CONTROL OF BODY FLUID CONDITION USING DIURETICS, BASED ON BIOLOGICAL PARAMETERS
The system for controlling body fluids overcomes the limitations of the prior art by automatically infusing diuretic and/or other drugs into a human patient. In one approach, the rate of infusion of the diuretic is adjusted based on a measured biological parameter of the patient. For example, this biological parameter can be transmitted wirelessly to a portable diuretic infusion device attached to the patient.
This application claims priority under 35 U.S.C. §119(e) to (a) U.S. Provisional Patent Application Ser. No. 60/967,025, “Apparatus and method to control body fluid balance,” filed Sep. 1, 2007, (b) U.S. Provisional Patent Application Ser. No. 60/979,634, “Controlling body fluid condition using diuretics,” filed Oct. 12, 2007, (c) U.S. Provisional Patent Application Ser. No. 60/986,974, “Controlling body fluid condition using diuretics,” filed Nov. 9, 2007, and (d) U.S. Provisional Patent Application Ser. No. 60/988,375, “Controlling body fluid condition using diuretics,” filed Nov. 15, 2007, and (e) U.S. Provisional Patent Application Ser. No. 61/048,113, “Controlling body fluid condition using diuretics,” filed Apr. 25, 2008. The subject matter of all of the foregoing is incorporated herein by reference in its entirety, including any appendices or attachments, for all purposes.
BACKGROUND OF THE INVENTION1. Field of the Invention
This invention relates to controlling body fluid condition using diuretics.
2. Description of the Related Art
Body fluid imbalance is associated with many diseases such as congestive heart failure, liver cirrhosis and kidney disease. Congestive heart failure in particular is a major cause of death and hospitalization. Despite currently available treatment, mortality and hospitalization from congestive heart failure remains high. Causes of heart failure include coronary artery disease, hypertension, valvular heart disease, myocardial infarction, etc. As pump function of the heart deteriorates, body fluid often increases and may lead to complications such as pulmonary edema.
When pumping capacity of the heart deteriorates, blood perfusion to the kidneys decreases. This results in retention and accumulation of body fluid because excessive body fluid is not delivered to the kidneys to be excreted. This excessive body fluid often manifests as swelling of the legs. If body fluid continues to expand, a weak heart may be no longer able to handle increased blood volume and finally fails to pump blood forward adequately. Symptoms of congestive heart failure include shortness of breath, fatigue, swelling of legs, orthopnea, paroxysmal nocturnal dyspnea (not being able to breathe suddenly at night). Many people come to the emergency room due to congestive heart failure exacerbation. People do not breathe well when fluid builds up in the lungs.
Diuretics such as hydrochlorothiazide, furosemide and bumetanide are often used to treat this fluid accumulation by increasing the excretion of body fluid and sodium through the kidneys. However, use of oral diuretics often fails to prevent heart failure exacerbation. This failure of diuretics to prevent heart failure can be explained by several mechanisms. First, the dosage of oral diuretics prescribed by the doctor is often fixed, but the ideal dosage often changes depending on changing body conditions. For example, when people with heart disease eat salty food high in sodium content, their body fluid may increase significantly. We often see people come to the emergency room after they eat excessive amount of salt at a party. In this situation, people will require a higher dose of diuretics in order to excrete excessive body fluid and salt. The required dose of diuretics is affected by the dietary intake of sodium, water and tendency to retain sodium. When body fluid builds up in the digestive system, it may cause intestinal edema (swelling). Bioavailability of diuretics may decrease with intestinal swelling. The body may not be able to absorb diuretics effectively. Patients may need to take higher dose of diuretics when poor bioavailability occurs.
Second, poor compliance plays a role. People sometimes forget to take medications. This poor compliance could result in heart failure. Third, treatment delay plays a role. When there is a sign of body fluid accumulation such as swelling of legs, many people ignore this early sign of heart failure and wait until their condition gets severe enough to require hospitalization. These explanations are associated with many cases of heart failure.
Sliding scale diuretic titration of oral diuretics has been attempted for the treatment of congestive heart failure by some heart failure management programs. In sliding scale diuretic titration, patients are instructed to measure body weights and adjust diuretics pill dose according to the instruction given by their physician or nurse. However, conventional diuretic sliding scale titration has several significant drawbacks. First, patients may not understand the sliding scale instruction or may not comply with it. Poor understanding of the instruction may also lead to inappropriate use of medication. Second, conventional instructions may be limited to instructions and sliding scale titration that are simpler than would be desired. In real clinical situations, a more complex diuretic titration may be required to maintain ideal body fluid condition. However, some patients may not be able to follow such complex instructions so instructions may be simplified at the cost of a less effective titration.
