Vascular monitoring system

Abstract

A Doppler blood flow monitoring device (150) includes a signal generating module, a signal receiving module, a signal filtering module, a signal converting module, at least one speaker, and a user interface (304). The signal generating module is configured to send a signal to a probe (106) in a probe receptacle on a blood vessel coupler positioned around a blood vessel of a patient. The signal receiving module is configured to receive a return signal from the probe. The signal filtering module is configured to filter the return signal. The signal converting module is configured to convert the filtered signal into an audible indication and a visual indication corresponding to a blood flow characteristic in the blood vessel of the patient. The at least one speaker (214) is configured to emit the first audible indication. Additionally, the user interface is configured to display the visual indication.

Description

BACKGROUND

[0001] Reconstructive and reconstructive surgery often uses free flaps, for example, in breast reconstruction. In free flap tissue surgery, a free flap (e.g., tissue and / or muscle and its associated arteries and veins) is removed from one part of the body or donor site and reattached to another part of the body or recipient site. The transferred tissue and / or muscle arteries and veins are then anastomosed to the native arteries and veins in order to achieve blood circulation in the transferred free flap (e.g., tissue and / or muscle).

[0002] Anastomosis of free flap tissue to native tissue is typically accomplished using microvascular techniques, including under a microscope. Over the past several years, several surgical instruments and techniques have been developed to aid in anastomosis. One known system for creating an anastomosis is the anastomosis coupler described in U.S. Patent No. 7,192,400, the disclosure of which is incorporated herein by reference. This anastomosis coupler is a surgical instrument that allows a surgeon to more easily and effectively join two blood vessel ends together. The coupler involves the use of two ring-shaped fastener portions having respective segments of a socket to be attached fixed thereon. Each fastener portion is also provided with a series of pins and corresponding holes for receiving the pins so as to close and join the portions together, and in turn, the blood vessels together (see Figure 7A 、 Figure 7C and Figure 7D ).

[0003] While free flap surgery has a successful history, very undesirable flap failure consequences still exist. One of the main causes of flap failure is a lack of blood supply to the flap tissue after reattachment of the free flap at the recipient site. Generally, factors that interfere with circulation in the flap include vessel occlusion, hemorrhage, or infection. When there is not enough blood supply to the flap tissue, tissue necrosis results. However, if the flap can be identified as not receiving adequate circulation early enough, it can be salvaged or rescued. The window of time for rescuing the flap after identifying insufficient blood flow is very small. Therefore, it is critical to quickly identify any insufficient blood flow in the transferred flap.

[0004] Handheld Doppler probes are typically permanently positioned at the distal tip of a pen-like device, rather than placed or left in the body, which aids in blood flow monitoring, but they have several drawbacks. One drawback of handheld probes is that they cannot be reliably positioned around a blood vessel.

[0005] After microvascular surgery, it is important to monitor the surgical area to ensure that blood flow is maintained at a desired level and that problems such as thrombosis do not occur. In the event of thrombosis, the transferred tissue will die. Other indirect monitoring by means of blood flow function of the blood vessel in which microvascular surgery has been performed is also often insufficient. For example, surface temperature measurements, transcutaneous PO2monitoring, photoplethysmography, and laser Doppler flowmetry have been employed. However, these solutions often require an accessible exposed portion of the flap. Furthermore, these methods cannot effectively monitor buried free tissue transfers and intraoral flaps. SUMMARY

[0006] The present disclosure provides improved blood vessel monitoring systems, devices, and methods to improve the accessibility, detection, and / or reliability of detecting blood flow to confirm patency of anastomosis sites.

[0007] In one example embodiment, a Doppler blood flow monitoring device includes a signal generating module, a signal receiving module, a signal filtering module, a signal converting module, at least one speaker, and a user interface. The signal generating module is configured to transmit a signal to a probe in a probe receptacle on a blood vessel coupler positioned around a patient's blood vessel. The signal receiving module is configured to receive a return signal from the probe. The signal filtering module is configured to filter the return signal. The signal converting module is configured to convert the filtered signal into an audible indication and a visual indication corresponding to a blood flow characteristic in the patient's blood vessel. The at least one speaker is configured to emit the first audible indication. Additionally, the user interface is configured to display the visual indication.

[0008] In another example embodiment, a Doppler blood flow monitoring system includes a blood vessel coupler, a transducer, and a monitor. The blood vessel coupler is positioned around a patient's blood vessel. The transducer is attached to the blood vessel coupler. The monitor is configured to generate a signal that is transmitted to the transducer, and the transducer is configured to emit an ultrasound signal based on the signal generated by the monitor. Further, the ultrasound signal is transmitted through the patient's blood vessel. The monitor is also configured to receive a return signal from the transducer and convert the return signal into a first indication and a second indication corresponding to a blood flow characteristic in the patient's blood vessel.

[0009] In another example embodiment, a remote monitoring system includes a monitor and a remote database. The monitor is configured to generate a signal to send to a transducer located within a vascular coupler. The vascular coupler is located around a patient's blood vessel, the transducer is configured to emit an ultrasound signal based on the signal generated by the monitor, and the ultrasound signal is transmitted through the patient's blood vessel. The monitor is further configured to receive a return signal from the transducer and convert the return signal into a first indication and a second indication corresponding to a blow flow characteristic in the patient's blood vessel. The remote database is configured to receive one or more files associated with the first indication and store the one or more files associated with the first indication, wherein the one or more files are remotely accessible via a user device.

[0010] Accordingly, it is an advantage of the present disclosure to improve the accessibility of blood flow data.

[0011] It is another advantage of the present invention to improve the detection of blood flow to confirm patency of a blood vessel.

[0012] It is another advantage of the present disclosure to provide remote monitoring of blood flow at an anastomosis site.

[0013] It is another advantage of the present disclosure to reduce background noise from an audio signal representative of blood flow within a blood vessel.

[0014] It is another advantage of the present invention to reduce the occurrence of free flap failure and serious adverse events due to insufficient blood flow in a free flap.

[0015] It is another advantage of the present disclosure to provide a system, device, and / or method for early detection of insufficient blood flow or circulation in a free flap.

[0016] Additional features and advantages of the disclosed vascular monitoring systems, devices, and methods are described in, and will be apparent from, the following and the drawings in which like reference characters refer to similar but not necessarily identical elements throughout the figures. The features and advantages described herein are not all-inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings and descriptions. Moreover, any particular embodiment does not have to have all of the advantages listed herein. Moreover, it should be noted that the language used in the specification is principally selected for readability and instructional purposes and not to limit the scope of the inventive subject matter. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1A is a schematic view of a probe system and monitor according to an example embodiment of the present disclosure.

[0018] Figure 1B is a perspective view of a probe system and monitor according to an example embodiment of the present disclosure.

[0019] Figure 2is a perspective view of a monitor according to example embodiments of the present disclosure.

