Methods and devices for inhibiting nerves when activating brown adipose tissue
Methods and devices are provided for inhibiting nerves when activating brown adipose tissue (BAT). In general, a first nerve type (e.g., sympathetic nerves) innervating BAT can be activated while at least one other nerve type (e.g., parasympathetic nerves and/or sensory nerves) innervating BAT is being suppressed. A first neuromodulator (e.g., an electrical signal, a chemical, a light, cooling, etc.) can be applied to activate the first nerve type, and a second neuromodulator can be applied to inhibit the at least one other nerve type. In this way, parasympathetic nerves and/or sensory nerves innervating BAT can be inhibited when activating sympathetic nerves innervating BAT.
1. A medical apparatus, comprising:
at least one electrode configured to directly contact a tissue of a patient proximate to a depot of brown adipose tissue (BAT) and to simultaneously deliver first and second electrical signals to the patient, the first electrical signal being configured to cause activation of a first nerve type in the BAT so as to increase energy expenditure of the BAT, and the second electrical signal being configured to inhibit a second nerve type in the BAT that is different from the first nerve type; and
at least one signal generator in electronic communication with the at least one electrode and configured to generate the first and second electrical signals delivered by the at least one electrode.
2. The apparatus of claim 1 , wherein the first nerve type includes sympathetic nerves, and the second nerve type includes parasympathetic nerves.
3. The apparatus of claim 1 , wherein the first nerve type includes sympathetic nerves, and the second nerve type includes sensory nerves.
4. The apparatus of claim 1 , wherein the first nerve type includes unmyelinated fibers, and the second nerve type includes myelinated fibers.
5. The apparatus of claim 1 , wherein nerves of the second nerve type have a larger diameter than nerves of the first nerve type.
6. The apparatus of claim 1 , wherein the second electrical signal has less energy than the first electrical signal by having less current than the first electrical signal, and a current of the first electrical signal is in a range of ten to one hundred times greater than a current of the second electrical signal.
7. The apparatus of claim 1 , wherein the second electrical signal has less energy than the first electrical signal by including a hyperpolarizing lower energy pulse as compared to the first electrical signal, or by including a depolarizing lower energy pulse as compared to the first electrical signal.
8. The apparatus of claim 1 , wherein the at least one electrode is configured to begin delivering the second electrical signal before beginning the delivery of the first electrical signal such that the inhibition of the second nerve type starts before the activation of the first nerve type; and such that the second nerve type is prevented from being activated by the delivery of the first electrical signal.
9. The apparatus of claim 8 , wherein the at least one signal generator is configured to begin generating the second electrical signal before beginning to generate the first electrical signal.
10. A medical apparatus, comprising:
at least one signal generator configured to generate first and second electrical signals, the at least one signal generator being configured to begin generating the second electrical signal before beginning to generate the first electrical signal; and
at least one electrode in electronic communication with the at least one signal generator, the at least one electrode being configured to directly contact a tissue of a patient proximate to a depot of brown adipose tissue (BAT) and to simultaneously deliver first and second electrical signals to the patient with the second electrical signal beginning delivery to the patient before the first electrical signal begins being delivered to the patient, the first electrical signal being configured to cause activation of a first nerve type in the BAT so as to increase energy expenditure of the BAT, and the second electrical signal being configured to inhibit a second nerve type in the BAT that is different from the first nerve type.
11. The apparatus of claim 10 , wherein the first nerve type includes sympathetic nerves, and the second nerve type includes parasympathetic nerves.
12. The apparatus of claim 10 , wherein the first nerve type includes sympathetic nerves, and the second nerve type includes sensory nerves.
13. The apparatus of claim 10 , wherein the first nerve type includes unmyelinated fibers, and the second nerve type includes myelinated fibers.
14. The apparatus of claim 10 , wherein nerves of the second nerve type have a larger diameter than nerves of the first nerve type.
15. The apparatus of claim 10 , wherein the second electrical signal has less energy than the first electrical signal by having less current than the first electrical signal, and a current of the first electrical signal is in a range of ten to one hundred times greater than a current of the second electrical signal.
16. The apparatus of claim 10 , wherein the second electrical signal has less energy than the first electrical signal by including a hyperpolarizing lower energy pulse as compared to the first electrical signal, or by including a depolarizing lower energy pulse as compared to the first electrical signal.
17. The apparatus of claim 10 , wherein the at least one signal generator includes a waveform generator and a modulator;
the waveform generator is configured to generate a first waveform and is configured to generate a second waveform;
the modulator is configured to receive the first waveform from the waveform generator and is configured to modulate the first waveform and thereby create a first modulated waveform that is the first electrical signal; and
the modulator is configured to receive the second waveform from the waveform generator and is configured to modulate the second waveform and thereby create a second modulated waveform that is the second electrical signal.
18. The apparatus of claim 15 , wherein the current of the second electrical signal is in a range of about 0.1 mA to 5 mA;
the second electrical signal has a non-zero pulse width that is less than a pulse width of the first electrical signal; and
the pulse width of the first electrical signal is in a range of about 50 to 300 μsec.
19. The apparatus of claim 1 , wherein the at least one signal generator includes a waveform generator and a modulator;
the waveform generator is configured to generate a first waveform and is configured to generate a second waveform;
the modulator is configured to receive the first waveform from the waveform generator and is configured to modulate the first waveform and thereby create a first modulated waveform that is the first electrical signal; and
the modulator is configured to receive the second waveform from the waveform generator and is configured to modulate the second waveform and thereby create a second modulated waveform that is the second electrical signal.
20. The apparatus of claim 6 , wherein the current of the first electrical signal is in a range of about 10 mA to 100 mA;
the second electrical signal has a non-zero pulse width that is less than a pulse width of the first electrical signal; and
the pulse width of the first electrical signal is in a range of about 300 μsec to 1000 μsec.
21. The apparatus of claim 1 , wherein the first electrical signal is a single electrical signal that lacks a carrier signal, and the second electrical signal is a single electrical signal that lacks a carrier signal.