In addition, if the sliding scale diuretic titration changes frequently, some patients may not understand the change of sliding scale diuretic titration and may end up taking the wrong dose of medication. This may lead to serious complications. Taking too much medication may lead to complications such as dehydration, electrolyte imbalance, hypotension, and kidney failure. Conventional sliding scale diuretic titration is also limited to oral diuretics, which may not be as effective as, for example, continuous infusion of diuretics.
As a result of these possible complications, sliding scale diuretic titration, when attempted, is typically based on a straightforward and simple protocol. More complex protocols generally have not been attempted because there is not a reliable way to carefully monitor and control the dispensing of diuretic or to adjust the dose according to varying conditions. In addition, there are not reliable safety measures to safeguard against the possible inappropriate use of diuretics. Without such controls and safety measures, more complex protocols can have a higher risk of inappropriate use of diuretics and possible adverse effects such as dehydration, electrolytes abnormalities, hypotension, and kidney failure.
Thus, there is a need for better, and preferably automatic, approaches to control body fluid condition using diuretics.
SUMMARY OF THE INVENTIONOne aspect of the present invention overcomes the limitations of the prior art by automatically infusing diuretic into a human patient. In one approach, the rate of infusion of the diuretic is adjusted based on various biological parameter(s) other than body weight, although possibly in combination with body weight. The biological parameter(s) can be transmitted wirelessly to a portable diuretic infusion device attached to the patient, for example.
In one aspect of the invention, a portable diuretic infusion device includes a reservoir, a pump and a controller. The reservoir can hold a diuretic or an antihypertensive drug to be infused into the patient. The pump is connected to the reservoir and is also connectable to the patient, for example using an infusion set. The pump is operated to infuse diuretic or other drug from the reservoir into the patient. The controller controls the pump based on some biological parameter(s), thereby controlling the rate of infusion of the diuretic or other drug.
In one embodiment, the controller adjusts the rate of infusion based on a measured intrathoracic electrical impedance of the patient. For example, the protocol may be designed to maintain a target intrathoracic electrical impedance for the patient, so that more diuretic is infused when the patient is over the target and less diuretic is infused when the patient is under the target. In another aspect, the patient's intrathoracic electrical impedance can be measured by an implantable device and then wirelessly transmitted to the diuretic infusion device. The controller on the diuretic infusion device receives the intrathoracic electrical impedance information and automatically adjusts the infusion rate.
In another aspect of the invention, the diuretic infusion device adjusts the diuretic infusion rate based on various biological parameter(s). These biological parameters can include, for example, vital signs, blood pressure, intracardiac pressure, intravascular pressure, biomarker(s), physical sign(s), weight, NYHA classification, and/or symptoms,
In still a further aspect of the invention, the diuretic infusion system includes a biological parameter measurement apparatus with a biological parameter measurement sensor for measuring a biological parameter of a human patient and a wireless transmitter for wirelessly transmitting measured biological parameter information. The diuretic infusion system also includes a portable diuretic infusion device with a reservoir for holding diuretic, a pump connected to the reservoir and connectable to the human patient, for infusing diuretic from the reservoir into the human patient, a wireless receiver for wirelessly receiving the biological parameter information transmitted by the biological parameter measurement apparatus, and a controller coupled to the wireless receiver, for controlling the pump and rate of infusion of the diuretic based on the received biological parameter information.
In further embodiments, the diuretic infusion system is remote control operated. The system can include a biological parameter measurement apparatus having a sensor for measuring a biological parameter of a human patient and a wireless transmitter for wirelessly transmitting biological parameter information based on the measured biological parameter. The system can further include a portable diuretic infusion device with a reservoir for holding diuretic, a pump connected to the reservoir and connectable to the patient, a controller for controlling the pump, and a wireless receiver for wirelessly receiving commands. The system can also include a remote control device with a wireless receiver for wirelessly receiving the biological parameter information transmitted, a wireless transmitter for wirelessly transmitting one or more commands to the portable diuretic infusion device, and a controller coupled to the receiver/transmitter for wirelessly controlling the pump and rate of infusion based on weight information. Other embodiments of the diuretic infusion system can include fewer or more components within the biological parameter measurement apparatus, the portable diuretic infusion device, and the remote control device.
