates all alignment sensors installed on the measurement board 545. When alignment is achieved, the local controller can also send to the master controller the specific drum section aligned with the door determined by the segment sensor and the segment mark detected when the alignment mark activates the alignment sensor.

[0095] In one aspect, the master controller cooperates with the status indicator board 273 and provides a state map for the module 210 based on information from the status indicator board 273. The state map is updated when bottles are manually input into and removed from the drum by a user, or when bottles are added or removed by an automated device that communicates with the module 210. When the module door is opened, the master controller shares the state map with the status indicator board 273. When bottles are added or removed from the module 210, the state map is updated and shared with the master controller. If the module is not operating in isolation mode, the master controller can share information with the command center.

[0096] In one aspect, the local controller will enter an error state and indicate to the user that the module door must be closed. The conditions that may lead to an error state are largely a matter of design choice, but may be such as module temperature drop, misalignment, etc.

[0097] like Fig. 7A As illustrated in , the status indicator board is equipped with a plurality of indicator lights that can convey information to the user. Although the lights are located behind the drum 240 and the bottle rack 220, the lights convey information to the user through the light pipe 515 in the rack 220. In one aspect, the status indicator board 273 can convey information in the form of light patterns / light of different colors. The pattern / color / meaning of the light is a matter of design choice. Examples of the information conveyed include the workbench / rack status (blocked, available, etc.) and the bottle status (positive, negative, etc.). The displayed status is communicated to the local controller by the master controller.

[0098] The measurement board 545 may be in communication with a panel that communicates the alignment status to a user. Fig. 9 is an example of a progression of alignment states displayed, which uses multiple lights to convey information about the alignment state of the instrument. For example, when the alignment mark 221 is not aligned with the alignment sensor 2731, the indicator lights are all dimmed 545_1. When the drum section moves into alignment, the columns are illuminated as the mark begins to activate the alignment sensor to move from left to right (first lighting the left column 545_2) or from right to left (first lighting the rightmost column 545_3). This progression of the alignment mark through the alignment sensors (from left to right or from right to left) is illustrated for detection of the alignment mark by the second alignment sensor (545_4; 545_5) or the third alignment sensor (545_6; 545_7). When all four alignment sensors detect the presence of the alignment mark, all alignment sensor indicator lights are illuminated (545_8). On the other hand, the panel will simply convey misalignment (all lights off) or full alignment (e.g., all indicator lights are on).

[0099] Once all alignment sensors are illuminated, the status indicator changes to the workbench state 273_9, and the user can begin manual operations, such as placing bottles in or removing bottles from the module 210. The panel will still provide alignment indications, but some tolerance will be built in because the rollers may move slightly during manual operations. This will avoid triggering misaligned readings that may require resetting the module. In one example, once full alignment is achieved, alignment will continue to be indicated as long as the left-most or right-most alignment sensor continues to detect the presence of the mark. If no alignment sensor detects the mark, the local controller turns off all indicator lights and begins a new alignment scheme.

[0100] Once alignment is confirmed, panel 273_9, which communicates with status indicator panel 273, will indicate the status of each bottle in the carriage. For example, a two-way cross-hatched light indicates a sample with negative microbial growth (column 1, row 1, column 2, rows 3 and 8, and column 4, row 5). A one-way cross-hatched light may indicate a bottle with positive microbial growth (column 1, rows 2, 4, 6, 8, and 9; column 2, rows 1 and 5; column 3, rows 2, 3, 5, 6, and 8; column 4, rows 2, 7, and 9). Unlit lights indicate that there are no bottles in those positions. An advantage of this design is that the user can manually advance the drum when the door is open. In order to automatically advance the drum, it is advantageous to close the door so that nothing gets stuck in the advancing drum. In one aspect, the drum may need to be powered off when the door is open. In this mode of operation, the drum may not be able to advance when the door is open.

[0101] In another aspect, a BDSI panel may be provided on the outside of the drum to convey alignment information, rather than on the outside of the drum as described above. Fig. 9 The BDSI controller will be connected to the BDSI panel to light up the indicator, which can be a light pipe, lens, etc.

[0102] As described above, the rotating drum rotates past the measurement plate 545. As the drum 240 rotates past the various detection devices on the measurement plate, the measurement is performed in a so-called "fly-by" manner, where the rotating drum moves the bottle past the measurement electronics as the measurement is performed. The measurement performed can determine whether the blood culture bottle is positive or negative for microbial growth. Therefore, a measurement sensor on the measurement plate 545 is provided to interrogate the bottle to determine whether its internal gas composition or pH is dynamically changing (i.e., changing) in a manner that indicates metabolic activity generated by microbial growth inside the bottle. For example, a bottle that measures an increase in carbon dioxide over time or a decrease in oxygen concentration over time can be determined to be positive for microbial growth in the bottle. To make this determination, an optical sensor is directed to a chemical sensor in the bottle that indicates the condition of the bottle (e.g., oxygen concentration, carbon dioxide concentration, pH). The location of the chemical sensor in the bottle will depend on what the sensor measures. The headspace in the bottle is the portion of the bottle where the gas inside is separated from the liquid and solid (i.e., sample, nutrients, etc.) in the blood culture fluid.

[0103] Since a culture bottle may be interrogated multiple times before it is determined to be positive or negative for microbial growth, the measurement conditions must be sufficiently consistent between measurements, or the measurement may need to be adjusted if the distance changes. This means that the light from the interrogation sensor 2501 and the distance from the bottle sensor to the photodiode detector 2602 should remain relatively constant between measurements.

[0104] As described above, as the drum 240 with the rows of bottle carriers 222 rotates past the measurement plate 545, the bottles are interrogated row by row. Figures 10A-10I , the sensor (e.g., light source 5451) and detector 5452 are arranged in a housing 5450, which is fastened to and extends from the measurement board 545. The light source 5451 is positioned around a single light detector (photodiode 5452). The housing has a fastening mechanism (flange 5453) for fastening the housing 5450 to the measurement board 273. Fig. 10B , the housing 5450 has ports 5454, 5455 for receiving a light source 5451 and for receiving a photodiode detector 5452. The ports 5454, 5455 are configured so that the light source 5451 surrounds the photodiode detector 5452 and is angled toward the photodiode detector 5452 so that light from the light source 5451 intersects above the photodiode detector 5452 on a bottle sensor (not shown) directly opposite the photodiode detector 5452.

[0105] As the distance between the bottle and the measurement plate 545 increases, the excitation light from the light source 5451 spreads out, and the fluorescence it induces in the bottle sensor is farther from the photodiode detector 5452, the combination of which results in a reduction in the signal generated by the photodiode detector 5452. The light source 5451 can be positioned radially farther from the photodiode 5452 because the intersection point of the light from the light source 5451 with respect to the bottle sensor provides consistency between measurements. It is advantageous if the light from the light source 5451 intersects the bottle behind the bottle sensor that the photodiode is facing. The intersection point is far enough behind the bottle sensor that the illumination of the sensor is off-center, causing the fluorescence induced by the light source 5451 to be partially outside the field of view of the photodiode 5452.

[0106] As the bottle moves away from measurement plate 545, light from light source 5451 converges to the center of the bottle sensor disposed in the blood culture bottle and thus moves into the field of view of detector 5452. The additional fluorescence of the sensor caused by the additional light from the light source impinging onto the bottle sensor offsets the reduction in fluorescence detected by detector 5452 because the bottle and the sensor in the bottle are slightly further away from detector 5452.

[0107] Reference Fig. 10C , housing 5450 has eight light sources 2501 in it. Four of the light sources are of a first color and are designated as 12501_1. The light sources are light emitting diodes (LEDs). In one aspect, four of the light sources are of a second color and are designated as 12501_2. In one aspect, the first color is green, and the second color is cyan. As illustrated, the colors of the light sources alternate around a light detector 5452. A housing 5450 having a port 5454 for receiving a light source 5451 and a port 5455 for receiving a photodiode detector 5452 is illustrated in the upper right corner. Fig. 10E -10J illustrates the transition of light striking the bottle sensor (from near to far). Figures 10E-10G illustrates this transition for a cyan LED, and Fig. 10H -10J illustrates the transition of the green LED (again, from near to far). The above design reduces the variation in measurements due to differences in distance measurements between the light source / light detector and the bottle sensor. The intensity of a diffuse light source drops off in direct proportion to the square of the distance from the light source. This is why the photodiode signal produced by the fluorescence generated by the light from the light source drops off as the distance between the measurement board 545 and the bottle increases. Not only does the intensity of the fluorescence received by the photodiode decrease, but the intensity of the light from the light source hitting the sensor also decreases.

[0108] Reference Fig.11, the bottle drum 240 has a cradle 220 for receiving a culture bottle with its neck placed therein as described above. The cradle 220 has a light pipe 515 formed at the bottom of the cradle, which also defines the bottom edge of the cradle 220. The light pipe is formed of a material that will transmit light through the light pipe structure but prevent light from emitting from the light pipe to prevent significant cross-talk from the light pipe that is lit to the light pipe that is not lit. Suitable materials include polycarbonates (such as Makrolon 2258) and acrylates (e.g., polymethyl methacrylate). (Original name ) is a trade name of Covestro (formerly Bayer MaterialSciences). These materials are all polycarbonate, a very tough, high-impact plastic material. Consider translucent materials, but partially transparent light pipe materials may make the color of the light pipe more challenging.

