Medical diagnostic instrument

A handheld diagnostic instrument includes a handle and an instrument head associated with the handle. An innerformer is disposed in an inner cavity of the instrument head in which the instrument head further includes a tab holder. A cushion member is disposed within the housing between the innerformer and the interior of the instrument head. Further, a lens is attached to the instrument head, the lens including a lens tab. A seal is formed between the lens and the innerformer when the lens tab is engaged with the tab holder wherein the cushion member acts to bias the innerformer to maintain the defined seal.

BACKGROUND

This disclosure relates generally to medical diagnostic instruments, such as ophthalmoscopes and otoscopes. For example, a number of known instrument designs, such as those manufactured by Welch Allyn Inc., of Skaneateles Falls, N.Y., are detailed in U.S. Pat. Nos. 6,106,457, 7,029,439, 7,399,275, and 7,670,287, each of which are incorporated herein by reference in their entirety.

Otoscopes can include a port that enables caregivers, such as clinicians, to insufflate the ear of a patient in order to provide a more complete diagnostic examination. An example of a known pneumatic otoscope400is partially depicted inFIG. 11, including an instrument head404that includes an attachment end408that is securable to a handle (not shown). The instrument head404is defined by a hollow interior and includes a distal end that retains a distal insertion portion410(partially shown) that is shaped and configured to support a speculum tip element412, the latter being insertable to a predetermined distance within the ear canal (not shown) of a patient. At the opposing rear or proximal end of the instrument head404, a viewing lens416is pivotally attached to the instrument head404at an upper end via a connection424, the viewing lens416including a lens tab428extending from a lower or bottom end. The viewing lens416forms a seal with the interior of the instrument head404wherein the viewing lens416can also include a peripheral bumper418. A insufflation port420extends into the interior of the instrument head404wherein a pneumatic bulb (not shown) and hose (not shown) can be fluidically connected to the insufflation port420. Squeezing the pneumatic bulb enables air under pressure to be directed to the ear of the patient.

Successful pneumatic otoscopy requires a sealed innerformer. A typical innerformer is disposed within the interior of the instrument head and serves to support the distal insertion portion and further enables optical fibers from a contained illumination assembly to be directed to the exterior of the distal insertion portion. Leaks developed in the instrument can prevent adequate pressurization. Without proper pressurization, the ear drum will not deflect as intended and the user may thus misdiagnose fluid behind the ear when in fact it does not exist. In the case of some leaks, the user may hear air hissing from the device and try to compensate with ever more vigorous hand pumping. These quick blasts do not allow adequate pressure modulation and in fact can injure the delicate ear drum.

Prior art otoscopes tend to suffer from leaks, either at the time of manufacturing or after a period of use. Leaks occur for many reasons, but among the most common is a poor seal between an interface defined between the viewing lens at the proximal end of the instrument head and the mating innerformer surface. This interface has a large perimeter that presents many opportunities for air to escape the instrument. If either the viewing lens or the innerformer deviates from flat surface to surface contact, an air passage can result along at least a portion of the periphery of the lens and the innerformer. One possible solution would be to manufacture these parts with extremely high tolerances. This solution would drastically increase the overall cost of the assembly and also increase the number of components that would have to be discarded in order to meet the higher tolerance thresholds. Still further, nicks, scratches or other manufacturing defect on either surface (the rear of the innerformer assembly and the interior periphery of the lens) would produce the same deleterious effect. While these problems may not exist at the time of manufacture, even with high tolerance manufacture, these problems could easily result over time and use of the instrument based subjecting the instrument to shock or impact loads (e.g., drops), the usual sliding motion of the lens relative to the innerformer to effect instrumentation, and other use case scenarios.

More specifically, a drop may produce gross deflection of the innerformer within the instrument head, thereby moving the rear surface relative to the interior peripheral contacting lens surface. This dynamic motion of one component relative to the other can scratch or otherwise damage the sealing surfaces. Otoscopic instruments that do not protect the innerformer from impact forces are especially vulnerable to this latter issue.

