GB2518887A

GB2518887A - Improvements in and relating to medical, handheld instruments

Info

Publication number: GB2518887A
Application number: GB1317628.4A
Authority: GB
Inventors: Adrian Carl Beasley; Stephen Church
Original assignee: Keeler Ltd
Current assignee: Keeler Ltd
Priority date: 2013-10-04
Filing date: 2013-10-04
Publication date: 2015-04-08
Also published as: WO2015049518A3; DE112014004113T5; GB201317628D0; WO2015049518A2; GB201403485D0; GB2518917A

Abstract

A medical, handheld instrument, such as an ophthalmoscope, retinoscope or otoscope, for use in inspecting a structure of the human or animal body comprises viewing means 8 for use in viewing the structure and the handle 1 for enabling the user to hold and use the instrument, wherein handle is not more than 10cm long and preferably 7.5cm long. The handle may be configured to house only one battery for operating a light source in the instrument. The light source may be an LED and the instrument may have a pocket clip 16.

Description

Title: Improvements in and relating to Medical, Handhold Instruments

Field of the invention

This invention relates to a medical, handheld instrument for use in inspecting a structure of the human or anim& body.

Background to the invention

io The invention is particularly applicable to otoscopes and handheld ophthalmoscopes, particularly direct ophthalmoscopes. Such instruments, over the course of a day, tend to be frequently used at a number of different locations, as a result of which it is common for the instruments to be kept on the body of the user (for example in a clinician's shirt pocket) between uses. Typically, thc handle for such an instrument comprises a stem depending from the instrument head and housing a power supply for a light source that is used to irradiate, i.e. illuminate, the portion of a subject's eye or car to be inspected. Since the uscr needs to bc able to control the position and movement of the instrument quite accurately, the handles of such instruments are normally designed to be long enough to bridge the entire palm of most users, and to that end are typically at least 12cm long. Such handles are long enough to accommodate a power source in the form of a pair of series connected, coaxial AA batteries arranged in an abutting relationship with each other. However, such instruments have been found to be awkward to store in a user's pocket.

Summary of the invention

According to the invention, there is provided a medical, handheld instrument for use in inspecting a structure of the human or animal body, the instrument comprising viewing moans for use in viewing the structure and a handle for enabling a user to hold and use the instrument, wherein the handle is not more than 10cm long.

Contrary to the conventional teaching that the handle should be long enough to traverse the palm of the user, it has been realised that an instrument with a shorter handle can still be effectively operated. The shorter handle enables the instrument to

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be more easily stored in a pocket, and effectively lowers the centre of gravity for the instrument, thus making it more stable either when sitting in a pocket or when in use.

The distance between the top of the instrument to its centre of gravity may actually be decreased by using a shorter handle. As a result, the instrument preferably has a pocket clip that also has a contact point with the external support (e.g. the top of a pocket) relatively higher to the instrument head, typically by 10-20mm, than on a conventional instrument. This can be achieved by means of a clip that extends upwardly from its point of attachment to the instrument by this distance, before io turning back on itself at the contact point. Alternatively, the clip may be attached to the instrument at a position closer to the top of the instrument than is the case with a conventional instrument.

Preferably, the handle is not more than Scm long, and more preferably is 7.5 cm long plus or minus 1mm.

The instrument preferably includes irradiating means for irradiating the structure to be inspected with electromagnetic radiation to enable said inspection. Thus the irradiating means may, for example, comprise a light source and projecting optics for projecting light from the source onto the structure to irradiate, by illuminating, the latter.

The invention has potential application to any handheld medical instrument, but the instrument preferably comprises a handheld ophthalmoscope, otoscope or retinoscope.

Since such instruments are commonly carried on the user's person, it is especially advantageous for them to be capable of being easily and safely retained in a pocket, for example a shirt or jacket pocket.

Preferably, the overall length of the instrument is no more than 13cm.

Conveniently, the instrument comprises a head from which a stem, comprising a handle, extends.