[0109] Referring again to the status indicator plate 273, the LED that illuminates the light pipe 515 can be a plurality of LEDs that can illuminate the light pipe in a plurality of different colors, each LED indicating a different state of a blood culture bottle housed in the rack 220 having the light pipe. In one aspect, the LED that illuminates the light pipe is located on the status indicator plate and is about 5 mm from the light pipe. As described herein, once the culture bottle status is determined, the BDSI determines the color (e.g., red for positive, green for negative, etc.) that illuminates the light pipe 515 in conjunction with the local controller or the master controller. The light pipe is configured to provide both a color indication of the bottle status and to retain the culture bottle 230 in the roller rack 220. In this configuration, the culture bottle bottom 416 is secured in the rack by a lug 417.

[0110] Fig. 12A 4 is a perspective view of a light pipe bracket 515, the light pipe 515 having a light inlet end 419 and a lug 417. The light pipe 515 is configured as a waveguide for an LED located at the light inlet end. Thus, the light pipe is configured to have total internal reflection, making it suitable for use as a waveguide. In one aspect, the light pipe 515 has a refractive index of about 1.52, which is higher than the refractive index of surrounding air. In one aspect, the light pipe is clad, and the refractive index of the waveguide portion of the light pipe 515 is higher than the refractive index of the cladding on the light pipe 515. Fig. 12B is the light entrance port 419, and Fig. 12C It is lug 417.

[0111] In order for the light pipe to have the necessary total internal reflection, any curves must be gentle, with no sharp curves or dead ends. Fig. 12A421 illustrates the gentle curvature. In one embodiment, the main body length of the light pipe from the light inlet end 419 to the lug 417 is about 110 mm. For the purity of transmission, it is advantageous if the presence of foreign particles and bubbles is minimized. In one aspect, the light pipe is a molded polyacrylate. Although 3D printing can be considered to form the light pipe, it is easier to control the quality of the light pipe formed by molding. In one aspect, the light pipe has very low, little or near zero internal absorption and is free of foreign particles and bubbles. For example, but not limited to, the low or little internal absorption is less than about 0.2 dB cm -1 .

[0112] Reference Fig.13 , the bottles 230 in the drum 240 (facing inward) are placed into one of the six sections (222A-222F) in the module 210. These sections are divided by vertical panels 221 extending outward from the drum 240. The span between adjacent panels is approximately equal to the span of the door of the housing 224 so that when a user accesses a section of the culture bottle, the user can be completely shielded from the module interior. The module 210 also includes a blower and heater 225 for maintaining the temperature of the bottle 230. The status indicator plate 273 is located inside the drum. The drive motor assembly 270 is used to rotate the drum 240. The measurement board 545 is located outside the drum and performs fly-by measurements of the bottle and drum marks to determine the status of the bottle and the alignment of the drum, respectively.

[0113] Reference Fig.14 , illustrates a tray with a light pipe 515 that diverts light from an indicator LED 520 from a distal end 525 of the tray (i.e., the interior of the drum 240 in which the tray is disposed). The light pipe 515, if present, holds the bottle 230 and extends over the proximal end 420 of the tray (i.e., the exterior surface of the drum 240). A flat spring 510 presses against an upper shoulder 535 of the culture bottle 230 to secure the culture bottle 230 on the lug 417. At the distal end 525 of the tray 220, the tray 220 is adjacent to a bottle presence detector 250. The distal end of a bottle 230 in the tray 220 is detected by the bottle presence detector 250. The bottle presence detector 250 is carried by the status indicator plate 273. As shown in FIG. Figures 15A-15E As illustrated in FIG. 2 , the spring is integrally formed with the bottle holder 220 .

[0114] The light pipe 515 is aligned with the indicator LED 260 on the status indicator plate 273. The end surface of the light pipe 515 outside the bottle drum 240 is textured to disperse the light from the indicator LED 260. When the bottle capper 410 is placed in the tray 220, it interrupts the bottle presence detector 250 (e.g., an optical switch or proximity sensor). The indicator LED 260 and the bottle presence detector 536 are located on the status indicator plate 273, which is located on the interior of the drum 240 and is arranged in a manner corresponding to each bottle 230 that is accessible to the user in the drum 240. When the door of the module is opened, the bottle presence detector 250 is monitored to detect in real time when a bottle 230 is placed in or removed from the tray.

[0115] Fig.15A A portion of a drum 240 is shown having multiple rows of vertical racks 220. The drum is illustrated in cross-section to show culture bottles 230 supported in the racks 220. The top racks 220 are empty. Fig.15A In the embodiment illustrated in FIG. 2 , a pivot arm 551 is provided to secure the culture bottle 230 in the bracket 220 instead of the previously described leaf spring 550. When the bottle 230 is pushed into the bracket 230, the pivot arm 551 rotates clockwise to secure the culture bottle 230 in the bracket. A coil spring 552 applies resistance to the pivot arm 551, which is secured in the bracket by a pin 556.

[0116] FIG. 15B to FIG. 15E The diagram is Fig.15A An alternative to the illustrated bracket. Fig. 15B , Fig.15A The pivot arm 551 illustrated in the figure is replaced by a deformable material 553. In one example, the deformable material 553 is a peristaltic tube, but other conventional deformable materials are also contemplated. The key aspect of the deformable material is that after being deformed each time a culture bottle is inserted into the bracket, its elastic force assumes its undeformed shape. At the bottom of the bracket 220 is a light pipe 515.

[0117] The deformable material 553 is placed in the tapered portion 554 of the bracket 220. Fig. 15C , an end view of the bracket (220) illustrates the deformable material 553 at the top of the bracket (along the tapered portion 554 of the bracket). In addition to the elastic peristaltic tubes described above, suitable deformable materials include elastomeric materials and foam materials.

[0118] Fig.15D4 is a perspective view of the bracket 220, which forms a portion of the second bracket above. As described above, the culture bottle is retained in the bracket. The lug 417 retains the culture bottle 230 in the bracket 220. Other materials that are considered for the deformable material are those that have sufficient frictional properties when in contact with the bottle 230. This friction prevents the bottle 230 from rotating, thereby allowing the measurement system to obtain a high quality signal with less noise caused by bottle vibration caused by the movement of the holder. Fig.15E It is a top view of a culture bottle retained in a rack 220 with a light pipe 515.

[0119] As explained herein, the module's rotating drum is used both to position the bottles for user access and for automated access. The module also rotates the culture bottles to agitate them.

[0120] As described above, an apparatus according to the present technology has at least the following advantages: 1) reduced noise (i.e., the ratio of the growth signal to the reference signal should be unaffected by bottle position, temperature, and sensor variability); 2) detection of growth in vials that experience a delay when entering the system (i.e., the dual measurement described above provides a reference so that continuous sampling of the vial contents during growth is not required to confirm positivity by detecting growth acceleration); and 3) a signal quality indicator (i.e., the reference signal is an independent indicator of the health of the workstation hardware).

[0121] As described above, the fly-by reading / measurement technique employed by the drum 240 and the measurement board 545 relies on a relatively constant or fixed measurement distance between the bottles 230 in the carrier 220 of the drum 240 and the array of sensors on the measurement board 545 used to measure and interrogate the bottles 230. Variations in the distance and position of the drum 240 relative to the measurement board 545 affect the distance between the bottles 230 and the corresponding sensors on the measurement board 545, thereby affecting the fluorescence readings of the culture medium bottles. Such variations in position and distance between measurements may cause noise in the culture medium bottle readings. Therefore, if not corrected, the readings obtained from the measurement board 545 may be inaccurate in the presence of these variations.

[0122] In one aspect, a fully loaded drum may weigh 80-90 lbs and rotate at 30 rpm. When imbalance is introduced by varying bottle loads and rotation for (fluorescent) measurement, the drum 240 may change direction slightly, e.g., wobble. Changes in the direction or position of the drum 240 relative to the plate 545 will also cause a change in the distance between the bottles in the drum 240 and the corresponding sensors on the measurement plate 545. Such a change in distance will cause a change in the fluorescent bottle signal (e.g., intensity decreases as the distance of the bottle from the corresponding sensor on the measurement plate 545 increases, and vice versa). Such a change in distance may result if the drum axis is slightly tilted from its normal position.

[0123] According to various aspects of the present technology, systems and methods are described below for detecting changes in the distance between the bottle and the measurement plate, which may be caused by changes in the position or orientation of the roller. In addition, systems and methods are described for offsetting or compensating or adjusting the readings obtained by the measurement plate in response to the detected changes in distance and position. It should be understood that various aspects of the systems and methods described below can be implemented and used with any of the aspects described above related to the blood culture device including the roller 240 and the measurement plate 545.