The above noted sealing interface between the lens and the rear surface of the innerformer may also leak if the lens retention means of the instrument applies inadequate or unbalanced forces to the lens. Insufficient restraining forces allow air pressure to push the lens away from the innerformer. As a result, airleaks are produced from the resulting gap. Similarly, an unbalanced restraining force may tip the lens such that one peripheral section lifts off or away in relation to the sealing interface. As a result, the section that is lifted away also becomes prone to undesired air leakage. This latter situation can arise at the time of manufacturing due to tolerance variations, but this undesired situation may also occur because the various components warp or otherwise migrate or creep over time and changes in environmental exposure.

Other than creating a higher degree of tolerancing, an alternative technique applied in some prior art otoscopes to effectuate a proper seal is the addition of an elastomeric sealing member disposed at the above-defined interface. While employing an elastomeric seal can provide an airtight junction, this proposed solution requires the added expense of the elastomeric component, as well as other parts or features that become necessary in order to constrain the elastomeric part. Elastomeric parts can also tear or wear away (erode) when the pivoting lens repeatably slides over them in use. Further, elastomeric compounds used in the manufacture of sealing members (e.g., O-rings) can degrade with time and temperature or exhibit a residual adhesion effect (i.e., ‘stiction’), whereby the elastomeric components adhere to the lens over time and rip away or are otherwise rendered unsuitable for providing an adequate air seal with the interior of the instrument head when the user finally slides the lens

BRIEF DESCRIPTION

According to one aspect, a diagnostic instrument is provided that comprises a handle and an instrument head associated with the handle, the instrument head comprising a housing that includes a tab holder. An innerformer is disposed in an inner cavity of the instrument head, as well as a cushion member disposed between the innerformer and the interior of the housing in addition to a lens attached to the instrument head, the lens including a lens tab. A seal is formed between the lens and the innerformer when the lens tab is engaged with the tab holder.

In addition, the diagnostic instrument may also include an insufflation port on a portion of the housing wherein a gap or spacing is defined between at least a portion of the innerformer and the interior of the instrument head. The gap or spacing enables the innerformer to “float” such that the cushion member creates a bias that maintains the seal between the innerformer and the viewing lens and more specifically between a rear surface of the innerformer and a peripheral surface of the viewing lens. The seal is effectively maintained while pressure is applied to the interior of the instrument head through the insufflation port.

In at least one version, a light source such as an LED is also included as part of one of or both of the handle and the instrument head. In at least one version, the LED is integrated directly into the instrument head.

According to another aspect, a method of manufacturing a handheld diagnostic instrument is provided. The method includes providing a handle and an instrument head associated with the handle. An innerformer is disposed in an inner cavity of the instrument head along with a cushion member that is disposed between the innerformer and the housing. According to this method, a viewing lens is further provided that is attached to the instrument head, the viewing lens including a lens tab. A seal is formed between the viewing lens and the innerformer when the lens tab is engaged with a tab holder of the instrument head.

According to one version, a light source such as an LED is associated with at least one of the handle and the instrument head. The LED can be integrated within the instrument head. A gap is formed between the innerformer and the interior of the instrument head. This gap enables the innerformer in combination with the cushion member to create a bias against the seal formed between the viewing lens and the innerformer when the lens tab is engaged with the tab holder. This seal can be maintained when pressure is added pneumatically to the interior of the instrument head using an insufflation port provided on the instrument head.

According to yet another aspect, a method of conducting pneumatic otoscopy with a handheld otoscope is provided. The method includes providing an otoscope. The otoscope includes an instrument head associated with the handle, the instrument head having a housing, wherein the housing comprises a tab holder. The otoscope further includes an insertion portion at a distal end of the instrument head, an innerformer disposed in an inner cavity of the instrument head, a cushion member disposed between the innerformer and the housing, and a viewing lens attached to the instrument head. The viewing lens includes a lens tab, wherein a seal is formed between the lens and the innerformer when the lens tab is engaged with the tab holder. The method further includes inserting the insertion portion into an ear canal of a patient and inserting a gas into the inner cavity of the instrument head through an insufflation port located on a portion of the instrument head. The gas passes through the inner cavity, through the insertion portion, and to the ear canal.