In yet another embodiment, the diuretic infusion system includes a urine output measurement apparatus with a urinary catheter, a urinary drainage apparatus, and a urine output sensor for measuring urine output of a human patient. In some embodiments, the urine output measurement apparatus also includes a wireless transmitter for wirelessly transmitting urine output information based on the measured urine output. The system can also include a portable diuretic infusion device with a reservoir for holding diuretic, a pump connected to the reservoir and connectable to the patient for infusing diuretic from the reservoir into the patient, and a controller that controls the pump, thereby controlling a rate of infusion of the diuretic based on received urine output information. Where the urine output measurement apparatus is configured for wireless communication, the portable diuretic infusion device can include a wireless receiver for wirelessly receiving the urine output information transmitted from the urine output measurement apparatus. In some embodiments, the infusion system further includes a remote control device with a wireless receiver for wirelessly receiving the urine output information transmitted from the urine output measurement apparatus, and a wireless transmitter for wirelessly transmitting one or more command to the portable diuretic infusion device. The remote control device can also include a controller coupled to the wireless receiver and transmitter for wirelessly controlling the pump and rate of infusion of the diuretic based on the received urine output information
Different protocols can be implemented using these devices and systems. For example, the infusion rate can include both basal and bolus components. Diuretic infusion can be supplemented and/or replaced by other delivery mechanisms, such as oral diuretics. Fairly complex protocols can be implemented, since the protocol is more automated and depends much less on the patient implementing the protocol. For example, infusion rate can vary by time of day, thus reducing urination at nighttime. Prospective infusion can also be implemented, for example if heavy salt intake is expected. The infusion rate can also be adjusted based on feedback other than just weight.
These approaches allow the dose of diuretics to be controlled much more carefully than by patient instructions alone, resulting in many possible advantages. For example, early detection and early treatment of various body fluid related diseases may be possible. This can reduce hospitalizations and death from congestive heart failure, pulmonary edema and fluid overload. In addition, patients can now have continuous infusion of diuretics by using a portable, ambulatory infusion pump. Continuous infusion of diuretics may be more effective than bolus use of diuretics. These approaches may also be more effective in maintaining target weight and/or dry weight, compared with using oral diuretics. The automated approach is also easier for patients and allows the implementation of more complex protocols, while also reducing the risk of over- or under-treatment. The automated devices can also record diuretic use (and also body weight), thus providing a reliable medical history. This information can be sent over the internet to the healthcare providers or others, for analysis or remote monitoring of patients.
Other aspects of the invention include methods corresponding to the devices and systems described above, and protocols for use with same.
The invention has other advantages and features which will be more readily apparent from the following detailed description of the invention and the appended claims, when taken in conjunction with the accompanying drawings, in which:
The figures depict embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the invention described herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTSVarious diuretics may be used with the diuretics infusion device. Examples include hydrochlorothiazide, chlorothiazide, chlorthalidone, metolazone, furosemide, bumetanide, ethacrynic acid, torsemide, spironolactone, indapamide and eplerenone. Vasopressin receptor antagonist may also be used. Examples include conivaptan, tolvaptan. Brain natriuretic peptide may also be used. One example is nesiritide.
An external keypad to allow the user to program an onboard processor. The onboard processor controls the rate of diuretic infusion. Various buttons 202, 203 are used for various functions, such as programming the diuretics pump and adjusting the diuretic infusion rate. Information such as rate of diuretic infusion, name of diuretics in use, weight information, and optimal or target weight, can be displayed on the screen 204. This screen also shows signals that indicate malfunction of the device and other signals such as time to change a diuretics cartridge or time to change a battery.
This diuretic infusion pump 201 includes a disposable reservoir or a disposable cartridge for the diuretic. The prefilled cartridge containing diuretics is replaced when empty. In alternative embodiments, the reservoir and/or cartridge may not be disposable. Instead, the reservoir may be refilled when empty.
