NEUROST1MULATING DEVICE
FIELD OF THE INVENTION
This invention relates to a neurostimulating device. In particular, the invention relates to a device for use in the mapping of peripheral nerves, the localization of nerves and the anaesthetizing of such nerves. The invention extends to an attachment for a neurostimulating device. Still further, the invention relates to a probe combination for a neurostimulating device.
BACKGROUND TO THE INVENTION
It is known to identify the location of nerves in a human or animal body by applying a suitable stimulus current transdermally via a cutaneous probe, which is connected to a signal generator. The signal generator is operable to deliver an electrical signal whose power, amplitude and wave form may be selectively varied. By moving a contact point of the probe in relation to the relevant human or animal body and by varying the signal, the location of a specific subcutaneous nerve may be relatively accurately identified.
It is further known to identify the location of a subcutaneous nerve in a human or animal body with greater accuracy by means of a subcutaneous probe, commonly in the form of a needle, which may be inserted through the skin of the relevant human or animal. Manipulation of the subcutaneous probe and of the electrical signal allows for accurate location of a specific subcutaneous nerve. Further, the subcutaneous probe may comprise of a hypodermic needle and, having identified the precise location of a specific nerve, the hypodermic needle may be used to dispense an anaesthetic or other drug to anaesthetize or block the nerve.
It will be appreciated that certain subcutaneous nerves are extremely fine and a precise location of the nerve is therefore difficult to establish. However, precise location is necessary in order to test nerve function and to apply certain treatments to diseased or damaged nerves or diseased or damaged parts of the body that may be treated by therapy applied to a relevant nerve. In particular, the application of anaesthetics or other drugs to a subcutaneous nerve generally requires the use, in combination, of a cutaneous probe, a subcutaneous probe and a dispenser of an anaesthetic or drug. These devices are used in combination, the cutaneous probe providing the gross location of the nerve and the subcutaneous probe providing a precise location and enabling the dispensing of a desired drug. Those skilled in the art will appreciate that the manipulation of the various probes and the application of an anaesthetic or other drug will generally require the use by a person applying treatment of both hands. It is therefore counter-productive for this person to have to plug various leads into a signal generator or even to have to manipulate the controls of the signal generator more than necessary. Still further, the use of hypodermic needles in itself poses problems of safety and it is generally accepted that such needles should be sheathed until used.
OBJECT OF THE INVENTION
It is an object of this invention to provide a neurostimulating device, an attachment for such a neurostimulating device and a probe combination for the device which, at least partially, alleviate the abovementioned disadvantages.
SUMMARY OF THE INVENTION
According to a first aspect of the invention there is provided an attachment for a neurostimulating device, the attachment including
a first transdermal probe for transmitting an electrical signal transdermally to a subcutaneous nerve, the probe having a first electrical connector connectable to an electrical lead; a second subcutaneous probe comprising a hypodermic needle for administering a drug to a subcutaneous nerve, the needle being connectable to a dispensing means for dispensing the drug and having a second electrical connector connectable to the electrical lead to transmit an electrical signal to the subcutaneous nerve; and an electrical lead connectable to a signal generator and having connectors complementary to the first and second connectors to permit transmission of electrical signals to the first and second probes.
The first transdermal probe may comprise an elongate electrically insulating body having an electrically conductive contact tip at a first end thereof, the first electrical connector being attached to the body at an opposed second end thereof and the contact tip being in electrical communication with the first electrical connector. The contact tip and the electrical connector may be in electrical communication via an electrical conductor lead carried within the body. The contact tip of the first transdermal probe may be spherical in shape.
The second subcutaneous probe may comprise a hypodermic needle attached to, and extending from, an electrically insulating body. The second probe may have a tube attached to the needle at an end opposed to the tip thereof, a free end of the tube being attachable to a dispensing means. The dispensing means may be a hypodermic syringe for dispensing an anaesthetic or other drug. Then, the second electrical connector may be attached to the body of the second probe at an end thereof spaced from the hypodermic needle.
In one preferred embodiment of the invention, the body of the first probe defines a cavity, shaped and configured to removably receive the needle and body of the second probe, the second probe being movable between an inoperative
condition in which it is sheathed in the cavity and an operative condition in which it is unsheathed, the electrical connector of the second probe standing proud of the body of the first probe when the second probe is in its sheathed condition. When the second probe is in its sheathed condition, the electrical connectors of both probes may be arranged proximate one another to define a set of connectors.
The first and second electrical connectors may comprise sets of electrical pins and the electrical lead may have a set of sockets defined in a first end thereof for receiving simultaneously the pins of the first and second probes and connection means arranged at a second, opposed end thereof for connection to the signal generator. The electrical lead may be connected to both the first and second probes when the second probe is in its inoperative condition and to only the second probe when the second probe is in its operative condition so that the first probe is thereby rendered inoperative.