DETAILED DESCRIPTION

Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although a number of specific terms are employed herein, these terms are used in a generic and descriptive sense only and not for purposes of limitation, except where so specifically indicated.

The following description relates to certain embodiments of a medical diagnostic instrument having a mechanical switch assembly and other features as described for a specific type of instrument (e.g., an otoscope). As will become apparent from the discussion, however, the inventive concepts can easily be applied to literally any form or instrument design that includes a light source and at least one contained battery. Moreover, certain terms are used throughout the discussion, such as “top”, “bottom”, “above”, “below”, “upward”, “downward”, and the like that are used to provide a frame of reference with regard to the accompanying drawings. These terms, however, should not be interpreted as limiting in the sense of the scope of the invention, except where specifically indicated.

Referring toFIGS. 1-6, a compact medical diagnostic instrument is shown, herein labeled by reference numeral30. As noted for purposes of each of the following embodiments, the herein described instrument30is an otoscope, used for examining the outer ear, including the tympanic membrane. The instrument30includes a handle34and an instrument head43that is releasably attached to the top of the handle34. According to this depicted embodiment, the handle34is substantially cylindrical in shape and is defined by a hollow tubular section having a pair of open ends37,39forming an interior41that includes a battery compartment that is sized and configured to retain a pair of vertically stacked batteries45. In this embodiment and to provide better perspective in combination with the accompanying drawings, a pair of AA batteries45are retained within the handle34.

The instrument30further includes a top cap portion49and a bottom cap portion53sized for covering each of the open ends37,39, of the hollow handle34, respectively. In the depicted version, each of the cap portions49,53are attached by means of screw threads78,58that engage with mating internal threads42,46that are formed in each of the open ends37,39of the tubular handle34, respectively. The handle34is sized to be fitted within the palm of the hand of the intended user.

More specifically, the bottom cap portion53includes a compression spring57fitted within a defined cavity for engaging the lowermost or bottom end of the stacked batteries45. As noted, this portion53includes a set of external screw threads58on an open distal end thereof that mate releasably with corresponding internal screw threads46provided on the open end39of the handle34.

The top cap portion49of the instrument30is defined by a substantially hollow member having an upper mating portion72, a lower mating portion76and an intermediate supporting portion80. The intermediate supporting portion80includes an exterior surface60that receives a fitted pocket clip63comprising a cylindrical band64and a vertically extending clip member68permitting the compact instrument30to be easily carried, for example, within the shirt pocket of the user. The exterior surface60of the intermediate supporting portion80further includes a vertically extending slot65that is sized to accommodate a portion of a movable member87of a mechanical switch assembly in accordance with the invention, as described in greater detail below.

The upper mating portion72is a tubular cylindrical section having a diameter that is smaller than that of the remainder of the top cap portion49, the upper mating portion72further including a set of external screw threads74. The lower mating portion76also includes a set of screw threads78and is sized to directly engage the internal screw threads42of the open top end37of the handle34, wherein the lower mating portion76is positioned within the handle when assembled thereto. Each of the top and bottom cap portions49,53are made from an electrically conductive metal, such as stainless steel or a die cast zinc alloy. The handle34according to this version is made from an extruded metal, such as aluminum or brass.

The instrument head43includes a housing59having a frusto-conical insertion portion61provided on a distal end that is sized for receiving a disposable speculum (not shown) permitting insertion thereof to a predetermined distance into the ear canal. The insertion portion61includes a defined distal tip opening66encircled with a ring of light transmitting ends (not shown) from a bundle of optical fibers (not shown), the bundle extending through the substantially hollow exterior of the instrument head43in proximity to a contained lamp assembly69installed at the base of the head43. The head43further includes a magnifying eyepiece73that is mounted on a proximal end77along a defined optical path aligned with the distal tip opening66. An opening (not shown) is also defined in one of the sides of the instrument head43for inclusion of a pneumatic or other pressurized source (not shown) for insufflation of a patient's ear during examination. It should be noted that the overall design and features of the otoscopic instrument head, as described in this paragraph, are commonly known to those in the field and require no further discussion, except where needed, in regard to the present invention.