[0020] Figure 3 various views of a monitor according to example embodiments of the present disclosure are shown.

[0021] Figure 4 is a schematic view of internal components of a monitor according to example embodiments of the present disclosure.

[0022] Figure 5 is a schematic view of an example monitoring system according to example embodiments of the present disclosure.

[0023] Figure 6 is a schematic view of a user interface of a monitoring application displayed on a user device according to example embodiments of the present disclosure.

[0024] Figure 7A is a partial perspective view of a vessel coupler with a transducer positioned around a patient's blood vessel according to example embodiments of the present disclosure.

[0025] Figure 7B is a partial perspective view of a transducer and lead wire a according to example embodiments of the present disclosure.

[0026] Figure 7C is a partial cross-sectional view of a fastener of a vessel coupler and transducer according to example embodiments of the present disclosure.

[0027] Figure 7D is a perspective view of a vessel coupler with a transducer and lead wire according to example embodiments of the present disclosure.

[0028] Figure 8 is a schematic view of an example pulse wave transmitted and received by a monitor according to example embodiments of the present disclosure. DETAILED DESCRIPTION

[0029] As discussed above, vascular monitoring systems, devices, and methods are provided to improve the detectability, detection, and / or reliability of blood flow, thereby confirming the patency of anastomosis sites. While free flap surgery has a successful history, the very undesirable consequences of flap failure can still occur. One of the main causes of flap failure is insufficient blood supply to the flap tissue after the free flap is reattached at the recipient site. Factors that typically interfere with circulation in the flap include vessel obstruction, hemorrhage, or infection. When there is not enough blood supply to the flap tissue, tissue necrosis results. However, the vascular monitoring systems, devices, and methods disclosed herein advantageously enable early detection of insufficient blood flow or circulation in a free flap, so that preservation or rescue can be performed before tissue necrosis.

[0030] The above-described blood vessel monitoring systems, devices, and methods can be used to monitor blood flow at anastomosis sites to confirm patency of blood vessels for surgical procedures such as free flap transfer microvascular reconstruction. The above-described systems, devices, and methods can be used in various environments, such as a hospital operating room or a post-anesthesia care unit, to detect blood flow and confirm patency of blood vessels during and after surgery (either on-site or remotely). Free flap transfer can be used to re-form body parts after cancer and injury surgeries using the patient’s own tissue. Examples include breast reconstruction, tongue reconstruction, maxillofacial reconstruction, hand and foot reconstruction after trauma, etc. Generally, microvascular anastomosis is a critical procedure in determining flap success. By providing blood flow monitoring capabilities at anastomosis sites and increasing access to these monitoring capabilities (e.g., via remote access through a monitoring application on a user device such as a smartphone), the systems, devices, and methods disclosed herein allow for early detection of low blood flow or insufficient blood flow within flap tissue, thereby enabling medical practitioners (e.g., surgeons) to take corrective measures before necrosis begins and the free flap becomes unusable.

[0031] Multi-component probe and monitor connection

[0032] Figure 1A A schematic diagram of a flow monitoring system 100A is shown, while Figure 1B A perspective view of a flow monitoring system 100B is shown (both systems can be generally referred to as flow monitoring systems 100). The flow monitoring system 100 can include multi-component probe systems 102a and 102b attached to a monitor 150 via external leads 110a and 110b. For example, the probe system 102a can be attached to “Channel A” of the monitor 150 via the external lead 110a, while the probe system 102b is attached to “Channel B” of the monitor 150 via the external lead 110b. Specifically, the monitor 150 can provide monitoring at at least two anastomosis sites by having at least two Doppler probe inputs or connector ports (shown in Figure 2 ), and the user-selectable monitoring can be performed on either channel (e.g., “Channel A” or “Channel B”). It should be understood that while the embodiments shown in Figure 1A and Figure 1B use leads 110a, 110b to connect the probe systems 102a, 102b to the monitor 150, a wireless system can also be used in which the probes are configured to communicate with the monitor without the use of leads 110.

[0033] The probe systems (e.g., probe systems 102a and 102b, generally referred to herein as probe systems 102) include a set of fasteners 104a, 104b that can form a blood vessel coupler that couples two veins and / or arteries in an end-to-end anastomosis manner (see Figure 7A). The probe systems 102 can also each include a transducer 106a, 106b (see Figure 7A , 7B , 7C and 7D) connected to at least one of the fasteners 104a, 104b. For example, one ring can include a probe holder with a press-fit Doppler probe or transducer 106. In one example, a set or pair of fasteners (e.g., a set of fasteners 104a, generally referred to herein as fasteners 104) can include a pair of high-density polyethylene (“HDPE”) rings with stainless steel pins (see Figure 7C and Figure 7D ). The pair of rings forms a permanent implant in the patient.

[0034] The set or pair of fasteners 104 or rings can be sized so that they fit similar sized arteries or veins. For example, the fasteners 104 or rings can have an inner diameter between 1.0 millimeter and 4.0 millimeters. In one example, the inner diameter of the fasteners 104 can be provided in size increments of 0.5 millimeters. It should be appreciated that the size and shape of the fasteners 104 or rings can accommodate veins and arteries commonly encountered in microsurgical and revascularization procedures and are suitable for end-to-end anastomosis of such veins and arteries in the peripheral vascular system.

[0035] The vascular coupler formed by the set or pair of fasteners 104 can advantageously reduce anastomosis and flap ischemia time and provide intima-to-intima contact without any intraluminal foreign bodies (e.g., suture material), which also advantageously reduces the rate of thrombosis. In addition, the vascular coupler advantageously provides stent support to the anastomosed vessels and can be used to correct for vessel size discrepancies. For example, the pair of fasteners 104 can be used to connect veins or arteries of different sizes. The fasteners also advantageously provide increased patency rates compared to hand suturing because they provide intima-to-intima contact without any intraluminal foreign bodies.

[0036] The vessel coupler formed by the pair of fasteners 104 is adapted to create an end-to-end anastomosis of a blood vessel (e.g., a vein or artery) while maintaining and preserving the position of the transducer(s) 106 or other sensing device(s). The sensing device(s) in turn can be used to monitor or assess parameters related to the success of the recovery and surgical procedure, such as blood flow at the anastomosis site to confirm patency of the blood vessel. As discussed in greater detail below, the sensing device(s) or transducer(s) 106 enable a medical practitioner (e.g., a surgeon) to monitor and analyze blood flow and / or blood velocity to determine the success of the procedure and / or confirm patency of the blood vessel. Blood flow within the vessel can be monitored, and one or more audio samples of the blood flow can be recorded and stored in a database. Multiple recordings of blood flow audio samples at different times stored in the database can allow a medical practitioner (e.g., a surgeon) to compare between recordings. The systems and methods disclosed herein advantageously allow for recording and evaluating blood flow data over time to analyze the success of the procedure and patient characteristics (e.g., blood flow and blood velocity). Because anastomosis failure tends to be fairly sudden, the ability to continuously and reliably monitor and compare blood flow can be used to generate and transmit a signal associated with the detection of a failure event, thereby enabling a medical practitioner (e.g., a surgeon) to take corrective action before necrosis begins and the free flap becomes unusable. Moreover, as described in greater detail below, the remote monitoring capabilities of the disclosed systems, devices, and methods advantageously provide remote access such that a medical practitioner (e.g., a surgeon) can detect a failure event regardless of their location (e.g., at a remote location) and without a reduction in audio quality.