The irradiating means preferably includes a source of electromagnetic radiation, the handle being configured to contain battery means for constituting the power source for the source of electromagnetic radiation.

S In the latter ease, the handle is preferably configured to contain a battery means constituting a single AA battery, the handle containing contacts, spaced apart by a distance corresponding to the length of a single AA battery, for connecting the terminals at either end of such a battery to the source of electromagnetic radiation.

Preferably, the source of electromagnetic radiation comprises an electroluminescent source of light, preferably an LED.

In the case of a conyentional handheld ophthalmoscope or otoscope, power for the instrument's light source, usually an incandescent light bulb, is provided by a pair of series connected AA batteries in the instrument's handle. By contrast, an instrument in accordance with the present invention, with just one battery, is smaller and lighter than its conventional counterpart, arid is also cheaper to run, as a result of the relative efficiency of an LED light source, and of the long life of an LED light source (compared with an incandescent light bulb).

The invention also lies in a handheld medical instrument comprising an otoscope, ophthalmoscope or retinoscope, wherein the instrument includes a light source and a handle for accommodating a single AA battery for providing power to operate the source, the handle containing contacts for connecting the end terminals of the battery to the source, the contacts being spaced apart by a distance corresponding to the length of such a battery.

Preferably, the source is electroluminescent, preferably an LED.

Brief description of the drawintzs

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is an clevational view, from the user's side, of an embodiment of ophthalmoscope in accordance with the invention; Figure 2 is a partially cutaway isometric view of the ophthalmoscope with a battery; Figure 3 is a partially cut-away isometric view of the ophthalmoscope (without battery), from the opposite side from the view of Figure 2; Figure 4 is an exploded isometric view of the handle assembly of the ophthalmoscope; Figure 5 is an isometric cut-away view of some of the components, including a switch mechanism, of the handle assembly; Figure 6 is a more detailed view of part of the switch mechanism; Figure 7 is an exploded isometric view of the head assembly of the ophthalmoscope; Figure 8 is an isometric view of a holder for an LED module of the ophthalmoscope; Figures 9 and 9A and 9B are respectively isometric, elevational and exploded isometric views of the LED module; Figure 10 is a circuit diagram for the power supply circuitry used in the ophthalmoscope; and Figure 11 is a side elevation of an otoscopc, also in accordance with the invention; and Figure 12 is an exploded isometric view of the head assembly of the otoscope.

Detailed description

The ophthalmoscope shown in Figure 1 comprises a generally cylindrical handle 1, in which is retained an internally screw threaded connector 42 via which an ophthalmoscope head 4 is screwed onto the handle 1. The instrument is a direct ophthalmoscope, and the head 4 is identical to a conventional ophthalmoscope head of the type used in the current applicant's KEELER JAZZTM ophthalmoscope. The head accordingly includes an upper arced brow rest 6 for the user, a viewing aperture 8 through which the user views an eye under examination, a knurled wheel 10 for use in selecting one of a number of different lenses of different magnifications through which the eye under examination is viewed through the aperture 8. A window 12 provides a display indicating the lens that has been selected (i.e. the lens that is aligned with the aperture 8).

An annular recess comprising circumferential groove 14 just below the collar 2 accommodates an attachment member in the form of a ring which, itself, is part of a pocket clip 16, the groove and ring thus serving to attach the clip 16 to the handle 1.

As can be seen from Figure 1, the clip 16 extends upwardly from the ring, turns back on its self at turning point 17 from which the clip 16 extends down to its distal end 19.

The turning point 17 constitutes the hanging (or contact) point from which the instrumcnt may be suspended in a user's pocket, when not in use. The vertical distance between the ring 14 and the turning point 17 is 10-20mm. The front of the housing 1 is provided with a slider switch 18 for activating and deactivating a light source in the form of a white LED 20 within the head.

The handle 1 is slightly tapered from top to bottom, and has a maximum diameter (at the collar end) of 22mm. The height of the handle 1 is 75 mm, whilst the overall height of the instrument is 129.75mm.