The lamp assembly69,FIG. 3, is defined by an assembly housing75made from a conductive material, such as brass or stainless steel, and contains a light source in the form of a miniature incandescent lamp81positioned within a defined cavity85,FIG. 5, thereof. The lamp assembly69further includes an electrical contact89at a proximal end93thereof. Such lamp assemblies are described, for example, in U.S. Pat. No. 4,147,163, and are commonly known, the assemblies themselves not forming an essential part of the invention. Alternatively, other types of miniature light sources are within the intended scope of the invention, including LEDs.

In this embodiment, the lamp assembly69is fixedly attached to the base of the instrument head43in a vertical orientation, such that the electrical contact89projects downwardly therefrom and the glass envelope of the lamp81is positioned at the top extending from the distal end of the assembly housing75. The instrument head43further includes a set of internal screw threads103that engage with the external screw threads74provided on the upper mating portion72of the top cap portion49, permitting releasable assembly thereto. When fully assembled, a through opening of the top cap portion49permits the top (e.g., the cathode) of the contained batteries45to make electrical contact with the extending electrical contact89of the lamp assembly69. As previously noted, the contained batteries45are biased into contact with the electrical contact89of the lamp assembly69by means of the compression spring57located in the bottom cap portion53. In passing, it should be noted that the lamp assembly69, though described as being part of the instrument head43, could alternately be attached directly to the top cap portion49.

As shown inFIGS. 4 and 6, the mechanical switch assembly according to this embodiment, consists of the movable member87. In at least one version, the movable member87is fabricated from a non-conductive material, such as plastic, that is made via a low cost manufacturing process, such as injection molding. The movable member87is installed through the vertical slot65formed in the intermediate supporting portion80of the top cap portion49. The slot65is then substantially covered and the movable member87is effectively retained by the cylindrical band64of the pocket clip63. The portion99of the movable member87extending into the top cap portion49is pivotally attached therein and is retained, by means of ribs97.

The movable member87further includes an extending or exterior lever portion101that can be rotated between a first or OFF position and a second or ON position by the user. According to the depicted embodiment, the top cap portion49includes a pair of stop plates86,88,FIG. 1, to prevent over rotation of the movable member87in either direction by the user, the stop plates86,88being arranged relative to the exterior lever portion101. The portion99of the movable member87extending into the top cap portion49includes a flap105, the flap105having a center cutout or recess109for avoiding the battery contact. In addition, detent features are provided such that the movable member87can be secured in the OFF position, as shown more particularly inFIGS. 9 and 10. In the depicted version, the lower stop plate86includes a pocket110at the predetermined end of travel of the movable member87, the pocket110being defined by a downwardly ramped surface114extending into a retaining surface117. The exterior lever portion101includes a beveled surface121that permits release of the movable member87from the defined pocket110of the stop plate86upon sufficient finger force by the user. In addition, a beveled surface125is also similarly provided on a leading edge of the flap105for creating an overcenter engagement with the top of the stacked batteries45,FIG. 2.

As shown, the threads of the instrument head43and the mating top cap portion49are designed in terms of their overall length and pitch such that, when assembled, the insertion portion61is juxtaposed relative to the movable member87. That is, the eyepiece73, in the case of the instrument head43, is directly above the exterior lever portion101of the movable member87.

In operation, the lamp81is energized when the exterior lever portion101is in the ON position ofFIGS. 3, 4 and 9in which the electrical contact89of the lamp assembly69is in electrical connection with the top of the batteries45. The compression spring57provides sufficient biasing force for the circuit to be completed, wherein the instrument handle34is made from a conductive material, such as metal, as it provides a continuous electrical path. The use of the compression spring57, as described herein, also compensates for small differences between battery lengths without impacting performance.

Rotation of the exterior lever portion101of the movable member87, in this instance, using a clockwise direction by the user, as shown by arrows102,FIG. 2, causes the engagement end99to pivot and causes the flap105to push the stacked batteries45against the biasing force supplied by the compression spring57. This action thereby creates a gap between the stacked batteries45and the electrical contact89at the proximal end of the assembly housing75, as shown most clearly inFIGS. 5, 6 and 10. As noted above, the exterior lever portion101is drawn over the stop plate86and into the defined pocket110, wherein the ramped surface114provides a detent, thereby securing the movable member87in this position. In the meantime, the beveled surface125at the leading edge of the flap105also creates positive engagement with the top of the stacked batteries45. In this OFF position for the instrument30, as shown inFIGS. 5 and 6, the battery contact is disconnected directly from the electrical contact89of the lamp assembly69.