[0124] For example, refer to Fig.16 , shows a block diagram of a measurement system 6000 for detecting a position or orientation of a rotating drum of a blood culture apparatus relative to a stationary measurement plate of the blood culture apparatus according to aspects of the present technology.

[0125] As shown, the system 6000 includes a plurality of timing targets 6002 disposed around the outer perimeter of the drum, a sensor (s) 6004, an analog-to-digital (A / D) converter 6008, a controller 6010, and one or more memories 6012. It will be appreciated that the components of the system 6000 may be separate from the components of the blood culture device, or may represent one or more components of the blood culture device described above. For example, the controller 6010 may be any of the controllers or modules associated with the drum 240, the measurement board 545, etc., described above, or may be a discrete controller of the system 6000.

[0126] As will be described in more detail below, the timing targets 6002 can be set at discrete locations on (or near) the outer perimeter of the drum. In one aspect, the timing targets are deployed as a series of timing targets along the outer perimeter of the drum. When the timing target 6002 passes the sensor 6004, the sensor (one or more) 6004 for detecting (the characteristics of) the timing target 6002 can be positioned at a position adjacent to the drum (e.g., on a measurement board adjacent to the drum) so that the timing target 6002 passes and / or passes through the sensor 6004 during the rotation of the drum. The readings from the sensor (one or more) 6004 can be converted from analog readings to digital readings by an A / D converter 6008 for use by the controller 6010 to detect the position or direction of the drum (and its changes) between each measurement and / or determine the change in distance between each bottle in the drum and the corresponding sensor on the measurement board fixed near the rotating drum. The sensor 6004 can also measure the time when the timing target 6002 passes or passes through the sensor 6004, indicating the change in distance. The controller 6010 (or another controller of the device) is configured to use the change in distance and / or position to adjust one or more stored readings obtained by the sensors on the measurement plate regarding the bottles in the drum.

[0127] In one aspect, during a test cycle, the system 6000 is used to determine the initial relative positions of a set of calibration and reference bottles at some or all of the bottle positions in the drum and the sensors at various positions on a stationary measurement plate near the drum, and the fluorescence readings of the calibration and reference bottles at these initial relative positions in the drum. This information is recorded in a memory, such as memory 6012. Any subsequent changes in the recorded initial relative positions can be determined or calculated by the controller 6010 (using measurements obtained from sensor(s) 6004 associated with the target 6002) to adjust the stored fluorescence readings at each position in the drum so that changes in the adjusted readings are due only to changes in the bottles and not to changes in the position of the drum relative to the stationary measurement plate.

[0128] Reference Fig.17 , 20 , 21 and 22, show a blood culture device including a drum-shaped fixture 6050 (hereinafter drum), a measurement plate 6060 and a measurement system 6000 according to aspects of the present technology. It should be understood that the drum 6050 may include any of the features of the drum 240 described above, and the measurement plate 6060 may include any of the features of the measurement plate 545 described above.

[0129] The drum 6050 includes columns and rows of bottles 6056 contained in an array of racks arranged around the outer perimeter of the drum. A motor 6054 and a gearbox 6052 are connected to the frame of the drum 6050 via a shaft 6058. The motor 6054 and the gearbox 6052 cooperate to rotate the drum 6050 so that the columns of bottles 6056 contained in the racks of the drum 6050 fly over or pass through a measurement board 6060, which includes a column or group of sensors 6062 for reading the bottles 6056 as they pass through the column of sensors 6062.

[0130] A plurality of targets 6002 are mounted to and extend radially from the outer perimeter of the drum 6050. The targets 6002 are disposed at discrete locations around the outer perimeter of the drum 6050. For example, the targets 6002 may be placed at the lower end of the drum 6050, at each column of brackets in the drum 6050, or at each vertical section divider of the drum 6050. Those skilled in the art will appreciate that the targets 6002 may be placed at various discrete locations around the drum 6050.

[0131] The position or orientation of the roller 6050 can be defined by three variables. The first variable can be the roller offset, which is the distance between the center of the roller and the center of motion at the level of the target 6002. The second variable can be the maximum roller offset angle relative to the target 6002 and the origin position of the roller 6050. The third variable can be the pivot point of the roller, which is the position of the point that limits the movement of the roller. The pivot point position is measured relative to the target 6002. An unbalanced roller (e.g., due to the roller carriage asymmetrically loading bottles 6056) will wobble around the pivot point. In one aspect, the pivot point of the roller 6050 is a fixed pivot point 6051 in the gearbox 6052. The roller 6050 can only rotate around the pivot point 6051. It is understood that the pivot point of the roller depends on the structure of the roller assembly and is known from the configuration of the assembly. The position of any bottle 6056 (or rack containing bottles) in the drum 6050 can be calculated based on the angles and offsets described above and the position of the pivot point 6051 above the target 6002.

[0132] like Fig.18 As shown in FIG. 60, in one aspect, a series of multiple targets 6002 extend radially from the outer circumference of a target ring base 6022 mounted on or integrated with a drum 6050.

[0133] like Fig.17 and 20 -22, the inner circumference of the ring base 6022 is shaped to be received by a portion of the drum 6050, for example, at the lower edge of the drum 6050 opposite the gearbox 6052 and the motor 6054. The ring base 6022 is mounted to the drum 6050 so that the drum 6050 and the target 6002 rotate synchronously together.

[0134] In one aspect, the sensor 6004 can be an optical switch having an optical path 6003 (e.g. Fig.19 ). The switch 6004 is mounted in a fixed position at a selected location so that when the drum 6050 and the targets 6002 rotate, at least a portion of each target 6002 passes through the optical path 6003 of the switch 6004. In one aspect, the switch 6004 remains fixed relative to the movement of the drum. Fig.17 and Figure 20-22 , in one aspect, the switch 6004 can be mounted to the bottom of the measurement board 6060. In another aspect, the switch 6004 can be mounted at a fixed location separate and spaced from the measurement board 6060. For example, the switch 6004 can be mounted to the cabinet surface where the drum 6050 is disposed so that at least a portion of each target 6002 passes through the optical path 6003 of the switch 6004.

[0135] Reference Fig.18 and Fig.19 , in one aspect, each target 6002 includes a radial edge 6026 that extends radially away from the exterior of the drum 6050 and is aligned with the center of the drum. Each target 6002 further includes an edge 6024 that includes a first end 6038 that connects to one end of the radial edge 6026 and a second end 6040 that connects to the radial edge 6026 of an adjacent target 6002 in one aspect. In another aspect, the second end 6040 of the first target may be a distance away from the radial edge 6026 of the adjacent target. In any case, the radial distance of the edge 6024 from the exterior of the drum continues to decrease from the first end 6038 to the second end 6040. It will be appreciated that the edge 6024 may be curved, such as Fig.18 or may be straight, as illustrated in Fig.19 As illustrated in .

[0136] As the drum 6050 rotates along the rotation direction 6070, the target 6002 moves through the optical path 6003 of the switch 6004. In one aspect, the switch 6004 is configured to be in a first state or a second state, depending on whether the optical path 6003 is blocked or not blocked. In one aspect, when no part of the target 6002 blocks the optical path 6003, the switch 6004 is in a first state (e.g., an open state). When any part of the target 6002 passes through or blocks the optical path 6003, the switch 6004 is in a second state (e.g., closed). Therefore, as the drum 6050 moves along the rotation direction 6070, when some parts of the edge 6024 pass through the optical path 6003, the state of the switch 6004 changes from closed to open, and when the edge 6026 passes through the optical path 6003, the state of the switch 6004 changes from open to closed. In this way, the state change of the switch 6004 indicates that the edges 6024, 6026 pass through the optical path 6003.

[0137] The controller 6010 is configured to monitor the state change of the switch 6004. In one aspect, the system 6000 includes an A / D converter 6008 configured to receive the change state of the switch 6004 as an analog output signal and convert the analog signal to a digital signal provided to the controller 6010 and / or the memory 6012. In one aspect, the switch 6004 is monitored by the controller 6010 at a clock rate of approximately (e.g., + / - 10%) 1 kHz during the A / D reading. It should be understood that this clock rate is exemplary and other suitable clock rates are also contemplated by the present disclosure. The controller 6010 is configured to maintain a counter (e.g., in software stored in the memory 6012 and executed by the controller 6010 or in a discrete processing component of the system 6000) that is incremented by the controller 6010 at each clock cycle. The number of clock cycles between changes in the state of the switch 6004 is recorded by the controller 6010 into the memory 6012.

[0138] From the state changes of the switch 6004 and the number of clock cycles between the state changes, the controller 6010 is configured to determine the amount of time that the switch 6004 is open or closed and the time that elapses between the detection of each edge 6024 and 6026 as the target 6002 passes the switch 6004. The time that elapses from the switch opening to the switch closing of the switch 6004 is proportional to the position of the roller 6050 and the distance between the roller 6050 and the measurement plate 6060.