According to a second aspect of the invention there is provided a probe combination for a neurostimulating device, the combination including a first transdermal probe for transmitting an electrical signal transdermally to a subcutaneous nerve, the probe having a first electrical connector connectable to an electrical lead; a second subcutaneous probe comprising a hypodermic needle for administering a drug to a subcutaneous nerve, the needle being connectable to a dispensing means for dispensing the drug and having a second electrical connector connectable to the electrical lead to transmit an electrical signal to the subcutaneous nerve; and the first probe being configured to provide a sheath for the hypodermic needle of the second probe and the second probe being operable between an inoperative condition in which the hypodermic needle is sheathed in the cavity and an operative condition in which it is unsheathed.
The first transdermal probe may comprise an elongate electrically insulating body having an electrically conductive contact tip at a first end thereof, the first electrical connector being attached to the body at an opposed second end thereof and the contact tip being in electrical communication with the first electrical connector. The contact tip and the electrical connector may be in electrical communication via an electrical conductor lead carried within the body. The contact tip of the first transdermal probe may be spherical in shape.
The second subcutaneous probe may comprise a hypodermic needle attached to, and extending from, an electrically insulating body. The second probe may have a tube attached to the needle at an end opposed to the tip thereof, a free end of the tube being attachable to a dispensing means. The dispensing means may be a hypodermic syringe for dispensing an anaesthetic or other drug. Then, the second electrical connector may be attached to the body of the second probe at an end thereof spaced from the hypodermic needle.
The body of the first probe may define a cavity, shaped and configured to removably receive the needle and body of the second probe, the electrical connector of the second probe standing proud of the body of the first probe when the second probe is in its sheathed condition. When the second probe is in its sheathed condition, the electrical connectors of both probes may be arranged proximate one another to define a set of connectors.
The first and second electrical connectors may comprise sets of electrical pins for connection to an electrical lead having a set of sockets defined in a first end thereof for receiving simultaneously the pins of the first and second probes and connection means arranged at a second, opposed end thereof for connection to a signal generator.
The entire second probe may be movable with respect to the first probe to sheathe and unsheathe the hypodermic needle thereof. Instead, the hypodermic
needle of the second probe may be axially extendible from its sheathed condition to its operative condition. The contact tip of the first probe may have an aperture defined therethrough and the hypodermic needle may be axially extendible via the aperture, thereby enabling use of the second probe without having to remove the first probe from its operative position in contact with the dermis, in use.
The invention extends to a neurostimulating device including an attachment as hereinbefore described in combination with a signal generator.
The attachment may be of the type in which the electrical lead is connected to both the first and second probes when the second probe is in its inoperative condition and to only the second probe when the second probe is in its operative condition so that the first probe is thereby rendered inoperative, and the signal generator may be operable to sense whether the first or second probe is operative and to select signal parameters according to which of the probes is operative. The signal parameters include any one of a range of signal frequencies, a range of signal amplitudes and a signal waveform.
The invention further extends to a neurostimulating device including a probe combination as hereinbefore described, in combination with a signal generator, the probe combination being connected to the signal generator via an electrical lead having connectors complementary to the first and second connectors to permit transmission of electrical signals from the signal generator to the first and second probes.
The probe combination may be of the type in which the first probe is rendered inoperative when the second probe is in its operative condition and the signal generator is operable to sense whether the first or second probe is operative and to select signal parameters according to which of the probes is operative and to transmit a signal within the said parameters to the operative probe. The signal
parameters may include any one of range of signal frequencies, a range of signal amplitudes and a signal waveform.
Thus, in one embodiment of the device, when the probes are in their sheathed condition and connected to the electrical lead, the signal generator may be operable to sense that both probes are connected to the lead and the generator may be configured to transmit a signal of preselected characteristics and within a preselected signal range to the first probe. On unsheathing of the second probe from the first probe, the first probe is disconnected from the electrical lead, leaving the second probe connected to the lead. The signal generator may then be operable to sense the disconnection of the first probe and to transmit signals having preselected characteristics and within preselected signal ranges to the second probe. Further, having identified the precise location of a desired subcutaneous nerve, the second probe may be used to administer an anaesthetic to the nerve.
Instead, the signal generator may have controls connected thereto and operable for manual manipulation to select transmission of a signal to either the first or the second probe. The manual controls may be carried on the signal generator. Instead, the manual controls may be carried on the electrical lead.
Preferably, the first and second probes are disposable.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is now described, by way of example, with reference to the accompanying diagrammatic drawings.