[0037] Any transducer 106a, 106b suitable for ultrasound Doppler monitoring can be used. In one example embodiment, the Doppler probe or transducer is made of an approved implantable material such as HDPE or silicone. In another example, the transducer 106a, 106b includes a piezoelectric crystal. The transducer 106a, 106b (hereinafter collectively referred to as transducer 106) can be any size that fits the corresponding transducer socket (see Figure 7C ) used on the fastener of the vessel coupler. For example, a circular transducer 106 is adapted to be received by a socket having a circular inner surface. The transducer 106 can be a circular piezoelectric crystal having a size between about 0.5 millimeters and about 1 millimeter. In one example, the Doppler probe or transducer 106 includes a tip having a circular piezoelectric crystal having a size between about 0.5 millimeters and about 1 millimeter, a Teflon-coated coaxial wire, and a metal connector.

[0038] The Doppler probe or transducer 106 can be a 20 MHz ultrasound Doppler transducer that emits pulsed ultrasound signals when connected to the monitor 150 via the lead 110. For example, the monitor 150 can receive and transmit the pulsed waves. In one example (as shown in FIG. 1), the monitor 150 is a handheld device that is connected to the transducer 106 via the lead 110.Figure 8 As shown, eighteen (18) pulses of 20MHz are enveloped and transmitted as a transmission pulse to the transducer 106. After receiving the transmission pulse, the pulse can excite the piezoelectric crystal so that the crystal vibrates and sends an ultrasound signal through the blood vessel. The enveloped transmission pulse can repeat at a frequency of 78kHz. After the transmission pulse is electronically stopped, the monitor 150 can receive or listen for a return signal. For example, the monitor 150 can switch from transmitting to receiving or listening (e.g., 6.4 seconds) for Doppler-shifted echoes immediately after the transmission pulse (150 nanoseconds dead time). The Doppler-shifted echoes are transmitted back to the monitor. When the probe or transducer 106 detects flow, an audible signal (e.g., from the Doppler-shifted echoes) is generated that varies. The audible signal can be processed and filtered by the monitor 150 before being provided to the user.

[0039] As shown, the transducer 106 can include a percutaneous lead (e.g., lead 108a of probe system 102a and lead 108b of probe system 102b, hereinafter collectively referred to as lead 108) attached to its surface. The percutaneous lead 108 has a proximal end (e.g., the end proximate to the transducer 106) and a distal end. The percutaneous lead 108 preferably includes two wires insulated by a common insulating material. The wires can be any wires suitable for monitoring the 20MHz signals from the transducer 106. In one example, the insulating material preferably includes a biocompatible material, such as a Class VI medical grade material. In one example, the monitor 150 can have a transmission frequency of 20MHz with continuous reception of pulsed wave transmission. The pulses can repeat at a pulse repetition frequency of 156.25kHz. Figure 1A

[0040] At the proximal end, the percutaneous lead 108 can have one wire attached to each surface of the transducer 106. Any manufacturing method that attaches the two wires of the lead 108 to each surface of the transducer 106 can be used so as to create a strong conductive bond with the transducer 106 itself. Suitable methods include, but are not limited to, soldering, friction bonding, adhesive bonding, or attaching the lead during the transducer manufacturing process. In one example, the strength of the bond between the transducer 106 and the two wires is preferably strong enough to allow the probe to be separated from the socket of the fastener by simply pulling on the wire itself. After use, the transducer can be left in the socket inside the body, or it can be removed, such as by applying sufficient force to the percutaneous lead 108 to pull the transducer 106 out of the socket, and then pulling the lead 108 through the skin and to the surface of the body. In one example, the strength of the bond between the transducer 106 and the percutaneous lead 108 is greater than the force required to remove the transducer 106 from the patient by applying a mechanical force to the percutaneous lead 108.

[0041] ​The distal end of the percutaneous lead 108 may be located within an optional conjoint pad (not shown) placed on human skin. In one example, the conjoint pad may be made of a medical-grade material suitable for contact with human skin, such as a USP Class V or VI material. Various alternatives can be used to attach the lead to the skin, including, for example, using patches and sutures. The conjoint pad or alternative can be attached to the skin such that the force required to remove the pad or alternative from the skin must be greater than the force required to separate the percutaneous lead 108 from the external leads 110a, 110b (hereinafter collectively referred to as external leads 110). In a preferred embodiment, the force required to disconnect the percutaneous lead 108 from the external leads 110 should be less than the force required to remove the conjoint pad or alternative attachment (e.g., patch, suture, etc.) from the skin.

[0042] like Figure 1A As shown, the distal end of the percutaneous lead 108 may be fitted with connectors 120a and 120b (hereinafter collectively referred to as connector 120), which allow the lead 108 to be further connected to the proximal end of the external lead 110. The external lead 110 consists of any wire suitable for transmitting signals and is insulated with a material suitable for skin contact. Preferably, the wire is adapted to transmit a 20 MHz signal.

[0043] Preferably, connector 120 is a medical-grade electrical connector. In an example embodiment, connector 120 is a non-locking connector. In another example, connector 120 is a medical-grade electrical connector. A non-locking connector helps reduce the probability of the transducer being accidentally removed from the anastomosis site. That is, if the external lead 110 is accidentally pulled, the non-locking connector 120 will disconnect it from the percutaneous lead 108 without interfering with the transducer 106. A mating pad or alternative attachment device can also help prevent interference with the transducer 106.

[0044] The distal end of external lead 110 is connected to monitor 150. It can be connected in any suitable manner. In an example embodiment, lead 110 is connected using connectors 130 (e.g., connector 130a for external lead 110a and connector 130b for external lead 110b), and connector 130 can be of the same type as connector 120. Connectors 120 and 130 can be metallic and may include plastic housings.

[0045] like Figure 1A As shown, both inputs or channels are utilized and connected to their own Doppler probes. Furthermore, while the preferred multi-component probe system uses leads 108, 110 to connect the probes to the monitor 150, a wireless system can also be used, wherein the probes are configured to communicate with the monitor 150 without using leads 108, 110.