[0139] It will be appreciated that the depth or radial length of the radial edge 6026 of each target 6002 determines the range of motion of the roller 6050 that can be measured. Therefore, the radial length of the radial edge 6026 is selected based on the known range of motion or distance variation between the roller 6050 and the measurement plate 6060. In one aspect, the radial length of each radial edge 6026 is selected to be approximately (+ / - 10%) 5 mm, however, it will be appreciated that other radial lengths of the radial edge 6026 are contemplated.

[0140] In one aspect, the controller 6010 is configured to determine that a radial edge 6026 of the target 6002 is detected when the state of the switch 6004 changes from an open state to a closed state. In addition, in this aspect, the controller 6010 is configured to determine that an edge 6024 of the target 6002 is detected when the state of the switch 6004 changes from a closed state to an open state.

[0141] In one aspect, the controller 6010 can be configured to use the alignment and / or sector markings described above to determine which target 6002 has passed through the switch 6004. For example, Fig. 22As shown in FIG. 6 , in one aspect, the drum 6050 includes an origin mark 6061 mounted thereon, and the measurement plate 6060 includes an origin mark sensor 6063 mounted thereon and configured to detect the origin mark 6061 when the origin mark 6061 passes through. The first radial edge 6026 of the target detected after the origin mark sensor 6063 detects the origin mark 6061 represents the 0° drum angle of the drum 6050, and identifies the target 6002 associated with this position of the drum 6050. Data from or representing the readings of the sensors 6063 and 6004 are provided to the controller 6010 so that the controller 6010 can use the data to detect or determine the drum angle at a given time. In this regard, each radial edge 6026 is associated with a drum rotation angle relative to the origin position. Therefore, by counting the number of radial edges 6026 detected after the origin mark 6061 is detected, the controller 6010 can detect the drum angle at that time. For example, as described above, in one aspect, the first radial edge 6026 detected after the origin mark 6061 is detected represents a 0° roller angle of the roller 6050 and identifies the target 6002 associated with that position of the roller 6050, the second radial edge 6026 detected after the origin mark 6061 is detected represents a 22.5° roller angle of the roller 6050 and identifies the target 6002 associated with that position of the roller 6050, the third radial edge 6026 detected after the origin mark 6061 is detected represents a 45° roller angle of the roller 6050 and identifies the target 6002 associated with that position of the roller 6050, etc. Thus, the controller 6010 is configured to determine the position and roller angle of each target 6002 as each target 6002 passes through the switch 6004. It should be understood that the angular spacing between the targets 6002 and the roller angle represented by each target are known to the controller 6010 (or stored and accessible via the memory 6012).

[0142] In one aspect, the controller 6010 is configured to determine based on the elapsed time between changes in state of the switch 6004. Fig.19 The times t1 and t2 shown in FIG. 6 are used to determine the change in the distance between the roller 6050 and the optical switch 6004 using the ratio of t1 / t2. The distance between the roller 6050 and the optical switch 6004 can then be used to determine the distance between the roller 6050 and the measurement plate 6060.

[0143] Time t1 is when the previous target 6002 (eg, Fig.19The instantaneous time (time instant) of the radial edge 6026 of the leftmost target in the figure and the detection of the latter target 6002 (e.g., the leftmost target in the figure) via the state change (e.g., the state change from closed to open) of the switch 6004. Fig.19 The time that elapses between the instantaneous times of edge 6024 of the rightmost target).

[0144] Furthermore, time t2 is the time elapsed between the instantaneous time when the radial edge 6026 of the preceding target 6002 is detected via a state change (e.g., a state change from open to closed) of the switch 6004 and the instantaneous time when the radial edge 6026 of the succeeding target 6002 is detected via the same state change (e.g., a state change from open to closed) of the switch 6004. In other words, t2 is the time required for the target 6002 to pass through the switch 6004 along the entire length in the rotation direction of the drum 6050.

[0145] In one aspect, the controller 6010 is configured to calculate the times t1 and t2 from the number of clock cycles recorded between changes in the state of the switch 6004 as each target 6002 passes through the switch 6004. The controller 6010 calculates a ratio of t1 / t2 for each target 6002. This ratio is proportional to the distance between the optical switch 6004 and the exterior of the drum 6050 and is used by the controller 6010 to determine the position or orientation of the drum 6050. If it is determined that the position of the drum 6050 has changed (or the distance between the bottles in the drum 6050 and the sensors on the plate 6060 has changed), the stored measurements obtained by the sensors of the measurement plate 6060 may be adjusted by the controller (e.g., the controller 6010, the controller of the measurement plate 6060, or another controller of the blood culture device) to compensate for the change.

[0146] Reference Fig.23 , shows a diagram illustrating roller position determination that may be performed according to the present technology using data derived from switch 6004. In one aspect, the length of a radial edge 6026 of a single target 6002 is multiplied by the controller 6010 by the ratio t1 / t2 to obtain a distance measurement of the single target 6002 at a particular angle between the target 6002 and the roller 6050. It should be understood that the angle of the target 6002 is the same as the roller angle and represents the degree that the roller 6050 is rotated from the origin mark position (after the origin mark position is detected). The controller 6010 is configured to calculate distance measurements of the target 6002 at multiple angles (ranging from 0-360°) and fit the calculated distance for each angle to a sine function, such as Fig.23 As shown. It is understandable that Fig.23The distance measurements in (boxes in the graph) each correspond to a different target 6002 in the plurality of targets 6002. In this regard, each measurement corresponds to a target 6002 that is currently located at the optical switch 6004 during the rotation. Fitting the calculated distance to a sine function can reduce the noise in the individual distance readings. The amplitude of the sine fit represents the offset in the drum position. For example, in Fig.23 In the example, the amplitude is 0.9 mm, which indicates the maximum offset of the roller position from its center of rotation. The phase of the sine fit indicates the angle of the roller relative to the origin angle where the maximum offset occurs. Fig.23 In , the phase is 45°, indicating the angle of the roller position. Thus, using the measurements from switch 6004 (and origin sensor 6063), controller 6010 is configured to determine the offset of the roller position and the angle of the roller position.

[0147] In use, the drum 6050 operates in a "test cycle" that is associated with data collection that occurs during calibration of the drum 6050 and during normal use of the drum 6050. The test cycle is the process of collecting fluorescence data (from sensor 6062) from the bottles in the drum 6050 and timing data from the target sensor 6004. Each test cycle may include several rotations of the drum 6050, during which target ratios for each target 6002 and fluorescence data for the bottles in the drum 6050 are collected in each rotation of the drum 6050. The test cycle may be performed during calibration of the drum (e.g., during the manufacturing stage) or during normal use of the drum. Calibration may be performed during final inspection of the instrument in production, with the drum 6050 filled with calibration bottles. The data collected during the test cycle that occurs during calibration is saved as the drum normalization parameters (described below). Data is also collected during the test cycle during normal use of the drum 6050 (e.g., testing culture bottle readings to detect positive bottles). Therefore, the test cycle is performed during both calibration and normal use of the drum 6050. The data collected during calibration and normal use are the same, but the data collected during calibration is saved as the drum normalization parameters. The test cycle process can be controlled by the controller 6010, where the user can select whether the test cycle is performed for calibration (so the data is saved as normalization parameters) or during normal use of the drum (so the data is saved for later adjustment if necessary).

[0148] In one aspect, the columns of the drum 6050 include reference bottles (also called calibration bottles) fixed in all positions of the columns of the drum 6050. The characteristics and contents of these bottles are known. The reference bottles in the reference bottle column remain in place during calibration and normal use of the drum 6050. In one aspect, the reference bottles in the reference bottle column cannot be removed by the user. During calibration, the remaining columns (except the reference bottle column) can be filled with calibration bottles. During normal use, the remaining columns (except the reference bottle column) can be filled with culture bottles tested using the measurement plate 6060.

[0149] In one aspect, the standardized parameters of the drum 6050 are collected during the manufacturing of the test cycle and then used to standardize the fluorescence readings (obtained from the sensor 6062) of the culture medium bottles stored in the drum 6050 and the timing ratio calculated for each target 6002. For example, during the calibration of the drum 6050 at the time of manufacturing, all the drum workstations (racks that receive bottles) in the drum 6050 are equipped with calibration bottles. As described above, the reference bottle column is fixed at all positions of the reference bottle column of the drum 6050. In addition, all columns except the reference bottle column of the drum 6050 are filled with calibration bottles. Therefore, all workstations or racks in the drum 6050 are filled with reference bottles / calibration bottles. During the test cycle, the drum 6050 rotates at a constant measurement speed, and the fluorescence readings are read from the calibration bottles and reference bottles via the measurement plate 6060. Additionally, as each target 6002 passes through measurement plate 6060, a timing ratio t1 / t2 is calculated for each target 6002 using the timing data for each target 6002 derived from switch 6004. The set of fluorescence readings and timing ratios is stored in memory (e.g., memory 6012) as standardized parameters for drum 6050.

[0150] Then, during each subsequent test cycle, such as during normal use of the drum 6050, the position of the drum 6050 is determined by the controller 6010 and used to calculate the change in distance between each bottle in the drum and its corresponding sensor in the measurement plate 6060 relative to the same distance measured when the drum was normalized. The controller 6010 is configured to adjust the stored fluorescence readings from the bottle using the change in distance between the bottle and its corresponding sensor in the measurement plate 6060 when the measured distance changes to account for the distance change. The adjustment is made to the stored raw fluorescence readings for all bottles, including the reference bottle in the reference bottle column.