In the drawings:-
FIG 1 shows a perspective view of a neurostimulating device, in accordance with a first aspect of the invention, with a first probe in an operative condition;
FIG 2 shows a perspective view of a neurostimulating device, in accordance with a first aspect of the invention, with a second probe in an operative condition; and
FIG 3 shows a detailed sectional view of a second embodiment of a probe combination for the neurostimulating device.
DETAILED DESCRIPTION OF THE INVENTION
In Figures 1 and 2, reference numeral 10 generally refers to a neurostimulating device in accordance with the invention.
The device 10 comprises a signal generator 12 and an attachment 20, in accordance with a further aspect of the invention. The attachment 20 has a first, transdermal probe 22 for transmitting an electrical signal transdermally to a subcutaneous nerve. The transdermal probe 22 comprises an elongate electrically insulating body 24 having a contact tip 26 at a first end 28 thereof. As can be seen in Figure 2, an electrical connector in the form of a set of conducting pins 30 is attached to the body 24 at an opposed second end 32 thereof. The contact tip 26 and the electrical connector 30 are in electrical communication via an electrical conducting lead (not shown) carried within the body 24. A free end 36 of the contact tip 26 of the transdermal probe 22 is spherical in shape.
Further, the attachment 20 has a second, subcutaneous probe 40 comprising a hypodermic needle 42 for administering a drug to a subcutaneous nerve, the needle 42 being attached to, and extending from, an insulating body 44. A first end 45 of a tube 46 is attached to the needle 42 at an end 48 opposed to a tip 50 thereof. A second end 52 of the tube 46 is attached to a dispensing means, in the
form of a hypodermic syringe 54, for dispensing an anaesthetic or other drug. A further electrical connector, in the form of a conducting pin 56, is attached to the body 44 of the second probe 40 at an end 58 thereof spaced from the hypodermic needle 42.
The attachment 20 further has an electrical lead 60, connected in the drawings to the signal generator 12. The lead 60 has connectors, in the form of sockets (not shown) complementary to the first and second connectors 30,56 to permit transmission of electrical signals to both the first and second probes, 22 and 40 respectively. The sockets are defined in a first end 62 of the lead 60 and receive simultaneously the pins 30,56 of the first and second probes 22,40. A second, opposed end 64 of the electrical lead 60 is connectable to the signal generator 12.
The elongate body 24 of the first probe 22 is of a transparent plastics material 68 and defines a cavity (not shown), shaped and configured to receive the needle 42 and body 44 of the second probe 40, so that, when sheathed, the electrical connector 56 of the second probe 40 protrudes from the cavity and stands proud of the elongate body 24 of the first probe 22, as shown in Figure 1. The arrangement is such that when the second probe 40 is sheathed by the first probe 22, electrical connectors 30,56 of both probes 22,40 are arranged proximate one another to define a set of connectors.
When the probes 22,40 are in their sheathed position, as shown in Figure 1 , and connected to the electrical lead 60, the signal generator 12 is operable to sense that both probes 22,40 are connected to the lead 60 and the generator 12 is configured to then transmit a signal of preselected characteristics and within a preselected signal range to the first probe 22, so that the first probe 22 is operable. On unsheathing of the second probe 40 from the first probe 22, as shown in Figure 2, the first probe 22 is disconnected from the electrical lead 60, leaving the second probe 40 connected to the lead 60 and thus operable. The
signal generator 12 is then operable to sense the disconnection of the first probe 22 and to transmit signals having preselected characteristics and within preselected signal ranges to the second probe 40. Further, having identified the precise location of a desired subcutaneous nerve, the second probe 40 may be used to administer an anaesthetic to the nerve.
Instead, in a further embodiment of the invention, the hypodermic needle 42 of the second probe 40 is axially extendible from a sheathed position to an operable position without having to unsheathe and detach the second probe 40 from its cavity within the first probe 22. In one example of this embodiment, as shown in Figure 3, the hypodermic needle 42 is axially extended via an aperture 70 defined in the contact tip 26 of the first probe 22, thereby enabling use of the second probe 40 without having to remove the first probe 22 from its operative position in contact with the dermis 72.
The invention provides a neurostimulating device 10 including an attachment 20, in combination with a signal generator 12. The signal generator 12 is operable to sense which of the first and second probes 22,40 is operable and to select a signal range according to which of the probes 22,40 is operable. Instead, the signal generator may have controls for manual manipulation to select transmission of a signal to either the first or the second probe 22,40. The manual controls may be carried on the signal generator 12. Instead, the manual controls may be carried on the electrical lead 60, at 66 for example.
Advantageously, the first and second probes 22,40 are disposable.