[0046] Figure 1BA perspective view of flow monitoring system 100B is shown, including multi-component probe system 102a attached to monitor 150 via external lead 110a. Figure 1B The illustrated embodiment shows probe system 102a attached to monitor 150 for a single channel (e.g., "Channel A"). It should be appreciated that more than two channels can be used. For example, monitor 150 can be capable of monitoring more than two channels.

[0047] Monitor housing, structure and internal components

[0048] Figure 2 An isometric view of an example embodiment of monitor 150 is shown, Figure 3 Various other views of monitor 150 are shown. Monitor 150 includes a housing 202 and a display or user interface 210, such as a color LCD touchscreen. In addition, as Figure 2 shown, monitor 150 includes a speaker 214 and a handle 216. Housing 202 and handle 216 can be made of injection molded plastic (e.g., PC-ABS). Monitor 150 can also include various controls associated with display 210 and / or speaker 214, such as a volume control 220 (e.g., a volume control button or membrane switch), a mute control 222 (e.g., a mute button or membrane switch), and channel selection controls 224a and 224b (e.g., channel selection buttons or membrane switches for "Channel A" and "Channel B"). Channel selection controls are associated with connector ports 226a and 226b for receiving external leads 110. In one embodiment, monitor 150 can be approximately 6.17" D x 8.18" W x 3.20" H and can weigh approximately 1.84 pounds (0.83 kilograms). In addition, as Figure 3 shown, monitor 150 can include an AC power jack 230, feet 240a-d, and a power control 250 (e.g., a power button or membrane switch). In addition, monitor 150 can have wireless capability to remotely access previously recorded audio and / or blood flow data, which will be described in more detail in Figure 5 .

[0049] Figure 4A schematic diagram of various internal components and modules of a flow monitor 150 is shown. The monitor 150 may include a power supply 302, a user interface or display 304, a touch screen 306, a touch screen controller 308, a processor 310, a memory 312, communication modules (e.g., a cellular communication module 316a and a WiFi communication module 316b), a debugging module 318, flash memory such as an ultra-secure digital high-capacity (“uSDHC”) flash memory card, a bootloader 330, test points 334 for each channel (e.g., “Channel A” and “Channel B”), an analog front end (“AFE”) 340, a filter module 342, an amplifier (“AMP”) 350, speakers 314a and 314b (collectively referred to as speaker 314), a battery 360, and a battery gauge 370.

[0050] The processor 310 can communicate with the touchscreen 306 via a serial peripheral interface (“SPI”). The touchscreen 306 can be a resistive touchscreen associated with the display 304, such as a liquid crystal display. Figure 2 Several of the buttons shown (e.g., volume control 220, mute control 222, and channel selection controls 224a and 224b) can alternatively be displayed as graphical representations on displays 210 and 304, which can be selected using touchscreen 306. Memory 312 may be DDR2 SDRAM and may temporarily store audio files before they are sent to a remote server or database by one or more of the communication modules. Communication modules (e.g., cellular module 316a and WiFi module 316b) may communicate with processor 310 via UART, USB, SPI, or other acceptable interfaces to send and receive data from a remote server or database. Similarly, debug module 318 and bootloader 330 may also communicate with processor 310 via an interface (e.g., SPI). In one example, debug module 318 and bootloader 330 may be used for manufacturing testing, diagnostics, and repair. The communication modules allow monitor 150 to provide remote monitoring to medical practitioners (e.g., surgeons), which will be described in more detail below. However, when on-site, medical practitioners (e.g., nurses and surgeons) can listen to the generated audio, which is amplified by the AMP 350 and then sent to speakers 314a and 314b.

[0051] Signal generation / detection and audio / video output

[0052] Monitor 150 generates a signal that is sent to transducer 106 (e.g., transducer 106 or probe emits pulsed ultrasound signals) and transmitted through the blood vessel. Transducer 106 then detects the signal transmitted through the blood vessel and sends the detected signal back to monitor 150, which converts the signal into a form readable by the user. When the probe detects flow, an audible signal with varying volume intensity is generated. For example, the signal can be converted into sound or a visual display, or both.

[0053] The frequency (i.e., pitch) of the signal is proportional to the blood flow within the vessel. This produces a unique tone pattern that indicates the pattern of blood flow relative to time. The tone pattern provides surgeons with a qualitative indication of blood flow. The volume of the tone can be adjusted via controls on a monitor. A transmitter in the monitor periodically drives an ultrasound crystal located at the tip of the probe. The ultrasound waves generated by the crystal travel in a fairly narrow beam through the tissue immediately below the tip of the probe. They are then reflected back to the probe whenever they encounter a boundary between tissues of different densities. During intervals when the unit is not transmitting, the probe passes any reflected signals it receives to a receiving circuit. This circuit amplifies the returning echoes, compares their frequencies with the frequency of the transmitted signal, and converts any frequency differences into an audible tone.

[0054] The Doppler probe and monitor 150 are adapted to detect blood flow at the anastomosis site and to confirm vascular patency at the anastomosis site during and after surgery. For example, blood flow can be detected for up to approximately 7 days postoperatively. Any monitor / probe combination capable of detecting both audio output frequency and blood flow velocity can be used. Preferably, the combination is capable of detecting audio output frequencies in the range of approximately 80 to approximately 3000 Hz and blood flow velocities in the range of approximately 0.5 cm / s to approximately 45 cm / s.

[0055] In a preferred embodiment, monitor 150 displays visual numerical values ​​representing the frequency shift of the Doppler signal. The use of these values ​​allows surgeons to store the numbers and understand how they change over time for pattern detection and analysis. Optionally, these numbers can also be downloaded to computer software for further analysis. In another preferred embodiment, monitor 150 allows monitoring at at least two anastomotic sites. In this embodiment, monitor 150 has one or more Doppler probe inputs (e.g., “Channel A” and “Channel B”) and is capable of user-selectable monitoring of either channel.

[0056] Monitor 150 is a pulsed Doppler ultrasound system designed to detect blood flow in blood vessels. When used in conjunction with probe system 102, monitor 150 can detect blood flow at the anastomosis site and confirm vascular patency during and after surgery. In one example, blood flow can be detected as needed for several days (e.g., 7 days) post-operatively. In one example, monitor 150 is connected to a probe or transducer, such as a 20 MHz ultrasound Doppler probe or transducer 106, which emits pulsed ultrasound signals when connected to monitor 150 via lead 110. When the probe or transducer 106 detects flow, it generates a changing audible signal. The audible signal can be displayed on or emitted from monitor 150, as discussed in more detail below.

[0057] like Figure 2 As shown, the display or user interface 210 provides a qualitative visual indication 212 of blood flow. In one example, the visual indication 212 may include various bars, each representing a frequency range or blood flow velocity threshold. For example, the visual indication 212 of monitor 150 is capable of indicating blood flow velocities as low as 0.5 cm / s or 0.75 cm / s, and also capable of indicating blood flow velocities up to 45 cm / s. Monitor 150 may also emit an audible indication of blood flow via speaker 214. Before displaying the visual indication and / or emitting the audible indication, monitor 150 may filter the signal to reduce noise. For example, monitor 150 may digitally filter the audio signal returned from probe or transducer 106 to reduce or remove noise.