[0151] Reference Fig.24, shows a method 7000 for detecting the position or orientation of a rotating drum (such as drum 6050) relative to a stationary measurement plate (such as measurement plate 6060) and processing the stored measurements of the measurement plate based on the detected drum position in accordance with aspects of the present technology. It will be appreciated that the test cycles and steps of method 7000 can be performed during calibration of drum 6050 as well as during normal use of drum 6050.

[0152] In step 7002, a test cycle of the blood culture device is initiated. In one aspect, during the test cycle, all stations in the drum 6050 are loaded with calibration bottles. A reference bottle column is fixed at all positions of the reference bottle column in the drum 6050. The drum 6050 rotates in the rotation direction 6070 at a predetermined and constant measurement speed.

[0153] In step 7004, during the test cycle, the timing ratio (t1 / t2, as described above) of each target 6002 is calculated by the controller 6010 and accumulated and stored in a memory (e.g., the memory 6012 of the system 6000 and / or another memory of the blood culture device). In addition, the readings of the sensors 6062 in the measurement plates 6060 of the bottles stored in the racks of the drum 6050 are also accumulated and stored in the memory. As described above, the test cycle may include multiple rotations of the drum 6050.

[0154] In step 7006, it is determined whether to standardize the blood culture device (i.e., roller 6050) relative to the measurement plate 6060. The roller 6050 is standardized using the calibration bottle at all workstations of the roller 6050. If it is determined in step 7006 that the roller 6060 is standardized, the method proceeds to step 7008. The determination in step 7006 can be based on the controller 6010 receiving user input (e.g., from a technician during manufacturing) to standardize the roller 6050. In one aspect, standardization is performed in manufacturing when requested by a technician. The technician fills the roller 6050 with the calibration bottle and then requests the system (e.g., by providing an input to the controller 6010) to run a test cycle to collect calibration data from the roller 6050.

[0155] In step 7008, the target normalization ratio and the roller table fluorescence normalization parameters are stored in a memory, such as the memory 6012 or the memory of the measurement board 6060 or the roller 6050. In one aspect, the target normalization ratio is composed of 16 floating point numbers, each floating point number corresponding to a different target 6002. The target normalization ratio and the roller table fluorescence normalization parameters together form a set of normalization parameters. As described above, the normalization parameters are determined by the data collected when the roller 6050 is filled with calibration bottles.

[0156] In step 7012, the roller table fluorescence normalization parameters are output for later use in steps 7014, 7026 when a test cycle is performed without normalizing the instrument and during normal use. Specifically, the target normalization ratio is provided for use in step 7014, and the roller table normalization parameters are provided for use in step 7026.

[0157] If it is determined in step 7006 that the roller associated with the measuring plate 6060 is not standardized (e.g., the roller is operated during normal use), the method enters step 7014. In step 7014, the target ratios accumulated in step 7004 are standardized using the target standardized ratios. For example, in one aspect, the cumulative ratios of each target 6002 are averaged, and the stored standardized ratios are subtracted from each average timing ratio. In this regard, the test cycle process includes several rotations of the roller, during which the target ratios of each target 6002 of each rotation are collected. The ratios of each target 6002 of all rotations are averaged to reduce the noise in the ratios of each target 6002. Therefore, the average target ratio of each target 6002 in the test cycle is calculated. Each resulting average target ratio is subtracted from its corresponding target standardized ratio (corresponding to the standardized ratio of a specific target 6002). For example, if the roller position changes, a set of differences will be generated when each average target ratio is subtracted from its target standardized ratio. This set of differences is fitted to a sine wave and indicates how much the roller has moved relative to the position at the time of calibration. Therefore, the roller 6050 loaded with the calibrator from the test cycle is considered to be the baseline position of the roller 6050, regardless of whether the roller 6050 is centered.

[0158] In step 7016, the controller 6010 is configured to fit the standardized target timing ratio from step 7014 to a sine function, as described above. This is performed once per test cycle. In step 7018, the controller 6010 is configured to calculate the offset and angle of the drum 6050 from the sine fit of step 7016. As described above, the amplitude of the sine fit represents the offset of the drum position, and the phase of the sine fit represents the angle of the drum position. The controller 6010 calculates the amplitude and phase of the sine fit. At this point in the method, the position of the timing target 6002 (and the drum 6050) relative to the timing target 6002 (and the drum 6050) when the drum 6050 is standardized is determined. It will be appreciated that since the target timing ratios are standardized with the drum standardization parameters (in step 7014), the standardized target timing ratios represent the position of each timing target relative to when the drum 6050 is standardized. Therefore, the position of the timing target is the same as the position of the drum 6050.

[0159] In step 7022, the controller 6010 is configured to calculate an adjustment value for each roller stage. In one aspect, the adjustment value for each roller stage is based on the angle of the individual stage to the roller offset angle, its height above the timing target 6002, and the height of the pivot point 6051 at the gearbox 6052 relative to the timing target 6002 (see Fig.17 ). As shown at 7020, step 7022 receives as input a number of constants stored in memory. In one aspect, the constants include the percentage change in the signal of the measurement plate 6060 reading per millimeter of distance change detected using the timing data from the switch 6004, and the physical dimensions of the roller 6050, such as the roller column angle and the roller row height. It is understood that the percentage change in the signal of the measurement plate 6060 reading per millimeter of distance change of the roller 6050 relative to the measurement plate 6060 can be determined and stored in memory prior to executing the method 7000. The physical dimensions of the roller 6050 are known.

[0160] In step 7024, the controller 6010 is configured to adjust the raw readings from all roller stages (racks) of the roller 6050, including the readings from the reference bottles in the reference bottle column and the readings from the non-reference bottles (i.e., the bottles being tested) in the other columns. In one aspect, the controller 6010 is configured to multiply the raw readings from each stage by the adjustment value for that stage obtained in 7022. The adjustment of the raw fluorescence readings from each position in the roller 6050 is selected so that changes in the adjusted readings are caused only by changes in the bottles, and not by changes in the position of the roller relative to the stationary measurement plate 6060.

[0161] In step 7026, the adjusted raw readings from step 7024 are normalized using the roller stage normalization parameters received from step 7012. In this regard, differences between the fluorescence readings from the reference vials in the reference vial column during normalization and during normal use indicate changes in the measurement system (e.g., due to changes in the position of the roller 6050). The controller 6010 applies this change to the fluorescence readings of the sample vials in the same row (i.e., covering a circle of stages around the roller) as the reference vials to normalize the fluorescence readings of these sample vials. This step is performed for all stages of the roller.

[0162] In step 7028, the normalized readings from step 7026 are output for processing and adjusting the readings from the measurement board 6060. After step 7028 is completed, the method ends in step 7030.

[0163] Understandably, Fig.24 The standardized process can be performed during the manufacture of the blood culture device or during normal use, and Fig.24The results can be used in post-processing to adjust and correct the stored readings in the measurement board 6060 after it is detected that the roller position has changed during use of the roller.

[0164] It should be appreciated that the present technology may be used to detect the position of the drum (and each rack and bottle contained therein) during any operating mode of the drum (eg, during calibration, normal operation, or any other mode).

[0165] For example, Fig.36 Illustrated is a method 7050 for detecting the position or orientation of a rotating drum (such as drum 6050) relative to a stationary measurement plate (such as measurement plate 6060) and processing stored measurements of the measurement plate based on the detected drum position in accordance with aspects of the present technology.

[0166] In step 7052, a drum-shaped fixture, for example, a drum 6050 having an outer perimeter, is rotated about the rotation axis of the drum. The drum 6050 includes a plurality of brackets configured to receive blood culture bottles. In addition, as described above, a plurality of timing targets 6002 are disposed around the outer perimeter of the drum 6050, which rotate with the drum 6050.

[0167] In step 7054, sensor signals from the array of sensors 6062 of the measurement board 6060 are accumulated. As described above, the measurement board 6060 is disposed in a fixed or stationary position adjacent to or opposite the outer perimeter of the drum 6050. The array of sensors 6062 is configured to interrogate the carriages in the array in the drum 6050 one by one as each array moves past the measurement board 6060 as the drum 6050 rotates about its axis of rotation.

[0168] In step 7056, data associated with the target sensor 60043 disposed at a fixed or stationary position near the drum 6050 is accumulated or obtained. As described above, the target sensor 6004 can be mounted to the measurement board 6060 and configured to detect a geometric feature (e.g., an edge) of each timing target 6002 as each timing target 6002 moves or rotates past (or passes) the target sensor 6004 as the drum 6050 rotates about the axis. The data associated with the target sensor 6004 can be data received directly from the target sensor 6004 or data derived from the target sensor 6004. For example, the data can be the timing ratio described above.

[0169] In step 7058 , the accumulated sensor signal from sensor 6062 and the accumulated target sensor data from target sensor 6004 are stored in a memory, such as memory 6012 .