A disposable infusion set for the diuretic infusion pump may include a cannula 209, an adhesive pad 205, a needle 208 and tubing system 206 (that delivers the diuretic reservoir to a user). The user inserts the needle 208 together with the cannula 209 under the skin. The needle 208 may be removed, leaving the cannula 209 under the skin. Preferably, the tip of the cannula 209 is located at the subcutaneous tissue. Alternatively, the tip of cannula 209 may be located in the abdominal cavity, intramuscular space, intravascular space or peritoneal cavity. The cannula 209 may be made with biocompatible materials such as polyethylene.
The processor 301 is in electrical communication with an electric motor and pump 313. The processor controls the electric motor 313 according to its program. The processor also controls a screen 304, an audible alarm 307, vibratory alarm 308 and telemetry system. Weight information that is transmitted from the weight measurement apparatus is received by the telemetry system of the diuretic infusion pump. It then enters the processor 301. Alternately, weight information may be input into the diuretic infusion pump manually by a user, for example from a keypad or a remote controller.
In this example, flash memory 314 and SRAM 315 are used for memory storage. This memory may store information such as pump settings, a historical log of weight, malfunctions of the pump, infusion rate, a historical log of infusion rate, medication, etc. In one design, the RAM has 100 kilobytes, ROM has 4 megabytes and flash memory has 4 megabytes memory. Alternate memory media include RAM, ROM, EPROM, DRAM, hard-drives and other types of flash memory.
The user may program the processor 301 using a keypad (or other user interface) on the diuretic infusion pump. In alternative embodiments, a user may use a remote controller or a computer station to program the processor 301.
Information and commands from other computers, portables devices such as PDAs (personal digital assistant), handheld computers, portable phones, remote controllers and the internet may be received through receiver 303. Examples of wireless technologies include radio frequency (RF), infrared (IR) and optical. Specific technologies include Bluetooth, DECT, ZigBee, NFC, GSM, UWB, UMTS, DAB, CDMA, WiFi and WIMAX. Wired communications ports can include Universal Serial Bus (USB) ports and/or RS-232 ports, as well as other technologies.
The diuretic infusion pump displays on its screen whether new weight information, command, or alerts are received. The diuretic infusion pump, weight measurement apparatus, corresponding computer systems and/or remote controller may be assigned a unique identifier and/or password to provide privacy for its users.
In
Various other inputs, such as various types of sensors, may also be included in the diuretic infusion pump (or communicate to the diuretic pump from other parts of the system). For example, motion detection sensor 312 may be used to detect the motion of a gear in the drive mechanism for the pump. Cartridge sensor or reservoir sensor 311 may be used to detect the amount of diuretic left within a cartridge or reservoir, and to notify a user when a new cartridge is required or a reservoir requires refilling.
In one embodiment, LCD is used as a screen. Feedback from the weight measurement apparatus, a computer, a remote control device as well as diuretic infusion pump status and programming changes may be displayed on a LCD screen. Time, name of drug, dose of drug used during a particular period of time, reservoir or cartridge usage and history may also be displayed.
A speaker can be used to send audio feedback. A user may choose to use a vibratory alarm instead of audible alarm. For example, if measured body weight is too low or too high, an audible or vibratory alarm may warn a user. If measured body weight is lower than a set value, a certain instruction such as “Drink more water and eat more because you may be dehydrated” may be shown on the screen or played through the speaker. When measured body weight is higher than a set value, certain instructions may be expressed, such as “Calibrate your weight measurement scale” or “Call your doctor if you feel shortness of breath.” Alarms may also be activated for pump malfunction, low battery, dead battery, occlusion of infusion set, near-empty cartridge (or reservoir), pump delivery error, if bolus is changed, if mode is changed, if pump is not primed, if infusion exceeds maximum limits, etc.
The diuretic infusion pump preferably uses a AAA alkaline battery. More than one AAA alkaline batteries may be used. Alternatively, different types of batteries may be used such as nickel cadmium battery, nickel metal hydride battery, lithium ion battery, carbon battery, lithium battery and 3.6V lithium battery. The battery may be included inside the housing 316 of the diuretic infusion pump.
Not all embodiments require all of the components described above.
In alternative embodiments, more than one type of drug may be used in the diuretic infusion pump. A processor may be coupled with more than one program, software, protocols and/or parameters that are tailored according to the specific drug that is used. The diuretic infusion pump may automatically recognize the inserted drug. Drug reservoir or cartridge may have a unique identification code. One example of a drug name recognition method is to decode the bar code of the drug name, which is attached on the reservoir or cartridge. Alternatively, the name of the inserted drug may be manually put into the diuretic infusion pump using the keypad which can select alphabets on the screen.
