Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N5/00—Radiation therapy
  • A61N5/06—Radiation therapy using light
  • A61N5/0613—Apparatus adapted for a specific treatment
  • A61N5/0622—Optical stimulation for exciting neural tissue
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K41/00—Medicinal preparations obtained by treating materials with wave energy or particle radiation ; Therapies using these preparations
  • A61K41/0042—Photocleavage of drugs in vivo, e.g. cleavage of photolabile linkers in vivo by UV radiation for releasing the pharmacologically-active agent from the administered agent; photothrombosis or photoocclusion
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N5/00—Radiation therapy
  • A61N5/06—Radiation therapy using light
  • A61N5/0601—Apparatus for use inside the body
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N5/00—Radiation therapy
  • A61N5/06—Radiation therapy using light
  • A61N5/0613—Apparatus adapted for a specific treatment
  • A61N5/062—Photodynamic therapy, i.e. excitation of an agent
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/18—Applying electric currents by contact electrodes
  • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
  • A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
  • A61N1/362—Heart stimulators
  • A61N1/3629—Heart stimulators in combination with non-electric therapy

Definitions

• the present invention relates generally to the field of therapeutic photolysis devices, and more particularly, to a device for regulating physiological function via flash photolysis therapy.
• Many disease conditions are caused by a disruption in normal physiological function that result in abnormal levels of specific ions or other molecules. Such conditions may cause, for example, abnormal myocardial or renal function.
• Abnormal myocardial function for instance, is a leading cause of mortality and morbidity in developed countries. This abnormality may manifest mechanically as reduced ejection fraction (EF), low cardiac output and poor diastolic function, or electrically as arrhythmias. These abnormalities are associated with an increased risk of death due to organ failure and cardiac arrhythmias, poor cardiac function, elevated heart rates, chronic fatigue, pulmonary congestion and diminished exercise capacity.
• EF ejection fraction
• arrhythmias electrically as arrhythmias.
• a therapeutic system modifies cellular function with a photo-reactive compound.
• a drug delivery device administers photo-reactive compound to cells, and a light delivery device delivers a light stimulus to activate the photo-reactive compound. When activated, the photo-reactive compound affects cellular function.
• the invention is useful, for example, to manage abnormal myocardial function.
• the photo-reactive compound is a calcium sensitive compound which causes a change in intracellular calcium concentration when it is activated. Improved myocardial contraction, relaxation, or both, can be achieved.
• FIG. 1 is a diagram illustrating a therapeutic system for managing myocardial function that includes an implantable drug delivery device and an implantable light delivery device.
• FIG. 2 is a block diagram of the system of FIG. 1
• FIG. 3 shows a timing diagram illustrating operation of the system of FIG. 1.
• FIG. 4 is a block diagram of another embodiment of a therapeutic system for enhancing myocardial function.
• FIG. 5 and 6 show a system having an optical lead that provides scanning of light pulses delivered to myocardial tissue.
• FIG. 7 shows a system having a multi-window optical lead.
• a flash photolysis device is used to regulate any of a number of physiological functions.
• a photo-reactive compound is administered to a patient.
• the photo-reactive compound is inert until exposed to light of a wavelength that activates the compound.
• a light source which is typically implanted within the patient (but alternatively could be located externally), emits light at the wavelength that activates the compound.
• the activated compound regulates a physiological function by increasing or decreasing the concentration of ions or molecules in and around the area where the active compound is formed.
• the photo-reactive compounds include a caging group that has either a high or low affinity for the ions or molecules. Once activated, the affinity of the caging group changes such that the level of ion or molecule decreases or increases.
• Table 1 includes examples of various caging groups that may be used with the present invention.
• DTT dithiothreitol
• FIG. 1 is a representative embodiment of flash photolysis system 10 as used to regulate abnormal myocardial function in heart H.
• System 10 includes drug pump 12 with delivery lead 14 and light delivery device 16 with optical lead 18 and sensing lead 20.
• Optical lead 18 further comprises light dispersion lens 22 and anchor tip 24.
• drug pump 12 is a hermetically sealed implantable device.
• Delivery lead 14 is shown inserted into the coronary sinus of heart H, but it may be inserted in other areas in or around the heart. Examples of suitable drug pumps are described in U.S. Patent Application Serial Nos. 10/407,996; 10/382,757; and 10/382,948.
• Light delivery device 16 is also a hermetically sealed implantable device with both optical lead 18 and sensing lead 20 being positioned within the right ventricle. In other embodiments, optical lead 18 and sensing lead 20 may be placed in other heart chambers, such as the left ventricle.