The handle assembly is shown in exploded form in Figure 4, from which it can be seen that the handle I is hollow, and accommodates a generally L-shaped copper strip 200, the foot of which carries an electrically conductive coil spring 24 that is attached to the strip 200 by a suitable means, for example by riveting. A strip of copper formed into a part-circular collar 202 is attached to the top of the strip 200. The strip is engaged by a contact strip 204 which co-operates with the switch 18 to slide relative to the strip 200 to activate and deactivate the LED in the ophthalmoscope head in the way described below. An insulation ring 206 is a close fit within the collar 202, and includes an upper portion 208 which is of an enlarged diameter so as to define an annular, downward facing shoulder on which the ring 206 sits on the collar 202. An electrically conductive metallic connector ring sits on an upward facing annular shoulder defined by the enlarged diameter portion 208 of the ring 206.

A recess, referenced 210, in the side of the connector 42 can receive the contact 204 S when the switch 18 is closed.

As can be seen from Figures 4 and 5, the connector 42 is internally screw-threaded and has an enlarged diameter lower portion (in which the recess 210 is formed), and a smaller diameter upper portion over which an externally screw-threaded end cap 212 sits. The screw-threaded portion of the cap 212 engages a correspondingly screw-threaded portion at the top of the interior of the handle 1 releasably to hold the cap 212 in place on the handle 1. At the top of the cap 212 there is an inturned annular lip which bears against the top of the connector 42 so as to sandwich the connector 42 and the portion 208 of the ring 206 between the top of the cap 212 and the collar 202, thus retaining those components, along with the spring 24 and strip 200 within the handle 1. The intumed lip, referenced 214 (Figure 5), of the cap 212 leads to an annular radially outwardly directed flange 216 on the end of the cap 212. The underside of the flange 216 is, with the cap in place on the handle, spaced from the top of the handle 1 so that the top of the handle 1 and the underside of the flange 216 define the annular circumferential groove 14. The releasable connection between the handle assembly, components of which are shown in Figure 4, and the head 4 is achieved by the engagement of the screw thread within the connector 42 with a corresponding screw-threaded portion 218 (see Figures 7 and 8) at the lower end of an LED module holder 38.

The LED holder has an out-turned radial flange 220 situated just above the screw-threaded portion 218, and which in use engages a radial inner lip 222 at the base of a head lock ring 2.

The holder 38 also contains an LED module 224 (described in further detail below) and is formed with two opposed slots 226 and 228 (Figure 8) into which extend lugs on the interior of a front cover 230 and a rear cover 232 of the head 4. In Figure 7, the lug on the rear cover 232 is shown at 234. A condenser lens 58 is held in a bracket 248 at the top of the holder 38.

The front and rcar covers are, in use, in abutment with each other so as to dcfinc a housing which contains various other components of the head, illcluding a chassis 236. When the covers 230 and 232 are so positioned, two semi-cylindrical end portions 238 and 240 also abut each other to define a cylindrical, externally screw threaded end connector onto which the lock ring 2 is scrcwcd. When thc lock ring 2 is screwed onto the connector, the lip 222 bears against the flange 220 to retain the holder 38 within the housing, in a position in which the lugs in the cover portions extend into the slots 226 and 228 to provide angular location of the holder 38. Axial io location of the holder 38 is provided by the interaction between the flange 220 and the lip 222 and the top of the holder 38 with the chassis 236.