[0058] In another example, monitor 150 may display visual numerical values ​​representing blood flow or blood flow velocity (e.g., frequency shift of a Doppler signal). The use of qualitative visual indicators 212 or numerical values ​​allows medical practitioners (e.g., surgeons) to review additional indicators of blood flow (in addition to audio signals) to analyze postoperative vascular patency. Optionally, these numerical and / or visual indicators may also be stored in a database (see below). Figure 5 and Figure 6 (A more detailed description) is provided for further analysis.

[0059] The visual indicator 212, displayed on the user interface 210 (or on the user device 402 described in more detail below), advantageously provides an auxiliary indicator of blood flow, enabling medical practitioners to monitor and analyze patient blood flow in noisy environments. For example, an operating room may have several other sources of ambient noise from other medical instruments, other medical personnel, etc. And the visual indicator 212 can be monitored regardless of the level of ambient noise. Conversely, audible indicators may be difficult to analyze and distinguish from other sources of interference or noise.

[0060] Back Figure 4The analog front-end 340 receives signals or pulses from the processor 310. For example, the AFE 340 may receive 1-microsecond and 0.8-microsecond @ 78 kHz pulses from the processor 310 and then send them to the Doppler probe or transducer 106. The AFE 340 then receives a return signal (e.g., a phase-shift signal) from the transducer 106, which is converted into an audio signal and sent to the filter 342 and / or AMP 350. The audio signal represents the phase shift or Doppler frequency shift detected by the monitor 150, which is converted into audio. For example, ultrasound energy bounces off red blood cells within a blood vessel at the anastomosis site, causing a phase shift if a signal is emitted from the transducer 106. This phase shift is detected and converted into audio. Specifically, the signal is proportional to the Doppler frequency shift and also proportional to the blood flow velocity.

[0061] Digital signal filtering

[0062] In some cases, particularly for low blood flow velocities, audio samples may be indistinguishable from or difficult to differentiate from background noise. Furthermore, low blood flow velocities may require medical practitioners (e.g., surgeons) to increase the volume of monitor speakers, which can become distracting or unpleasant when accompanied by a large amount of background noise. Specifically, medical practitioners (e.g., surgeons) determine vascular patency using different sound or audio signals, which are often difficult to detect when drowned out by the "hissing" background noise from speakers 214 and 314. By digitally filtering the signal, audio samples are clearly separated and removed from the background noise, making them easily identifiable and reviewable by medical practitioners without the unpleasant "buzzing" or "hissing" background noise from the speakers.

[0063] Audio signals can be digitally filtered to control background noise levels. For example, filter module 342 can perform waveform shaping on the audio signal, utilizing low-pass and high-pass digital filtering. In another example, filter module 342 can perform a Fast Fourier Transform (FFT) on the signal to separate the audio signal into multiple digitally filtered frequency components. Digital filtering may include applying bandpass (low and high) filters and signal boosting (e.g., a 236Hz boost).

[0064] Furthermore, audio from low blood flow velocities is often difficult to distinguish from the low-frequency roll-off of a speaker. To improve audio quality, the signal can be boosted (e.g., a 236Hz boost) before waveform shaping to pull up the low-end frequencies on the speaker's low-frequency roll-off. The digital filtering described herein advantageously improves noise reduction while maintaining the monitor's ability to produce an audible signal when blood flow is detected within a specific velocity range. Digital filtering advantageously allows medical practitioners to easily detect weak, low-frequency signals associated with low blood flow velocities. Without digital filtering, the audio signal might be lost or drowned out by the background noise emitted by speakers 214, 314.

[0065] Remote monitoring

[0066] Figure 5 An example system 400 with a monitor 150 is shown, which communicates with one or more of a management station 470, a cloud computing infrastructure 480, and a user device 402. The management station 470 can be used to apply configuration and licensing to various mobile devices or user devices 402 that communicate with the cloud computing infrastructure 480. The monitor 150 may include... Figures 2 to 4 Each of the components shown. For example... Figure 5 As shown, several monitor components are illustrated (some of which were previously shown in...). Figure 4 As described in the document, such as processor 410, receiver-transmitter such as universal asynchronous receiver-transmitter (“UART”) 412, complex programmable logic device (“CPLD”) 420, bootloader 430, connectivity module 440, storage devices 450a and 450b (generally referred to as storage device 450), and input / output (I / O) device 460.

[0067] Monitor 150 can communicate with cloud computing infrastructure 480 (e.g., Amazon Web Services (“AWS”)). Cloud computing infrastructure 480 may include backend server 482 (e.g., a backend AWS Elastic Compute Cloud (“EC2”) server), audio server 484, database search tool (e.g., MongoDB), and database 488 (e.g., Amazon Simple Storage Service (“S3”)). Communication between monitor 150 and cloud computing infrastructure 480 via communication module 440 (such as a WiFi module) can be encrypted. For example, communication encryption at 405 may include over-the-air (“OTA”) encryption of Wi-Fi Protected Access (“WPA”) or Wi-Fi Protected Access II (“WPA2”). Additionally, communication between monitor 150 and cloud computing infrastructure 480 can utilize communication protocols at 407, such as Transport Layer Security (“TLS”) protocol, to provide secure communication for data transfer over the Internet, for example, when transferring patient audio files 490 to a remote server (e.g., backend server 482 or audio server 484) or database 488.

[0068] During communication, backend server 482 can request device status or query the latest audio samples from monitor 150 at arrow 425. For example, backend server 482 can request device status information such as transducer ID, which channel on the monitor is active, or whether the monitor is actively listening (e.g., recording audio samples). Additionally, backend server 482 can query monitor 150 for the latest audio samples. For example, device status and / or audio samples from monitor 150 can be transmitted between connection module 440 and backend server 482. Furthermore, backend server 482 can obtain audio information, such as audio file 490, from monitor 150 via connection module 440 at arrow 435. At arrow 445, both device status information and audio information can be passed to database search tool 486. At arrow 455, monitor 150 can also upload audio information, such as audio file 490, to audio server 484. At arrow 465, audio server 484 can store data, such as audio information, in database search tool 486. Additionally, audio server 484 can store audio information (such as audio file 490) in database 488 at arrow 475.