Typically known hand-held diagnostic instruments utilize a metal top cap. To insure the tight tolerances, this part is typically machined from a material such as brass. The handle of the instrument is also typically made from brass, and more typically plated machined brass. Because of the relative lack of complexity afforded the instrument of the present invention, these components can be fabricated using a metal die cast process (for the top cap) or extruded aluminum (for the handle), thereby providing a substantial cost reduction. The metal die cast process is similar to injection molding, in that a hard tool is created and the material is injected in a molten state in order to fill the tool. The resulting product of manufacture is a high tolerance, very repeatable part. This same process can be utilized to make parts for any other diagnostic instrument utilizing the present invention. To our knowledge, metal die cast bases are currently not utilized in diagnostic products today.

Referring toFIG. 2, another novel aspect of the present invention includes the utilization of a printed plastic graphic sleeve member100to visually enhance the look of the instrument30. Most products today have an external “look” of machined metal (smooth, knurled, etc.) or plastic (ribs, smooth, etc.). A proposed solution to this problem is to use commercial “shrink sleeves” that can incorporate multi-colored printed graphics. Images can include both text and graphics, covering literally any content, ranging from corporate logos, photographs, sports themes, etc. It is believed this has never been done on any medical diagnostic product(s). In addition, the sleeve member100can also include instructions for operating the switch assembly, wherein the instructions or other information can be written in any language, thereby customizing the instrument for use anywhere in the world.

A number of alternative embodiments to the switch assembly83ofFIGS. 1-6are conceivable. Examples of such embodiments are herein briefly described.

As shown inFIGS. 7 and 8, a mechanical switch assembly130in accordance with a second embodiment is herein described. For purposes of clarity, those features that are substantially similar to those of the preceding embodiment are labeled with the same reference numerals. In this example, a diagnostic instrument similarly includes a substantially cylindrical hollow handle34and an instrument head43, as in the preceding, wherein a pair of batteries45are retained in a stacked configuration within the interior41of the hollow handle34. A lamp assembly69is positioned relative to the top of the handle34, or as in this embodiment, the lamp assembly69is fixedly disposed in the bottom of the instrument head43. The lamp assembly69includes a light source, such as a miniature incandescent lamp or other emitting source.

The switch assembly130according to this embodiment includes a movable pin-like member134having an angled wedge portion or section138at one end. The pin-like movable member134is movable within aligned openings that are provided in the top cap portion49in a direction that is substantially perpendicular to the vertical or battery axis of the instrument.

According to this embodiment, one end of the movable member134extends from the exterior of the top cap portion49of the handle34and is accessible by the user, wherein the angled wedge section138can selectively be interposed between the top surface of the upper or topmost battery45and the lamp electrical contact89, thereby creating respective ON and OFF positions. Preferably, the angled wedge section138is insulated electrically. As in the preceding and in the absence of the angled wedge section138, the biasing force of the compression spring57is sufficient to create necessary engagement between the electrical contact89of the lamp assembly69and the batteries45. Features similar to the detent features described in the preceding embodiment can be added to insure positive engagement in one or both of the ON and OFF positions.

As noted, the preceding describes various examples of switch assemblies and it is anticipated that other similar approaches could be contemplated for moving either one or both of the batteries and/or the lamp assembly.

Moreover, it should be pointed out that the location of the herein described switch assembly can easily be varied. For example, a lever or other movable element (not shown) made in accordance with the inventive concepts discussed herein could be alternatively be provided that breaks the electrical connection at the bottom of the instrument handle. Furthermore, all movements described herein have related to those of the stacked batteries. It should be readily apparent that similar mechanisms could be developed for moving the lamp assembly in lieu of the batteries to selectively break electrical contact or that each of the batteries and the lamp assembly can be made movable relative to one another.