[0170] In step 7060, a controller or processor, such as controller 6010, is configured to calculate or determine the position (or orientation) of roller 6050 relative to stationary measurement plate 6060 (or relative to another reference object that is stationary relative to roller 6050) based at least in part on stored target sensor data from target sensor 6004. As described above, the calculated roller position or orientation may include roller offset (the distance from the center of roller 6050 to the axis of rotation of roller 6050) and roller angle (the maximum roller offset angle relative to the target 6002 and the origin position of roller 6050). The roller offset and roller angle may be calculated by fitting the timing data (e.g., the timing ratio described above) to a sine function and determining the amplitude and phase of the sine fit. Step 7060 may further include determining the position of each individual bracket in roller 6050 relative to a fixed or stationary reference object (e.g., measurement plate 6060) based on the position of roller 6050. As described above, the physical dimensions of roller 6050 (including the position / layout of each bracket) are known. In addition, the pivot point 6051 of the roller 6050 is known. From the position of the roller 6050 and the known dimensions and pivot point of the roller, the controller 6010 can determine the position of each individual rack (or bottle therein) and its distance from the measurement plate 6060.

[0171] In step 7062, the controller 6010 is configured to calculate an adjustment value and adjust at least one of the sensor signals accumulated from the sensor 6062 of the measurement plate 6060. It will be appreciated that the controller 6010 may be configured to determine whether any adjustment is required by determining whether the position of the drum 6050 has changed relative to the position of the drum 6050 during the calibration of the drum 6050 prior to step 7062. If it is determined that an adjustment is necessary, the controller 6010 is configured to calculate an adjustment value and adjust at least one (or all) of the previously accumulated sensor signals from the sensor 6062. As described above, the adjustment value may be based on the change in distance (relative to the origin position) between the measurement plate 6060 and each bottle / rack of the drum 6050.

[0172] Figure 25-33 The results of several drum position detection tests performed using the techniques described above in connection with the system 6000 and method 7000 are illustrated. Figure 25-33 Each one of them.

[0173] Fig.25 The radial diagram of the position of the roller 6050 under various load conditions according to the present technology is illustrated. Fig.25, calibration bottles were placed in a rack around the drum 6050. Weights were added to the drum 6050 centered in one of the columns of the drum 6050. The weights were placed in different drum columns of the drum 6050, but kept in the same row, and the effect of each placement on the angular offset and distance offset was observed. For each weight placement, including the case where no weight was placed, fluorescence readings of the calibration bottles (obtained from the measurement board 6060) and the drum position were collected. Fig.25 The graph in shows the offset and angle for each weight position measured using switch 6004 and target 6002. The center point indicates no weight added. The offset measurements are in millimeters.

[0174] Fig.26 is a graph of the percentage change in the signal measured from board 6060 for a bottle stored in drum 6050 versus the change in distance between the bottle and a sensor on board 6060 that reads the bottle in accordance with the present technology. Fig.26 The slope of the line in the graph represents the percent change in fluorescence signal for each millimeter of distance change from the bottle to the sensor (on board 6060). Fig.26 In the example of , the slope is -13.7% / mm.

[0175] Fig. 27 6050 and the like. FIG. 6060 is a graph of an adjusted signal 8004 from a sensor on plate 6060 and an unadjusted signal 8002 (raw) from a sensor on plate 6060 based on changes in drum position detected using system 6000 and the above-described techniques in accordance with the present technology. Unadjusted signal 8002 was recorded as the weight was moved to different positions around drum 6050. Adjusted signal 8004 was obtained based on the offset and angle of drum 6050 measured using switch 6004 and target 6002 and the above-described techniques and the position of the bottle in the drum.

[0176] Fig.28 A radial diagram of the position of the drum 6050 under various loading conditions according to the present technology is illustrated. Calibration bottles are placed at random locations around the drum 6050. Bottles filled with steel shot are placed symmetrically with respect to the fixed rack located at 0°. Weight bottles are then gradually added to the other side of the drum 6050 symmetrically with respect to the fixed rack located at approximately 192°. Fig.28 The graph in shows the offset and angle measured using target 6002 and switch 6004 for each dosing configuration.

[0177] Fig.29 is another graph of the relationship between the percentage change in the signal measured from plate 6060 for a bottle stored in drum 6050 and the change in the distance between the bottle and the sensor on plate 6060 that reads the bottle in accordance with the present technology. Fig.29The slope of the line in the graph represents the percentage change in the fluorescent signal for each millimeter change in the distance from the bottle to the sensor (on board 6060). Fig.29 In the example of , the slope is -15.7% / mm.

[0178] Fig.30 6050 and the like. FIG. 6060 is a graph of an adjusted signal 9004 from a sensor on plate 6060 and an unadjusted signal 9002 (raw) from a sensor on plate 6060 based on changes in drum position detected using system 6000 and the above-described techniques in accordance with the present technology. Unadjusted signal 9002 was recorded as the weight was moved to different positions around drum 6050. Adjusted signal 9004 was obtained based on the offset and angle of drum 6050 measured using switch 6004 and target 6002 and the above-described techniques and the position of the bottle in drum 6050.

[0179] Fig.31 is a radial plot of the position of the drum 6050 under various loading conditions according to the present technology. Calibration bottles are placed at random locations around the drum 6050. Media bottles are added to a column of the drum 6050, such as the 10th column, and then placed individually in a series of rows, such as the 10th column, row 1 to row 5. Media bottles are then added in pairs to a series of rows, such as the 9th column and the 11th column, such as rows 1 to 5. Fig.31 The radial plot shows the offset and angle for each media bottle configuration measured using target 6002 and switch 6004.

[0180] Fig.32 6060 is another graph of the relationship between the percentage change in the signal measured from plate 6060 for a bottle stored in drum 6050 and the change in the distance between the bottle and a sensor on plate 6060 reading the bottle in accordance with the present technology. Fig.31 The slope of the line in the middle graph represents the percentage change in the fluorescence signal for each millimeter change in the distance between the bottle and the sensor (on plate 6060). Fig.29 In the example of , the slope is -21.0% / mm. As with the previous figures, the x-axis is the change in distance in mm, and the y-axis is the change in fluorescence signal in %.

[0181] Fig.336050 and the like. FIG. 9 is a graph of an adjusted signal 10004 from a sensor on plate 6060 and an unadjusted signal 10002 (raw) from a sensor on plate 6060 based on changes in drum position detected using system 6000 and the above-described techniques in accordance with the present technology. Unadjusted signal 10002 was recorded as the weight was moved to different positions around drum 6050. Adjusted signal 9004 was obtained based on the offset and angle of drum 6050 measured using switch 6004 and target 6002 and the above-described techniques and the position of the bottle in drum 6050.

[0182] In one aspect, the measurement system 6000 may include multiple sets of targets 6002 disposed at different locations outside the drum 6050 and multiple sets of switches 6004 for detecting the timing of the targets 6002 passing through the switches 6004 to detect changes in distance and position relative to the drum 6050. For example, referring to Fig.34 , a drum 6050 is shown with a first plurality of targets 6002 disposed around the lower end of the drum 6050 and a second plurality of targets 6002 disposed around the upper end of the drum 6050. Switches 6004 are shown mounted at corresponding positions on a measuring plate 6060, and the first plurality of targets 6002 can pass through the first switch 6004 when the drum 6050 rotates, and the second plurality of targets 6002 can pass through the second switch 6004 when the drum 6050 rotates. The switches 6004 can be vertically aligned with the drum's column of carriers or the drum's vertical section dividers. The first plurality of targets 6002 and the second plurality of targets 6002 can also be vertically aligned so that the individual targets of each group are vertically aligned. The targets 6002 and the switches 6004 are configured in the manner described above. In this regard, the controller 6010 is configured to detect a change in the distance between any bottle 6056 in the column of bottles and its corresponding sensor in the measuring plate 6060 by interpolating the distance determined at the top and bottom of the measuring plate and the drum based on the drum layer where the bottle is located. As described above, the detected distance can be used to adjust the signal of the sensor in the measurement board 6060 as needed.

[0183] It should be understood that in other aspects, it is possible to use Figure 17-22 6002 and the target described above. For example, referring to Fig.35, shows a timing target 6092 for use in system 600 according to another aspect of the present technology. Timing target 6092 includes portions 6094, 6098, and 6096. Timing target 6092 is one of a plurality of timing targets 6092 disposed around drum 6050 (e.g., the lower end) so that it passes switch 6004 during rotation of the drum. Portions 6094, 6096 extend radially from the drum, and portion 6098 includes edges 6097, 6099 that are shaped in the same manner as edges 6024, 6026 of target 6002 described above. Portions 6094, 6098, and 6096 are configured to interrupt the optical path of switch 6004, so that controller 6010 can detect the time elapsed for a change in state of switch 6004 when portions 6094, 6098, and 6096 interrupt the optical path during rotation of the drum in the manner described above. From the change in state, controller 6010 can detect Fig.35 The times t3 and t4 are illustrated in FIG. As long as the speed is constant, the following relationship holds true at any speed of the drum:

[0184]

[0185] As the distance between the roller and the measuring plate increases, t4 increases, while t3+t4 remains constant, so the ratio in equation 1 increases. Both t3 and t4 are proportional to the roller speed, so the ratio is independent of the roller speed. The controller 6010 can use the ratio in equation 1 to detect the position of the roller and the change in the distance between the roller and the measuring plate, and adjust the stored readings of the sensor of the measuring plate 6060 as described above.