[0069] At arrow 485, a healthcare practitioner, such as a nurse, can communicate with and manage data within the cloud infrastructure 480. In one example, probe or transducer IDs or model numbers, audio identification information, patient identification information, hospital information, or healthcare practitioner (e.g., surgeon) information can be associated with a specific patient, audio identifier, probe or transducer 106, and / or healthcare practitioner (e.g., surgeon), allowing certain audio files that only the surgeon has been granted access to to be retrieved by that surgeon via his or her user device 402. Communication between the management station 470 and the cloud infrastructure 480 can also utilize communication protocols such as TLS. Other healthcare practitioners or privileged users, such as surgeons, can request audio at arrow 495 and play audio at arrow 497 by communicating with the cloud infrastructure 480. Specifically, user device 402 can communicate with backend server 482 and database 488 to play audio file 490.

[0070] As used herein, a physical processor or processor 410 refers to a device capable of executing instructions that encode arithmetic, logic, and / or I / O operations. In one illustrative example, the processor may follow the Von Neumann architecture model and may include an arithmetic logic unit (ALU), a control unit, and multiple registers. Alternatively, the processor may be a single-core processor typically capable of executing one instruction at a time (or processing a single instruction pipeline), or a multi-core processor capable of executing multiple instructions simultaneously. Furthermore, the processor may be implemented as a single integrated circuit, two or more integrated circuits, or may be a component of a multi-chip module (e.g., where individual microprocessor dies are included in a single integrated circuit package and thus share a single socket). The processor may also be referred to as a central processing unit (CPU). Additionally, the processor may be a microprocessor, a microcontroller, or a microcontroller unit (MCU).

[0071] As discussed herein, memory device 450 refers to a volatile or non-volatile memory device, such as random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), or any other device capable of storing data. As discussed herein, I / O device 460 refers to a device capable of providing an interface between one or more processor pins and an external device capable of inputting and / or outputting binary data.

[0072] Processor 410 can be interconnected using various technologies, from point-to-point processor interconnects to system area networks, such as Ethernet-based networks. Local connectivity within monitor 150, including connections between processor 410, CPLD 410, connectivity module 440, storage device 450, and I / O device 460, can be provided by one or more local buses of a suitable architecture, such as peripheral component interconnect (PCI).

[0073] Remote monitoring application

[0074] In some situations, healthcare professionals (such as surgeons) may not be physically present to review and analyze audible instructions emanating from monitor 150 and / or qualitative visual instructions 212 displayed by monitor 150. In these cases, either the patient must wait for the surgeon to return to the hospital operating room or post-anesthesia care unit, or the information can be relayed to the surgeon by another professional or staff member. For example, in some situations, the surgeon may attempt to listen to audible instructions (e.g., audio played by monitor 150) in real time via telephone, which may result in degraded signal due to cell reception, cell carrier, etc. The inconvenience of having to review and analyze the patient's blood flow data on-site often leads to a reduction in monitoring frequency.

[0075] To improve the accessibility and ease of patient monitoring, user equipment 402 can run an application to remotely access audio files 490 stored on database 488. Healthcare practitioners (e.g., nurses) can assign access credentials to specific healthcare practitioners (e.g., surgeons) at management station 470. Once granted access or privileges, a user (e.g., a surgeon) using the monitoring application on user equipment 402 can retrieve and play audio files associated with a specific implanted Doppler probe or transducer 106. For example, blood flow audio files from multiple patients in multiple different hospitals can be stored in database 488, but "Surgeon_A" can be assigned access or privileges to listen to the audio files associated with "Doppler Probe_A" implanted in "Patient_A". Similarly, "Surgeon_B" can be assigned access or privileges to listen to the audio files associated with "Doppler Probe_B" implanted in "Patient_B" and "Doppler Probe_C" implanted in "Patient_C".

[0076] When accessing audio files on user device 402, medical practitioners (such as surgeons) can request to listen to the "current" blood flow audio file. For example, as Figure 6As shown, a medical practitioner (e.g., a surgeon) can select the graphical representation of the "Request-Current" button 502 to listen to the "current recording" of blood flow at the anastomosis site. In one example, selecting the "Request-Current" button 502 initiates recording, which may not be a real-time audio signal of blood flow, but rather a short delay (e.g., 10 seconds, 15 seconds, 20 seconds, etc.). For example, by selecting button 502, a 15-second recording of the patient's blood flow audio signal can be recorded and uploaded to database 488, which can then be retrieved and played back by user device 402 to provide an audible indication of blood flow via the user device 402's speaker. The application can also allow a medical practitioner (e.g., a surgeon) to play, listen to, and review previous audio recordings of the patient. For example, by selecting any of the graphical representations of "Previous Record_1," "Previous Record_2," or "Previous Record_3" buttons 504, 506, or 508, a medical practitioner (e.g., a surgeon) can listen to previous recordings of the patient's blood flow audio signal. By doing so, surgeons can compare audio signals and determine whether the patient's blood flow is improving, worsening, or remaining roughly the same.

[0077] Recording intervals can range from 5 to 20 seconds, but it should be understood that other intervals may be used. In another example, the interval may be selected by a medical practitioner (e.g., a surgeon) via a mobile application.

[0078] In another example, the application can provide qualitative visual indications of blood flow 512, similar to Figure 2 The qualitative visual indicator 212 is shown. In one example, the visual indicator 512 may include various bars, each representing a frequency range or blood flow velocity threshold. Similar to the qualitative visual indicator 212 of the monitor 150 discussed above, the qualitative visual indicator 512 of the application on the user equipment 402 is capable of indicating blood flow velocities as low as 0.5 cm / s or 0.75 cm / s and as high as 45 cm / s.

[0079] For example, various aspects of blood flow within a blood vessel can be monitored and recorded. By accessing several previous records, medical practitioners (such as surgeons) can make objective comparisons between the current record and previous records. For example, qualitative visual indicators 512 associated with a record can provide benchmark values ​​that can be compared with other records.

[0080] The application can display audio ID 520, probe ID 530, and other recording information 540, allowing healthcare professionals to identify which patient and / or probe the audio file corresponds to. Additionally, the recording information 540 can indicate the date and time of recording, etc.

[0081] It should be understood that user equipment 402 may be a smartphone, tablet, laptop, computer, smartwatch, or any other suitable device.

[0082] The aspects of the subject matter described herein can be used alone or in combination with one or more other aspects described herein. In a first exemplary aspect of this disclosure, a Doppler blood flow monitoring device includes a signal generation module, a signal receiving module, a signal filtering module, a signal conversion module, at least one speaker, and a user interface. The signal generation module is configured to send a signal to a probe in a probe port on a vascular coupler located around a patient's blood vessel. The signal receiving module is configured to receive a return signal from the probe. The signal filtering module is configured to filter the return signal. The signal conversion module is configured to convert the filtered signal into audible and visual indications corresponding to the blood flow characteristics in the patient's blood vessel. At least one speaker is configured to emit a first audible indication. Additionally, the user interface is configured to display a visual indication.

[0083] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, wherein the signal sent by the signal generation module is a pulsed ultrasound signal.