Examples of medications that may be contained in the reservoir 807 or cartridge include hydrochlorothiazide, chlorothiazide, chlorthalidone, metolazone, furosemide, bumetanide, ethacrynic acid, torsemide, spironolactone, eplerenone, vasopressin receptor antagonists, conivaptan, tolvaptan, brain natriuretic peptide, and nesiritide.
Some medications may not be compatible each other so these medications may need to be delivered through separate channels. More than two medications, channels and holes may be used in alternative embodiments. A processor 610 controls an electric motor 605 and a pump 606 according to its program. More than two electric motors and pumps may be used in alternative embodiments. A separate electric motor and pump may be used to deliver different medications in alternative embodiments.
ANP (Atrial natriuretic peptide), CNP (C-type natriuretic peptides), NT-pro BNP, ventricular natriuretic peptides and other bio markers that indicate volume overload and heart failure may also be used to compute the diuretic infusion rate.
Physical signs of volume overload, such as ankle swelling, leg swelling, arm swelling, and abdominal distension can also be used. For example, a user may use a scale of one to four in body swelling as one being no swelling, four being severe swelling, three being moderate swelling, two being mild swelling. The diuretic infusion pump might adjust the infusion rate to return body swelling to the zero score condition of no swelling. The diuretic infusion pump may also adjust the infusion rate based on blood pressure.
The diuretic infusion pump may also adjust the infusion rate by using symptom scores such as a shortness of breath scale (one to four, one-no difficulty breathing, two-mild difficulty, three-moderate difficulty, four-severe difficulty) or a walking scale (one- can walk without limitations, two-can walk less than one block, three-can barely walk even inside home).
The diuretic infusion pump may use the NYHA (New York Heart Association) classification to compute the diuretics infusion rate. The NYHA classification is widely used to assess the stage of heart failure. The diuretic infusion pump may adjust diuretics infusion rate to improve patient condition from class II, III or IV to class I.
Combinations of variables may be used for the computation of diuretic infusion rate and/or dose. These variable(s) may be used for the computation of the dose and/or infusion of other drugs. Some examples of these drugs include, but not limited to, anti-hypertensive drug, inotropic agents, and anti-arrhythmic drugs.
Adjusting the diuretic dose according to intracardiac pressure or central vein pressure is another possibility.
A plastic tube 801 (a catheter) is attached to a silicone bubble 804 (septum). Tip 808 of the plastic tube may be located into a peritoneal space or a vein (or an artery). A needle 803 is inserted into the silicone bubble. Medication is delivered from the infusion pump 807 through a tubing system 808, a needle 803 and a plastic tube 801 into a target space of a user. Examples of a target space include a peritoneal space, a vein, an artery and a muscle. A port 802 and silicone bubble 804 may be located in subcutaneous tissue or may be located outside the skin.
In this example, the tube 908 merges with tube 909. However, there are different channels within the tube to deliver each medication through different channels to prevent mixture of non-compatible medications. These two medications are delivered through separate openings 910, 913. Two medications may be delivered according to two separate programs, protocols, parameters.
In alternative embodiments, a diuretic inhaler may be used. Examples include a furosemide inhaler, a bumetanide inhaler, and so forth. If measured body weight is above a previously set target weight, the display on the weight measurement apparatus, the diuretic inhaler or a separate device may show instructions on the dose of drug to be inhaled. For example, if measured body weight is one kilogram above the target weight, a user may be instructed to have one extra-inhalation of furosemide. Other diuretic inhalers, including (but not limited to) furosemide, bumetanide, and torsemide, may be used in alternative embodiments.
The diuretic infusion device may also be connected with a blood pressure cuff, either wirelessly or in a wired manner. Blood pressure information measured by the blood pressure cuff is transmitted to the diuretic infusion pump. Certain instructions may be provided on the display 1002. See
Instructions to take potassium supplement, magnesium supplement and other electrolyte supplement may be displayed on the screen. These electrolytes may be lost by the kidneys as diuretics dose increases. In
In
In one approach, a user inputs a target pressure into the diuretic infusion pump. The diuretic infusion pump adjusts its infusion rate to maintain the target pressure. One example of a suitable implant is the Chronicle heart monitor made by MEDTRONIC™. In alternative embodiments, a pacemaker, an automatic implantable cardioverter defibrillator (AICD), or a cardiac resynchronization therapy (CRT) device may be coupled with the pressure measuring sensor, wireless communication module, processor and software program to transmit pressure signals to the diuretic infusion pump.