[0186] It should be understood that while the above drum position detection aspects of the present technology describe the use of optical switch 6004, in other aspects, other types of sensor(s) may be used for drum position detection with system 6000. For example, the sensor(s) may be a proximity detection device(s) configured to detect the proximity of drum 6050 (or an object and object features on the drum) to measurement plate 6060. The proximity detection device(s) may have an accuracy on the order of 0.1 mm within a range of 5-15 mm and may be configured to accurately detect the distance within approximately (e.g., + / - 25%) 1 millisecond when the object passes the proximity device.

[0187] In one aspect of the above-mentioned drum detection technology, when the measuring plate 6060 measures the bottle, the rotation speed of the drum is constant. However, in practice, such a constant measurement may not be guaranteed. In another aspect, as an alternative to measuring or determining the time between interruptions from the optical switch 6004, an optical encoder strip is used to directly measure the distance. In this regard, the system 6000 includes an optical encoder strip and an encoder mounted on the outside of the drum 6050. On the one hand, the encoder is added to the measuring plate 6060. On the other hand, the encoder is mounted in a stationary position outside the drum 6050 other than the measuring plate 6060 so that the optical encoder strip passes through the encoder. The controller 6010 or the controller or processor on the measuring plate 6060 accumulates the encoder counts when the drum 6050 rotates and captures the number of encoder counts that occur between the optical switch 6004 interruptions. The ratio of the encoder counts replaces the timing to obtain the same ratio proportional to the distance between the drum 6050 and the measuring plate 6060. Thus, in this regard, the controller 6010 or a controller / processor on the measurement board 6060 is configured to use the encoder counts and the ratio of the encoder counts to determine changes in the roller position 6050 and changes in the distance between the roller 6050 and the measurement board 6060.

[0188] It should be understood that the above aspects regarding roller position detection can also be used to detect potential shape changes or mechanical failures of the roller 6050. For example, as described above, the initial shape of the assembled roller 6050 is known. The initial shape can also be determined by the above-mentioned roller standardized parameters. Relative to the position or distance detected during manufacturing, changes in the position of the roller 6050 or changes in the distance between the roller 6050 and the measuring plate 6060 may indicate changes in the shape of the roller 6050, for example, due to loose mechanical connections of the roller 6050. The controller 6010 can detect these shape changes based on changes in the detected roller position or distance relative to the position or distance detected during manufacturing, and can alert the user (e.g., via a communication signal sent from the controller 6010 and / or the communication module of the system) to the possibility of a shape change of the roller 6050 caused by a loose mechanical connection. In one aspect, the change in the initial shape can be considered as a possible cause of a change in the position of the roller or a change in the distance between the roller and the measuring plate, where the position / distance is different during two measurements performed when the roller is completely unloaded. A change in shape can also be assumed in the case of a position or distance change detected by the drum model, which does not change even if loaded differently or in an unbalanced manner.

[0189] Although the roller position detection technology disclosed in this article is described with respect to a blood culture device including a rotating roller, the present technology can be implemented by other devices or systems including a rotating structure that rotates relative to a stationary structure, so that changes in the position of the rotating structure relative to the stationary structure and changes in the distance of various points between the rotating structure and the stationary structure can be detected and used for various purposes.

[0190] In one aspect, a system for detecting the position of a drum and bottles carried in the drum is described. The system includes a drum-shaped fixture, a measurement board, a plurality of timing targets, a target sensor, and a controller. The drum has an outer perimeter and a plurality of brackets, each of which is configured to receive a blood culture bottle. The outer perimeter is arranged around the rotation axis of the drum. The plurality of brackets are arranged in a bracket array in the drum. The array has vertically and horizontally arranged brackets, and the vertically arranged brackets form columns, and the horizontally arranged brackets form rows. The measurement board is arranged at a stationary position adjacent to the drum and includes a sensor column for interrogating a column of bottles in the drum that moves past the measurement board when the drum rotates around the axis. A plurality of timing targets are arranged at the outer perimeter of the drum, which rotate with the drum. The target sensor is arranged at a stationary position adjacent to the drum, and the target sensor is configured to detect one or more features of the timing target when each timing target moves past the target sensor when the drum rotates around the axis. The controller is configured to determine the position of the drum based on data from the target sensor.

[0191] In one aspect of the system, the determined roller position includes a roller offset and a roller angle.

[0192] In one aspect of the system, the controller is configured to detect a position of the drum based on timing data associated with detected characteristics of a timing target moving past the target sensor as the drum rotates.

[0193] In one aspect of the system, the timing data includes timing ratios associated with a plurality of timing targets.

[0194] In one aspect of the system, the controller is configured to normalize the timing ratio.

[0195] In one aspect of the system, the controller is configured to fit the normalized timing ratio to a sinusoidal function.

[0196] In one aspect of the system, the controller is configured to calculate the roller offset from the amplitude of the sinusoidal fit of the normalized timing ratio.

[0197] In one aspect of the system, the controller is configured to calculate the drum angle from the phase of the sinusoidal fit of the normalized timing ratio.

[0198] In one aspect of the system, the target sensor is an optical sensor.

[0199] In one aspect of the system, the optical sensor is configured to change state when a feature of the timing target interrupts an optical path of the optical sensor.

[0200] In one aspect of the system, the controller is configured to detect the position of the drum based at least in part on a change in state of the optical sensor.

[0201] In one aspect of the system, the one or more characteristics of each timing target include a first edge and a second edge of the timing target.

[0202] In one aspect of the system, the first edge extends radially from the outer periphery of the drum, and the second edge includes a first end and a second end, wherein a radial distance from the outer periphery of the drum to the second edge continuously decreases from the first end of the second edge to the second end of the second edge.

[0203] In one aspect of the system, the first end of the second edge is connected to the first edge.

[0204] In one aspect of the system, the second end of the second edge is connected to a first edge of an adjacent timing target of the plurality of timing targets.

[0205] In one aspect of the system, a plurality of timing targets are each vertically aligned with a carriage column of rollers.

[0206] In one aspect of the system, the controller is configured to adjust at least one signal of at least one sensor in the sensor column in the measurement board based on the determined position of the roller.

[0207] In one aspect of the system, the at least one signal is a signal stored in a memory of the system.

[0208] In one aspect of the system, the drum has an upper end and a lower end, and a plurality of timing targets are disposed proximate the lower end of the drum.

[0209] In one aspect of the system, a target sensor is mounted to a measurement board.

[0210] In one aspect, a method for detecting the position of a drum and bottles loaded in the drum is described. The method includes: rotating a drum-shaped fixture having an outer perimeter about a rotation axis of the drum-shaped fixture, the drum-shaped fixture having a plurality of brackets arranged in an array of rows and columns, each bracket configured to receive a blood culture bottle, and a sensor measurement board positioned opposite the outer perimeter of the drum-shaped fixture, the sensor measurement board including a plurality of sensors arranged in a column such that each sensor in the sensor panel is aligned with a bracket in the drum-shaped fixture, wherein a plurality of timing targets are disposed around the outer perimeter of the drum, which rotate with the drum, each target including a geometric feature extending from the perimeter of the drum-shaped fixture; accumulating sensor signals from the sensor columns of the measurement board, the measurement board being disposed at a fixed position opposite the outer perimeter of the drum-shaped fixture, the sensor columns being configured to be aligned with the outer perimeter of the drum-shaped fixture at the same time as the outer perimeter of the drum-shaped fixture; As the frame rotates about its axis, the brackets in the roller-shaped fixed frame are interrogated column by column as each column moves past the measuring plate; data is obtained from a target sensor set at a stationary position relative to the outer perimeter of the roller-shaped fixed frame, and the target sensor is configured to detect the geometric characteristics of each timing target as each timing target rotates past the target sensor as the roller-shaped fixed frame rotates about the axis; storing accumulated sensor signals and target sensor data in a memory; calculating the position of the roller relative to the stationary measuring plate based on the stored target sensor data from the target sensor; and determining whether at least one signal from the stored sensor signals needs to be adjusted based on the calculated position of the roller; and if adjustment is determined to be required, adjusting at least one signal from the stored sensor signals.

[0211] In one aspect of the method, the calculated position of the roller includes a roller offset and a roller angle.

[0212] In one aspect of the method, the position of the drum is calculated based on timing data associated with detected geometric features of a timing target that moves past a target sensor as the drum rotates.

[0213] In one aspect of the method, the timing data includes a timing ratio associated with a plurality of timing targets, wherein the timing ratio is based on an amount of time a geometric feature activates a target sensor and a time between a first geometric feature activating the target sensor and a subsequent geometric feature activating the target sensor.