As noted, the preceding instrument included an otoscopic instrument head, but other instrument heads can be similarly attached to the handle34. By way of a nonlimiting example, an ophthalmoscopic head (not shown) can be attached in lieu of an otoscopic head.

With reference toFIGS. 12-16, there is depicted a medical diagnostic instrument in accordance with another embodiment. More specifically, the instrument200herein described is an otoscope used for examining the ears of a patient, and more specifically a pneumatic otoscope. Insufflation (or pneumatic otoscopy) is accomplished by providing, for example, any useful air or gas through an insufflation port preferably located on a portion of an exterior housing wherein the insufflation port permits access to an interior space of the device200in communication with an interior of the innerformer, and an interior of the distal insertion portion.

The otoscope200is defined by an instrument head204that is releasably and securably attached to the upper end of a handle (partially shown inFIGS. 12, 13 and 15). The instrument head204according to this version comprises a pair of housings; namely, a front housing208and a rear housing212, each being a shell-like component made from a moldable plastic material. When assembled to one another, the front and rear housings208,212define an enclosure having an inner cavity or interior213as well as front (distal) and rear (proximal) ends220,224, in which each end further includes a defined opening. A distal insertion portion228extends outwardly from the distal end220of the assembled instrument head204, the insertion portion228being configured and shaped to support a speculum tip element (not shown) that is suitably sized for insertion into the ear to a predetermined depth.

A viewing lens232, including a magnifying optic, is attached to the proximal end224of the instrument head204. In one version, the viewing lens232is manufactured as a single component that is pivotally attached to the proximal end224of the instrument head204and more specifically to the rear housing212, the latter having a rear or proximal opening that is aligned with the smaller front opening of the instrument200, as well as openings in the distal insertion portion228and attached speculum tip element (not shown) to enable viewing of the ear by a caregiver. When assembled, the viewing lens232is sized to fully cover the rear opening of the instrument head204. Optionally, the viewing lens232can include a peripheral bumper (not shown). As best shown inFIGS. 13 and 14, the viewing lens232is mounted to the instrument head204according to this specific embodiment by means of a retaining screw242inserted through a hollow swivel pin244can be supported by the rear housing212, the swivel pin244and retaining screw242being biased by a coil spring245. When assembled, the viewing lens232can rotate about an axis created by the retaining screw242and swivel pin244so as to selectively cover and uncover the rear opening of the instrument head204for access to the interior of the instrument200, as needed, by a caregiver.

As shown most clearly inFIGS. 13 and 16, the distal insertion portion228is attached to one end of an innerformer254, the latter forming a contained sub-structure of the instrument head204that is configured and sized to fit within substantially the entire interior of the instrument head204. The innerformer254can be made as a single component fabricated from a moldable plastic or other suitable material. More specifically, the innerformer254is defined by respective distal and proximal ends256,257, in which the distal insertion portion228is attached to the distal end256, the latter having a defined opening that is aligned with an opening of the distal insertion portion228. The innerformer254is further defined by a rear opening and peripheral rear surface267that are substantially coplanar with the rear opening at the proximal end of the instrument head204when the innerformer254is assembled. An insufflation port258extends outwardly from one lateral side of the innerformer254and more specifically through an opening provided in the rear housing212to enable access by a caregiver. The specific location of the insufflation port258can be varied, provided that the port258enables fluid connectivity with the hollow interior of the instrument head204.

When assembled, the exterior surface of the innerformer254engages the interior surfaces of the front and rear housings208,212as well as an attachment portion218at the lower end of the instrument head204. In this assembled position, the peripheral rear surface267of the innerformer and an inner peripheral surface272of the viewing lens232form a junction274that defines a seal. According to this specific embodiment, a conformal member (also referred to as a cushion member262), is attached to an external surface portion of the innerformer254. The cushion member262according to this specific embodiment is a contoured section of urethane foam, such as Poron™ that is adhesively attached to the exterior of the innerformer254for engaging an interior surface of the front housing208.