In another embodiment, a user can use one reservoir that contains diuretics and a second reservoir that contains an inotropic drug that increases blood pressure. Examples of inotropic drugs include (but are not limited to) dopamine, dobutamine, phosphodiesterase inhibitor, amrinone, milrinone, enoximone, pimobendan, levosimendan, calcium sensitizing agent, venarinone, and ibopamine. In alternative embodiments, the diuretic infusion pump contains a combination of antihypertensive drugs, inotropic agents, diuretics, and it adjusts the infusion rate according to blood pressure measured by non-invasive blood pressure measurement device and/or measured body weight.
As shown in
In alternative embodiments, the diuretic infusion pump system is an open loop drug infusion system. The diuretic infusion pump can receive measured weight or other biological parameters from sensor(s) wirelessly or manually, however the diuretic infusion pump may or may not automatically adjust the rate of infusion in an open loop system. A user, a doctor, a nurse and/or other people that are involved in the use of the diuretic infusion pump system may need to approve or choose particular protocol(s) and methods. These people can also control the controller of the diuretic infusion pump. Healthcare provider(s) can transmit a new order or new drug infusion protocols to the diuretic infusion pump system via the Internet, a phone, or other methods. In an open loop drug infusion system, wireless communication among the devices may or may not be used.
In some embodiments, a user chooses an open loop system, a closed loop system, or mixed loop system (e.g., a closed loop system when a certain conditions are met and open loop system when a certain conditions are not met). The diuretic infusion pump system can be programmed to be a closed loop system when measured blood pressure is within a certain parameter, when a user does not have symptoms, such as chest pain, and/or when the dosage of an infused drug is within a certain range. The diuretic infusion pump can be programmed to be an open loop system when these conditions are not met in a mixed loop system.
A photograph of the user's legs or other parts of the body can be taken by the diuretic infusion pump system by a camera or a cell phone. The photograph can be transmitted to a healthcare provider. The healthcare provider reviews the photograph of legs, and may be able to verify the body fluid condition by comparing the measured weight with the photograph. The diuretic infusion pump can also have a built-in camera. The healthcare provider can detect malfunction of the weight scale when the measured body weight is far greater than the target weight but the photograph of the legs does not show any swelling.
As one example, a physician programs the diuretic infusion pump system to achieve 2400 ml of urine output over a 24-hour period. In order to achieve this, a urine output of 100 ml per hour is required on average over 24 hours. Various diuretic infusion protocols shown in other figures may be programmed into the diuretic infusion pump. The sensor of the urine output measurement system measures the amount of the urine output. The transmitter of the urine output measurement system transmits the urine output information wirelessly or by other means (e.g., wired, manual data input, etc.) to the diuretic infusion pump system and/or a separate computer, a remote control device, etc. If the urine output over a predetermined period of time is less than the target urine output, the diuretic infusion pump can increase diuretic infusion to increase urine output. If the urine output over a predetermined period of time is greater than the target urine output, the diuretic infusion pump can decrease diuretic infusion to decrease urine output. If the urine output were 80 ml over one hour, the diuretic infusion pump would increase the diuretic infusion to achieve 120 ml over the next hour to achieve 100 ml per hour of urine output. The diuretic infusion pump 3901 can deliver the diuretic intravascularly, subcutaneously, intramuscularly, etc. In one embodiment, the diuretic infusion pump 3901 can communicate wirelessly or by other means (e.g., wired, manual data input, etc.) with a non-invasive blood pressure monitoring system 3907. The non-invasive blood pressure monitoring system 3907 can have a processor, a controller, software, a wireless transmitter/receiver, though it may have fewer or more components in alternative embodiments.
When blood pressure is measured using a blood pressure cuff 3906, the measured blood pressure is transmitted wirelessly or by other means (e.g., wired, manual data input, etc.) to the diuretic infusion pump 3901. If blood pressure is below a predetermined level, the diuretic infusion pump 3901 can stop the diuretic infusion or adjust the diuretic infusion based on the program. This system may reduce the risk of hypotension. If blood pressure is above a predetermined level, the diuretic infusion pump 3901 can increase diuretic infusion or adjust the diuretic infusion based on the program.