[0214] In one aspect of the method, the method further comprises normalizing the timing ratio.

[0215] In one aspect of the method, the method further comprises fitting the normalized timing ratio to a sinusoidal function.

[0216] In one aspect of the method, the method further comprises calculating the roller offset from the amplitude of the sinusoidal fit of the normalized timing ratio.

[0217] In one aspect of the method, the method further comprises calculating the drum angle from the phase of the sinusoidal fit of the normalized timing ratio.

[0218] In one aspect of the method, the target sensor is an optical sensor.

[0219] In one aspect of the method, the optical sensor is configured to change state when a geometric feature of the timing target interrupts an optical path of the optical sensor.

[0220] In one aspect of the method, the position of the drum is calculated based at least in part on a change in state of the optical sensor.

[0221] In one aspect of the method, the one or more geometric features of each timing target include a first edge and a second edge of the timing target.

[0222] In one aspect of the method, the first edge extends radially from the outer perimeter of the drum, and the second edge includes a first end and a second end, wherein a radial distance from the outer perimeter of the drum to the second edge continuously decreases from the first end of the second edge to the second end of the second edge.

[0223] In one aspect of the method, the second end of the second edge is connected to a first edge of an adjacent timing target of the plurality of timing targets.

[0224] In one aspect of the method, a plurality of timing targets are each vertically aligned with a carriage column of rollers.

[0225] In one aspect of the method, the drum has an upper end and a lower end, and a plurality of timing targets are disposed proximate the lower end of the drum.

[0226] In one aspect of the method, a target sensor is mounted to a measurement board.

[0227] In the present specification, the word "comprising" is to be understood in its "open" sense, i.e., the sense of "including", and is therefore not limited to its "closed" sense, i.e., the sense of "consisting only of". The corresponding words "comprise", "comprised of" and "comprises" also have corresponding meanings in the case where they appear.

[0228] Although the specific embodiments of the present technology have been described, it is obvious to those skilled in the art that the present technology can be embodied in other specific forms without departing from its essential characteristics. Therefore, the embodiments and examples of the present invention should be considered in all aspects as illustrative rather than restrictive.

[0229] It should be further understood that any reference herein to art-known subject matter does not constitute an admission that the subject matter is commonly known to those skilled in the art to which the technology pertains, unless otherwise indicated.

Claims

1. A system comprising: a drum-shaped fixture having an outer perimeter, the drum having a plurality of brackets, each bracket being configured to receive a blood culture bottle, wherein the outer perimeter is disposed about a rotational axis of the drum, wherein the plurality of brackets are arranged in the drum as a bracket array, the array having vertically and horizontally arranged brackets, the vertically arranged brackets forming columns, and the horizontally arranged brackets forming rows; a measurement plate disposed at a fixed position adjacent the drum, the measurement plate including a sensor column configured to interrogate a column of bottles moving past the measurement plate in the drum as the drum rotates about the axis; a plurality of timing targets disposed about an outer perimeter of the drum that rotate with the drum; a target sensor disposed at a stationary position adjacent the drum, the target sensor configured to detect one or more features of each timing target as the timing target moves past the target sensor as the drum rotates about the axis; as well as A controller is configured to determine a position of the drum based on data from the target sensor. 2 . The system of claim 1 , wherein the determined position of the roller includes a roller offset and a roller angle.

3. The system of claim 2, wherein the controller is configured to detect the position of the drum based on timing data associated with detected characteristics of a timing target moving past the target sensor as the drum rotates.

4. The system of claim 3, wherein the timing data comprises timing ratios associated with the plurality of timing targets. The system of claim 4 , wherein the controller is configured to normalize the timing ratio.

6. The system of claim 5, wherein the controller is configured to fit the normalized timing ratio to a sinusoidal function.

7. The system of claim 6, wherein the controller is configured to calculate the roller offset from an amplitude of a sinusoidal fit of the normalized timing ratio.

8. The system of claim 6, wherein the controller is configured to calculate the drum angle from a phase of a sinusoidal fit of the normalized timing ratio.

9. The system of any one of claims 1-8, wherein the target sensor is an optical sensor.

10. The system of claim 9, wherein the optical sensor is configured to change state when a feature of the timing target interrupts an optical path of the optical sensor.

11. The system of claim 10, wherein a controller is configured to detect the position of the drum based at least in part on a change in state of the optical sensor.

12. The system of any one of claims 1-11, wherein the one or more features of each timing target include a first edge and a second edge of the timing target.

13. The system of claim 12, wherein the first edge extends radially from the outer periphery of the drum, and the second edge includes a first end and a second end, wherein a radial distance from the outer periphery of the drum to the second edge decreases continuously from the first end of the second edge to the second end of the second edge.

14. The system of claim 13, wherein a first end of the second edge is connected to the first edge.

15. The system of claim 14, wherein a second end of the second edge is connected to a first edge of an adjacent timing target of the plurality of timing targets.

16. The system of any one of claims 1-15, wherein each of the plurality of timing targets is vertically aligned with the column of brackets of the roller.

17. The system of any one of claims 1-16, wherein the controller is configured to adjust at least one signal of at least one sensor in the sensor column in the measurement board based on the determined position of the roller.

18. The system of claim 17, wherein the at least one signal is a signal stored in a memory of the system.

19. The system of any one of claims 1-18, wherein the drum has an upper end and a lower end, and the plurality of timing targets are disposed proximate the lower end of the drum.

20. The system of any one of claims 1-19, wherein the target sensor is mounted to the measurement board.

21. A method comprising: rotating a drum-shaped fixture having an outer perimeter about a rotation axis of the drum-shaped fixture, the drum-shaped fixture having a plurality of brackets arranged in an array of rows and columns, each bracket configured to receive a blood culture bottle, and a sensor measurement panel positioned opposite the outer perimeter of the drum-shaped fixture, the sensor measurement panel including a plurality of sensors arranged in columns such that each sensor in the sensor panel is aligned with a bracket in the drum-shaped fixture, wherein a plurality of timing targets are disposed around the outer perimeter of the drum that rotate with the drum, each target including a geometric feature extending from the perimeter of the drum-shaped fixture; accumulating sensor signals from a sensor column of a measurement board disposed in a fixed position relative to an outer perimeter of the drum-shaped fixture, the sensor column being configured to interrogate the carriages in the drum-shaped fixture column by column as each column moves past the measurement board as the drum-shaped fixture rotates about its axis; obtaining data from a target sensor disposed at a stationary position relative to an outer perimeter of the drum-shaped mount, the target sensor being configured to detect a geometric feature of each timing target as each timing target rotates past the target sensor as the drum-shaped mount rotates about an axis; storing the accumulated sensor signals and target sensor data in a memory; calculating a position of the roller relative to a stationary measurement plate based on stored target sensor data from the target sensor; and determining whether at least one of the stored sensor signals requires adjustment based on the calculated position of the drum; and If it is determined that adjustment is required, an adjustment is made to at least one of the stored sensor signals.

22. The method of claim 21, wherein the calculated position of the roller includes a roller offset and a roller angle.

23. The method of claim 22, wherein the position of the drum is calculated based on timing data associated with detected geometric features of the timing target moving past the target sensor as the drum rotates.

24. The method of claim 23, wherein the timing data comprises a timing ratio associated with the plurality of timing targets, wherein the timing ratio is based on an amount of time that a geometric feature activates the target sensor and a time between when a first geometric feature activates the target sensor and when a subsequent geometric feature activates the target sensor.

25. The method of claim 24, further comprising normalizing the timing ratio.

26. The method of claim 25, further comprising fitting the normalized timing ratio to a sinusoidal function.

27. The method of claim 26, further comprising calculating the roller offset from the amplitude of a sinusoidal fit of the normalized timing ratio.

28. The method of claim 26, further comprising calculating the drum angle from a phase of a sinusoidal fit of the normalized timing ratio.

29. The method of any one of claims 21 to 28, wherein the target sensor is an optical sensor.

30. The method of claim 29, wherein the optical sensor is configured to change state when a geometric feature of the timing target interrupts an optical path of the optical detector.

31. The method of claim 30, wherein the position of the drum is calculated based at least in part on a change in state of the optical sensor.

32. The method of any one of claims 21-32, wherein the one or more geometric features of each timing target include a first edge and a second edge of the timing target.

33. The method of claim 32, wherein the first edge extends radially from the outer periphery of the drum, and the second edge includes a first end and a second end, wherein a radial distance from the outer periphery of the drum to the second edge decreases continuously from the first end of the second edge to the second end of the second edge.

34. The method of claim 33, wherein a first end of the second edge is connected to the first edge.

35. The method of claim 34, wherein the second end of the second edge is connected to a first edge of an adjacent timing target in the plurality of timing targets.

36. The method of any one of claims 21-35, wherein each of the plurality of timing targets is vertically aligned with a bracket column of the roller.

37. The method of any one of claims 21-36, wherein the drum has an upper end and a lower end, and the plurality of timing targets are disposed proximate the lower end of the drum.

38. A method according to any one of claims 21 to 37, wherein the target sensor is mounted to the measurement plate.

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