• Myocardial contraction and relaxation are regulated by intracellular calcium handling proteins that regulate calcium release and uptake inside myocardial cells. Severe remodeling of these proteins results in abnormal calcium release and uptake, leading to poorly developed contraction and relaxation.
• System 10 makes use of one or more light-activated compounds to dynamically release and/or buffer intracellular calcium, which, in turn, controls myocardial contraction and/or relaxation.
• one or more light-activated compounds are administered to a patient through any of a number of means for administering.
• the means of administering may be, for example, an injection device, an orally administered composition, a patch or topically administered composition, a suppository, etc.
• the means for administering may also be drug delivery pump 12.
• Drug delivery pump 12 is typically refillable and implantable.
• a suitable pump is the SynchroMedELTM Drug Delivery Pump from Medtronic Inc.
• Delivery lead 14 is shown placed within the coronary sinus to allow delivery of light-activated compounds directly into the heart. In alternative embodiments, delivery lead 14 may be positioned within other chambers or even outside of the heart.
• U.S. Patent Application Serial No. 11/124,984 describes a device for delivering therapeutic agents to the pericardial sac. With the light-activated compounds delivered locally in and/or around the heart, the dosage of light-activated compounds is minimized as compared to administering the compounds orally, where they circulate systemically. This also minimizes side effects that could result from the compounds.
• Optical lead 18 is positioned at a location dependent on where the compounds are delivered and/or where treatment is needed.
• Light delivery device 16 includes a flash lamp or light emitting diode that discharges high intensity, short duration light pulses at one or more wavelengths (depending on the number of photo-reactive compounds that are administered).
• the pulses are carried by optical lead 18, which is typically a fiber optic lead, to the treatment site.
• the treatment site is the right ventricle.
• the light is dispersed into the chamber by light dispersion lens 22, such as a spherical lens that directs light in all directions simultaneously.
• a light emitting diode may be located at the distal end of optical lead 18 and be energized by electrical pulses from light delivery device 16 to produce the light pulses.
• Anchoring tip 24 is attached at or near the tip of optical lead 18.
• Anchoring tip 24 is shown in FIG. 1 as a helical fixation element that anchors optical lead 18 in place by being screwed into tissue. Any of a number of types of anchoring mechanisms that are known in the art may be used with optical lead 18, such as spring loaded arms that extend radially outward once deployed into tissue.
• sensing lead 20 may incorporate sensing lead 20 to sense physiological parameters or markers.
• sensing lead 20 may include sensing electrodes to sense electrogram (EGM) signals from which atrial and ventricular sensed events may be derived.
• sensing lead 20 may include a pressure sensor to sense hemodynamic parameters such as ventricular pressure, an accelerometer to sense mechanical activity of the heart, a bioimpedence sensor, or a chemical sensor to sense concentrations of ions, proteins, or other molecules related to cardiac function.
• sensing lead 20 can comprise electrodes mounted on the can or housing of light delivery device 16, without a lead body.
• Light delivery device 16 controls flash photolysis such that the timing of the light pulses from light delivery device 16 is coordinated with or is a function of the physiological markers and parameters sensed. The delivery of light pulses may be required with every heart beat, or may be required less frequently based upon the physiological parameters and markers sensed.
• drug pump 12 may also be controlled as a function of one or more of the sensed physiological parameters or markers. For example, timing of delivery by drug pump 12 of a bolus of the light-activated compound(s) to the heart may vary based on patient activity. Similarly, pump 12 may not operate while the patient is asleep, physiologically stable or is in no need for flash photolysis therapy.
• System 10 may be used as therapy for myocardial function regulation.
• myocardial contraction and relaxation are regulated by intracellular calcium handling.
• intracellular homeostasis is maintained by calcium handling proteins that regulate calcium release and re-uptake inside the cell.
• severe remodeling of these proteins leads to poorly developed contraction and slow relaxation.
• the sarcoplasmic reticulum (SR) exhibits a reduced calcium release upon electrical activation due to a reduction in calcium re-uptake back into the SR.
• defective calcium regulatory proteins cause abnormal elevations in intracellular calcium levels.
• photo- reactive compounds activated at different wavelengths are used to dynamically release and buffer intracellular calcium. These photo-reactive compounds supplement the abnormally functioning calcium handling proteins, which forces the heart to better contract and relax without increasing metabolic demand or energy requirements.
• Drug pump 12 delivers a controlled dose of two photo-reactive compounds over time into the coronary perfusion bed.
• One photo-reactive compound forces myocardial contraction, while the other photo-reactive compound forces myocardial relaxation.
• These compounds are large polar molecules that do not normally cross cellular membranes. Therefore, they are administered in a membrane-permeable acetoxymethyl ester (AM) form that neutralizes the charge.