In alternative embodiments, the urine output measurement system comprises a urinary catheter, a urine drainage bag, and a sensor to measure urine output, but does not include a wireless transmitter and receiver. The user may input the urine output over a certain period of time manually into a diuretic infusion pump system and/or a separate computer or a remote control device. In alternative embodiments, the diuretic infusion pump system can communicate wirelessly or by other means (e.g., wired, manual data input, etc.) with the urine output measurement system and other biological parameter sensors (see other figures). The diuretic infusion pump system can adjust the diuretic infusion to maintain the target urine output, as well as to maintain the target biological parameter (e.g., the target intravascular pressure, the target intracardiac pressure, and/or the target intrathoracic impedance).
The urine output information signal is received by a receiver of the diuretic infusion pump. The receiver of the diuretic infusion pump is electrically connected to a processor which is housed in the diuretic infusion pump. The processor receives the urine output information and performs computations to determine the diuretic infusion rate, such as basal rate and bolus rate, according to programmed parameters, protocols and algorithms. The processor controls an electric motor to deliver diuretic from a reservoir to a user through an outlet, a tube, and an infusion set of the diuretic infusion pump. In alternative embodiments, the user manually inputs measured urine output into the diuretic infusion device. This urine output information enters a processor which is housed in the diuretic infusion pump. The processor performs computations to determine the diuretic infusion rate as described with regard to other figures.
The urine output signal(s) can be sent to different receivers. The diuretic infusion pump receives the signal(s) 4106 through an onboard receiver 4108 via an antenna 4107. A handheld communication device, such as a remote control device, an iPOD™, an MP3 player, a handheld computer, or a portable phone may receive the signal 4106 through an onboard receiver 4112 via an antenna 4111. The user may choose to send information to a computer or handheld communication device for the purpose of saving urine output information on the computer or connecting with the Internet to send urine output information to healthcare providers. The diuretic infusion pump system and/or handheld communication device can receive biological parameter signal(s) wirelessly or by other means (e.g., wired, manual data input, etc.) from the biological parameter sensor, transmitter, or processor 4110.
Even though the term “diuretic infusion pump” (or “diuretic infusion system” or similar variants) is used in this application, one of ordinary skill in the art would know that this term is not limited to the use of diuretics, but can also use other types of drugs, as well. Thus, this term is not limited to diuretics. Many different drugs can be used for the diuretic infusion pump. Examples of such drugs are described in other parts of the application.
Diuretic infusion pumps can contain two reservoirs in some embodiments. One reservoir can contain furosemide. The other reservoir can contain buffering solution. Buffering solution includes (but is not limited to) sodium chloride solution, Lactated Ringer's solution, or Dextrose 5% solution. Some furosemide solution may have a high pH of about 9. Mixing a furosemide solution with a sodium chloride solution, Lactated Ringer's solution or Dextrose 5% solution may lower the pH of the furosemide solution.
Furosemide discolors when it is exposed to light. Discolored furosemide is not recommended to be used. A reservoir and cartridge within a diuretic infusion pump may be light resistant to protect furosemide or other drugs from being exposed to the light.
In all of the above embodiments, the diuretic infusion pump was located external to the body. However, alternatively, internal and implantable diuretic infusion pumps may also be made. The diuretic infusion pumps are also shown as portable in the above description. In alternative embodiments, the diuretic infusion pump may not be portable.
In another aspect of the invention, a user of the diuretic infusion pump may choose to use the device for long term or may choose to use it for short term when his body weight changes. The diuretic infusion pump can also be used in various locations: home, outpatient facilities and hospitals, as well as the intensive care unit.
Programs and protocols coupled with the diuretic infusion pump preferably have various safety measures to minimize side effects of diuretics. One example of a safety measure is that the diuretic infusion pump stops infusing diuretics when a user does not measure body weight in a certain period after previous weight measurements. For example, the diuretic infusion pump may be programmed to stop diuretic infusion in two days if the diuretic infusion pump does not receive a new body weight measurement. This safety measure helps to avoid using inappropriately high dose of diuretics when previously measured body weight is higher than actual body weight. Alarms and display on the screen may be programmed to request a user to enter a new body weight measurement into the diuretic infusion pump.