[0084] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, wherein the signal sent by the signal generation module is a pulse wave Doppler signal.

[0085] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, filtering the returned signal including applying a low bandpass filter to the returned signal, applying a high bandpass filter to the returned signal, and applying a fast Fourier transform to the returned signal.

[0086] According to another exemplary aspect of this disclosure, which can be used in combination with any one or more of the foregoing aspects, filtering the returned signal includes applying frequency adjustment to the returned signal. Frequency adjustment is applied to the returned signal before waveform shaping.

[0087] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, wherein the frequency adjustment is a frequency boost between 150 Hz and 300 Hz.

[0088] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, with the frequency boost between 230 Hz and 240 Hz.

[0089] The aspects of the subject matter described herein can be used alone or in combination with one or more other aspects described herein. In a second exemplary aspect of this disclosure, a Doppler blood flow monitoring system includes a vascular coupler, a transducer, and a monitor. The vascular coupler is located around a patient's blood vessel. The transducer is attached to the vascular coupler. The monitor is configured to generate a signal to be transmitted to the transducer, and the transducer is configured to transmit an ultrasound signal based on the signal generated by the monitor. Furthermore, the ultrasound signal is transmitted through the patient's blood vessel. The monitor is also configured to receive a return signal from the transducer and convert the return signal into a first indication and a second indication corresponding to the characteristics of the flow in the patient's blood vessel.

[0090] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, wherein the first instruction is an audible instruction.

[0091] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, and the second indication is a visual indication.

[0092] According to another exemplary aspect of this disclosure, which can be used in combination with any one or more of the foregoing aspects, the vascular coupler is a first vascular coupler, and the transducer is a first transducer. Additionally, the first vascular coupler and the first transducer are associated with a first channel of the monitor. In one example, the system further includes a second vascular coupler and a second transducer located around different blood vessels of the patient. The second vascular coupler and the second transducer are associated with a second channel of the monitor. Furthermore, the monitor is configured to generate another signal to send to the second transducer, receive different return signals from the second transducer, and convert the different return signals into primary and secondary indications corresponding to the blowing characteristics in different blood vessels of the patient.

[0093] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, with the primary indication being an audible indication.

[0094] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, and the second indication is a visual indication.

[0095] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, wherein the signal emitted from the transducer is a pulsed ultrasonic signal.

[0096] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, wherein the signal generated by the monitor is a pulsed ultrasound signal.

[0097] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, wherein the signal emitted from the transducer is a pulse wave Doppler signal.

[0098] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, wherein the signal generated by the monitor is a pulse wave Doppler signal.

[0099] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, with the transducer removably retained within the vascular coupler.

[0100] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, wherein the transducer is removably held within the vascular coupler by at least one of friction fit, mechanical coupler, and adhesive.

[0101] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, and the vascular coupler is adapted to allow the transducer to be subsequently removed from the socket of the vascular coupler.

[0102] According to another exemplary aspect of this disclosure, which can be used in combination with any one or more of the foregoing aspects, the monitor is also configured to filter the return signal before converting the return signal into at least one of a first indication and a second indication.

[0103] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, filtering the returned signal including applying a low bandpass filter to the returned signal, applying a high bandpass filter to the returned signal, and applying a fast Fourier transform to the returned signal.

[0104] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, filtering the returned signal includes applying frequency adjustment to the signal, wherein the frequency adjustment is applied to the returned signal before waveform shaping of the returned signal.

[0105] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, wherein the frequency adjustment is a frequency boost between 150 Hz and 300 Hz.

[0106] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, with the frequency boost between 230 Hz and 240 Hz.

[0107] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, and the transducer includes a piezoelectric crystal.

[0108] The aspects of the subject matter described herein may be used alone or in combination with one or more other aspects described herein. In a third exemplary aspect of this disclosure, a remote monitoring system includes a monitor and a remote database. The monitor is configured to generate signals to be sent to a transducer located within a vascular coupler. The vascular coupler is located around a patient's blood vessel, and the transducer is configured to transmit ultrasound signals based on the signals generated by the monitor, and the ultrasound signals are transmitted through the patient's blood vessel. The monitor is also configured to receive return signals from the transducer and convert the return signals into a first indication and a second indication corresponding to the flow characteristics in the patient's blood vessel. The remote database is configured to receive one or more files associated with the first indication and to store one or more files associated with the first indication, wherein one or more files are remotely accessible via a user device.

[0109] According to another exemplary aspect of this disclosure, which can be used in combination with any one or more of the foregoing aspects, the monitor is also configured to filter the return signal before converting the return signal into at least one of a first indication and a second indication.

[0110] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, filtering the returned signal including applying a low bandpass filter to the returned signal, applying a high bandpass filter to the returned signal, and applying a fast Fourier transform to the returned signal.

[0111] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, filtering the returned signal includes applying frequency adjustment to the signal, wherein the frequency adjustment is applied to the returned signal before waveform shaping of the returned signal.

[0112] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, wherein the frequency adjustment is a frequency boost between 150 Hz and 300 Hz.

[0113] According to another exemplary aspect of this disclosure, it can be used in combination with any one or more of the foregoing aspects, with the frequency boost between 230 Hz and 240 Hz.

[0114] According to another exemplary aspect of this disclosure, which can be used in combination with any one or more of the foregoing aspects, the remote database is also configured to receive and store one or more files associated with the second instruction. Additionally, the one or more files associated with the second instruction can be remotely accessed via a user equipment.

[0115] Many features and advantages of this disclosure are apparent from the written description, and therefore the appended claims are intended to cover all such features and advantages. Furthermore, since many modifications and variations will readily occur to those skilled in the art, this disclosure is not limited to the exact construction and operation shown and described. Therefore, the described embodiments should be considered illustrative rather than restrictive, and this disclosure should not be limited to the details given herein but should be defined by the full scope of the appended claims and their equivalents, whether now or in the future foreseeable or unforeseeable.

Claims

1. A Doppler blood flow monitoring device, comprising: a signal generation module configured to send a signal to a probe positioned in a probe socket on a blood vessel coupler positioned around a blood vessel of a patient; a signal reception module configured to receive a return signal from the probe; a signal filtering module configured to filter the return signal; a signal conversion module configured to convert the filtered signal into an audible indication and a visual indication corresponding to a blood flow characteristic in the blood vessel of the patient, wherein the visual indication comprises a plurality of bars, wherein each respective bar of the plurality of bars represents a blood flow velocity threshold, and wherein the visual indication is displayed on a user device; at least one loudspeaker configured to emit the audible indication; and a connection module configured to transfer the audible indication wirelessly from the Doppler blood flow monitoring device to a remote database, wherein the audible indication is remotely accessible via the user device, and wherein an administrative station is configured to assign an access credential to the user device to access the audible indication associated with the Doppler blood flow monitoring device, and wherein the user device is capable of requesting the Doppler blood flow monitoring device to record and upload a second audible indication, and, wherein the second audible indication is a current recording of blood flow.