• AM membrane-permeable acetoxymethyl ester
• drug pump 12 and light delivery device 16 communicate via a wireless link to coordinate their operation.
• drug pump 12 may provide light delivery device 16 with a signal indicating whether drug pump 12 is on or off. As a result, light delivery device does not continue to produce light flashes (and thus waste energy) when drug pump 12 is empty or otherwise not operating.
• drug pump 12 and light delivery device 16 may be contained in a common housing. This allows devices 12 and 16 to share sensor signals and to communicate directly without telemetry.
• FIG. 2 shows a block diagram of system 10 shown in FIG. 1.
• Drug pump 12 includes reservoir 30, pump 32, controller 34, and telemetry circuitry 36.
• the photo- reactive compounds are stored in reservoir 30 and are delivered under pressure through delivery lead 14 by pump 32.
• Controller 34 controls the operation of pump 32, and communicates with light delivery device 16 through telemetry circuitry 36.
• the communication can include messages from controller 34 indicating when drug pump 12 is in an operating state, and when it is not operating (e.g. when reservoir 30 is empty or when there is no need for the drug in response to the physiological marker or signal).
• Light delivery device 16 includes light pulse generator 40, signal processing circuit
• Light pulse generator 40 produces high intensity light pulses at one or more wavelengths at timing determined by controller 44.
• Signal processing circuit 42 processes the physiological signals sent by sensing lead 20 and provides signals to controller 44 representing sensed parameters or markers.
• Controller 44 controls the light pulses produced by light pulse generator 40 and delivered through optical lead 18 as a function of the sensed physiological parameters or markers, as well as information provided from drug pump 12 to telemetry circuit 46. Controller 44 may also provide sensed parameter or marker information by telemetry to drug pump 12, so that controller 34 can control operation of pump 32 based upon those parameters or markers.
• FIG. 3 is a representation of a timing protocol for delivering light pulses and photo-reactive compounds.
• FIG. 3 includes ECG signal 50, relaxation light pulse waveform 52, contraction light pulse waveform 54 and drug infusion waveform 56.
• a photo-reactive compound such as NP-EGTA, which has a low affinity for Ca 2+ in its inert state, is delivered at a time and rate that provides a therapeutic concentration to the heart.
• diastole which can be determined from ECG signal 50, a short light pulse of about 260 nm is delivered to the ventricular chamber as indicated by waveform 52.
• NP-EGTA When activated by the light, NP-EGTA develops a high affinity for Ca 2+ , which buffers and lowers the intracellular calcium concentration in the myocardial cells and forces myocardial relaxation. Once NP-EGTA binds to calcium, it becomes inert again and is actively transported out of myocardial cells by anionic transporters on the sarcolemmal membrane.
• DMNP-EDTA which has a high affinity for calcium in its inert state
• a therapeutic concentration preloaded with calcium.
• systole which can be determined from ECG signal 50
• a short pulse of light at about 355 nm is delivered to the ventricular chamber.
• the DMNP-EDTA loses its high affinity for calcium, which releases it and increases the intracellular calcium concentration to force myocardial contraction.
• the DMNP-EDTA releases its calcium store, it is actively transported out of the cells as previously described.
• an individual may require forced relaxation, forced contraction or both.
• Individuals with abnormal intracellular calcium handling have typically been treated pharmacologically with drugs that regulate calcium handling in the cell (catecholamines, channel blockers, ⁇ -blockers, etc.). Such therapy has a dramatic systemic effect.
• Implanted cardiac devices using electrical stimulation although effective at stimulating contraction, do not increase contractility or elicit relaxation.
• system 10 may also be effective in treating hypertension, pulmonary edema, diastolic dysfunction, renal dysfunction and many other serious conditions.
• system 10a includes implantable cardioverter defibrillator (ICD) 60 (or an implantable pulse generator), electrical lead(s) 62 and physiological sensor 70 are combined with the components of system 10 (shown in ICD) 60 (or an implantable pulse generator), electrical lead(s) 62 and physiological sensor 70 are combined with the components of system 10 (shown in ICD) 60 (or an implantable pulse generator), electrical lead(s) 62 and physiological sensor 70 are combined with the components of system 10 (shown in ICD) 60 (or an implantable pulse generator), electrical lead(s) 62 and physiological sensor 70 are combined with the components of system 10 (shown in ICD) 60 (or an implantable pulse generator), electrical lead(s) 62 and physiological sensor 70 are combined with the components of system 10 (shown in ICD) 60 (or an implantable pulse generator), electrical lead(s) 62 and physiological sensor 70 are combined with the components of system 10 (shown in ICD) 60 (or an implantable pulse generator), electrical lead(s) 62 and physiological sensor 70 are combined with the components
• ICD 60 with electrical lead(s) 62 is connected to light delivery device 16. Electrical lead(s) 62 may deliver pacing pulses or cardioversion/defibrillation shocks to the heart. Although shown as separate components, ICD 60 may reside within the same housing as light delivery device 16, and sensing lead 20 may be combined with electrical lead(s) 62.