The above description and illustration of preferred embodiments of the invention has been presented to provide illustration and description. It is not intended to limit the invention to the precise forms that are disclosed. Many variations and modifications will be apparent to people skilled in this art.
Depending on the form of the components, “coupling” or “connection” between components may take different forms. Dedicated circuitry can be coupled to each other by hardwiring or by accessing a common register or memory location, for example. Software “coupling” can occur by any number of ways to pass information between software components (or between software and hardware, if that is the case). The term “coupling” is meant to include all of these and is not meant to be limited to a hardwired permanent connection between two components. In addition, there may be intervening elements. For example, when two elements are described as being coupled to each other, this does not imply that the elements are directly coupled to each other nor does it preclude the use of other elements between the two.
Claims
1. A diuretic infusion system comprising:
- a biological parameter measurement apparatus including: a biological parameter measurement sensor for measuring a biological parameter of a human patient; and
- a diuretic infusion device including: a reservoir for holding a diuretic; a pump connected to the reservoir and connectable to the human patient, for infusing diuretic from the reservoir into the human patient; and a controller for controlling the pump and rate of infusion of the diuretic based on the measured biological parameter.
2. The system of claim 1, wherein:
- the biological parameter measurement apparatus further includes a wireless transmitter for wirelessly transmitting measured biological information; and
- the diuretic infusion device further includes a wireless receiver for wirelessly receiving the biological parameter information transmitted by the biological parameter measurement apparatus, the controller controlling the pump and rate of infusion of the diuretic based on the received biological parameter information.
3. The system of claim 1, wherein the biological parameter measurement sensor is a patch sensor.
4. The system of claim 1, wherein the biological parameter measurement sensor is an intracardiac pressure measurement sensor and the controller adjusts the rate of infusion based on a measured pressure within a cardiac chamber of the patient.
5. The system of claim 4, wherein the controller adjusts the rate of infusion based on the measured pressure within the cardiac chamber to maintain a target pressure in the cardiac chamber.
6. The system of claim 1, wherein the biological parameter measurement sensor is an intravascular pressure measurement sensor and the controller adjusts the rate of infusion based on a measured pressure within a blood vessel of the patient.
7. The system of claim 6, wherein the controller adjusts the rate of infusion based on the measured pressure within the blood vessel to maintain a target pressure in the blood vessel.
8. The system of claim 1, wherein the biological parameter measurement sensor is an intrathoracic electrical impedance measurement sensor and the controller adjusts the rate of infusion based on a measured intrathoracic electrical impedance.
9. The system of claim 1, wherein the biological parameter measurement apparatus is a non-invasive blood pressure measurement device. and the controller adjusts the rate of infusion based on a measured blood pressure of the patient
10. The system of claim 1 wherein the biological parameter measurement apparatus is coupled to a pacemaker.
11. The system of claim 1 wherein the biological parameter measurement apparatus is coupled to an implantable cardioverter defibrillator.
12. The system of claim 1 wherein the biological parameter measurement apparatus is coupled to a cardiac resynchronization therapy.
13. The system of claim 1, wherein the biological parameter is a biomarket and the controller adjusts the rate of infusion based on the measured biomarker.
14. The system of claim 13, wherein the biomarker is selected from the group consisting of an atrial natriuretic peptide, a brain natriuretic peptide, and a NT-pro brain natriuretic peptide.
15. The system of claim 1, wherein the system is further configured for administering a drug selected from a group consisting of: ACE inhibitor, calcium channel blocker, beta blocker, inotropic agent, hydralazine, loop diuretics, thiazide diuretics, and vasopressin receptor antagonist
16. The system of claim 1, wherein the pump is a portable pump.
17. The system of claim 1, wherein the pump is a non-portable pump.
18. The system of claim 1, wherein the pump is an ambulatory drug infusion pump.
19. The system of claim 1, wherein the pump is an implantable drug infusion pump.
20. A method for infusing diuretic to a human patient comprising:
- receiving non-weight biological parameter information based on measurements of a non-weight biological parameter for a patient; and
- adjusting an infusion rate of diuretic into the patient based on the measured non-weight biological parameter according to a predetermined protocol.
Type: Application
Filed: Aug 29, 2008
Publication Date: Mar 5, 2009
Inventor: San Hoon Woo (Palo Alto, CA)
Application Number: 12/202,094
International Classification: A61M 5/168 (20060101);