\rith reference to Figures 9, and 9A and 9B, the LED module is generally cylindrical and carries at its upper end the LED light source 20. Thc moduic 224 comprises a housing 225 of nickel plated brass c121. On either side of the LED 20 there is provided a pair of resilient splayed arms 244 which provide an interference fit for the moduic 224 within the holdcr 38. Thc anns 244 arc pa of a cap 235 also fonned from nickel plated brass czl2l and which is screwed into the housing 225 to retain the contents of the module 224. The bottom of the housing 225 includes an integral sleeve 246 through which a conductive rod 30 of brass (Figures 2 and 3) extends, the lower end of the rod 30 providing a contact 26 for providing an electrical contact with the positive terminal of a single AA baftery contained within the handle 1. An insulating member 227 of black acetal has a sleeve 229 which extends from a cap 231 of the member. The sleeve 229 fits over the rod 26 to separate, and electrically insulate the rod 26 from the sleeve 246. The rod is connected to the terminal 46 (Figure 10) of a powcr converter 36 which converts powcr from thc AA battery into a suitable form for operating the LED 20.

The coil spring 24 is situated at thc basc of the handlc 1 and acts a contact for thc negative terminal of the battery, whilst the contact 26 is spaced from the screen 24 by distance with corresponds to, but is slightly less than, the length of a single AA battery. Thus, when such a battery, such as the battery 22 in Figure 2, is accommodated in the handle I it is compressed between the spring 24 and the contact 26. When the switch 18 is closed, the contact 204 acts as a bridge over the insulating ring 206, and thus achieves an electrical connection, via strip 200, between the negative terminal of the battery and a ground terminal constituted by connector 42 of the power converter 36. When the switch 18 is open, the end of the contact 204 not engaging the strip 200 rests against the insulated ring 206.

With reference to Figure 10, the power convertor 36 comprises a 1 lA, 1MHz synchronous boost WLED driver, in this case the MP3412 integrated circuit 48 from Monolithic Power Systems. The ground input of the integrated circuit 48is connected to the terminal 42, and hence to the negative terminal of battery 22 when the switch 18 is closed (to hold the strip 40 in contact with the terminal 42). The integrated circuit 48 also has a feedback (FB) input to an error amplifier that is also connected to the terminal 42, and to the anode of the LED 20. The connection of the terminal 42 to the input FB is via a resistor 50 of 7.5 0. The output from the RC (OUT) is connected to the cathode of the LED, and a 10 jiF capacitor 52 is connected across the is LED 20 and resistor 50.

The terminal 46, which is connected to the positive terminal of the battery 22, constantly supplies a positive voltage input to the battery supply input (IN) of the integrated circuit 48 and also to an enabled control input (EN) of that circuit. The integrated circuit 48 includes an internal NMOS switch and synchronous switch, the output of which is in turn connected to the output SW of the integrated circuit 48.

This output is, in turn, connected in series with an inductor 54 of 4.7jtH, the other side of which is connected to the terminal 46 and the input IN. As can be seen from Figure 10, that side of the inductor 54, the input IN and the terminal 46 are also connected to ground through a capacitor 56 of 4.7jiF.

The power convertor 36 uses a known method of current switching to cause the induction, in the inductor L, of a voltage which is higher than the input voltage (i.e. the voltage between terminals 42 and 46). This particular device uses a switching frequency of 1MHz and stores the increased voltage in ceramic capacitors, forming part of the integrated circuit, and then provides a voltage output which is higher than the voltage input. The convertor converts the voltage of the AA battery, typically 0.8V-1.6V, into the voltage needed to power the white LED 20, typically 2.5V-5V.

Whcn in position in the head, the condenser lens 58 is in register with an aperture 250 in a lower wcb 252 of the chassis 236. That lowcr web is spaccd from and parallel to an intermediate web 254 in the chassis 236 to defile a space for accommodating a known type of graticule and filter wheel assembly 256 rotatably mounted on a ball can type spindle 258 which is received in generally U-shaped recesses in the edges of the wcbs 250 and 254. The graticulc whccl asscmbly has a knurled outer surface part of which extends through an opening in the front cover 230 to allow the user to rotate the wheel assembly 256 to bring a selected filter or graticule into register with the lens 58. A projection lens 60 is also mounted in the chassis 236 at a position above the io assembly 256 and in register with the lens 58. The projection lens 60 directs light onto an angled mirror 62 which is mounted in the chassis 236 immediately above the lens 60.