2. The device of claim 1, wherein, the signal sent by the signal generation module is a pulsed ultrasound signal.

3. The device of claim 1, wherein, the signal sent by the signal generation module is a pulsed wave Doppler signal.

4. The apparatus of claim 1, wherein, filtering the return signal comprises: at least one of applying a low bandpass filter to the return signal, applying a high bandpass filter to the return signal, and applying a fast Fourier transform to the return signal.

5. The apparatus of claim 1, wherein, filtering the return signal comprises: applying a frequency adjustment to the return signal, wherein, the frequency adjustment is applied to the return signal prior to waveform shaping the return signal.

6. The device of claim 5, wherein, the frequency adjustment is a frequency boost between 150 Hz and 300 Hz.

7. The device of claim 6, wherein, the frequency boost is between 230 Hz and 240 Hz.

8. A Doppler blood flow monitoring system, comprising: a blood vessel coupler positioned around a blood vessel of a patient; a transducer affixed to the blood vessel coupler; and a monitor configured to: generate a signal to send to the transducer, wherein the transducer is configured to emit an ultrasound signal based on the signal generated by the monitor, and wherein the ultrasound signal is transmitted through the blood vessel of the patient, receive a return signal from the transducer, ​ convert the return signal into a first indication and a second indication corresponding to a blood flow characteristic in a blood vessel of the patient, wherein the second indication is a visual indication, the visual indication comprising a plurality of bars, wherein each respective bar of the plurality of bars represents a blood flow velocity threshold, wherein the second indication is displayed on a user device, and wherein the user device is configured to retrieve the first indication from a remote database, and wirelessly transfer the first indication from the monitor to the remote database via a connection module, wherein the first indication is remotely accessible via the user device, wherein the management station is configured to assign access credentials to the user device to access the first indication associated with the Doppler blood flow monitor system, and wherein the user device is capable of requesting the monitor to record and upload a third indication, and wherein the third indication is a current recording of blood flow.

9. The monitoring system of claim 8, wherein the first indication is an audible indication.

10. The Doppler blood flow monitoring system of claim 8, wherein the blood vessel coupler is a first blood vessel coupler and the transducer is a first transducer, and wherein the first blood vessel coupler and the first transducer are associated with a first channel of the monitor, and the Doppler blood flow monitoring system further comprises: a second blood vessel coupler positioned around a different blood vessel of the patient; a second transducer, wherein the second blood vessel coupler and the second transducer are associated with a second channel of the monitor; and the monitor is further configured to: generate another signal to transmit to the second transducer, receive a different return signal from the second transducer, and convert the different return signal into a primary indication and a secondary indication corresponding to a blood flow characteristic in the different blood vessel of the patient.

11. The monitoring system of claim 10, wherein the primary indication is an audible indication.

12. The monitoring system of claim 10 or 11, wherein the second indication is a visual indication.

13. The monitoring system of claim 8, wherein the signal emitted from the transducer is a pulsed ultrasound signal.

14. The monitoring system of claim 8, wherein the signal generated by the monitor is a pulsed ultrasound signal.

15. The monitoring system of claim 8, wherein the signal emitted from the transducer is a pulsed wave Doppler signal.

16. The monitoring system of claim 8, wherein the signal generated by the monitor is a pulsed wave Doppler signal.

17. The monitoring system of claim 8, wherein the transducer is removably retained within the blood vessel coupler.

18. The monitoring system of claim 17, wherein the transducer is removably retained within the blood vessel coupler by at least one of a friction fit, a mechanical coupler, and an adhesive.

19. The monitoring system of claim 8, wherein The vessel coupler is adapted to allow the transducer to be subsequently removed from the socket of the vessel coupler.

20. The monitoring system of claim 8, wherein, The monitor is further configured to: filter the return signal prior to converting the return signal into at least one of the first indication and the second indication.

21. The monitoring system of claim 20, wherein, Filtering the return signal includes: applying at least one of a low bandpass filter to the return signal, a high bandpass filter to the return signal, and a fast Fourier transform to the return signal.

22. The monitoring system of claim 20 or 21, wherein, Filtering the return signal includes: applying a frequency adjustment to the signal, wherein, the frequency adjustment is applied to the return signal prior to waveform shaping the return signal.

23. The monitoring system of claim 22, wherein: the frequency adjustment is a frequency boost between 150 Hz and 300 Hz.

24. The monitoring system of claim 23, wherein: the frequency boost is between 230 Hz and 240 Hz.

25. The monitoring system of claim 8, wherein: the transducer includes a piezoelectric crystal.

26. A remote monitoring system, comprising: a monitor configured to: generate a signal to transmit to a transducer located within a vessel coupler, wherein: the vessel coupler is located around a blood vessel of a patient, the transducer is configured to emit an ultrasound signal based on the signal generated by the monitor, and the ultrasound signal is transmitted through the blood vessel of the patient, receive a return signal from the transducer, and convert the return signal into a first indication and a second indication corresponding to a blood flow characteristic in the blood vessel of the patient, wherein the second indication is a visual indication including a plurality of bars, wherein each respective bar of the plurality of bars represents a blood flow velocity threshold, and wherein the second indication is displayed on a user device; and wirelessly transfer the first indication from the monitor to a remote database via a connection module, wherein a management station is configured to distribute access credentials to the user device to access the first indication associated with the remote monitoring system, wherein the user device can request the monitor to record and upload a third indication, wherein the third indication is a current recording of blood flow, and wherein the remote database is configured to: receive one or more files associated with the first indication, and store the one or more files associated with the first indication, wherein the one or more files are remotely accessible via the user device.

27. The remote monitoring system of claim 26, wherein, the monitor is further configured to: filter the return signal prior to converting the return signal into at least one of the first indication and the second indication.

28. The remote monitoring system of claim 27, wherein, Filtering the return signal includes: applying at least one of a low bandpass filter to the return signal, a high bandpass filter to the return signal, and a fast Fourier transform to the return signal.

29. The remote monitoring system of claim 26 or 27, wherein, Filtering the return signal includes: applying a frequency adjustment to the signal, wherein, the frequency adjustment is applied to the return signal prior to waveform shaping the return signal. applying the frequency adjustment to the return signal prior to waveform shaping the return signal.

30. The remote monitoring system of claim 29, wherein, the frequency adjustment is a frequency boost between 150 Hz and 300 Hz.

31. The remote monitoring system of claim 30, wherein, the frequency boost is between 230 Hz and 240 Hz.

32. The remote monitoring system of claim 26, wherein, the remote database is configured to: receive one or more files associated with the second indication, and store the one or more files associated with the second indication, wherein the one or more files associated with the second indication are remotely accessible via the user device.

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