• ICD 60 may be adapted or programmed to serve several purposes. For example, ICD 60 may act as a backup to the operation of pump 12 and light delivery device 16. In the event that an element of the optical components fails, malfunctions or a slowing in the pacing is sensed or drug pump 12 is empty and not refilled, ICD 60 may be activated to provide electrical therapy until the problem is resolved. Further, ICD 60 may supplement flash photolysis therapy if electrical stimulation is needed in addition.
• FIG. 4 also shows physiological sensor 70, which is separate from drug pump 12 and light delivery device 16. Sensor 70, which is typically an implantable device, senses one or more physiological parameters or markers and provides information regarding those parameters or markers to one or more of drug pump 12, light delivery device 16 and ICD 60 via telemetry.
• system 10b includes scanning optical lead 80.
• Optical lead 80 includes cladding 82, rotating light guide 84, prism 86 with exit window 88, and anchor tip 90.
• Rotating light guide 84 is typically comprised of a fiber optic, UV-grade material such as fused silica or a liquid light guide. Cladding 82 is opaque to insure total internal reflection. Prism 86 is a fully enclosed, 90° prism that delivers light in a radial direction through exit window 88.
• Rotating guide 84 is connected to prism 86 and can rotate in order to scan the light pulses in a circular fashion.
• Stepper motor 92 shown in FIG. 6 within light delivery device 16 will rotate guide 84 based on the therapeutic requirements of the patient.
• light delivery device 16 can be programmed to deliver light to a specific area by keeping prism 86 fixed in one orientation. If needed, the orientation can be adjusted using rotating guide 84.
• rotating prism 86 with rotating guide 84 light pulses may travel or scan across the tissue, which can force contraction and/or relaxation in a manner that mimics the natural conduction across the heart.
• System 10b is generally similar to system 10 of FIG. 2, except for stepper motor 92 and optical lead 80. Similar elements are designated with the same reference numerals. Alternatively, system 10b can include additional elements such as ICD 60, electric lead(s) 62 and physiological sensor 70 shown in FIG. 4.
• FIG. 7 shows flash photolysis system 10c, which is generally similar to system 10 (FIG 1) and system 10a (FIG. 5).
• System 10c includes optical lead 90, which has multiple optical windows 92 along its length from which activating light is emitted.
• Windows 92 may include lenses similar to light dispersion lens 22 of FIG. 1.
• windows 92 may include scanning elements similar to FIG. 5, and may feature separate rotation speeds or directions.
• Multi-window optical lead 90 may also be advantageous for therapy in other parts of the body such as the kidneys or the neurological system.
• the flash photolysis system may be used to treat other conditions, such as kidney stones. A majority of kidney stones are caused by excess calcium in urine and some individuals are predisposed to forming kidney stones.
• a sensing lead is positioned in or around the urinary tract to monitor calcium levels in the urine.
• a delivery lead is positioned within or around the kidney to deliver a photo-reactive compound such as diazo-2 that, upon activation, will buffer calcium levels in the urine.
• the photo-reactive compound may be administered orally or by injection when high calcium levels are detected and any of a number of types of alerts are provided by the light delivery device.
• An optical lead is positioned within or around the kidney such that a light pulse is able to access the urine.
• diazo-2 is administered to the individual by any of the means described previously.
• the light delivery device delivers light pulses that activate the diazo-2 causing it to develop a high affinity for calcium. The result is lower urine calcium levels and a reduced likelihood of kidney stone formation.
• flash photolysis system for kidney stone therapy may reduce or eliminate chronic usage of systemic medications.
• flash photolysis therapy begins treatment prior to formation of kidney stones.
• Flash photolysis therapy may also be used to treat other diseases including neurological disorders
• GABA ⁇ -aminobutyric acid
• GABA concentrations are decreased in the basal ganglia of Huntington's disease patients and may contribute to the dementia, mood disorders, and psychoses related to this condition.
• postmortem studies of Alzheimer's patients have shown GABA deficits.
• a photo-reactive compound such as CNB can be used to cage GABA.
• An optical lead placed strategically within the brain is used to release GABA in specific regions to alleviate symptoms of these or other neurological disorders.

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• 2007
  • 2007-10-30 WO PCT/US2007/083009 patent/WO2008055159A2/en not_active Ceased
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