The minor 62 is positioned immediately bchind an illumination and vicwing aperture 64 in the front cover 230 and this aperture is aligned with a viewing aperture 8 in the rear cover 232. The size and positions of the apertures 64 and 8 aM the minor 62 are such that the mirror 62 does riot occlude tlic apcPurc 8 so that the user can see through the aperture 64 (over the top of the minor 62).

A maywheel 66 is rotatably mounted for rotation about a horizontal axis on the rear cover 32, and carries a series of lenses through which the user can view the eye under examination.

The lenses are all positioned at the same radial distance from the centre of the may-wheel 66, and at equi-angular intervals around the maywheel. In addition, the wheel face also carries markings, each of which indicates the power of a respective one of the lenses, and is positioned diametrically opposite that lens. The markings are thus also cqui-angularly distributcd around thc maywhccl 66, but are positioncd at a smaller radial distancc from thc disc ccntrc. Thc radial distance of thc aperture 8 from the disc centre corresponds to that of the lenses, whilst the radial distance of the window 12, which is in the rear cover 232, corresponds to that of the markings, so that the marking visible in the window 12 at any one time will be an indication of the strength of the lens which is at that time in register with the aperture 8. It will be appreciated that the apertures 8 and 64 and the maywheel 66 comprise the viewing means for the instrument. The maywheel 66 has a knurled circumferential surface 10 that protrudes the rough opposed openings 260,262 in the rear cover 232 to enable the user to select a desired lens through which the subject's eye is to be viewed through the aperture 8. The ophthalmoscope head includes a ball can (not shown) in which a ball bearing is biased against the knurled surface 10 to provide a series of detents, each corresponding to the alignment of a respective lens in the maywhcel 66 with the viewing aperture 8.

Reference numeral 68 in Figure 1 denotes the approximate position of the centre of io gravity of the instrument, from which it can be seen that the centre of avity is closer to the bottom than it is to the top of the instrument, making the instrument more stable than conventional anangements (having a handle long enough to accommodate two AA batteries in line), which are more top heavy.

In use, light emitted from the LED 20 passes through the condenser lens and through the selected part of the graticule and filter wheel assembly 256 which, depending upon the position of the assembly may cause the light to bc passed through a graticule, a colour filter or through an aperture in the wheel assembly which does not affect the light from the LED 20. Light then passes from the wheel assembly to the projection lens 60 which directs the light on to the minor 66. The minor 66 reflects this incident light through the aperture 64 and into an eye under examination. Light returning from the eye can pass through the aperture 64, over the top of the minor 66 and through the aperture 8 via a selected lens in the maywheel 66, so that the user can view the eye under examination through the aperture 8. The identity of the selected lens in the maywheel 66 will be displayed in the window 12.

The front and rear covers 230 and 232 are also held together by means of a screw 233 which passes into correspondingly screw-threaded openings in the top regions of the covers.

The otoscope shown in Figure 11 shares many of the features of the ophthalmoscope of Figures 1-10, and these features are denoted by the same reference numerals as are used in Figures 1-10, raised by 100. Thus the otoscope has a handle 101 in which there is provided a switch 118. The handle 101 also canies a pocket clip 116.

Reference numeral 170 denotes the head of the otoseope, which is identical to the head of the current KEELER JAZZTM otoscope. Within the otoseope of Figure 11, there are many components which correspond to those within the ophthalmoscope of Figures 1-10. In particular, everything within the space bounded by the handle 101 is S identical to a corresponding component in the same space within the ophthalmoscope of Figures 1-10. Thus, for example, the arrangement of contacts for the battery within the handle 101, their connection to a power converter, and the LED, and the way in which they are mounted/housed are the same as the corresponding components in the ophthal moscopc.