As discussed herein, the cushion member262added to the innerformer254helps ensure the device200can maintain a pneumatic seal to facilitate insufflation by a clinician. In a version, the innerformer254can include a set of guides263that define a recess266to facilitate the placement/positioning of the cushion member262. Alternatively, the cushion member262can be integrated with the innerformer254. In use the cushion member262acts as a spring that can absorb impact loads and urges the innerformer254toward the rear of the instrument200, as herein described.

That is, the innerformer254having the attached cushion member262acts to basically “float” within the confines of the instrument head204with the innerformer254being disposed within the front and rear housings208,212and having a defined space based on the compressibility of the attached cushion member262in which the innerformer254can move. As shown in the enlargedFIG. 14, a gap or spacing276,FIG. 14, is created between the innerformer254and the rear housing212. The cushion member262, when wrapped around the exterior portion of the innerformer254, helps to locate the innerformer254within the confines of the instrument head204, yet permits movement in response to applied loads or impact forces. The cushion member262further functions as a balancer against the lens tab234as supported by the tab holder238. That is, and when the lens tab234applies a force to the innerformer254and more specifically the rear peripheral surface267thereof, the entire innerformer254being an single supported section rocks or pivots slightly within the interior of the instrument head204. As a result, the cushion member262deflects and the associated forces that are created against the interior of the instrument head204resist the rocking. This resistive force balances the force applied by the lens tab234within the lens tab holder238. If the lens force relaxes due to mechanical creep or other time dependent phenomenon, the cushion member262will act to bias the innerformer254toward the lens tab234and thus help restore the sealing force of the innerformer254and more specifically the force applied by the rear peripheral surface267against the inner peripheral surface272of the viewing lens232, maintaining the seal at the defined junction274. The above arrangement has an additional advantage in that it helps compensate for part (tolerance) variation. If the lens tab dimensions vary such that they would produce excess deflection, the cushion member262will deflect an additional amount and thus limit the effect of this variation. Prior art devices having rigid innerformers that fail to provide a floating configuration as described herein do not possess this capability. In those cases and at a minimum, excess lens tab forces created due to part variation would compromise any prior formed seal.

In the embodiments illustrated inFIGS. 12-16and as previously noted, the seal that is formed in the interior chamber of the otoscope200due to the herein described “floating” innerformer configuration can stay intact to at least 1 inches of H2O (1.866 mm Hg) and preferably to at least 2 inches of H2O (3.732 mmHg) or more.

With further review toFIGS. 12-16, the instrument head204includes an attachment mechanism216at its lower or bottom end. The attachment mechanism216includes a substantially cylindrical portion218having a plurality of external threads219that are configured to engage a set of internal threads (not shown) formed in the upper end of a handle (not shown). In addition, the attachment mechanism216retains an illumination assembly, the latter being fully integrated within the instrument head204unlike prior art instruments in which the illumination assembly, typically a miniature incandescent bulb used as a light source, is retained within a necked portion (not shown) of the handle. The illumination assembly according to this embodiment includes an LED286disposed within the cylindrical portion218of the attachment mechanism216and an LED lens assembly292and printed circuit board296interconnecting the assembly components. According to this embodiment, the LED lens assembly292and the printed circuit board296are commonly provided in a receptacle294(partially shown inFIG. 15) that is disposed and sized to fit within or align with a lower or bottom part of the innerformer254using a threaded or other suitable form of connection. When assembled, the LED286and the LED lens assembly292are aligned with one another along a defined illumination axis and are further aligned with the polished end of a bundle of optical fibers (not shown) also provided in the receptacle294. The bundle of optical fibers are directed by the innerformer254wherein the fibers further extend between the distal end of the innerformer254and the distal insertion portion228.

The illumination assembly components are further connected to a switch (not shown) on the handle of the instrument200for purposes of energization. A polarity protection component300,FIG. 12, is associated with the bottom of the attachment mechanism216and relative to a stacked configuration of batteries (not shown) disposed within the handle of the instrument200.

PARTS LIST FOR FIGS.1-16

It will be readily apparent that the embodiments described herein are examples for purposes of relating and conveying the inventive concepts. As a result, other variations and modifications are readily discernible that embody these concepts, and as further defined by the following claims.