\yith reference to Figure 12, the otoscope head 170 has a housing constructed in a similar fashion to the ophthalmoscope previously described. Thus the housing has a front cover 264 and a rear cover 266 held together at their tops by means of a screw 268 and at their bases by a screw-threaded locking ring 270 that engages correspondingly screw-threaded portions 272 and 274 on the covers. The ring 270 also helps to locate in position an LED holder 276 which is substantially the same as the LED holder 38 of the ophthalmoscope except in that it has a flared upper portion 278 to assist location (by engaging corresponding recesses in the covers 264 and 266), and in that instead of a bracket a its top, the holder 276 includes a cylindrical connecting socket 280 for receiving a corresponding plug 282 depending from a fibre optic cone assembly 284. In addition, the holder 276 includes an opening 286 which co-operates with a spring-loaded ball bearing mechanism 288 retained on the rear cover 266 to provide angular location for the holder 276 during assembly.

The holder 276 includes an LED module which is the same as the LED module used in the ophthalmoscope, and which is operable to emit light that passes into the optical fibres in the assembly 284 to be directed out of the front of the instrument and into an ear under examination. The assembly 284 is also so configured that the user can look through the assembly to view illuminated structures of the ear.

Claims

Claims 1. A medical, handhcld instrument for use in inspecting a structure of the human or animal body, the instrument comprising viewing means for use in viewing the structure and a handle for enabling a user to hold and use the instrument, wherein the handle is not more than 10cm long.
2. An instrument according to claim 1, in which the handle is not more than 8cm long.

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3. An instrument according to claim 2, in which the handle is 7.5cm long plus or minus 1mm.
4. An instrument according to any one of the preceding claims, in which the overall length of the instrument is no more than 15cm.
5. An instrument according to any of the preceding claims, in which the instrument comprises a head from which a stem, comprising a handle, extends.
6. An instrument according to any of the preceding claims, in which an instrument preferably includes irradiating means for irradiating the structure to be inspected with electromagnetic radiation to enable said inspection.
7. An instrument according to claim 3, in which the instrument comprises a handheld ophthalmoscope, otoscope or retinoscope.
8. An instrument according to claim 6 or claim 7, in which the irradiating means preferably includes a source of electromagnetic radiation, the handle being configured to contain battery means for constituting the power source for the source of electromagnetic radiation.
9. An instrument according to claim 8, in which the handle is configured to contain a battery means constituting a single AA battery, the handle containing contacts, spaced apart by a distance corresponding to the length of a single AA battery, for connecting the terminals at either end of such a battery to the source of electromaetic radiation.
10. An instrument according to any of claims 6 to 9, in which the source of electromagnetic radiation comprises an electroluminescent source of light, preferably an LED.
11. A handheld medical instrument comprising an otoscope, ophthalmoscope or retinoscope, wherein the instrument includes a light source and a handle for accommodating a single AA battery for providing power to operate the source, the handle containing contacts for connecting the end terminals of the battery to the source, the contacts being spaced apart by a distance corresponding to the length of such a battery.
12. An instrument according to claim 11, in which the source is electroluminescent.
13. An instrument according to claim 12, in which the source is an LED.
14. An instrument according to any of the preceding claims, in which the instrument includes a pocket clip attached to the instrument at and configured to define a hanging point from which the instrument is suspended, the hanging point being at a higher level than the handle when the instrument is so suspended.
15. An instrument according to any of the preceding claims, in which the instrument includes a pocket clip attached to the instrument at an attachment region of the latter, and so configured as to define a hanging point from which the instrument is suspended, when held by the clip in a pocket, which point is above the region of the attachment of the clip.
16. An instrument according to claim 15, in which the clip extends upwards from the region of attachment by a distance of 10-20mm. to a turning point from which the clip extends downwards to its distal end, the turning point constituting the hanging point of the clip.
17. An instrument according to claim 15 or claim 16, in which the region of attachment comprises an annular recess in the instrument, which recess accommodates an attachment member which is itself attached to the clip.
18. An ophthalmoseope substantially as herein described with reference to, and illustrated in, Figures 1-10 of the accompanying drawings.
19. Au otoscope substantially as described herein with reference to, and as illustrated in, the accompanying drawings.